BULLETIN NUMBER 28 TABLE OF CONTENTS PAGE SEISMICITY OF THE SOUTHEASTERN UNITED STATES DURING 1993................. 1 Acknowledgments........................................................ 2 References............................................................. 2 SEUSSN EARTHQUAKE CATALOG STATISTICS..................................... 7 SOUTHEASTERN U.S. EARTHQUAKES DURING 1993................................ 13 SOUTHEASTERN U.S. RESERVOIR RELATED EARTHQUAKES DURING 1993.............. 37 SEISMIC STATION LISTING AND NETWORK MAPS................................. 39 ACCESSING DIGITAL WAVEFORM DATA AND OTHER INFORMATION FROM THE VIRGINIA TECH SEISMOLOGICAL OBSERVATORY................................ 45 DEFINITIONS AND NETWORK OPERATOR CODES................................... 47 APPENDIX A: Summary of the Howard County, Maryland, Earthquakes of 1993.. 49 APPENDIX B: August 08, 1993 Aiken, South Carolina Earthquake............. 57 APPENDIX C: Probabilistic Seismic Hazard Analysis for Virginia........... 59 APPENDIX D: Earthquake Strong Motion Recording in the Southeastern U.S... 61 APPENDIX E: Determination of the Coefficient of Seismic Attenuation in Florida................................................... 63 APPENDIX F: Errata....................................................... 65 MAILING LIST............................................................. 67 FIGURES 1. Epicenter Map for the Report Period............................... 3 2. Epicenter Map for the Report Period (Scaled to Magnitude)......... 4 3. Epicenter Map for the Period from July 1977 through this Report Period..................................................... 5 4. Epicenter Map for the Period from July 1977 through this Report Period (Scaled to Magnitude, M ge 3.0)............................ 6 5. Focal Depth Distributions of Southeastern U.S. Earthquakes........ 8 6. Magnitude Distributions of Southeastern U.S. Earthquakes.......... 9 7. Magnitude Recurrence Relation for the Southeastern U.S............ 10 8. Cumulative Strain Factor Histories for the Southeastern U.S....... 11 9. Epicenter Density Contour Map (Scaled to Magnitude, M ge 2.0)..... 12 10. Seismic Stations Operating During Report Period................... 41 11. Georgia Tech - Geological Survey of Alabama Seismic Network....... 42 12. South Carolina Seismic Network.................................... 42 13. Center for Earthquake Research and Information - SARSN............ 43 14. Tennessee Valley Authority Seismic Network........................ 43 15. University of Flordia Seismic Network............................. 44 16. Virginia Tech Seismic Network..................................... 44 TABLES 1. SEUSSN Report Period/Cumulative Earthquake Catalog Statistics..... 7 2. Estimates of Completeness for the Southeastern United States...... 9 SEISMICITY OF THE SOUTHEASTERN UNITED STATES DURING 1993 There were 78 earthquakes (0.0 le M le 3.2) located within the SEUSSN monitoring area during 1993. Of those, 24 included felt reports. Earthquakes reported included 3 in Alabama, 1 in Delaware (felt; 8 November 18:47, MD= 1.7, MMI= felt), 15 in Georgia, 1 in Kentucky, 16 in Maryland (15 felt; largest was 15 March 04:29, mb(Lg)= 2.7, MD= 2.1, MMI= V), 4 in North Carolina (2 felt; largest was 1 January 05:08, MD= 3.0, MMI= felt), 12 in South Carolina (5 felt; largest was 8 August 09:24, mb(Lg)= 3.2, MD= 2.9, MMI= V), 20 in Tennessee (1 felt; largest was 15 January 02:02, mb(Lg)= 3.1, MD= 3.3, MMI= IV), and 6 in Virginia. The area of highest activity was eastern Tennessee, while the activity in Maryland was the most unusual (see Appendix A). Figures 1 and 2 are epicenter maps of tectonic earthquakes (M ge 0) located within the region during the report period. Figures 3 and 4 are cumulative epicenter maps for the 16.5 year period from July 1977 through December 1993 (SEUSSN Bulletins 1 through 28). SEUSSN EARTHQUAKE CATALOG STATISTICS includes report period and cumulative earthquake catalog statistics, focal depth distribution plots, magnitude distribution plots, estimates of catalog completeness, a magnitude recurrence relation, cumulative strain factor history plots, and an epicenter density contour map. SOUTHEASTERN U.S. EARTHQUAKES DURING 1993 lists hypocentral parameters, magnitudes, and arrival times for tectonic earthquakes (i.e., not reservoir related) in the southeastern United States. The largest earthquake for the report period was an mb(Lg)= 3.2 event (8 August 09:24) that was felt with MMI= V in Aiken, South Carolina. Appendix B includes an abstract and isoseismal map for this earthquake. SOUTHESTERN U.S. RESERVOIR ACTIVITY DURING 1993 lists hypocentral parameters for 10 small reservoir related earthquakes (M < 2) near the Monticello Reservoir in South Carolina and Lake Jocassee on the South Carolina, North Carolina, and Georgia borders. None of these events was felt. SEISMIC STATION LISTING AND NETWORK MAPS contains a listing of seismic stations operating during the report period and maps showing the major network operators in the region. The number of stations operating during 1993 was 107. The SEUSSN monitoring area is considered to include all of Florida, Georgia, Alabama, South Carolina, North Carolina, Virginia, West Virginia (south of latitude 37.72 deg N), Maryland, and Delaware; and includes Tennessee and Kentucky - east of longitude 87 degrees West (see Figure 10). ACCESSING WAVEFORM DATA AND OTHER INFORMATION AT THE VIRGINIA TECH SEISMOLOGICAL OBSERVATORY describes how to access, by the computer Internet, digital waveforms, earthquake catalogs, and other data from the Virginia Tech Seismological Observatory. In the future, this section will contain similar descriptions for other contributors. DEFINITIONS AND NETWORK OPERATOR CODES contains definitions of various terms and abbreviations used in the Bulletin as well as a listing of codes for network operators and/or contributors. APPENDIX A from the Maryland Geological Survey describes a sequence of 20 earthquakes (most felt locally) from March through November 1993 near Columbia, Maryland. This interesting swarm of small shallow earthquakes felt strongly in a very localized area is similar to other activity observed elsewhere in the southeastern United States (e.g., Macon, Georgia, 1982-83, see SEUSSN Bulletin 11; and Richmond, Virginia, 1986-87, see SEUSSN Bulletin 19). APPENDIX B from the University of South Carolina and the Westinghouse Savannah River Company is an abstract and isoseismal map for the MD = 3.2 August 8, 1993 Aiken, South Carolina, earthquake. APPENDIX C from Virginia Tech is a summary of a county-by-county probabilistic seismic hazard analysis for Virginia. Included are example hazard maps showing 1.0 and 3.3 Hz pseudo-relative spectral acceleration for a deep soil site condition, with 10% probability of exceedance during a 50 year exposure period. APPENDIX D from the Tennessee Valley Authority discusses their listing of strong-motion instruments in the southeastern United States. It is likely that in future Bulletins information on the siting of strong-motion instrumentation and data availablity will be included. APPENDIX E from the University of Florida describes preliminary models of seismic attenuation for the Florida Plateau. Acknowledgments This report is the twenty-eighth BULLETIN OF SEISMICITY OF THE SOUTHEASTERN UNITED STATES and covers the period from January through December, 1993. The organizations supplying data for this Bulletin are Charleston Southern University, Delaware Geological Survey, Georgia Institute of Technology, Maryland Geological Survey, Memphis State University (Center for Earthquake Research and Information), Tennessee Valley Authority, United States Geological Survey, University of Florida, University of South Carolina, Virginia Department of Mines, Minerals, and Energy - Division of Mineral Resources, Virginia Polytechnic Institute and State University (Virginia Tech Seismological Observatory), and the Westinghouse Savannah River Company. In addition to the support furnished by the host institutions of the network contributors, partial or full support by other agencies for the operation of portions of the SEUSSN is gratefully acknowledged. The agencies providing support to the members of SEUSSN are as follows: The Georgia Power Company, The National Science Foundation, The Nuclear Regulatory Commission, The Tennessee Valley Authority, The United States Geological Survey, Virginia Power. References Bollinger, G. A., Frederick C. Davison, Jr., Matthew S. Sibol, and Jeffrey B. Birch, (1989), Magnitude recurrence relations for the southeastern United States and its subdivisions, Journal of Geophysical Research, 94, pp. 2857-2873. Chapman, M. C., J. A. Snoke, and G. A. Bollinger, (1988), A procedure for calibrating short-period telemetered seismograph systems, Bulletin of the Seismological Society of America, 78, pp. 2077-2088. Hoaglin, David C., Frederick Mosteller, and John W. Tukey, (1983), Understanding Robust And Exploratory Data Analysis, John Wiley & Sons, New York, NY, 447 pp. Lahr, J. C., (1980), HYPOELLIPSE/VAX: A computer program for determining local earthquake hypocentral parameters, magnitude, and first-motion pattern, U.S. Geological Survey Open-File Report 80-59, 59 pp. Lee, W. H. K., and J. C. Lahr, (1974), HYPO71: A computer program for determining hypocenter, magnitude, and first motion pattern of local earthquakes, U.S. Geological Survey Open-File Report 75-311, Revised: January 1974, 134 pp. Lee, W. H. K., and S. W. Stewart, (1981), Principles and Applications of Microearthquake Networks, Academic Press, New York, NY, 293 pp. Nuttli, O. W., (1973), Seismic wave attenuation and magnitude relations for eastern North America, Journal of Geophysical Research, 78, pp. 876-885. Shedlock, Kaye M., (1987), Earthquakes recorded by the South Carolina Seismic Network (1974-1986), U.S. Geological Survey Open-File Report 87-437, 92 pp. FIGURE 1. Epicenters (circles) for earthquakes (M ge 0.0) in the southeastern United States for this report period. FIGURE 2. Epicenters (circles scaled to magnitude) for earthquakes (M ge 0.0) in the southeastern United States for this report period. FIGURE 3. Epicenters (circles) for earthquakes (M ge 0.0) in the southeastern United States from July 1977 through this report period. FIGURE 4. Epicenters (circles scaled to magnitude) for earthquakes (M ge 3.0) in the southeastern United States from July 1977 through this report period. SEUSSN EARTHQUAKE CATALOG STATISTICS TABLE 1 SEUSSN Report Period/Cumulative Earthquake Catalog Statistics PERIOD: January through December 1993 (1 year) Tectonic Reservoir Number of Earthquakes with M ge 0.0 .................... 78 10 Number of Earthquakes with M ge 2.5 .................... 10 0 Number of Earthquakes with M ge 3.5 .................... 0 0 Number of Felt Earthquakes.............................. 24 0 Rate of Earthquakes with M ge 0.0 (per year)............ 78 10 Rate of Earthquakes with M ge 2.5 (per year)............ 10 0.0 Rate of Earthquakes with M ge 3.5 (per year)............ 0.0 0.0 Rate of Felt Earthquakes (per year)..................... 24 0.0 Mean Earthquake Magnitude............................... 1.7 1.2 Median Earthquake Magnitude............................. 1.7 1.2 Number of Earthquakes with Known Dmin le 5.0 km........ 8 4 Number of Earthquakes with Known Dmin le 10.0 km........ 9 6 Number of Earthquakes with Known Dmin le 25.0 km........ 28 10 Number of Earthquakes with Known ERH le 5.0 km.......... 52 7 Number of Earthquakes with Known ERZ le 5.0 km.......... 48 7 Number of Blasts or Questionable Events Reported........ 0 Number of Events Outside the SEUSSN Area Reported....... 1 Number of Seismograph Stations Operating................ 107 Largest Earthquake..........: 8 August 1993; 09:24 - Aiken, SC mb(Lg)= 3.2, MD= 2.9, MMI= V PERIOD: July 1977 through December 1993 (16.5 years) Tectonic Reservoir Number of Earthquakes with M ge 0.0 ....................1348 691 Number of Earthquakes with M ge 2.5 .................... 217 63 Number of Earthquakes with M ge 3.5 .................... 25 2 Number of Felt Earthquakes.............................. 173 20 Rate of Earthquakes with M ge 0.0 (per year)............ 82 42 Rate of Earthquakes with M ge 2.5 (per year)............ 13 3.8 Rate of Earthquakes with M ge 3.5 (per year)............ 1.5 0.1 Rate of Felt Earthquakes (per year)..................... 10 1.2 Mean Earthquake Magnitude............................... 1.6 1.4 Median Earthquake Magnitude............................. 1.6 1.4 Number of Earthquakes with Known Dmin le 5.0 km........ 98 79 Number of Earthquakes with Known Dmin le 10.0 km........ 234 114 Number of Earthquakes with Known Dmin le 25.0 km........ 721 150 Number of Earthquakes with Known ERH le 5.0 km..........1176 179 Number of Earthquakes with Known ERZ le 5.0 km..........1006 123 Number of Blasts or Questionable Events Reported........ 179 Number of Events Outside the SEUSSN Area Reported....... 16 Largest Earthquake........: 27 July 1980; 18:52 - Sharpsburg, KY mb= 5.2, MMI= VII FIGURE 5. Focal depth distributions of southeastern U.S. earthquakes. The upper half of the figure shows the interval (left) and cumulative (right) depth distributions for the current report period (M ge 0.0, known ERZ le 5.0 km, Dmin le 20 km, and free depth determination) while the lower half of the figure is a similar display for earthquakes reported during the period from July 1977 through this report period. Displayed above both interval distributions is a box plot (Hoaglin and others, 1983, pp. 58-65). Indicated are the mean (star), the 25% and 75% quartile (box outline), the median (center bar), the upper and lower adjacent values (small vertical bars), and outliers (small squares). On the cumulative depth distributions arrows show the 10% and 90% depths. TABLE 2 Estimates of Completeness (Years) By Magnitude For The Southeastern United States And Subregions (Bollinger and Others, 1989) MAGNITUDE 2.25 2.75 3.25 3.75 4.25 4.75 5.25 5.75 6.25 6.75 Southeastern US 6 10 15 85 145 145 215 215 215 215 Valley & Ridge and Blue Ridge 9 10 20 75 110 215 215 215 215 215 Piedmont 10 10 115 215 215 215 215 215 215 215 Coastal Plain 10 10 60 145 145 215 215 215 215 215 Giles County, VA 10 15 15 30 30 215 215 215 215 215 Central Virginia 15 60 215 215 215 215 215 215 215 215 Eastern Tennessee 5 10 10 85 115 115 215 215 215 215 Charleston, SC 10 70 70 70 130 215 215 215 215 215 FIGURE 6. Magnitude distributions of southeastern U.S. earthquakes. The left half of the figure shows the interval magnitude distribution for the report period while the right half of the figure shows a similar distribution for earthquakes from July 1977 through this report period. Displayed above both distributions is a box plot (Hoaglin and others, 1983, pp. 58-65). Indicated are the mean (star), the 25% and 75% quartile (box outline), the median (center bar), the upper and lower adjacent values (small vertical bars), and outliers (small squares). FIGURE 7. Magnitude recurrence relation for the southeastern United States. The upper half of the figure shows the seismicity map with historical (circles) and network (X's) epicenters for the time period 1772-1986. The lower half of the figure shows a plot of Log(NI) (interval number of earthquakes per year, M +- 0.25) versus mb(Lg) for the southeastern United States. The maximum likelihood line includes 95% confidence intervals (Bollinger and others, 1989). FIGURE 8. Cumulative strain factor histories for the southeastern United States. The upper half of the figure shows the cumulative strain factor history for the report period, while the lower half of the figure shows a similar plot for earthquakes from July 1977 through this report period. FIGURE 9. Epicenter density contour map for earthquakes (circles scaled to magnitude; M ge 2.0) in the southeastern United States from July 1977 through this report period. Contours represent number of earthquakes within 50 km of a grid point scaled to number per 10,000 square km; grid spacing is 0.2 degrees. Lowest and highest contours are 5 and 20 events per 10,000 square km, respectively (contour interval is 5). SOUTHEASTERN U. S. EARTHQUAKES DURING 1993 Events are listed chronologically (this also applies to multiple hypocenter locations for the same event). All times are Universal Coordinated Time. Most entries in the listing are self-explanatory. Items that might require further explanation are defined in the section entitled DEFINITIONS AND NETWORK OPERATOR CODES. ***** 1993 JANUARY 1; 05:08 - SPRUCE RUN, NORTH CAROLINA ***** TVA Felt at Spruce Pine and parts of Mitchell and Yancey Counties, NC (USGS). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I CERI 930101 050805.2 35.878 82.086 2.3 26 63 115 0.3 C B/D 0.6 -64 0.4 2.1 B 3.0 NEIC 930101 050805.3 35.877 82.090 3.5 22 63 3.0 F TVA 930101 050805.3 35.880 82.086 4.1 11 63 115 0.2 C B/D 0.5 -65 0.4 1.8 B 2.9 F SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) CERI SLTN 62.9 357 iP 05:08:16.20 ( 0.00 ) iS 05:08:24.19 (-0.03X) CERI TRYN 69.2 192 ePc :17.18 (-0.13 ) eS :26.18 ( 0.04 ) CERI PKNC 85.8 77 ePc :20.20 ( 0.15 ) eS :30.98 ( 0.11 ) CERI FGTN 117.3 302 ePd :25.00 (-0.16 ) eS :40.04 ( 0.32X) CERI PLVA 120.8 43 ePc :25.36 (-0.41 ) eS :40.48 (-0.29 ) CERI TKL 154.5 261 ePd :30.92 ( 0.08 ) eS :49.56 ( 0.01 ) CERI CRTN 162.1 283 iP :32.09 ( 0.07 ) iS :53.09 ( 1.51 ) CERI WMV 169.3 36 P :34.50 ( 1.32 ) eS :53.50 (-0.09 ) CERI PWV 186.5 30 P :36.80 ( 1.02 ) eS :57.80 (-0.30 ) CERI BBG 192.2 235 eP :37.32 ( 0.61 ) eS :09:00.20 ( 0.50X) CERI NAV 197.3 36 P :38.10 ( 0.69 ) eS :01.00 ( 0.08 ) CERI ORT 200.3 272 eP :38.54 ( 0.68 ) eS :03.04 ( 1.35 ) CERI BLA 210.1 45 P :39.30 (-0.08 ) eS :04.96 ( 0.64 ) CERI GRB 212.2 84 P :37.50 (-2.15X) eS :03.50 (-1.29 ) CERI HWV 220.3 30 P :41.40 ( 0.47 ) eS :06.80 (-0.20 ) CERI VWV 232.4 40 P :42.90 ( 0.07X) eS :10.60 ( 0.31X) CERI TQTN 242.2 261 iP :45.45 ( 1.18X) iS :12.69 (-0.09X) CERI BHT 258.2 270 eP :46.88 ( 0.18X) eS :15.88 (-1.10X) CERI GMG 260.4 245 eP :46.52 (-0.48X) eS :14.60 (-2.90X) CERI CEH 270.3 89 P :45.00 (-3.09X) eS :16.50 (-2.89X) CERI WMTN 270.9 256 eP :47.54 (-0.65X) iS :18.54 (-1.02X) CERI ANTN 285.3 277 eP :50.04 ( 0.05X) eS :23.64 ( 0.97X) CERI LKGA 338.1 247 eP :57.54 ( 1.10X) eS :36.50 ( 2.67X) CERI PDTN 347.6 260 iP :59.64 ( 2.08X) eS :36.04 ( 0.26X) CERI FDKY 347.9 288 eP :57.79 ( 0.19X) eS :35.84 ( 0.00X) CERI ABTN 363.2 271 eP :59.24 (-0.24X) iS :39.44 ( 0.35X) CERI HAKY 425.5 290 iP :09:10.39 ( 3.35X) iS :51.94 (-0.23X) CERI MSAL 432.2 256 eP :10.84 ( 2.94X) eS :53.89 ( 0.23X) CERI TCT 493.4 273 eS :10:06.79 ( 0.20X) CERI LAL 504.3 253 eS :10.14 ( 1.22X) NEIC SLTN 63.4 358 iP 05:08:16.20 (-0.5 ) NEIC TRYN 72.3 193 ePc :17.18 (-1.1 ) eS 05:08:26.18 ( X) NEIC PKNC 85.6 77 ePc :20.20 (-0.6 ) NEIC FGTN 116.7 302 ePd :25.00 (-0.8 ) NEIC PLVA 121.2 43 ePc :25.36 (-1.1 ) NEIC TKL 154.6 261 ePd :30.92 (-0.6 ) NEIC CRTN 162.3 283 iP :32.09 (-0.4 ) NEIC WMV 169.0 36 ePn :32.57 (-1.0 ) S :52.78 ( X) NEIC PWV 186.8 30 ePn :36.20 ( 0.5 ) eS :57.46 ( X) NEIC BBG 192.4 235 eP :37.32 ( 0.8 ) NEIC JSC 192.4 157 P :36.53 ( 0.1 ) iS :59.51 ( X) NEIC LHS 194.6 143 eP :36.66 ( 0.0 ) S :09:00.11 ( X) NEIC NAV 197.9 36 ePn :37.00 (-0.1 ) eS :00.09 ( X) NEIC ORT 200.1 272 eP :38.54 ( 1.1 ) NEIC BLA 210.1 45 eP :39.42 ( 0.6 ) eS :04.04 ( X) NEIC HWV 220.2 30 ePn :40.46 ( 0.3 ) S :06.76 ( X) NEIC VWV 232.4 40 ePn :41.71 (-0.1 ) eS :09.88 ( X) NEIC TQTN 242.4 261 P :45.45 ( 2.6 ) S :12.69 ( X) NEIC BHT 258.0 270 eP :46.88 ( 1.8 ) NEIC GMG 260.2 245 eP :46.52 ( 1.2 ) NEIC CEH 270.2 89 eP :46.07 (-0.5 ) NEIC ANTN 284.6 278 eP :50.04 ( 1.6 ) TVA SLTN 62.5 357 iP 05:08:16.20 ( 0.02 ) TVA TRYN 69.6 192 ePc :17.18 (-0.14 ) eS 05:08:26.18 ( 0.08 ) TVA PKNC 85.7 77 ePc :20.20 ( 0.22 ) eS :30.98 ( 0.28 ) TVA FGTN 117.2 302 ePd :25.00 (-0.06 ) eS :40.04 ( 0.54 ) TVA PLVA 120.5 43 ePc :25.36 (-0.28 ) eS :40.48 (-0.01 ) TVA TKL 154.6 261 eP :30.94 ( 0.17 ) iS :49.39 ( 0.01 ) TVA CRTN 162.1 283 iP :32.09 ( 0.16X) iS :53.09 ( 1.71X) TVA WMV 169.0 36 P :34.50 ( 1.45X) eS :53.50 ( 0.19X) TVA PWV 186.2 30 P :36.80 ( 1.15X) eS :57.80 (-0.01X) TVA BBG 192.4 235 eP :37.32 ( 0.67X) eS :09:00.20 ( 0.65X) TVA NAV 197.0 36 P :38.10 ( 0.82X) eS :01.00 ( 0.36X) TVA ORT 200.4 272 eP :38.54 ( 0.76X) eS :03.04 ( 1.54X) TVA BLA 209.8 45 P :39.30 ( 0.05X) eS :04.96 ( 0.91X) TVA HWV 220.0 30 P :41.40 ( 0.61X) eS :06.80 ( 0.08X) TVA VWV 232.2 40 P :42.90 ( 0.20X) eS :10.60 ( 0.58X) TVA TQTN 242.3 261 P? :45.45 ( 1.51X) S? :12.69 ( 0.53X) TVA BHT 258.3 270 eP :46.88 ( 0.92X) eS :15.88 ( 0.23X) TVA GMG 260.6 245 eP :46.52 ( 0.24X) eS :14.60 (-1.60X) TVA CEH 270.2 89 P :45.00 (-2.33X) eS :16.50 (-1.53X) TVA WMTN 271.0 256 eP :47.54 ( 0.08X) iS :18.54 ( 0.30X) TVA ANTN 285.4 277 eP :50.04 ( 0.80X) eS :23.64 ( 2.31X) TVA LKGA 338.2 247 eP :57.54 ( 1.83X) eS :36.50 ( 3.97X) TVA PDTN 347.7 260 P? :59.64 ( 2.81X) eS :36.04 ( 1.58X) TVA FDKY 347.9 288 eP :57.79 ( 0.94X) eS :35.84 ( 1.35X) TVA ABTN 363.3 271 eP :59.24 ( 0.50X) iS :39.44 ( 1.68X) TVA HAKY 425.4 290 P? :09:10.39 ( 4.08X) S? :51.94 ( 1.08X) TVA MSAL 432.4 256 eP :10.84 ( 3.67X) eS :53.89 ( 1.54X) TVA TCT 493.4 273 eS :10:06.79 ( 1.54X) TVA LAL 504.5 253 eS :10.14 ( 2.53X) ***** 1993 JANUARY 7; 23:55 - CHARLESTON, SOUTH CAROLINA ***** CSU Felt (I) between Middleton Place and Summerville, SC. Magnitude 1.5. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 930107 235518.4 32.909 80.196 5.7 6 0 149 0.2 C 3.4 360 3.4 4.1 1.3 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC RGR 0.2 140 iPd 23:55:19.89 ( 0.25 ) USC MGS 5.3 104 iPd :20.05 (-0.03 ) USC SVS 8.2 323 iPu :20.15 (-0.35 ) USC HBF 13.5 288 iPd :21.24 ( 0.00 ) USC BCS 14.5 57 iPd :21.55 (-0.08 ) USC TWB 24.4 21 iPd :23.45 ( 0.24 ) ***** 1993 JANUARY 8; 21:19 - CLEVELAND, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930108 211925.5 35.165 84.606 13.2 16 35 179 0.2 C B/C 0.5 -35 0.3 0.6 A 1.6 CERI 930108 211925.7 35.154 84.605 21.4 6 33 84 0.1 C C/B 1.3 13 0.7 5.7 D 1.7 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA WMTN 34.7 285 iP 21:19:32.00 ( 0.13 ) TVA TQTN 40.4 344 iP :33.00 ( 0.23 ) iS 21:19:37.70 (-0.35 ) TVA ORT 87.0 18 iP :40.32 ( 0.27 ) iS :50.66 ( 0.01 ) TVA TKL 93.2 54 iPd :40.95 (-0.06 ) iS :52.26 (-0.05 ) TVA LKGA 99.4 233 eP :42.00 ( 0.01 ) eS :53.70 (-0.30 ) TVA PDTN 113.9 276 eP :44.32 ( 0.15 ) iS :57.67 (-0.11 ) TVA ANTN 125.2 333 iPd :45.96 ( 0.03 ) iS :20:01.00 ( 0.18 ) TVA MSAL 192.0 260 iP :55.75 (-0.38 ) iS :18.80 ( 0.33 ) TVA LAL 262.7 253 eP :20:06.80 ( 1.16 ) eS :36.70 ( 1.78X) TVA SLTN 265.6 57 P? :08.50 ( 2.37X) TVA TCT 282.9 290 P :00.00 (-8.10X) eS :41.05 ( 1.87X) CERI GMG 32.8 190 eP 21:19:32.22 ( 0.01 ) eS 21:19:36.70 (-0.28X) CERI RCG 70.6 254 eP :37.62 (-0.05 ) eS :45.98 (-0.46X) CERI BBGE 78.9 113 eP :39.12 ( 0.12 ) eS :48.54 (-0.20 ) CERI BHT 82.9 338 eP :39.60 ( 0.04 ) eS :49.48 (-0.23X) CERI TKLZ 94.0 53 eP :41.12 (-0.09 ) eS :52.36 (-0.21X) ***** 1993 JANUARY 15; 02:02 - CLEVELAND, TENNESSEE ***** TVA Felt in southeastern Tennessee and Georgia; felt (IV) at McDonald, TN (USGS). Felt also in Bradley, Hamilton, McMinn Counties in Tennessee. NEIC Felt (IV) at McDonald and (III) at Apison, Calhoun, Chattanooga, Collegedale, Ooltewah and Varnell. Felt in the Cleveland and Etowah areas. Also felt in parts of northern Georgia. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930115 020250.9 35.039 85.025 8.1 34 24 136 0.3 C B/C 0.3 -7 0.2 0.5 A 3.3 4 CERI 930115 020251.0 35.049 85.006 5.8 14 32 132 0.4 C C/C 1.4 23 1.0 2.9 C 3.3 NEIC 930115 020251.8 35.075 84.974 1.8 20 19 3.1 3.2 4 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA WMTN 23.7 11 iP 02:02:55.36 ( 0.12 ) TVA RCG 30.4 257 iPc :56.52 ( 0.20 ) eS 02:03:00.30 ( 0.00 ) TVA GMG 37.8 121 iPc :57.86 ( 0.28 ) eS :02.70 ( 0.23 ) TVA TQTN 59.5 27 iPd :03:00.92 (-0.20 ) iS :08.48 (-0.11 ) TVA PDTN 79.6 289 iPc :04.08 (-0.35 ) iS :14.60 ( 0.28 ) TVA BHT 90.0 5 iPd :06.02 (-0.16 ) eS :17.28 (-0.08 ) TVA BBG 112.3 99 iP :09.72 ( 0.03 ) eS :22.98 (-0.44 ) TVA ORT 116.6 34 iPd :10.20 (-0.06 ) eS :25.10 ( 0.69 ) TVA ANTN 127.1 352 iPd :11.73 (-0.16 ) TVA TKL 132.8 58 eP+ :12.62 (-0.12 ) eS :28.46 (-0.24 ) TVA ABTN 136.1 314 iP :13.38 ( 0.14 ) TVA MSAL 152.1 262 iPc :15.25 (-0.43 ) iS :33.60 (-0.19 ) TVA FDKY 206.4 341 iP- :24.38 ( 0.38 ) TVA FGTN 226.6 46 eP+ :27.02 (-0.09 ) eS :53.60 ( 0.04 ) TVA BRTN 243.9 53 eP :29.73 ( 0.43 ) TVA TCT 253.2 296 eP+ :30.43 ( 0.05 ) TVA TRYN 254.5 83 eP :31.30 ( 0.67 ) eS :04:00.56 ( 0.92 ) TVA HAKY 269.0 329 eP+ :32.98 ( 0.67 ) eS :04.20 ( 1.64X) TVA SOKY 288.7 343 P :35.00 ( 0.27 ) eS :09.00 ( 2.26X) TVA SLTN 305.4 58 eP :36.53 (-0.38 ) iS :10.58 ( 0.07 ) TVA MOTN 319.9 304 eP :39.42 ( 0.88 ) TVA SMKY 333.1 323 P :44.00 ( 3.85X) eS :24.00 ( 7.88X) TVA ROKY 333.4 17 P :41.00 ( 0.78 ) eS :23.00 ( 6.76X) TVA LLKY 347.1 308 P :46.50 ( 4.65X) eS :24.00 ( 4.93X) TVA UTM 380.8 293 eP :48.82 ( 2.85X) TVA FLKY 392.8 16 P :51.00 ( 3.55X) eS :38.00 ( 9.24X) TVA CRU 400.2 297 eS :40.44 TVA DRTN 411.8 288 eP :56.48 ( 6.72X) TVA ELC 452.9 305 eP :04:02.58 ( 7.80X) eS :55.56 TVA LGAR 516.8 267 eP :06.60 ( 4.01X) TVA LRDO 524.7 283 eP :13.72 CERI RCG 32.2 255 iPc 02:02:56.52 (-0.19 ) eS 02:03:00.30 (-0.59X) CERI GMG 37.0 124 iPc :57.86 ( 0.33 ) eS :02.70 ( 0.38X) CERI BHT 88.7 4 iPd :03:06.02 (-0.05 ) eS :17.28 ( 0.19X) CERI BBG 110.9 100 iP :09.72 ( 0.01 ) eS :22.98 (-0.40 ) CERI TKL 130.9 59 eP+ :12.62 (-0.06 ) eS :28.46 (-0.06 ) CERI FGTN 224.7 46 eP+ :27.02 (-0.03 ) eS :53.60 ( 0.21X) CERI TRYN 252.7 84 eP :31.30 (-0.05 ) eS :04:00.56 (-0.26X) CERI SOKY 288.1 343 P :35.00 (-0.59 ) eS :09.00 ( 0.85 ) CERI ROKY 331.8 17 P :41.00 ( 0.03 ) eS :23.00 ( 5.54X) CERI SMKY 333.2 323 P :44.00 ( 2.90 ) eS :24.00 ( 6.31X) CERI FLKY 391.2 16 P :51.00 ( 2.79 ) eS :38.00 ( 8.02X) CERI LLKY 423.4 301 P :46.50 (-5.63X) NEIC WMTN 18.9 0 iP 02:02:55.36 ( 0.1 ) NEIC RCG 35.6 252 iP :58.30 ( 0.0 ) NEIC GMG 36.7 130 iP :58.10 (-0.3 ) NEIC TQTN 53.4 25 iPd :03:00.91 (-0.6 ) iS 02:03:07.80 ( X) NEIC PDTN 82.3 286 iPc :04.07 (-2.6 ) iS :14.60 ( X) NEIC BHT 85.6 2 iP :06.50 (-0.7 ) NEIC BBG 109.0 102 iP :10.80 (-0.4 ) NEIC ORT 111.2 33 iPd :10.19 (-1.3 ) NEIC TKL 126.8 59 ePn :12.56 (-1.4 ) eS :27.59 ( X) NEIC MSAL 156.8 261 iPc :15.25 (-3.3 ) iS :33.59 ( X) NEIC TRYN 246.8 85 iP :32.20 ( 1.8 ) NEIC PRM 263.5 114 ePn :31.71 (-0.7 ) eS :04:04.24 ( X) iPg :33.29 ( ) NEIC JSC 351.4 103 ePn :42.15 (-1.5 ) eSn :27.90 ( X) NEIC LHS 386.9 99 ePn :46.66 (-1.5 ) eS :37.44 ( X) ePg :53.98 ( ) NEIC GRT 423.6 289 ePn :52.61 (-0.3 ) eS :47.76 ( X) ePg :58.34 ( ) NEIC NAV 450.3 55 P? :55.24 (-1.1 ) eS :56.38 NEIC ELC 454.8 304 ePn :55.83 (-0.9 ) eS :55.33 ePg :04:02.28 ( ) NEIC BLA 473.7 59 P? :07.23 ( 8.0 ) eSg :05:03.39 ( X) NEIC HBF 485.9 118 Pn? :03:59.08 (-1.8 ) eS :05.29 ( X) NEIC FVM 584.9 305 ePg :04:24.00 (10.5 ) eS :29.08 ( X) ***** 1993 JANUARY 15; 05:45 - CLEVELAND, TENNESSEE ***** TVA Aftershock of 1/15/93, 02:02 UTC, M = 3.3 event. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930115 054517.0 35.104 85.082 2.7 8 19 201 0.2 C B/D 1.2 -31 0.3 1.0 A 1.7 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA WMTN 18.8 32 eP 05:45:20.58 ( 0.16 ) iS 05:45:22.83 (-0.06 ) TVA RCG 28.2 239 eP :22.02 (-0.05 ) TVA TQTN 56.0 35 eP :22.78 (-4.10X) eS :34.08 ( 0.02 ) TVA PDTN 72.3 285 eP :28.66 (-0.92 ) iS :38.78 ( 0.04 ) TVA ORT 113.8 38 S? :50.16 (-0.38 ) TVA MSAL 148.1 259 P? :40.33 (-1.31X) eS :59.08 (-0.52 ) ***** 1993 JANUARY 22; 03:46 - CHARLESTON, SOUTH CAROLINA ***** CSU Felt (I) between Middleton Place and Summerville, SC. Magnitude <1. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 930122 034636.3 32.931 80.138 8.5 4 4 253 0.0 C 1.0 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC MGS 3.7 185 P 03:46:38.20 ( 0.00 ) USC RGR 5.9 244 P :38.35 ( 0.00 ) USC SVS 11.2 292 iPu :39.08 ( 0.00 ) USC HBF 18.3 276 iPd :40.08 ( 0.00 ) USC DRC 30.5 310 P :37.85 (-4.35X) ***** 1993 JANUARY 28; 01:51 - MURPHY, NORTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I CERI 930128 015139.4 35.141 84.262 28.3 4 48 255 0.0 D D/D 4.1 -56 2.4 23.7 D 1.5 TVA 930128 015140.2 35.149 84.251 5.0 13 50 103 0.2 C C/C 0.8 -12 0.7 3.2 C 1.5 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) CERI GMG 48.4 231 eP 01:51:48.56 ( 0.00 ) eS 01:51:55.04 (-0.20X) CERI BBG 50.7 126 eP :48.92 ( 0.00 ) eS :55.86 ( 0.00 ) CERI TKL 72.6 38 eS :52:01.10 ( 0.00 ) TVA GMG 49.7 230 eP 01:51:48.56 (-0.37 ) eS 01:51:55.04 (-0.25 ) TVA BBG 50.4 127 eP :48.92 (-0.13 ) eS :55.86 ( 0.36 ) TVA WMTN 66.7 280 P? :51.80 ( 0.12 ) eS :52:00.15 ( 0.09 ) TVA TKL 71.2 37 P? :52.23 (-0.19 ) eS :01.08 (-0.25 ) TVA ORT 84.5 357 P :52:00.00 ( 5.37X) S? :05.07 (-0.09 ) TVA CRTN 122.4 18 P :00.00 (-0.70X) eS :15.68 ( 0.03 ) TVA ABTN 187.3 296 iPc :10.80 ( 0.16 ) eS :32.82 (-0.02 ) TVA MSAL 223.7 262 S? :41.80 (-0.66 ) ***** 1993 JANUARY 28; 06:12 - SMYRNA, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930128 061243.8 36.153 86.571 6.4 15 51 100 0.3 D C/D 0.3 -3 0.3 1.3 A 1.8 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA ABTN 51.2 125 iP+ 06:12:52.70 ( 0.07 ) iS 06:12:58.75 (-0.34 ) TVA TCT 89.9 260 eP :59.14 ( 0.10 ) iS :13:09.90 (-0.28 ) TVA FDKY 99.2 44 iP :13:00.82 ( 0.24 ) iS :12.92 ( 0.09 ) TVA HAKY 105.7 359 P? :01.85 ( 0.27 ) eS :14.21 (-0.35 ) TVA PDTN 117.5 146 eP :03.55 ( 0.15 ) eS :17.95 ( 0.24 ) TVA ANTN 120.6 89 P? :05.60 ( 1.70X) eS :16.50 (-2.07X) TVA MSAL 145.3 184 P? :08.11 ( 0.46 ) eS :25.40 ( 0.33 ) TVA WMTN 176.1 124 eP :12.60 ( 0.22 ) eS :32.95 (-0.29 ) TVA LAL 202.8 200 P? :17.80 ( 1.34X) iS :41.40 ( 1.08 ) TVA CRTN 245.7 88 S? :53.81 ( 2.89X) TVA TKL 258.4 101 S? :55.75 ( 2.17X) ***** 1993 FEBRUARY 13; 11:35 - ETOWAH, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930213 113554.8 35.346 84.490 13.1 11 29 225 0.1 C A/D 0.6 -42 0.3 0.5 A 1.0 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA TQTN 28.5 312 iP 11:36:00.33 ( 0.17 ) iS 11:36:04.04 (-0.04 ) TVA WMTN 45.2 256 iP :02.84 ( 0.02 ) iS :08.56 (-0.11 ) TVA ORT 64.8 15 ePd :05.97 ( 0.04 ) iS :13.94 (-0.11 ) TVA CRTN 111.5 32 P? :13.34 ( 0.25 ) S? :26.64 ( 0.20 ) TVA PDTN 123.9 267 S? :29.49 (-0.21 ) TVA ABTN 158.4 293 eP :20.34 ( 0.07 ) iS :38.94 ( 0.08 ) ***** 1993 FEBRUARY 19; 21:37 - ELK CREEK, VIRGINIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I CERI 930219 213706.5 36.696 81.144 7.9 5 4 336 0.1 D D/D 43.4 90 3.4 8.8 D 2.2 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) CERI PLVA 3.6 205 iPc 21:37:08.16 (-0.06 ) eS 21:37:09.56 ( 0.07 ) CERI PKNC 72.1 181 eP :19.00 ( 0.17 ) eS :27.74 (-0.10 ) CERI TRYN 187.1 212 eP :39.58 ( 2.86X) eS :58.78 ( 0.00 ) ***** 1993 FEBRUARY 20; 01:10 - JEFFERSON CITY, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I CERI 930220 011013.2 36.306 83.665 16.4 7 45 243 0.1 D C/D 1.6 -66 0.8 17.2 D 2.0 TVA 930220 011013.3 36.288 83.654 7.7 23 44 142 0.2 C B/C 0.9 -30 0.2 1.1 A 1.9 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) CERI FGTN 44.5 71 iPd 01:10:21.10 (-0.03 ) eS 01:10:27.00 ( 0.07 ) CERI TKL 72.5 188 iPc :25.42 ( 0.04 ) eS :34.16 (-0.12 ) CERI BHT 126.1 247 eS :48.60 ( 0.03 ) CERI BBG 159.4 185 eP :38.52 (-0.27 ) eS :58.04 ( 0.55 ) CERI TRYN 172.4 132 eS :11:01.70 ( 0.83X) TVA FGTN 44.2 68 iPd 01:10:21.10 ( 0.09 ) eS 01:10:27.00 ( 0.36 ) TVA TKL 70.7 189 iPc :25.42 ( 0.03 ) eS :34.16 (-0.06 ) TVA BRTN 71.0 84 eP :25.33 (-0.12 ) eS :33.93 (-0.39 ) TVA ORT 72.1 235 eP :26.04 ( 0.41 ) iS :34.50 (-0.12 ) TVA BHT 126.2 248 eS :48.60 (-0.88 ) TVA TQTN 129.3 229 eP :34.50 (-0.13 ) eS :50.10 (-0.10 ) TVA SLTN 138.7 82 iP :36.00 (-0.16 ) S? :53.05 ( 0.20 ) TVA ANTN 142.4 265 P? :36.15 (-0.53 ) TVA BBG 157.5 185 eP :38.52 (-0.54 ) eS :58.88 ( 1.02X) TVA WMTN 166.0 226 eP :40.22 (-0.05 ) iS :11:00.10 ( 0.15 ) TVA TRYN 170.4 131 eP :49.78 ( 8.79X) eS :02.80 ( 1.61X) TVA FDKY 199.6 287 P? :45.70 ( 0.29 ) S? :08.55 (-0.30 ) TVA ABTN 225.6 259 iP :49.30 (-0.10 ) S? :17.29 ( 1.55X) TVA PDTN 228.2 241 P? :49.71 (-0.08 ) eS :17.60 ( 1.17 ) TVA LKGA 247.7 222 eP :54.30 ( 2.07X) eS :22.38 ( 1.73 ) TVA HAKY 277.2 290 P :11:00.00 ( 4.22X) S? :29.57 ( 2.78X) ***** 1993 MARCH 10; 14:32 - COLUMBIA, MARYLAND ***** NEIC Felt (IV) at Columbia, Maryland, and (II) at Ellicott City and Fulton, Maryland. Also felt in the Baltimore area, Maryland. MGS Felt (II - IV) in the Columbia, Maryland, area (see special report on this earthquake and associated events in Appendix A). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I NEIC 930310 143221.6 39.233 76.882 5.0F 11 97 2.5 4 VTSO 930310 143222.1 39.261 76.941 0.4F 15 96 168 0.3 D D/D 2.8 -59 0.6 2.2 C 2.5 MGS 930310 1432 39.19 76.87 2.5 4 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) NEIC MVL 96.7 28 Pg 14:32:38.00 (-0.8 ) Sg 14:32:49.50 ( X) NEIC NED 113.4 62 iPd :41.00 (-0.4 ) S :56.09 ( X) NEIC CBN 122.3 201 P :57.00 (14.3X ) NEIC CNV 122.3 201 eP :42.09 (-0.6 ) S :57.58 ( X) NEIC BWD 129.0 60 iPd :43.50 (-0.2 ) S :59.50 ( X) NEIC BVD 133.4 63 iPd :45.00 ( 0.6 ) S :33:00.08 ( X) NEIC NA5 154.6 209 P :47.47 (-0.2 ) S :04.45 ( X) NEIC NA12 163.4 212 iPc :48.72 (-0.1 ) eS :07.63 ( X) NEIC GHV 192.4 214 P :52.89 ( 0.4 ) S :15.01 ( X) NEIC CVL 195.7 225 eP :53.34 ( 0.4 ) eS :14.73 ( X) NEIC GPD 285.8 45 P? :33:05.12 ( 0.5 ) eS :41.65 ( X) NEIC TBR 310.2 46 P? :08.17 ( 0.4 ) eS :47.19 ( X) NEIC PAL 321.3 51 P :13.18 ( 4.1X ) S :43.88 ( X) NEIC WCC 332.5 52 P :14.13 ( 3.6X ) S :46.66 ( X) NEIC CRNY 365.8 50 Pn? :16.65 ( 1.9X ) NEIC BLA 382.5 235 P? :23.47 ( 6.4X ) NEIC NAV 402.5 239 P? :24.77 ( 5.1X ) eS :34:12.49 ( X) NEIC CEH 419.2 208 P? :25.71 ( 4.0X ) eS :15.67 ( X) VTSO MVL 96.4 32 P 14:32:38.00 ( 0.05 ) S 14:32:49.50 ( 0.00 ) VTSO NED 116.9 65 P :41.00 (-0.32 ) VTSO CNV 123.1 198 eP :42.09 (-0.23 ) S :57.58 ( 0.51 ) VTSO BWD 131.7 63 P :43.50 (-0.24 ) VTSO BVD 136.5 65 P :45.00 ( 0.47 ) VTSO NA12 163.7 210 iPu :48.72 (-0.27 ) eS? :33:07.64 (-0.86 ) VTSO GHV 191.9 212 P :52.89 ( 0.13 ) eS? :15.01 (-0.02 ) VTSO CVL 194.1 223 P :53.29 ( 0.25 ) S? :15.67 ( 0.17 ) VTSO GPD 287.6 46 P :33:05.10 ( 0.61 ) VTSO TBR 311.8 47 P :08.10 ( 0.67 ) VTSO PAL 322.9 52 P :13.10 ( 4.33X) VTSO CEH 419.5 208 P :25.70 ( 5.12X) Additional Data: DGS NED 113.8 iPd 14:32:41.0 iS 14:32:56.1 DGS BWD 128.7 iPd :43.5 iS :59.5 DGS BVD 133.3 iPd :45.0 iS :33:00.8 ***** 1993 MARCH 11; 14:15 - CHARLESTON, SOUTH CAROLINA ***** CSU Felt (II) between Middleton Place and Summerville, SC. Magnitude 2.3. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 930311 141508.8 32.997 80.230 9.1 10 4 69 0.1 A 0.5 360 0.5 0.7 1.4 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC SVS 3.6 209 iPu 14:15:10.92 ( 0.13 ) S 14:15:12.36 ( 0.02X) USC RGR 10.4 161 iPu :11.50 ( 0.05 ) S :13.15 (-0.37X) USC HBF 11.0 241 iPd :11.62 ( 0.12 ) S :13.41 (-0.21X) USC MGS 13.7 143 iPu :12.02 ( 0.05 ) S :14.40 (-0.05X) USC BCS 15.5 97 iPd :12.20 (-0.17 ) S :14.70 (-0.47X) USC WAS 17.0 193 Pu :12.55 ( 0.13 ) S :18.30 ( 3.05X) USC TWB 17.7 42 iPu :12.69 ( 0.08 ) S :15.25 (-0.34X) USC DRC 19.2 310 P :13.00 ( 0.16 ) S :15.60 (-0.39X) USC CFS 31.7 10 iPd :14.67 (-0.14 ) USC SGS 34.0 310 iPd :15.02 (-0.14 ) S :15.02 (-5.11X) USC JSC 171.7 326 eP :35.66 ( 0.30X) Additional Data: CSU RGR P 14:15:11 CSU WAS P :12 CSU MGS P :12 CSU DRC P :12.5 CSU TWB P :13 ***** 1993 MARCH 12; 00:54 - COLUMBIA, MARYLAND ***** NEIC Felt (III) at Columbia, Maryland. Hypocenter based on macroseismic information. MGS Felt (II - III) in the Columbia, Maryland, area (see special report on this earthquake and associated events in Appendix A). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I NEIC 930312 005421.0 39.20 76.90 5.0F 117 2.0 3 MGS 930312 0054 39.19 76.87 2.0 3 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) NEIC NED 116.7 61 iPc 00:54:41.00 (-0.3 ) iS 00:54:56.50 ( X) NEIC BWD 132.3 59 iPc :43.00 (-0.6 ) S :59.09 ( X) NEIC CVL 192.4 226 eP :52.67 ( 0.9 ) eS :55:15.79 ( X) Additional Data: DGS NED 117.1 iPu 00:54:41.0 iS 00:54:56.5 DGS BWD 132.6 iPu :43.0 iS :59.1 ***** 1993 MARCH 12; 09:56 - SWEETWATER, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930312 095638.1 35.715 84.466 3.9 15 26 122 0.2 C B/C 0.3 -9 0.2 0.8 A 1.8 CERI 930312 095638.1 35.722 84.473 20.7 6 45 168 0.1 C C/C 1.0 4 0.3 4.2 C 1.8 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA ORT 26.0 34 iP 09:56:43.05 ( 0.22 ) iS 09:56:46.12 (-0.13 ) TVA BHT 45.7 289 iPc :46.22 (-0.02 ) eS :52.26 ( 0.10 ) TVA TKL 62.9 96 eP :49.08 ( 0.02 ) iS :56.96 (-0.06 ) TVA WMTN 69.3 222 iP :50.15 ( 0.04 ) iS :58.81 (-0.04 ) TVA ANTN 85.7 306 eP :52.05 (-0.78 ) TVA LKGA 151.9 217 eP :57:03.23 (-0.02 ) S? :57:22.18 ( 0.59 ) TVA FDKY 168.8 315 P :00.00 (-5.81X) iS :26.10 ( 0.09 ) TVA MSAL 222.7 245 S? :40.10 (-0.20 ) TVA SLTN 226.2 68 eS :41.90 ( 0.53 ) TVA TCT 280.7 277 S? :54.18 ( 1.02 ) CERI BHT 44.9 288 iPc 09:56:46.22 (-0.04 ) eS 09:56:52.26 ( 0.03 ) CERI TKL 63.6 96 eP :49.12 ( 0.11 ) iS :56.96 (-0.03 ) CERI GMG 97.0 191 eP :54.10 (-0.05 ) eS :57:05.92 ( 0.03 ) ***** 1993 MARCH 15; 04:29 - COLUMBIA, MARYLAND ***** NEIC Felt in the Columbia-Laurel area, Maryland. MGS Felt (III - V) in the Columbia, Maryland, area (see special report on this earthquake and associated events in Appendix A). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I NEIC 930315 042954.0 39.233 76.897 5.0F 13 97 2.7 F VTSO 930315 042954.7 39.197 76.870 0.9F 13 100 160 0.2 D C/D 1.4 -49 0.6 1.7 B 2.1 MGS 930315 0430 39.19 76.87 2.7 5 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) NEIC MVL 96.7 29 Pg 04:30:11.00 (-0.2 ) Sg 04:30:23.00 ( X) NEIC NED 114.5 63 iPc :13.69 (-0.2 ) iS :27.29 ( X) NEIC BWD 130.1 61 iPc :15.39 (-0.8 ) iS :31.60 ( X) NEIC BVD 134.5 63 iPc :16.89 ( 0.0 ) iS :34.59 ( X) NEIC NA5 154.6 209 eP :19.50 (-0.4 ) S :36.63 ( X) NEIC GHV 191.2 214 P :25.13 ( 0.4 ) S :47.18 ( X) NEIC CVL 194.6 225 eP :25.41 ( 0.3 ) eS :48.65 ( X) NEIC PBV 255.7 193 P :32.22 (-0.9 ) S :31:05.00 ( X) NEIC GPD 286.9 46 Pn? :37.76 ( 0.6 ) S :13.55 ( X) NEIC TBR 311.3 46 Pn? :41.00 ( 0.8 ) S :19.49 ( X) ePg :44.01 ( ) NEIC PAL 321.3 51 Pn? :41.66 ( 0.1 ) S :22.88 ( X) NEIC CRNY 366.9 50 Pn? :51.23 ( 4.0X ) S :34.38 ( X) NEIC BLA 381.4 235 Pn? :51.65 ( 2.4X ) S :38.79 ( X) NEIC NAV 401.4 239 Pn? :50.58 (-1.2 ) S :44.31 ( X) NEIC CEH 418.1 208 Pn? :55.72 ( 1.8 ) S :47.77 ( X) VTSO MVL 99.6 26 P 04:30:11.00 (-0.05 ) S 04:30:23.00 ( 0.01 ) VTSO NED 114.7 60 iPu :13.70 ( 0.17 ) iS :27.30 ( 0.01 ) VTSO BWD 129.8 59 iPu :15.40 (-0.60 ) iS :31.60 ( 0.04 ) VTSO BVD 134.2 61 iPu :16.90 ( 0.17 ) iS :34.60 ( 1.78X) VTSO NA5 151.8 210 eP :19.50 (-0.11 ) VTSO GHV 189.5 215 eP :25.10 ( 0.12 ) :47.16 ( 0.17 ) VTSO CVL 193.4 226 eP :25.32 (-0.16 ) :48.15 ( 0.31 ) VTSO PBV 252.5 193 eP :32.22 (-0.47 ) Additional Data: DGS NED 114.9 iPu 04:30:13.7 iS 04:30:27.3 DGS BWD 130.6 iPu :15.4 iS :31.6 DGS BVD 134.4 iPu :16.9 iS :34.6 ***** 1993 MARCH 16; 07:59 - COLUMBIA, MARYLAND ***** MGS Felt (II - III) in the Columbia, Maryland, area. M < 2 (see special report on this earthquake and associated events in Appendix A). NEIC Felt at Columbia, Maryland. Hypocenter based upon macroseismic information. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I MGS 930316 0759 39.19 76.87 3 NEIC 930316 075924.0 39.20 76.90 5.0F 117 1.8 F SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) NEIC NED 116.7 61 iPd 07:59:43.60 (-0.7 ) iS 07:59:57.50 ( X) NEIC BWD 132.3 59 iPd :45.60 (-1.0 ) iS 08:00:01.60 ( X) NEIC TBR 313.6 46 P 08:00:13.90 ( 3.3 ) NEIC CEH 414.7 208 P :01:15.70 (52.1 ) Additional Data: DGS NED 117.1 iPd 07:59:43.6 iS 07:59:57.5 DGS BWD 132.6 iPd :45.6 iS 08:00:01.6 DGS BVD 136.4 eP? :4? iS :04.7 ***** 1993 MARCH 16; 16:59 - COLUMBIA, MARYLAND ***** MGS Felt (II - III) in the Columbia, Maryland, area (see special report on this earthquake and associated events in Appendix A). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I MGS 930316 1659 39.19 76.87 1.8 3 ***** 1993 MARCH 19; 05:50 - COLUMBIA, MARYLAND ***** MGS Felt (I - II) in the Columbia, Maryland, area. Magnitude approximately 1.0 (see special report on this earthquake and associated events in Appendix A). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I MGS 930319 0550 39.19 76.87 1.0 2 ***** 1993 MARCH 21; 02:40 - FLAT RIDGE, VIRGINIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I CERI 930321 024007.2 36.692 81.360 20.8 6 18 198 0.1 D D/D 3.9 48 2.4 10.3 D 2.8 VTSO 930321 024007.8 36.643 81.423 1.0F 7 24 179 0.3 C C/C 2.8 -55 1.2 5.0 C 1.7 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) CERI PLVA 18.1 99 iP 02:40:11.90 ( 0.00 ) CERI FGTN 166.7 261 eP :34.00 ( 0.17 ) eS 02:40:53.20 (-0.10 ) CERI TRYN 177.1 207 eP :35.10 (-0.35 ) eS :56.30 ( 0.19 ) CERI TKL 245.5 243 eS :41:14.30 ( 1.62 ) VTSO PLVA 23.6 84 iP 02:40:11.90 (-0.07 ) VTSO WMV 65.5 38 P+ :19.80 ( 0.45 ) eS 02:40:26.50 (-0.36 ) VTSO HWV 117.2 26 eS :41.80 ( 0.04 ) VTSO FGTN 160.4 262 eP :34.00 (-0.43 ) eS :53.20 ( 0.20 ) VTSO TRYN 172.7 206 eP :35.10 (-1.25X) eS :56.30 ( 0.04 ) VTSO TKL 238.1 243 eS :41:14.30 ( 1.08X) ***** 1993 MARCH 22; 10:26 - COLUMBIA, MARYLAND ***** MGS Not felt. Magnitude approximately 0.0 (see special report on this earthquake and associated events in Appendix A). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I MGS 930322 1026 39.19 76.87 0.0 ***** 1993 MARCH 22; 14:10 - MADISONVILLE, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930322 141024.8 35.491 84.449 10.6 24 25 66 0.2 C B/C 0.5 -45 0.3 1.0 A 2.1 CERI 930322 141024.9 35.481 84.451 6.3 8 60 187 0.1 D C/D 0.3 -6 0.2 15.2 D 1.7 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA TQTN 25.2 276 iP 14:10:29.80 ( 0.26 ) TVA ORT 48.2 16 eP :33.00 (-0.25 ) iS 14:10:39.30 (-0.10 ) TVA WMTN 54.7 241 iP :34.20 (-0.12 ) TVA BHT 59.8 311 eP- :35.16 (-0.01 ) eS :42.98 ( 0.25 ) TVA TKL 64.0 73 eP- :36.00 ( 0.17 ) eS :43.98 ( 0.12 ) TVA GMG 72.6 196 eP :37.04 (-0.26 ) eS :46.08 (-0.32 ) TVA BBG 89.8 139 eP+ :40.18 ( 0.15 ) TVA CRTN 95.9 35 iP :40.85 (-0.04 ) TVA RCG 99.9 235 eP :41.70 ( 0.21 ) TVA LKGA 134.1 224 eP :46.35 (-0.39 ) eS :11:02.45 (-0.29 ) TVA BRTN 172.0 56 eP :52.90 ( 0.35 ) eS :13.43 ( 0.64 ) TVA FDKY 188.2 320 eP :55.40 ( 0.40 ) S? :20.12 ( 3.09X) TVA MSAL 214.9 251 eP :59.20 ( 0.12 ) eS :24.40 ( 0.32 ) TVA SLTN 235.1 63 eP :11:02.40 ( 0.43 ) TVA HAKY 262.5 314 eP :06.40 ( 1.23 ) TVA TCT 286.4 282 eP :08.60 ( 0.49 ) S? :40.20 ( 0.49 ) CERI BHT 60.4 312 eP- 14:10:35.22 (-0.08 ) eS 14:10:42.98 ( 0.08 ) CERI TKL 64.5 72 eS :43.98 (-0.03 ) CERI GMG 71.5 196 eP :37.04 (-0.10 ) eS :46.08 (-0.01 ) CERI BBG 89.1 139 eP+ :40.18 ( 0.11 ) CERI RCG 99.1 236 eP :41.70 ( 0.03 ) CERI FGTN 155.0 47 eP :51.06 ( 0.79X) CERI TRYN 201.8 96 eS :11:21.62 ( 0.37 ) ***** 1993 MARCH 31; 21:47 - CHARLESTON, SOUTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 930331 214710.9 32.999 80.040 5.2 4 14 245 0.0 C 1.2 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC TWB 14.1 335 P 21:47:13.90 ( 0.00 ) USC MGS 14.7 220 P :13.95 ( 0.00 ) USC RGR 17.7 235 P :14.40 ( 0.00 ) USC WAS 27.5 232 P :16.10 ( 0.00 ) ***** 1993 APRIL 3; 08:27 - GUINEA MILLS, VIRGINIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I VTSO 930403 082706.2 37.464 78.335 12.9 6 42 308 0.2 D D/D 5.1 -10 2.6 4.5 C 1.4 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) VTSO GHV 41.9 29 eS 08:27:18.60 (-0.08 ) VTSO CVL 58.5 349 eP 08:27:15.91 (-0.17 ) eS :23.39 ( 0.12 ) VTSO NA12 70.3 35 eS :26.89 ( 0.36 ) VTSO NA5 80.5 41 eP :19.77 ( 0.17 ) :28.91 (-0.39 ) ***** 1993 APRIL 4; 17:31 - COLUMBIA, MARYLAND ***** MGS Felt (I - III) in the Columbia, Maryland, area. Magnitude approximately 1.5 (see special report on this earthquake and associated events in Appendix A). NEIC Felt at Columbia, Maryland, area. Hypocenter based upon macroseismic information. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I NEIC 930404 173129.5 39.17 76.80 5.0F 3 111 1.5 F MGS 930404 1732 39.19 76.87 1.5 3 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) NEIC NED 111.2 57 iPd 17:31:49.60 ( 0.7 ) iS 17:32:03.10 ( X) NEIC BWD 126.8 56 iP :51.50 ( 0.3 ) iS :06.60 ( X) NEIC BVD 130.1 59 eP :50.80 (-1.0 ) iS :05.70 ( X) Additional Data: DGS NED iPu 17:31:49.6 iS 17:32:03.1 DGS BWD iPu :51.5 iS :06.6 DGS BVD ePu :50.8 iS :05.7 ***** 1993 APRIL 4; 17:33 - COLUMBIA, MARYLAND ***** MGS Felt (I - III) in the Columbia, Maryland, area. Magnitude approximately 1.5 (see special report on this earthquake and associated events in Appendix A). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I MGS 930404 1733 39.19 76.87 1.5 3 ***** 1993 APRIL 8; 09:10 - COLUMBIA, MARYLAND ***** NEIC Felt at Columbia, Maryland. Hypocenter based upon macroseismic information. MGS Felt (I - II) in the Columbia, Maryland, area. Magnitude 1-1.5 (see special report on this earthquake and associated events in Appendix A). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I MGS 930408 0910 39.19 76.87 2 NEIC 930408 091004.7 39.17 76.80 5.0F 111 F SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) NEIC NED 111.2 57 iPc 09:10:24.30 ( 0.2 ) iS 09:10:37.50 ( X) NEIC BWD 126.8 56 iPc :26.20 (-0.2 ) iS :42.30 ( X) Additional Data: DGS NED iPu 09:10:24.3 iS 09:10:37.5 DGS BWD iPu :26.2 iS :42.3 ***** 1993 APRIL 10; 15:42 - CHARLESTON, SOUTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 930410 154259.5 32.886 80.216 5.0 3 3 190 0.0 C 1.2 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC RGR 3.1 40 P 15:43:00.80 ( 0.00 ) USC WAS 6.8 230 P :01.28 ( 0.00 ) USC DRC 29.4 327 P :05.15 ( 0.00 ) ***** 1993 APRIL 15; 06:34 - SEVIERVILLE, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930415 063456.4 35.867 83.620 16.5 8 27 239 0.1 D C/D 1.1 -44 0.7 4.0 C 1.3 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA TKL 27.1 211 iP 06:35:01.70 (-0.03 ) iS 06:35:05.65 ( 0.02 ) TVA CRTN 42.0 332 iP :03.95 ( 0.00 ) eS :09.45 (-0.02 ) TVA ORT 62.1 275 P? :07.42 ( 0.43 ) eS :14.70 (-0.03 ) TVA ANTN 149.2 284 eP :20.42 ( 0.06 ) eS :37.96 ( 0.10 ) ***** 1993 APRIL 23; 17:36 - CRAWFORDVILLE, GEORGIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930423 173653.9 33.376 82.853 0.0 19 217 265 0.5 D D/D 3.7 -61 1.6 3.2 C 2.7 CERI 930423 173655.6 33.561 83.051 0.9 5 203 305 0.2 D D/D 25.0 -30 8.2 28.5 D 2.9 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA TRYN 217.1 15 ePd 17:37:28.80 ( 0.16 ) eS 17:37:53.10 (-0.21 ) TVA TKL 266.9 342 eP :34.80 (-0.21 ) eS :38:04.57 (-0.85 ) TVA LKGA 278.8 300 eP :36.60 ( 0.09 ) S? :09.30 ( 1.24 ) TVA WMTN 285.0 317 eP :37.16 (-0.09 ) eS :12.95 ( 3.58X) TVA TQTN 293.2 325 eP :38.00 (-0.25 ) eS :14.40 ( 3.25X) TVA ORT 311.0 335 P? :39.10 (-1.35 ) S? :19.20 ( 4.15X) TVA CRTN 326.1 344 eP :41.50 (-0.82 ) S? :23.25 ( 4.90X) TVA BRTN 330.7 360 eP :48.10 ( 5.19X) eS :20.21 ( 0.82 ) TVA BHT 334.6 326 eP :42.90 (-0.51 ) eS :21.50 ( 1.23 ) TVA FGTN 340.7 355 eP :45.20 ( 1.07 ) TVA SLTN 346.8 11 eP :44.40 (-0.56 ) eS :20.60 (-2.41X) TVA PDTN 346.9 308 eP :47.10 ( 2.22X) S? :26.48 ( 3.60X) TVA ANTN 378.9 326 eP :48.42 (-0.43 ) eS :37.32 ( 7.41X) TVA PLVA 396.4 22 eP :51.00 (-0.08 ) TVA LAL 431.1 287 P? :54.90 (-0.36 ) eS :51.12 ( 9.87X) TVA FDKY 464.1 326 P? :58.46 (-0.87 ) S? :39:01.81 (13.36X) CERI TRYN 203.2 21 ePd 17:37:28.80 (-0.03 ) eS 17:37:53.10 (-0.01 ) CERI TKL 242.0 344 eP :34.80 ( 0.09 ) eS :38:05.20 ( 1.90X) CERI BHT 307.3 326 eP :42.90 (-0.33 ) eS :21.50 ( 3.47X) CERI FGTN 319.0 358 eP :45.20 ( 0.58 ) CERI PLVA 385.2 26 eP :51.00 (-1.82X) Additional Data: GIT ATL Pn 17:37:16.8 Sn 17:37:33.0 P :19.0 S :35.5 GIT CDG P :28.6 S :54.0 ***** 1993 MAY 5; 04:57 - LAFAYETTE, GEORGIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930505 045716.0 34.774 85.269 7.5 17 25 149 0.1 C B/C 0.9 -48 0.3 1.8 B 1.1 CERI 930505 045716.3 34.761 85.234 10.0 5 26 360 0.1 D D/D 5.4 26 1.8 6.7 D 0.8 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA LKGA 25.0 228 eP 04:57:20.70 ( 0.08 ) eS 04:57:23.89 (-0.07 ) TVA GMG 55.6 80 eP :25.64 (-0.05 ) eS :32.54 (-0.19 ) TVA WMTN 59.1 27 eP :26.27 ( 0.05 ) iS :33.62 (-0.03 ) TVA PDTN 76.7 316 iP- :29.14 ( 0.02 ) eS :39.40 ( 0.74X) TVA TQTN 96.1 31 eP :32.52 ( 0.22 ) TVA MSAL 128.8 274 eS :52.40 (-0.43 ) TVA ORT 153.5 35 eS :58.72 (-0.67 ) TVA ANTN 155.1 1 eP :41.32 (-0.06 ) eS :59.80 (-0.07 ) TVA CRTN 204.5 39 eS :58:14.08 ( 1.15 ) TVA FDKY 228.7 348 eP :52.42 (-0.21 ) eS :19.94 ( 0.61 ) TVA TCT 248.5 304 eP :54.92 (-0.11 ) eS :24.72 ( 1.23 ) CERI RCG 25.9 336 ePc 04:57:21.08 ( 0.00 ) eS 04:57:24.58 ( 0.00 ) CERI GMG 52.8 78 eP :25.70 ( 0.22X) eS :32.22 ( 0.01 ) CERI BHT 123.3 12 eP :37.58 ( 0.98X) eS :51.54 ( 0.10 ) CERI TKL 166.1 53 eS :58:02.10 (-0.60 ) ***** 1993 MAY 19; 10:31 - DAYTON, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930519 103118.2 35.505 84.890 22.7 10 15 72 0.1 B B/A 0.6 -54 0.4 1.7 B 2.3 CERI 930519 103119.5 35.496 84.878 14.4 10 40 134 0.1 C C/C 1.3 -30 0.5 2.9 C 2.2 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA TQTN 14.9 85 iP 10:31:22.70 (-0.04 ) TVA WMTN 29.4 195 iPd :24.40 ( 0.03 ) TVA BHT 38.3 352 eP :26.50 ( 0.89X) eS 10:31:32.00 ( 1.01X) TVA ORT 69.4 49 eP :30.20 ( 0.10 ) iS :38.85 ( 0.09 ) TVA RCG 72.0 216 eP :31.50 ( 0.99X) eS :41.50 ( 2.04X) TVA GMG 73.9 164 eP :32.00 ( 1.15X) TVA ANTN 80.2 337 iP :31.60 (-0.15 ) iS :41.70 ( 0.09 ) TVA PDTN 90.9 254 eP :33.30 (-0.04 ) eS :44.37 ( 0.00 ) TVA TKL 102.5 80 eP :35.05 (-0.06X) eS :47.45 ( 0.02X) TVA ABTN 118.2 291 eS :52.55 ( 1.00 ) TVA BBG 120.6 125 eP :39.00 ( 1.05X) eS :52.50 ( 0.16 ) TVA CRTN 122.2 51 eP :38.15 ( 0.04X) eS :52.45 (-0.17X) TVA FDKY 164.2 331 eP :44.70 ( 0.17X) iS :32:05.15 ( 1.43X) TVA MSAL 178.1 246 eP :46.21 (-0.44X) eS :07.65 ( 0.26X) TVA BRTN 205.5 62 eS :16.25 ( 2.21X) TVA HAKY 234.0 320 P? :55.05 ( 1.13X) eS :21.65 ( 1.69X) TVA SLTN 270.6 67 P? :32:00.15 ( 1.61X) S? :30.95 ( 3.00X) CERI BHT 39.5 351 iP 10:31:26.50 (-0.19 ) iS 10:31:32.10 ( 0.17 ) CERI RCG 71.9 217 iP :31.50 (-0.14 ) eS :40.60 ( 0.10 ) CERI GMG 72.7 165 iP :31.90 ( 0.08 ) eS :41.00 ( 0.18 ) CERI TKL 101.7 79 eP :36.10 (-0.09 ) eS :48.40 ( 0.02 ) CERI BBG 119.1 125 eP :39.00 ( 0.04 ) eS :53.10 (-0.06 ) ***** 1993 MAY 19; 10:37 - DAYTON, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930519 103757.8 35.518 84.895 15.2 16 15 137 0.2 C B/C 0.6 -68 0.3 1.1 A 1.4 CERI 930519 103758.4 35.490 84.878 11.5 8 40 173 0.3 C C/C 2.9 -31 1.6 7.9 D 1.6 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA TQTN 15.3 91 iP 10:38:01.65 ( 0.19 ) iS 10:38:04.05 (-0.10 ) TVA WMTN 30.7 193 iP :03.75 ( 0.15 ) iS :07.70 (-0.15 ) TVA BHT 36.8 353 eP :05.00 ( 0.44 ) eS :11.00 ( 1.48X) TVA ORT 68.9 51 P :00.00 (-9.42X) eS :17.76 (-0.16 ) TVA RCG 72.9 215 eP :11.00 ( 0.95X) eS :38.19 TVA GMG 75.5 164 eP :11.00 ( 0.51 ) TVA ANTN 78.7 337 eP :10.43 (-0.51 ) eS :20.35 (-0.20 ) TVA TKL 102.8 81 eP :14.30 (-0.31 ) eS :26.60 (-0.29 ) TVA CRTN 121.7 51 eP :17.02 (-0.50 ) eS :32.30 ( 0.36 ) TVA BBG 121.8 126 eP :20.50 ( 2.87X) eS :32.00 (-0.12 ) TVA FDKY 162.7 330 eP :23.62 (-0.18 ) eS :43.44 ( 0.64 ) TVA HAKY 232.6 320 eP :29.54 (-4.43X) CERI BHT 40.0 351 iPd 10:38:05.10 (-0.42 ) iS 10:38:11.00 ( 0.27 ) CERI RCG 71.4 217 eP :10.60 (-0.02 ) eS :19.80 ( 0.24 ) CERI GMG 72.1 165 eP :10.90 ( 0.11 ) eS :19.80 (-0.06 ) CERI TKL 101.8 79 eS :28.00 ( 0.39 ) CERI BBG 118.8 125 eS :32.10 (-0.17 ) ***** 1993 MAY 20; 15:07 - RUINS, VIRGINIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I VTSO 930520 150732.5 38.086 77.435 11.1 15 14 162 0.2 C B/C 1.1 -27 0.5 1.2 A 2.4 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) VTSO CNV 14.3 22 iPu 15:07:35.51 ( 0.03 ) iS? 15:07:37.46 (-0.19 ) VTSO NA5 27.7 253 iPu :37.61 ( 0.20 ) iS :41.04 ( 0.05 ) VTSO NA2 27.7 280 iPd :37.62 ( 0.21 ) eS :40.89 (-0.10 ) VTSO NA12 40.6 254 P :39.48 ( 0.06 ) eS :44.22 (-0.26 ) VTSO GHV 67.4 241 P- :43.48 (-0.23 ) eS? :51.97 ( 0.07 ) VTSO CVL 90.8 263 eP? :47.56 ( 0.04 ) S1 :58.67 ( 0.18 ) VTSO PBV 122.8 184 eP :52.75 ( 0.28 ) eS? :08:06.01 (-0.93X) VTSO FRV 127.5 220 eP :52.99 (-0.22 ) eS? :07.88 (-0.32 ) Additional Data: DGS NED 233.8 ePu 15:08:02.8 iS 15:08:39.0 DGS BWD 249.3 ePu :03.4 iS :42.0 DGS BVD 251.7 iS? :42.5 ***** 1993 MAY 24; 14:39 - WHITE GATE, VIRGINIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I VTSO 930524 143907.0 37.175 80.811 10.1 12 16 159 0.2 C B/C 0.8 -14 0.6 2.3 B 2.1 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) VTSO NAV 15.7 6 iPc 14:39:10.15 (-0.11 ) eS 14:39:12.30 (-0.16 ) VTSO WMV 15.9 243 iPd :10.27 (-0.08 ) iS :12.54 (-0.07 ) VTSO PWV 27.6 310 iPc :12.10 ( 0.02 ) iS :15.85 ( 0.33 ) VTSO BLA 35.0 83 iPc :13.37 ( 0.12 ) eS :17.93 ( 0.41 ) VTSO HWV 46.2 357 ePd :15.19 ( 0.11 ) iS :20.72 ( 0.08 ) VTSO VWV 49.3 49 iPd :15.17 (-0.44 ) eS :21.47 (-0.07 ) ***** 1993 MAY 25; 01:10 - RINGOLD, GEORGIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930525 011059.8 34.951 85.036 11.6 10 34 173 0.2 C C/C 1.8 -55 0.6 1.8 B 1.2 CERI 930525 011100.9 34.925 85.034 6.6 6 29 181 0.1 D C/D 9.1 12 0.4 19.5 D 1.6 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA WMTN 33.5 10 eP 01:11:06.19 ( 0.27 ) iS 01:11:10.39 ( 0.04 ) TVA LKGA 54.0 228 eP :09.09 (-0.17 ) eS :16.19 ( 0.06 ) TVA TQTN 68.8 24 eS :19.97 (-0.31 ) TVA PDTN 82.3 296 S? :23.70 (-0.21 ) TVA ORT 125.4 32 eS :35.99 ( 0.67 ) TVA ANTN 136.6 353 eS :38.34 ( 0.01 ) TVA TKL 139.0 55 eS :39.30 ( 0.36 ) TVA MSAL 150.1 266 eS :42.14 ( 0.29 ) CERI RCG 29.2 281 eP 01:11:06.20 ( 0.11 ) eS 01:11:09.80 (-0.11 ) CERI GMG 33.9 102 iP :07.00 ( 0.09 ) eS :11.20 (-0.13 ) CERI BHT 102.6 4 eS :30.90 ( 0.00 ) CERI BBG 111.9 93 eS :32.90 (-0.54 ) ***** 1993 JUNE 7; 10:35 - JASPER, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930607 103506.0 35.030 85.517 12.6 17 41 122 0.2 C B/C 0.6 63 0.3 0.9 A 1.6 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA PDTN 40.6 312 iP 10:35:13.37 ( 0.10 ) iS 10:35:18.48 (-0.08 ) TVA LKGA 45.2 175 eP :14.17 ( 0.13 ) iS :19.77 (-0.12 ) TVA TQTN 90.0 53 eP :20.77 (-0.27 ) eS :31.57 (-0.42 ) TVA MSAL 107.6 259 iP+ :23.45 (-0.28 ) eS :36.83 ( 0.18 ) TVA ANTN 129.3 11 eP :27.55 ( 0.45 ) S? :42.82 ( 0.34 ) TVA ORT 147.1 48 P? :30.92 ( 1.13X) eS :49.82 ( 2.68X) TVA LAL 179.2 249 eP :34.62 (-0.08 ) eS :56.37 ( 0.73 ) TVA FDKY 196.9 353 P? :37.62 ( 0.20 ) eS :36:01.67 ( 1.33 ) TVA CRTN 199.8 49 P? :38.58 ( 0.70 ) S? :03.12 ( 1.99X) TVA TCT 214.0 301 eP :39.37 (-0.66 ) eS :05.62 ( 0.76 ) TVA HAKY 249.7 338 eS :15.47 ( 2.72X) ***** 1993 JUNE 15; 13:19 - CHARLESTON, SOUTH CAROLINA ***** NEIC Felt in the Ladson-Summerville area. Felt (II) at Charleston Air Force Base. CSU Felt (III) in the Summerville/Ladson area, SC. Magnitude 2.2. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 930615 131902.9 32.977 80.186 6.9 8 6 86 0.1 A 0.6 360 0.6 0.8 1.9 NEIC 930615 131902.9 32.979 80.226 5.0F 8 9 2.2 2 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC SVS 5.9 261 iPu 13:19:04.84 ( 0.08 ) USC RGR 7.7 186 iP :05.40 ( 0.48X) USC MGS 9.7 154 P :05.40 ( 0.15 ) USC BCS 11.3 88 P :05.60 (-0.02 ) USC HBF 14.1 257 iPu :05.89 ( 0.04 ) USC DRC 23.9 307 P :07.40 (-0.17 ) USC HWD 27.9 199 P :08.00 (-0.19 ) USC CFS 33.4 2 iPd :09.14 ( 0.01 ) USC SGS 38.6 308 iPu :09.96 (-0.04 ) NEIC RGRS 8.9 160 P 13:19:05.00 ( 0.3 ) NEIC MGS 12.2 139 P :05.40 ( 0.2 ) NEIC HBF 15.6 250 eP :04.83 (-0.8 ) NEIC BCS 15.6 89 P :05.40 (-0.3 ) NEIC DRC 21.1 313 P :07.40 ( 0.7 ) NEIC HWD 26.7 191 P :08.00 ( 0.2 ) NEIC SGS 35.6 312 eP :09.90 ( 0.6 ) NEIC JSC 173.5 327 eP :30.34 (-0.9 ) eS 13:19:50.58 ( X) NEIC PRM 233.5 302 ePn :37.47 (-1.6X ) eS :20:08.06 ( X) NEIC CEH 339.1 18 Pn? :48.15 (-4.5X ) Additional Data: CSU RGR P 13:19:04.8 CSU MGS P :05.0 CSU BCS P :05.3 CSU DRC P :07.7 CSU HWD P :07.7 ***** 1993 JUNE 23; 08:36 - LAFAYETTE, GEORGIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930623 083622.2 34.793 85.280 14.5 7 26 193 0.1 D C/D 4.4 -20 1.1 5.8 D 0.6 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA LKGA 25.8 223 eP 08:36:27.26 (-0.01 ) eS 08:36:30.81 (-0.17 ) TVA OLT 45.9 30 eP :30.38 ( 0.05 ) eS :36.21 (-0.08 ) TVA MSAL 127.7 273 eS :57.76 (-0.16 ) TVA ABTN 142.7 328 P? :46.11 ( 0.96 ) eS :37:01.67 (-0.25 ) TVA LAL 192.8 259 eS :16.78 ( 1.59X) ***** 1993 JUNE 29; 06:15 - NEESES, SOUTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I WSRC 930629 061504.1 33.465 81.245 4.3 9 35 101 0.3 C C/C 1.3 360 1.3 25.0 2.2 USC 930629 061504.3 33.483 81.243 1.0 14 47 152 0.1 C 0.8 360 0.8 99.0 2.5 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) WSRC SRN 35.3 245 P 06:15:09.74 (-0.28 ) S 06:15:14.05 (-0.60X) WSRC SRW 42.6 227 P :11.22 ( 0.07 ) S :16.74 ( 0.07X) WSRC SRV 43.3 249 P :11.04 (-0.23 ) S :16.22 (-0.66X) WSRC MTT 48.5 311 P :11.85 (-0.22 ) S :17.73 (-0.58X) WSRC COW 51.6 100 P :12.33 (-0.23 ) S :18.43 (-0.74X) WSRC VRN 55.3 149 P :13.42 ( 0.28 ) S :20.47 ( 0.26X) WSRC SRD 55.5 232 P :13.30 ( 0.13 ) WSRC JSC 90.6 359 P :18.66 ( 0.00 ) S :29.02 (-1.02X) WSRC PRM 124.2 304 P :24.38 ( 0.47 ) USC MTT 47.1 309 iPu 06:15:11.76 (-0.08 ) USC COW 51.7 102 iPd :12.36 (-0.21 ) USC VRN 57.0 150 iPd :13.43 ( 0.00 ) USC SGS 75.3 115 ePu :16.40 ( 0.07 ) USC MR02 78.7 1 iPu :16.82 (-0.11 ) USC MR05 87.4 354 eP :17.23 (-1.02X) USC JSC 88.4 359 iPd :18.45 ( 0.04 ) USC MR01 94.3 357 eP :19.82 ( 0.48 ) USC MR10 95.0 355 iP :19.75 ( 0.29 ) USC MR07 98.7 356 iP :20.25 ( 0.21 ) USC HBF 101.2 127 iP :20.82 ( 0.19 ) USC CFS 102.4 103 eP- :21.06 ( 0.43 ) USC SVS 108.9 122 iP :22.11 ( 0.45 ) USC LHS 117.6 20 eP :22.99 (-0.05 ) USC PRM 123.1 303 iPd :24.09 ( 0.17 ) ***** 1993 JULY 1; 21:24 - YANCY COUNTY, NORTH CAROLINA ***** TVA Probable earthquake. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I CERI 930701 212431.7 35.991 82.460 0.8 6 174 318 0.3 D D/D 48.7 66 3.8 77.5 D 2.3 TVA 930701 212434.0 35.972 82.519 2.4 18 53 207 0.3 D C/D 0.9 -9 0.5 2.1 B 2.3 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) CERI BBG 174.4 225 eP 21:25:00.40 (-0.20 ) eS 21:25:21.80 ( 0.11 ) CERI BHT 224.9 267 eP :09.00 ( 0.72 ) eS :34.80 (-0.19 ) CERI GMG 236.5 239 ePc :09.90 (-0.20 ) eS :38.00 (-0.13 ) CERI RCG 285.3 248 eS :48.00 (-1.46X) TVA BRTN 53.0 324 eP 21:24:42.19 (-0.28 ) eS 21:24:48.70 ( 0.20 ) TVA SLTN 63.4 34 iP :44.25 ( 0.12 ) TVA TKL 118.7 253 eP :53.05 ( 0.09 ) S? :25:08.05 ( 1.60X) TVA CRTN 121.7 282 eP :52.90 (-0.55 ) S? :06.36 (-0.93 ) TVA ORT 161.3 268 eP :59.70 (-0.08 ) eS :18.90 ( 0.79 ) TVA TQTN 206.0 256 eP :25:07.00 ( 0.08 ) S? :32.90 ( 2.58X) TVA OLT 244.8 249 ePc :11.71 (-0.39 ) eS :40.70 ( 0.44 ) TVA ANTN 245.4 276 eP :12.39 ( 0.19 ) eS :43.70 ( 3.27X) TVA LKGA 307.5 242 eP :20.96 ( 1.10 ) eS :53.90 (-0.08 ) TVA FDKY 307.6 288 eP :22.51 ( 2.67X) eS :56.00 ( 2.04X) TVA PDTN 311.5 257 eP :21.70 ( 1.37 ) eS :55.80 ( 0.98 ) TVA ABTN 324.2 269 P? :21.25 (-0.64 ) S? :58.15 ( 0.57 ) ***** 1993 JULY 9; 06:30 - COLUMBIA, MARYLAND ***** MGS Felt (II - III) in the Columbia, Maryland, area (see special report on this earthquake and associated events in Appendix A). NEIC Felt at Columbia, Maryland. Hypocenter based upon macroseismic information. DGS Felt. Duration magnitude 1.9. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I MGS 930709 0630 39.19 76.87 1.9 3 NEIC 930709 063101.4 39.20 76.90 5.0F 117 1.9 F SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) NEIC NED 116.7 61 iPc 06:31:21.79 ( 0.1 ) iS 06:31:36.70 ( X) NEIC BWD 132.3 59 iPc :23.79 (-0.2 ) iS :38.20 ( X) NEIC BVD 136.8 62 eP :24.70 ( 0.0 ) S :39.50 ( X) Additional Data: DGS NED iPu 06:31:21.8 iS 06:31:36.7 DGS BWD iPu :23.8 iS :38.2 DGS BVD ePu :24.7 iS :39.5 ***** 1993 JULY 12; 04:48 - GREENSBORO, NORTH CAROLINA ***** NEIC Felt (IV) at Greensboro, North Carolina. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I NEIC 930712 044820.8 36.035 79.823 5.0F 10 68 2.7 4 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) NEIC CEH 67.8 103 ePd 04:48:32.28 (-0.7 ) eS 04:48:39.99 ( X) NEIC PKNC 120.1 271 P :41.04 (-0.6 ) S :54.77 ( X) NEIC PLVA 139.0 301 P :43.68 (-0.9 ) S :49:00.64 ( X) NEIC NAV 166.8 329 eP :48.16 (-0.3 ) eS :06.57 ( X) NEIC FRV 184.6 45 P :51.20 ( 0.6 ) S :11.00 ( X) NEIC LHS 194.6 208 P? :52.21 ( 0.2 ) eS :14.72 ( X) NEIC SLTN 211.3 283 P :55.09 ( 0.8 ) S :18.20 ( X) NEIC JSC 234.6 214 eP :57.06 (-0.2 ) eS :25.34 ( X) NEIC TRYN 237.9 249 P :58.54 ( 0.8 ) S :24.07 ( X) NEIC CVL 248.0 29 P? :59.35 ( 0.4 ) eS :28.61 ( X) NEIC BRTN 275.8 278 P :49:05.59 ( 3.0X ) S :36.75 ( X) NEIC CRTN 362.5 274 P :18.64 ( 5.0X ) NEIC GBTN 398.1 265 P? :23.36 ( 5.2X ) eS :50:10.08 ( X) ***** 1993 JULY 12; 21:24 - COLUMBIA, MARYLAND ***** MGS Felt (II - III) in the Columbia, Maryland, area (see special report on this earthquake and associated events in Appendix A). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I MGS 930712 2124 39.19 76.87 2.1 3 Additional Data: SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) DGS NED iPu 21:24:56.6 iS 21:25:11.5 DGS BWD iPu :58.6 iS :13.1 DGS BVD iPu :59.4 iS :14.3 ***** 1993 JULY 16; 10:54 - QUITMAN, MISSISSIPPI ***** TVA Felt in southwestern Alabama; slight damage (VI) at Gilbertown, AL (USGS). VTSO This event outside SEUSSN monitoring area. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930716 105435.7 32.013 88.568 0.0 26 292 299 1.2 D D/D 13.2 25 1.5 19.6 D 3.4 6 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA LAL 292.3 23 eP 10: :79.33 (-0.37 ) eS 10:54:51.65 (-0.74 ) TVA EBZ 354.5 348 eP :35.34 ( 7.98X) eS :55:37.14 TVA MSAL 360.3 29 eP :87.30 (-0.78 ) iS :06.00 (-1.23 ) TVA SFTN 394.7 340 eP :35.34 ( 3.04X) eS :37.12 TVA PDTN 440.9 34 eP :37.68 (-0.34 ) TVA RCG 444.3 41 eP :44.82 ( 6.35X) eS :37.64 TVA TCT 452.7 12 eP :40.30 ( 0.82 ) eS :26.40 (-0.99 ) TVA UTM 475.7 356 eP :44.46 ( 2.16 ) eS :54.64 TVA OLT 478.8 42 eP :44.00 ( 1.29 ) eS :37.00 ( 3.88X) TVA GMG 480.8 48 eP :42.76 (-0.27 ) eS :45.42 TVA ABTN 486.0 27 P? :43.30 (-0.29 ) eS :36.50 ( 1.83 ) TVA MOTN 513.7 6 eP :47.55 ( 0.56 ) iS :42.60 ( 1.91 ) TVA TQTN 526.9 41 eP :47.65 (-0.97 ) iS :45.30 ( 1.72 ) TVA BHT 541.3 37 eP :49.68 (-0.78 ) eS :09.58 TVA BBG 544.3 53 eP :51.80 ( 0.92 ) eS :02.32 TVA ANTN 554.6 33 eP :50.60 (-1.48 ) TVA FDKY 588.1 25 eP :55.75 (-0.43 ) TVA HAKY 593.6 17 eP :57.70 ( 0.86 ) eS :00.10 ( 1.98 ) TVA CRTN 637.0 42 P? :55:00.52 (-1.71 ) TVA TRYN 688.5 57 eP :07.94 (-0.68 ) eS :39.08 TVA SLTN 770.7 49 eP :19.40 ( 0.61 ) TVA PLVA 854.6 51 eP :27.36 (-1.79 ) ***** 1993 JULY 28; 03:58 - KINGSTON, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930728 035825.0 35.928 84.433 23.5 11 12 112 0.1 B B/B 0.7 -2 0.3 1.2 A 1.4 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA ORT 11.7 100 eP 03:58:29.31 (-0.01 ) eS 03:58:32.51 ( 0.00 ) TVA TQTN 52.8 210 eS :41.36 ( 0.11 ) TVA CRTN 61.3 60 eP :35.61 (-0.03 ) eS :43.43 ( 0.01 ) TVA TKL 66.6 116 iP- :36.46 ( 0.03 ) eS :44.91 ( 0.11 ) TVA ANTN 76.9 291 eP :37.91 (-0.09 ) eS :47.59 ( 0.08 ) TVA FDKY 155.2 308 eP :50.11 ( 0.24 ) eS :59:08.61 ( 0.56 ) ***** 1993 JULY 28; 04:15 - SERVILLA, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I CERI 930728 041551.5 35.258 84.436 12.8 12 49 79 0.2 C B/C 0.7 -66 0.5 1.3 A 2.3 TVA 930728 041551.7 35.259 84.430 13.0 26 39 80 0.2 C B/C 0.3 -40 0.3 0.7 A 2.4 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) CERI GMG 48.8 206 iPd 04:16:00.20 ( 0.03 ) eS 04:16:06.16 (-0.31 ) CERI GBTN 49.7 24 iPd :00.38 ( 0.12 ) eS :06.48 (-0.14 ) CERI BBG 71.2 127 iPc :03.90 ( 0.13 ) eS :12.98 ( 0.29 ) CERI TKL 74.8 53 eP :04.06 (-0.17 ) eS :13.12 (-0.36 ) CERI BHT 80.0 325 iPc :05.28 ( 0.21 ) eS :15.08 ( 0.15 ) CERI RCG 88.9 250 eP :06.12 (-0.27 ) eS :16.64 (-0.59 ) CERI TRYN 199.3 89 eP :23.98 ( 0.63X) eS :46.98 ( 0.42X) TVA TQTN 39.2 317 iP 04:15:58.86 ( 0.17 ) TVA GMG 49.1 207 iPd :16:00.20 (-0.15 ) eS 04:16:06.16 (-0.53 ) TVA GBTN 49.4 24 iPd :00.38 ( 0.05 ) eS :06.50 (-0.17 ) TVA BBG 70.8 127 iPc :03.90 ( 0.09 ) eS :12.98 ( 0.31 ) TVA ORT 73.1 9 eP :04.31 ( 0.24 ) S? :13.19 ( 0.07 ) TVA TKL 74.2 53 iP :04.11 (-0.13 ) eS :13.14 (-0.28 ) TVA BHT 80.2 325 eP+ :05.28 ( 0.08 ) eS :15.08 (-0.01 ) TVA RCG 89.4 250 eP :06.12 (-0.45 ) eS :16.66 (-0.80X) TVA CRTN 117.2 27 eP :10.91 ( 0.07 ) S? :24.76 (-0.08 ) TVA LKGA 118.5 234 eP :10.81 (-0.23 ) iS :25.61 ( 0.42 ) TVA ANTN 124.6 325 eP :11.61 (-0.36 ) S? :25.61 (-1.19X) TVA TRYN 198.8 89 eP :24.16 ( 0.80 ) eS :46.98 ( 0.47 ) TVA MSAL 209.7 258 eP+ :24.31 (-0.67 ) eS :49.21 (-0.09 ) TVA FDKY 209.7 325 eP :25.21 ( 0.23 ) eS :50.51 ( 1.20X) TVA LAL 281.1 252 eP :34.01 (-0.03 ) S? :17:06.61 ( 1.63X) TVA HAKY 282.1 317 eP :36.91 ( 2.77X) eS :07.01 ( 1.85X) TVA TCT 294.7 287 P? :29.91 (-5.79X) eS :08.41 ( 0.56 ) TVA MOTN 354.6 296 eP :46.26 ( 3.25X) eS :23.51 ( 3.02X) ***** 1993 JULY 31; 06:04 - LAWRENCEVILLE, GEORGIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930731 060430.1 33.879 84.015 0.9 14 158 262 0.3 D D/D 3.5 -19 1.7 3.2 C 1.6 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA LKGA 157.6 302 eP 06:04:56.40 ( 0.09 ) S? 06:05:15.60 ( 0.12 ) TVA OLT 168.7 327 eP :58.35 ( 0.36 ) TVA TQTN 192.9 340 eP :05:01.94 ( 0.25 ) eS :24.70 (-0.08 ) TVA ORT 226.8 353 eP :06.70 (-0.19 ) eS :34.40 ( 0.62 ) TVA PDTN 228.6 313 eP :06.70 (-0.46 ) eS :33.61 (-0.64 ) TVA MSAL 267.1 294 eS :42.55 (-0.33 ) TVA ABTN 293.6 320 P? :15.95 ( 0.55 ) eS :48.75 ( 0.24 ) TVA BRTN 294.1 21 eS :48.55 (-0.13 ) TVA LAL 312.5 282 eS :53.20 ( 0.70 ) ***** 1993 AUGUST 1; 08:49 - JEFFERSON CITY, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930801 084943.2 36.033 83.487 0.9 28 75 138 0.4 D C/D 0.6 15 0.3 1.5 B 1.8 CERI 930801 084943.5 36.036 83.495 3.0 8 132 225 0.2 D C/D 1.9 5 0.8 5.2 C 1.9 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA ORT 75.0 260 iPc 08:49:56.70 ( 0.36 ) iS 08:50:05.70 (-0.21 ) TVA TQTN 125.9 243 eP :50:04.50 (-0.10 ) S? :23.95 ( 3.76X) TVA BBG 131.9 193 eP :05.88 ( 0.26 ) eS :21.86 (-0.10 ) TVA BHT 133.2 262 eP :05.76 (-0.01 ) eS :22.10 (-0.11 ) TVA TRYN 140.9 127 iP- :06.96 ( 0.00 ) eS :28.46 ( 4.18X) TVA ANTN 157.8 276 eP :09.20 (-0.32 ) eS :28.10 (-0.61 ) TVA GMG 168.5 220 eP :11.04 (-0.17 ) eS :31.24 (-0.39 ) TVA OLT 170.3 235 eP :11.50 ( 0.08 ) eS :31.72 (-0.27 ) TVA RCG 205.6 236 eP :16.88 ( 0.05 ) TVA PLVA 220.3 71 eP :18.64 (-0.52 ) eS :46.18 ( 0.80 ) TVA FDKY 223.3 293 eP :19.90 ( 0.37 ) eS :46.07 ( 0.05 ) TVA PDTN 230.0 249 eP :20.55 ( 0.01 ) eS :47.60 (-0.18 ) TVA ABTN 237.1 267 eP- :20.75 (-0.89 ) iS :50.40 ( 0.72 ) TVA LKGA 238.8 230 eP :21.61 (-0.31 ) eS :50.70 ( 0.54 ) TVA TCT 366.5 271 P? :37.00 (-0.47 ) eS :51:17.10 ( 0.03 ) TVA PWLA 431.3 256 eP :44.82 (-0.57 ) CERI BBG 132.1 193 eP 08:50:05.88 ( 0.18 ) eS 08:50:21.86 (-0.06 ) CERI BHT 132.5 261 eP :05.76 ( 0.04 ) eS :22.10 ( 0.14X) CERI TRYN 141.7 127 iP- :06.96 (-0.18 ) eS :24.74 ( 0.33 ) CERI GMG 168.3 220 eP :11.04 (-0.19 ) eS :31.24 (-0.24 ) CERI RCG 205.2 236 eP :16.88 ( 0.06 ) CERI PLVA 220.9 71 eP :18.64 (-0.67X) eS :46.18 ( 0.71X) CERI PWLA 430.7 256 eP :44.82 (-1.06X) ***** 1993 AUGUST 2; 15:44 - ROCKDALE COUNTY, GEORGIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I CERI 930802 154432.5 33.864 84.085 0.4 7 115 287 0.1 D C/D 6.1 -4 1.0 10.2 D 2.0 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) CERI BBG 114.8 13 eP 15:44:52.38 ( 0.02 ) eS 15:45:06.80 (-0.03 ) CERI GMG 123.2 334 eP :53.66 ( 0.04 ) eS :08.94 (-0.06X) CERI GBTN 200.3 357 eP :45:05.10 (-0.25 ) eS :30.38 ( 1.08X) CERI TRYN 229.6 47 eP :09.48 (-0.41 ) eS :37.30 ( 0.14 ) CERI BHT 233.6 341 eP :10.64 ( 0.13 ) eS :40.36 ( 2.14X) ***** 1993 AUGUST 8; 09:24 - AIKEN, SOUTH CAROLINA ***** NEIC Felt (V) at Aiken; (IV) at Montmorenci; (III) at Graniteville, Langley and Williston. Also felt at Eureka and New Ellenton. USC/WSRC An abstract and isoseismal map for this earthquake appear in Appendix B. WSRC Mainshock felt at Couchton, SC. Magnitude 3.2. CSU Felt (V) at Aiken/Eureka, SC. Magnitude 3.2 (USGS, CSU). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I NEIC 930808 092431.1 33.633 81.595 5.0F 9 78 3.2 5 WSRC 930808 092432.3 33.594 81.585 8.0 11 18 111 0.1 C B/C 0.5 360 0.5 1.7 3.2 F USC 930808 092432.4 33.597 81.591 8.5 12 18 112 0.1 B 0.6 360 0.6 1.5 2.9 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) NEIC JSC 77.8 23 eP 09:24:45.24 ( 0.1 ) NEIC PRM 86.7 305 iPc :46.76 ( 0.0 ) eS 09:24:57.45 ( X) NEIC SGS 112.3 116 eP :50.37 (-0.3 ) eS :25:03.50 ( X) NEIC LHS 119.0 38 eP :51.60 (-0.1 ) NEIC DRC 126.8 117 eP :52.79 (-0.1 ) NEIC HBF 137.9 124 iPd :54.67 ( 0.1 ) eS :10.17 ( X) NEIC TWB 150.1 112 eP :57.00 ( 0.5 ) NEIC RGRS 153.4 121 eP :57.00 ( 0.0 ) NEIC MGS 157.9 121 eP :57.50 (-0.1 ) NEIC BLA 411.4 15 P? :25:35.68 ( 5.5X ) NEIC NAV 414.7 10 P? :36.52 ( 5.8X ) WSRC MTT 18.1 344 iPu 09:24:35.62 ( 0.02 ) S 09:24:38.15 ( 0.06X) WSRC SRN 29.5 181 iPd :37.20 (-0.12 ) S :40.72 (-0.38X) WSRC SRV 31.1 197 eP- :37.56 (-0.01 ) S :41.18 (-0.36X) WSRC SRW 43.5 179 iPu :39.56 ( 0.06 ) S :44.48 (-0.43X) WSRC SRD 50.1 194 iP+ :40.55 ( 0.03 ) S :46.12 (-0.59X) WSRC MR02 74.1 26 iPd :44.26 ( 0.01 ) WSRC MR05 78.2 17 iPd :44.83 (-0.07 ) S :53.84 (-0.53X) WSRC JSC 82.0 21 iPd :45.40 (-0.08 ) S :54.43 (-0.95X) WSRC MRO 85.5 15 iPu :46.07 ( 0.05 ) S :55.75 (-0.59X) WSRC COW 85.6 106 iP- :46.43 ( 0.38 ) S :56.27 (-0.11X) WSRC VRN 86.2 136 iPu :46.72 ( 0.58X) S :57.14 ( 0.60X) WSRC PRM 90.2 307 iPu :46.76 ( 0.00 ) S :57.33 (-0.29X) WSRC SGS 109.5 114 iPd :50.50 ( 0.72X) S :25:03.83 ( 0.93X) WSRC LHS 121.4 36 iPd :51.76 ( 0.11X) WSRC DRC 123.7 116 ePd :52.80 ( 0.79X) S :07.70 ( 0.89X) WSRC CFS 136.1 105 iP- :54.61 ( 0.79X) S :11.07 ( 1.10X) WSRC HBF 136.9 121 iPu :54.71 ( 0.78X) S :10.80 ( 0.63X) WSRC SVS 142.6 119 iPd :55.74 ( 1.00X) S :12.70 ( 1.11X) WSRC TWB 147.8 111 iPd :56.77 ( 1.27X) S :14.45 ( 1.53X) WSRC RGR 150.3 120 iPd :56.82 ( 0.96X) S :15.05 ( 1.50X) WSRC HWD 154.0 128 iPd :57.44 ( 1.04X) S :15.87 ( 1.38X) WSRC MGS 155.1 119 iPd :57.70 ( 1.15X) S :16.20 ( 1.44X) WSRC BCS 157.1 115 ePu :25:03.91 ( 7.07X) WSRC JVW 202.4 320 iPu :03.26 (-0.02X) USC MTT 17.7 346 iPu 09:24:35.62 ( 0.08 ) S 09:24:38.15 ( 0.21X) USC SRPN 29.7 180 iPd :37.20 (-0.14 ) S :40.72 (-0.39X) USC SRAV 31.3 195 eP- :37.56 (-0.02 ) S :41.08 (-0.45X) USC SRPW 43.8 178 iPd :39.56 ( 0.04 ) S :44.48 (-0.46X) USC SRPD 50.3 193 iP+ :40.55 ( 0.01 ) S :46.12 (-0.62X) USC MR02 74.1 27 iPd :44.26 (-0.07 ) USC MR05 78.1 18 iPd :44.83 (-0.09 ) S :53.84 (-0.60X) USC JSC 81.7 22 iPd :45.40 (-0.09 ) S :54.43 (-1.02X) USC MR10 85.3 16 iPu :46.07 ( 0.01 ) S :55.75 (-0.70X) USC MR01 86.0 18 eP :45.82 (-0.34X) USC COW 86.0 106 iP- :46.43 ( 0.26 ) S :56.27 (-0.37X) USC VRN 86.8 136 iPu :46.72 ( 0.42 ) S :57.14 ( 0.27X) USC MR07 89.3 16 iP :20.25 (-26.4X) USC PRM 89.5 307 iPu :46.76 ( 0.04 ) S :57.33 (-0.29X) USC SGS 109.9 114 iPd :50.50 ( 0.55X) S :25:03.83 ( 0.53X) USC LHS 121.7 36 iPd :51.76 (-0.05X) USC DRC 124.3 116 ePd :52.80 ( 0.49X) S :07.70 ( 0.25X) USC HBF 134.8 123 iPu :54.71 ( 0.61X) S :10.80 ( 0.20X) USC CFS 136.8 105 iP- :54.61 ( 0.40X) S :11.07 ( 0.27X) USC SVS 143.1 119 iPd :55.74 ( 0.53X) S :12.70 ( 0.14X) USC TWB 148.4 111 iPd :56.77 ( 0.89X) S :14.45 ( 0.71X) USC RGR 150.9 120 iPd :56.82 ( 0.63X) S :15.05 ( 0.77X) USC HWD 154.6 128 iPd :57.44 ( 0.79X) S :15.87 ( 0.78X) USC MGS 155.9 120 iPd :57.70 ( 0.89X) S :16.20 ( 0.83X) USC JVW 201.8 320 iPu :25:03.26 ( 0.78X) USC BC 206.0 320 ePu :03.91 ( 0.92X) Additional Data: CSU DRC P 09:24:52.5 CSU RGR P :56.5 CSU TWB P :56.5 CSU HWD P :57.5 CSU MGS P :57.5 ***** 1993 AUGUST 8; 16:00 - AIKEN, SOUTH CAROLINA ***** USC Aftershock of August 8 09:24 Aiken, SC, event. Magnitude 1.6. WSRC Aftershock at Couchton, SC. Magnitude of about 1. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 930808 160015.6 33.615 81.595 9.0 8 16 170 0.1 B 0.5 360 0.5 0.5 1.6 WSRC 930808 160015.9 33.590 81.584 6.0 9 19 143 0.2 C C/C 1.4 360 1.4 9.7 1. SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC MTT 15.6 344 iPu 16:00:19.23 ( 0.08 ) USC MR02 72.4 28 iPd :27.89 (-0.11 ) USC JSC 80.1 23 iPd :29.07 (-0.07 ) USC COW 87.1 107 iPu :30.23 ( 0.03 ) USC PRM 88.1 306 iPu :30.35 (-0.02 ) USC VRN 88.5 136 iPu :30.38 (-0.06 ) USC SGS 111.3 115 iPd :34.10 ( 0.13 ) USC LHS 120.1 37 iPd :35.47 ( 0.14 ) WSRC MTT 18.5 344 P 16:00:19.23 ( 0.02 ) S 16:00:21.56 (-0.13X) WSRC SRN 29.1 181 P :20.52 (-0.33 ) S :24.28 (-0.27X) WSRC SRV 30.8 197 P :21.40 ( 0.29 ) S :24.86 (-0.16X) WSRC SRW 43.1 179 P :23.44 ( 0.40 ) S :28.72 ( 0.33X) WSRC SRD 49.8 194 P :24.32 ( 0.24 ) S :29.80 (-0.40X) WSRC MR02 74.4 26 P :27.90 (-0.03 ) WSRC JSC 82.3 21 P :29.12 (-0.04 ) S :39.24 ( 0.15X) WSRC PRM 90.5 307 P :30.37 (-0.07 ) S :41.06 (-0.27X) WSRC LHS 121.7 36 P :35.42 ( 0.11 ) ***** 1993 AUGUST 14; 08:55 - LAFAYETTE, GEORGIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930814 085533.8 34.723 85.291 4.4 7 20 206 0.1 D C/D 3.7 -16 1.1 6.7 D 0.8 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA LKGA 19.9 236 iP 08:55:37.61 ( 0.14 ) iS 08:55:40.02 (-0.12 ) TVA OLT 53.2 27 eP :43.11 ( 0.01 ) eS :49.66 (-0.21 ) TVA PDTN 79.5 320 eS :57.80 ( 0.43 ) TVA TQTN 101.9 30 S? :56:03.88 ( 0.10 ) TVA LAL 190.4 261 eS :27.30 (-0.03 ) ***** 1993 AUGUST 15; 01:46 - GILMER COUNTY, GEORGIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I CERI 930815 014634.3 34.701 84.426 10.0F 3 29 329 0.0 D C/D 99.0 2 2.2 99.0 D 1.5 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) CERI GMG 28.7 309 eP 01:46:39.62 ( 0.00 ) CERI BBGE 59.4 71 eP :37.78 (-6.87X) eS 01:46:52.18 ( 0.00 ) CERI BHT 135.6 340 eP :56.54 ( 0.00 ) CERI TRYN 208.7 72 eS :47:23.06 (-9.07X) ***** 1993 AUGUST 16; 23:17 - LAWRENCEVILLE, GEORGIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930816 231749.5 33.711 84.021 0.0 28 131 243 0.5 D C/D 1.2 -31 0.9 1.0 A 2.4 CERI 930816 231750.0 33.828 83.997 0.9 8 117 278 0.2 D C/D 13.3 -11 1.0 21.7 D 2.6 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA BBG 130.5 8 eP 23:18:10.32 (-0.01 ) eS 23:18:24.82 (-0.33 ) TVA GMG 141.1 335 eP :11.82 (-0.20 ) TVA LKGA 167.8 307 eP :16.04 (-0.26 ) eS :35.04 (-0.32 ) TVA OLT 184.3 330 eP :19.09 ( 0.15 ) S? :39.39 (-0.49 ) TVA TQTN 210.4 342 eP :22.45 (-0.67 ) eS :46.74 (-0.29 ) TVA GBTN 217.6 355 ePc :23.48 (-0.79 ) eS :48.70 (-0.29 ) TVA TRYN 237.4 43 eP+ :27.34 ( 0.37 ) TVA PDTN 241.4 316 eP :27.34 (-0.06 ) eS :54.84 (-0.54 ) TVA ORT 245.3 354 eP :27.94 ( 0.05 ) eS :56.34 ( 0.10 ) TVA MSAL 274.9 298 eP :32.19 ( 0.67 ) eS :19:03.37 ( 0.70 ) TVA CRTN 276.6 3 eP :31.64 (-0.12 ) eS :04.31 ( 1.21 ) TVA ANTN 294.6 338 eP :34.39 ( 0.40 ) eS :09.54 ( 2.51X) TVA ABTN 307.8 322 eP :36.14 ( 0.55 ) eS :11.54 ( 1.67X) TVA LAL 316.5 286 eP :37.25 ( 0.58 ) eS :12.44 ( 0.66 ) TVA SLTN 349.2 29 eP :40.44 (-0.35 ) S? :25.54 ( 6.48X) TVA FDKY 377.8 335 eP :44.54 ( 0.32 ) eS :26.94 ( 1.79 ) TVA TCT 411.2 309 eP :49.04 ( 0.71 ) CERI BBG 117.3 8 eP 23:18:10.10 (-0.08 ) eS 23:18:25.00 ( 0.11 ) CERI GMG 130.4 332 eP :12.10 (-0.07 ) eS :28.20 (-0.13 ) CERI RCG 177.8 316 eP :20.10 ( 0.73 ) CERI BHT 240.2 339 eP :28.90 (-0.05 ) eS :55.90 (-1.47 ) CERI PLVA 407.2 39 eP :49.30 (-0.68 ) Additional Data: GIT CDG P 23:18:08.0 S 23:18:20.0 ***** 1993 AUGUST 17; 00:56 - GWINNET COUNTY, GEORGIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I CERI 930817 005610.0 33.870 84.074 1.4 6 114 322 0.3 D D/D 99.0 -7 3.9 99.0 D 2.2 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) CERI BBG 114.0 12 eP 00:56:29.40 (-0.19 ) eS 00:56:44.00 ( 0.11 ) CERI GMG 123.1 334 eP :31.50 ( 0.55 ) eS :46.00 (-0.25 ) CERI BHT 233.4 340 eP :48.70 ( 0.88 ) eS :57:14.70 (-0.74 ) ***** 1993 AUGUST 18; 21:56 - CONYERS, GEORGIA ***** TVA This event identified as being part of Lithonia, GA, swarm by GIT. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930818 215621.2 33.724 84.040 0.0 21 166 256 0.4 D C/D 1.5 4 0.9 1.4 B 2.5 CERI 930818 215621.2 33.776 84.047 7.5 6 124 325 0.1 D C/D 67.4 -8 1.4 67.4 D 2.6 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA LKGA 165.5 307 eP- 21:56:47.60 (-0.04 ) iS 21:57:06.35 (-0.09 ) TVA OLT 182.1 331 eP :50.50 ( 0.20 ) eS :11.45 ( 0.45 ) TVA TQTN 208.5 343 eP :53.90 (-0.62 ) eS :17.75 (-0.45 ) TVA PDTN 239.1 316 ePd :58.70 (-0.13 ) eS :25.60 (-0.99 ) TVA ORT 243.6 354 iP :59.34 (-0.05 ) eS :27.60 ( 0.01 ) TVA MSAL 272.6 298 eP :57:03.60 ( 0.65 ) eS :34.65 ( 0.76 ) TVA CRTN 275.2 4 eP :03.62 ( 0.32 ) eS :35.89 ( 1.38 ) TVA ANTN 292.5 338 iP :06.90 ( 1.45 ) eS :41.05 ( 2.75X) TVA ABTN 305.5 322 iP :06.40 (-0.62 ) TVA LAL 314.4 285 P? :09.10 ( 0.98 ) eS :44.45 ( 1.42 ) TVA SLTN 348.7 30 eP :11.65 (-0.80 ) eS :50.45 (-0.23 ) TVA MOTN 482.0 313 eP :27.65 (-1.11 ) CERI BBG 123.7 10 eP 21:56:41.90 ( 0.08 ) eS 21:56:56.80 (-0.05 ) CERI GMG 133.5 335 eP :43.20 (-0.10 ) eS :59.50 ( 0.09 ) CERI BHT 244.0 341 eP :57:00.40 ( 0.21 ) eS :57:30.00 ( 1.36 ) ***** 1993 SEPTEMBER 6; 11:48 - GREENBACK, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930906 114820.1 35.664 84.149 7.0 19 31 163 0.3 C C/C 0.5 -52 0.3 0.8 A 1.7 CERI 930906 114820.4 35.670 84.184 16.5 5 72 312 0.1 D D/D 4.6 54 3.0 99.0 D 2.1 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA ORT 30.7 333 iPc 11:48:25.82 ( 0.22 ) iS 11:48:29.74 ( 0.15 ) TVA TQTN 54.8 253 iP :29.82 ( 0.25 ) iS :36.17 (-0.30 ) TVA CRTN 65.6 25 eP+ :31.32 (-0.06 ) eS :39.28 (-0.31 ) TVA OLT 97.8 235 P? :37.02 ( 0.32 ) eS :48.92 ( 0.12 ) TVA ANTN 112.8 300 iP :38.47 (-0.53 ) iS :52.87 ( 0.09 ) TVA BRTN 138.7 56 eP :44.07 ( 1.09X) S? :49:01.00 ( 1.34X) TVA PDTN 160.3 255 eP :46.12 (-0.14 ) TVA LKGA 166.9 227 eP- :47.57 ( 0.27 ) eS :07.42 ( 0.28 ) TVA ABTN 178.9 278 iP :49.01 (-0.10 ) TVA FDKY 193.6 311 eP :51.22 (-0.14 ) eS :14.62 ( 0.46 ) TVA SLTN 202.2 64 eP :52.92 ( 0.17 ) TVA MSAL 247.0 249 P :49:00.00 ( 1.01X) eS :29.22 ( 1.85X) TVA HAKY 270.9 307 P? :02.97 ( 1.07 ) eS :34.32 ( 1.92X) TVA TCT 309.9 278 eP :08.27 ( 1.59 ) eS :42.47 ( 1.81X) CERI BHT 71.6 286 iS 11:48:41.30 (-0.01 ) CERI BBG 94.6 159 eP 11:48:36.00 (-0.05 ) eS :47.50 ( 0.00 ) CERI GMG 99.8 206 eP :37.10 ( 0.26 ) eS :48.80 (-0.06 ) ***** 1993 SEPTEMBER 8; 07:41 - LAFAYETTE, GEORGIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930908 074113.0 34.705 85.268 13.0 11 21 211 0.1 D C/D 2.3 -21 1.1 2.1 B 0.8 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA LKGA 20.8 244 iP 07:41:17.30 ( 0.05 ) iS 07:41:20.32 (-0.03 ) TVA PDTN 82.4 320 eP :26.59 (-0.26 ) eS :37.14 ( 0.19 ) TVA MSAL 129.6 277 eS :49.39 (-0.04 ) TVA ABTN 151.7 330 eP :37.09 (-0.37 ) eS :56.04 ( 0.74 ) TVA ORT 159.8 33 S? :57.44 (-0.02 ) TVA ANTN 162.8 1 eS :58.44 ( 0.16 ) TVA LAL 192.2 262 P? :43.72 ( 0.07 ) eS :42:06.46 ( 0.44 ) ***** 1993 SEPTEMBER 14; 03:10 - CUMMING, GEORGIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930914 031023.8 34.071 84.195 17.7 9 133 284 0.4 D D/D 4.5 -29 1.9 2.5 C 1.1 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA LKGA 132.6 298 eP 03:10:44.90 (-0.31 ) TVA PDTN 202.0 312 eP :56.37 ( 0.57 ) eS 03:11:18.79 (-0.39 ) TVA ORT 204.2 357 eP :56.09 (-0.05 ) TVA CRTN 238.4 8 eP :59.79 (-0.69 ) eS :26.57 (-0.71 ) TVA MSAL 243.5 291 eP :11:02.04 ( 0.96 ) S? :28.49 ( 0.18 ) TVA ABTN 266.6 320 eP :04.04 ( 0.12 ) eS :30.58 (-2.65X) ***** 1993 SEPTEMBER 16; 10:16 - ROGERSVILLE, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 930916 101606.4 36.380 82.834 14.7 8 4 186 0.2 D C/D 2.4 -14 0.4 0.5 B 1.3 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA BRTN 4.0 230 eP 10:16:09.10 (-0.02 ) eS 10:16:11.10 ( 0.01 ) TVA SLTN 64.4 84 iP :17.81 ( 0.33 ) iS :25.30 (-0.25 ) TVA CRTN 92.6 258 eP+ :21.65 (-0.07 ) eS :32.72 (-0.17 ) TVA TKL 116.6 227 eP :25.28 (-0.10 ) eS :39.25 ( 0.03 ) TVA ORT 142.3 249 P? :30.81 ( 1.49X) eS :49.55 ( 3.52X) ***** 1993 OCTOBER 3; 06:24 - BARBOURVILLE, KENTUCKY ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 931003 062458.0 36.892 83.763 21.0 7 77 201 0.2 D C/D 2.3 -13 1.2 6.4 D 0.5 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA CRTN 77.2 185 eP 06:25:10.70 (-0.34 ) iS 06:25:20.55 ( 0.02 ) TVA BRTN 99.7 126 eS :26.30 (-0.17 ) TVA ORT 119.4 204 iS :32.55 ( 0.89X) TVA TKL 137.0 180 eS :35.99 (-0.31X) TVA SLTN 155.1 108 eP :25.75 ( 2.74X) eS :41.52 ( 0.29 ) TVA TQTN 175.6 210 S? :46.80 ( 0.31X) TVA FDKY 181.5 267 eS :47.80 (-0.28 ) TVA ABTN 238.3 243 eP :34.80 ( 0.37 ) eS :26:02.55 ( 1.55 ) ***** 1993 OCTOBER 3; 11:55 - JASPER, ALABAMA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 931003 115537.5 33.686 87.416 9.6 11 84 292 0.3 C B/D 1.0 43 0.6 1.5 B 2.8 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA LAL 83.5 5 iP 11:55:51.79 ( 0.09 ) iS 11:56:02.15 ( 0.07 ) TVA MSAL 145.8 28 iPd :56:01.35 ( 0.13 ) iS :18.20 (-0.35 ) TVA LKGA 207.2 59 iPc :10.40 (-0.27 ) iS :35.30 ( 0.40 ) TVA PDTN 227.4 39 eP :13.26 (-0.43 ) iS :40.65 ( 0.54 ) TVA ABTN 271.7 26 iP :18.95 (-0.16 ) TVA OLT 273.3 53 ePd :20.05 ( 0.73X) iS :52.40 ( 2.55X) TVA TQTN 319.5 50 P? :26.20 ( 1.26X) S? :57:00.07 ( 0.49X) TVA MOTN 329.4 351 eP :26.50 ( 0.37 ) S? :00.50 (-1.15 ) TVA FDKY 374.7 23 P? :33.95 ( 2.26X) eS :12.25 ( 1.00X) TVA ORT 376.7 48 P? :37.80 ( 5.86X) eS :18.15 ( 6.46X) TVA HAKY 386.8 11 P? :35.30 ( 2.14X) eS :20.50 ( 6.71X) TVA TKL 399.1 56 S? :21.90 ( 5.48X) TVA CRTN 429.4 49 P? :40.90 ( 2.49X) eS :28.80 ( 5.92X) ***** 1993 OCTOBER 3; 23:50 - CHARLESTON, SOUTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 931003 235053.1 32.992 80.211 3.5 6 4 89 0.1 B 0.8 360 0.8 3.0 1.0 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC SVS 4.3 233 iPd 23:50:54.40 (-0.06 ) USC RGR 9.5 171 iPd :55.18 (-0.04 ) USC MGS 12.3 148 iPu :56.30 ( 0.55X) USC HBF 12.4 247 iPd :55.71 ( 0.02 ) USC BCS 13.7 96 iPu :56.17 ( 0.04 ) USC DRC 21.0 308 iPd :57.73 ( 0.45 ) USC CFS 32.0 7 iPu :59.10 (-0.03 ) USC SGS 35.7 309 iPd :51:00.40 ( 0.63X) ***** 1993 OCTOBER 6; 00:42 - DAYTON, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 931006 004248.5 35.459 84.957 21.9 9 22 117 0.1 B B/B 1.5 -59 0.4 2.2 B 1.4 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA TQTN 21.9 73 iP 00:42:53.50 (-0.09 ) iS 00:42:57.35 ( 0.02 ) TVA OLT 34.9 190 iP :55.25 (-0.01 ) iS :43:00.20 (-0.01 ) TVA ORT 77.3 50 eP :57.40 (-4.11X) eS :11.40 ( 0.38 ) TVA PDTN 83.7 256 eS :12.80 ( 0.12 ) TVA LKGA 104.0 207 S? :18.50 ( 0.45 ) TVA ABTN 114.5 295 P? :43:07.40 ( 0.25 ) S? :20.50 (-0.29 ) TVA CRTN 130.1 51 S? :28.70 ( 3.76X) ***** 1993 OCTOBER 19; 07:43 - FLORENCE, ALABAMA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 931019 074348.1 34.834 87.574 20.3 7 82 272 0.2 D C/D 2.7 53 0.9 25.1 D 1.1 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA MSAL 82.3 89 eP 07:44:01.55 (-0.32 ) eS 07:44:11.50 (-0.41 ) TVA TCT 130.0 1 eP- :09.25 ( 0.09 ) iS :24.45 (-0.05 ) TVA PDTN 164.7 72 eS :34.55 ( 0.85 ) TVA ABTN 177.0 48 eP :16.65 ( 0.29 ) eS :37.25 ( 0.28 ) TVA OLT 235.4 81 eS :53.50 ( 2.91X) ***** 1993 OCTOBER 28; 06:00 - COLUMBIA, MARYLAND ***** MGS Felt (IV) in the Columbia, Maryland, area (see special report on this earthquake and associated events in Appendix A). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I MGS 931028 0600 39.25 76.77 2.1 4 ***** 1993 OCTOBER 28; 06:01 - COLUMBIA, MARYLAND ***** MGS Felt (IV) in the Columbia, Maryland, area (see special report on this earthquake and associated events in Appendix A). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I MGS 931028 0601 39.25 76.77 1.8 4 ***** 1993 NOVEMBER 6; 08:26 - LIMESTONE COUNTY, ALABAMA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 931106 082653.4 34.997 86.961 7.6 17 31 211 0.2 C B/D 1.0 52 0.3 1.2 A 1.5 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA MSAL 31.1 122 iPc 08:26:59.15 ( 0.17 ) iS 08:27:02.95 (-0.07 ) TVA FKT 87.3 359 P? :27:06.30 (-1.96X) iS :19.10 ( 0.01 ) TVA PDTN 105.8 73 eP :11.10 (-0.09 ) eS :24.10 (-0.05 ) TVA TCT 124.1 335 eP :13.90 (-0.08 ) iS :28.88 (-0.09 ) TVA ABTN 125.3 38 eP :14.25 ( 0.08 ) S? :29.30 (-0.01 ) TVA LKGA 142.4 107 eP :16.80 (-0.02 ) eS :34.30 ( 0.41 ) TVA OLT 177.5 84 S? :43.25 ( 0.10 ) TVA MOTN 202.3 333 eP :21.40 (-4.56X) eS :50.60 ( 0.91 ) TVA ANTN 203.9 50 eP :26.70 ( 0.47 ) eS :51.15 ( 0.99 ) TVA FDKY 225.1 28 S? :56.25 ( 0.50 ) TVA HAKY 236.4 8 eP :35.50 ( 4.56X) eS :59.30 ( 0.98 ) ***** 1993 NOVEMBER 8; 18:47 - WILMINGTON, DELAWARE ***** DGS Felt. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I DGS 931108 1847 39.748 75.563 6 1.7 F SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) DGS BWD 5.9 iPu 18:47:27.8 iS 18:47:20.0 DGS BVD 6.3 iPu :28.0 iS :29.0 DGS NED 13.7 iPu :29.2 iS :30.8 ***** 1993 NOVEMBER 16; 06:25 - LAFAYETTE, GEORGIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 931116 062507.8 34.773 85.307 9.5 16 23 89 0.2 C B/C 0.4 -29 0.3 0.7 A 2.6 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA LKGA 22.5 222 iP 06:25:12.14 ( 0.06 ) TVA OLT 49.2 32 iPd :16.57 ( 0.18 ) TVA PDTN 74.4 318 iP+ :20.44 (-0.10 ) iS 06:25:29.84 ( 0.03 ) TVA TQTN 98.0 33 iP :24.13 (-0.13 ) eS :36.04 (-0.21 ) TVA MSAL 125.3 274 iPc :27.99 (-0.45 ) iS :44.04 ( 0.55 ) TVA ABTN 143.4 330 iP :31.04 (-0.18 ) iS :48.44 ( 0.15 ) TVA ANTN 155.3 3 iP :33.24 ( 0.16X) iS :52.04 ( 0.54X) TVA ORT 155.6 36 iP- :33.24 ( 0.15X) iS :51.64 ( 0.12X) TVA SMLT 162.2 134 P :34.10 ( 0.01 ) S :54.00 ( 0.75 ) TVA ATL 173.4 149 P? :34.50 (-1.31X) S? :55.00 (-1.24X) TVA CRTN 206.8 40 iP :41.14 ( 0.19 ) eS :26:05.04 (-0.08 ) TVA FDKY 228.1 349 iP :44.92 ( 0.80X) eS :11.64 ( 1.03X) TVA TCT 245.6 304 iP :46.14 (-0.12X) eS :16.29 ( 1.99X) TVA HAKY 283.4 336 P? :52.99 ( 2.13X) eS :24.69 ( 2.42X) TVA MOTN 317.4 311 eP :57.99 ( 2.97X) TVA SLTN 343.1 56 eP :58.56 ( 0.26 ) eS :35.14 (-0.01 ) Additional Data: GIT SMLT P 06:25:34.1 S 06:25:54.0 GIT ATL P :34.5 S :55.0 ***** 1993 NOVEMBER 16; 06:32 - LAFAYETTE, GEORGIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 931116 063209.5 34.773 85.321 7.8 17 22 180 0.2 C B/D 0.7 -47 0.3 1.5 B 1.9 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA LKGA 21.6 220 iP 06:32:13.74 ( 0.24 ) iS 06:32:16.24 (-0.20 ) TVA OLT 49.9 33 iP :18.24 ( 0.10 ) iS :24.29 (-0.16 ) TVA PDTN 73.6 319 eP :22.14 ( 0.09 ) eS :31.34 ( 0.12 ) TVA TQTN 98.7 33 eP :25.79 (-0.34 ) eS :37.54 (-0.74X) TVA MSAL 124.1 274 P? :29.69 (-0.32 ) eS :44.69 (-0.31 ) TVA ABTN 142.8 330 iP :32.89 ( 0.00 ) eS :49.69 (-0.28 ) TVA ANTN 155.4 3 eP :34.89 ( 0.04 ) eS :53.29 (-0.08 ) TVA ORT 156.3 36 eS :54.04 ( 0.48 ) TVA CRTN 207.6 40 P? :42.89 ( 0.06 ) S? :33:08.42 ( 1.25X) TVA FDKY 227.9 349 eS :13.24 ( 0.72 ) TVA TCT 244.6 305 eS :16.54 ( 0.46 ) ***** 1993 NOVEMBER 17; 15:35 - COLUMBIA, MARYLAND ***** MGS Felt (III) in the Columbia, Maryland, area. Magnitude 1.5-1.8? (see special report on this earthquake and associated events in Appendix A). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I MGS 931117 1535 39.19 76.87 3 ***** 1993 NOVEMBER 25; 06:26 - CHARLESTON, SOUTH CAROLINA ***** CSU Between Middleton Place and Summerville, SC. No felt reports. Magnitude 1.0. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 931125 062614.1 32.936 80.140 7.5 6 4 126 0.0 B 0.6 360 0.6 1.2 1.0 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC MGS 4.3 181 P 06:26:16.00 ( 0.12 ) USC RGR 6.0 238 P :15.95 (-0.06 ) USC BCS 8.5 55 P :16.50 (-0.01 ) USC SVS 10.7 289 iPd :16.72 ( 0.01 ) USC WAS 15.8 231 P :17.40 (-0.03 ) USC HBF 18.1 274 iPd :17.75 (-0.01 ) Additional Data: CSU RGR P 06:26:16 CSU MGS P :16 CSU BCS P :16.5 CSU WAS P :17 ***** 1993 NOVEMBER 27; 17:43 - COLUMBIA, MARYLAND ***** MGS Felt (II) in the Columbia, Maryland, area. Magnitude approximately 1.5 (see special report on this earthquake and associated events in Appendix A). SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I MGS 931127 1743 39.19 76.87 1.5 2 ***** 1993 DECEMBER 6; 03:48 - CHARLESTON, SOUTH CAROLINA ***** CSU Between Middleton Place and Summerville, SC. No felt reports. Magnitude 1.2. SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 931206 034821.8 32.938 80.143 5.0 3 5 183 0.1 C 1.0 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC MGS 4.5 178 P 03:48:23.20 (-0.10 ) USC RGR 5.9 235 iPd :23.50 ( 0.06 ) USC BCS 8.6 57 iPd :24.02 (-0.01 ) Additional Data: CSU MGS P 03:48:23 CSU RGR P :23.5 CSU BCS P :24 ***** 1993 DECEMBER 19; 05:50 - CUMBERLAND, VIRGINIA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I VTSO 931219 055007.3 37.549 78.194 14.7 8 28 197 0.2 D C/D 1.6 66 0.8 1.4 B 1.9 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) VTSO GHV 28.3 16 iPc 05:50:12.74 ( 0.15 ) iS 05:50:16.13 (-0.28 ) VTSO CVL 53.5 334 eP :16.68 ( 0.22 ) eS :22.79 (-0.31 ) VTSO NA12 55.6 30 eP :16.91 ( 0.13 ) eS :23.77 ( 0.12 ) VTSO PBV 86.0 137 ePd :21.41 (-0.06 ) eS :31.55 (-0.15 ) ***** 1993 DECEMBER 29; 02:48 - TIFTONA, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 931229 024854.4 35.064 85.446 18.8 16 40 182 0.1 C B/D 0.8 12 0.3 1.8 B 1.6 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA OLT 39.7 76 iP 02:49:01.70 ( 0.03 ) iS 02:49:07.00 ( 0.00 ) TVA PDTN 43.5 302 iP :02.21 ( 0.00 ) iS :07.95 ( 0.01 ) TVA TQTN 82.5 52 eP :08.45 ( 0.32 ) eS :18.10 (-0.07 ) TVA ABTN 109.2 327 iP :11.90 (-0.31 ) iS :25.35 ( 0.11 ) TVA MSAL 114.6 258 eP :13.15 ( 0.12 ) eS :26.60 (-0.06 ) TVA ANTN 124.5 9 iP :14.62 ( 0.06 ) eS :28.50 (-0.81 ) TVA FDKY 194.1 351 eP :25.20 ( 0.01 ) eS :48.00 ( 0.30 ) TVA TCT 217.7 299 eP :28.25 (-0.17 ) eS :54.00 ( 0.71 ) ***** 1993 DECEMBER 31; 10:54 - SPRING CITY, TENNESSEE ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I TVA 931231 105423.4 35.622 84.942 17.7 8 23 87 0.2 C C/B 1.0 -77 0.5 2.6 B 0.8 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) TVA TQTN 22.9 121 iP 10:54:28.03 (-0.17 ) iS 10:54:31.83 ( 0.08 ) TVA OLT 53.0 188 eP :32.63 ( 0.02 ) iS :39.43 ( 0.07 ) TVA ORT 65.8 61 eS :42.53 (-0.21 ) TVA ANTN 66.3 337 eS :41.53 (-1.38X) TVA PDTN 91.0 245 eS :49.03 (-0.36 ) TVA CRTN 118.3 57 eS :57.03 ( 0.41 ) TVA FDKY 150.5 330 iS :55:05.28 ( 0.14 ) SOUTHEASTERN U. S. RESERVOIR RELATED EARTHQUAKES DURING 1993 Events are listed chronologically (this also applies to multiple hypocenter locations for the same event). All times are Universal Coordinated Time. Most entries in the listing are self-explanatory. Items that might require further explanation are defined in the section entitled DEFINITIONS AND NETWORK OPERATOR CODES. ***** 1993 JANUARY 26; 19:00 - LAKE KEOWEE, SOUTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 930126 190013.4 34.730 83.068 7.9 5 15 304 0.1 D 5.5 360 5.5 7.2 1.4 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC MMC 15.0 68 P 19:00:16.25 ( 0.08 ) S 19:00:18.34 (-0.01X) USC SMT 24.0 22 P :17.56 ( 0.04 ) S :20.27 (-0.48X) USC JVW 29.9 12 P :18.43 ( 0.00 ) S :21.82 (-0.55X) USC BG3 31.8 23 P :18.74 ( 0.01 ) S :22.50 (-0.40X) USC CCK 33.3 12 P :18.86 (-0.11 ) S :22.70 (-0.63X) ***** 1993 FEBRUARY 10; 15:36 - LAKE KEOWEE, SOUTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 930210 153611.7 34.716 83.111 1.0 5 19 309 0.1 D 19.8 360 19.8 99.9 1.0 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC MMC 19.3 68 P 15:36:14.89 (-0.02 ) USC SMT 27.1 28 P :16.09 (-0.08 ) S 15:36:18.85 (-0.82X) USC JVW 32.4 19 P :17.10 ( 0.07 ) USC BG3 34.8 28 P :17.58 ( 0.16 ) S :20.88 (-1.02X) USC CCK 35.8 18 P :17.46 (-0.11 ) ***** 1993 FEBRUARY 19; 20:51 - MONTICELLO RESERVOIR, SOUTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 930219 205147.4 34.387 81.363 2.2 8 4 309 0.0 C 0.6 360 0.6 0.7 1.0 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC MR07 4.0 118 iPd 20:51:48.09 (-0.05 ) S 20:51:48.75 ( 0.03 ) USC MR10 6.1 157 iPu :48.43 (-0.02 ) S :49.27 ( 0.00 ) USC MR01 8.7 135 iPd :50.75 ( 1.89X) S :51.87 ( 1.89X) USC MR05 13.5 169 iPd :49.62 ( 0.01 ) S :50.50 (-0.81X) USC JSC 15.2 141 iPu :49.89 ( 0.01 ) S :50.72 (-1.06X) USC MR02 24.8 150 iPd :51.52 ( 0.08 ) S :54.51 (-0.02 ) USC LHS 52.0 79 iPu :55.54 (-0.18X) S :52:02.32 ( 0.26X) ***** 1993 MARCH 2; 23:14 - LAKE JOCASSEE, SOUTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 930302 231459.3 34.922 82.912 2.0 3 6 294 0.0 C 1.0 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC SMT 5.5 281 P 23:15:00.35 ( 0.00 ) S 23:15:00.78 (-0.36X) USC BG3 8.1 347 P :00.76 ( 0.00 ) S :01.54 (-0.33X) USC CCK 13.4 327 P :01.61 ( 0.00 ) S :02.61 (-0.77X) ***** 1993 MARCH 22; 18:55 - MONTICELLO RESERVOIR, SOUTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 930322 185510.0 34.299 81.264 0.7 11 2 200 0.1 C 0.3 360 0.3 0.5 1.0 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC JSC 2.1 170 iPd 18:55:10.35 (-0.03 ) S 18:55:10.68 (-0.01 ) USC MR01 4.7 321 iPd :10.75 (-0.04 ) S :11.33 (-0.08 ) USC MR05 7.3 242 iPd :11.31 ( 0.10 ) S :12.11 (-0.05 ) USC MR10 7.9 301 iPu :11.32 ( 0.01 ) S :12.33 ( 0.01 ) USC MR07 9.7 325 iPd :11.87 ( 0.28X) S :12.89 ( 0.07 ) USC MR02 12.2 165 iPd :12.05 ( 0.02 ) S :13.62 ( 0.02 ) ***** 1993 JULY 10; 02:59 - BAD CREEK RESERVOIR, NORTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 930710 025906.6 35.019 83.044 2.0 5 1 299 0.1 D 3.7 360 3.7 2.2 1.1 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC BC 1.1 99 ePd 02:59:06.95 (-0.03 ) S 02:59:07.79 ( 0.50X) USC CCK 4.8 85 ePu :07.46 (-0.01 ) S :08.03 (-0.14X) USC JVW 5.2 125 ePu :07.67 ( 0.14 ) S :08.67 ( 0.40X) USC BG3 10.6 106 ePu :08.37 (-0.03 ) S :09.58 (-0.24X) USC SMT 11.9 146 ePu :08.45 (-0.14 ) S :09.92 (-0.25X) ***** 1993 OCTOBER 28; 16:41 - LAKE KEOWEE, SOUTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 931028 164120.6 34.784 83.008 8.5 8 9 269 0.1 C 2.1 360 2.1 2.3 1.6 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC MMC 8.5 93 iPu 16:41:22.63 ( 0.05 ) iSu 16:41:24.22 ( 0.09 ) USC JVW 23.2 2 iPd :24.73 ( 0.09 ) iSu :27.86 ( 0.07 ) USC BG3 24.2 17 iPu :24.74 (-0.07 ) iSu :28.10 ( 0.01 ) USC CCK 26.6 3 iPu :25.11 (-0.05 ) iSd :28.50 (-0.22 ) ***** 1993 DECEMBER 6; 16:40 - LAKE KEOWEE, SOUTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 931206 164005.7 34.747 83.062 7.0 8 14 297 0.1 C 1.4 360 1.4 2.8 1.5 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC MMC 13.9 75 iPu 16:40:08.28 ( 0.01 ) iSu 16:40:10.31 ( 0.04 ) USC JVW 27.9 12 iPd :10.45 ( 0.04 ) iSd :14.11 ( 0.02 ) USC BG3 29.8 23 iPd :10.76 ( 0.04 ) iSd :14.59 (-0.04 ) USC CCK 31.3 12 iPd :10.86 (-0.09 ) iSd :15.02 (-0.03 ) ***** 1993 DECEMBER 14; 17:33 - LAKE KEOWEE, SOUTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 931214 173348.7 34.755 83.068 7.1 10 14 288 0.0 C 0.6 360 0.6 1.3 1.5 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC MMC 14.2 79 iPd 17:33:51.26 (-0.02 ) eSd 17:33:53.33 ( 0.01 ) USC JVW 27.1 14 ePu :53.29 ( 0.03 ) eSu :56.89 ( 0.05 ) USC BG3 29.2 25 ePu :53.62 ( 0.04 ) eSd :57.40 (-0.02 ) USC BC 29.4 6 ePu :53.60 (-0.01 ) eSd :57.41 (-0.05 ) USC CCK 30.6 13 iPu :53.78 (-0.01 ) eSd :57.85 ( 0.05 ) ***** 1993 DECEMBER 17; 16:25 - BAD CREEK RESERVOIR, SOUTH CAROLINA ***** SRCE DATE HRMN SEC LAT-N LON-W DEPTH PH DMN GAP RMS Q SQD ERH1 AZ ERH2 ERZ Q MN MD MAGT I USC 931217 162534.1 35.015 83.015 2.2 6 2 279 0.0 C 0.4 360 0.4 0.4 1.2 SRCE STA DIST(KM) AZM PHASE ARRIVAL TIME (RES) PHASE ARRIVAL TIME (RES) USC CCK 2.3 68 iPu 16:25:34.61 (-0.05 ) iSu 16:25:35.10 ( 0.01 ) USC JVW 3.0 148 iPu :34.77 ( 0.02 ) iSu :35.18 (-0.06 ) USC BG3 8.0 108 iPu :35.54 ( 0.02 ) iSd :36.62 ( 0.01 ) SEISMIC STATION LISTING AND NETWORK MAPS Stations operating in the SEUSSN during the report period are listed below. Changes to the network (new stations, stations that have been closed, etc.) may be found at the end of this listing. A list of operator code definitions may be found in the section entitled DEFINITIONS AND NETWORK OPERATOR CODES. After the station listing is a plot of all the stations, followed by maps of individual networks (with station identification codes) operated by major member agencies or groups of the SEUSSN. Sta. Lat. N Lon. W Elev. Dates Current Code (Dg-Min) (Dg-Min) (M) Open-Close Operator Locality ABTN 35-53.13 86-06.54 363 8409- TVA Auburntown, TN AMG 32-03.56 84-13.06 122 7309- GSW Americus, GA ANTN 36-10.30 85-13.88 612 8305- TVA Anderson, TN ATL 33-26.00 84-20.25 272 6306- GIT Atlanta, GA BAV 37-13.32 80-25.50 622 7309- VTSO Blacksburg, VA BBG 34-52.44 83-48.66 1355 8201- CERI Brasstown Bald, GA BC 35-01.06 83-01.88 860 8701- DPC Bad Creek Res., SC BCS 32-58.78 80-03.92 9 8701- CSU -USGS Charleston Southern Univ., SC BENN 35-33.90 81-39.66 878 8201- CERI Benn Knob, NC BG3 34-59.58 82-55.90 366 86 - DPC Lake Jocassee, SC BHT 35-50.82 84-56.70 826 8110- CERI Blowhole, TN BLA 37-12.68 80-25.21 634 6209- VTSO Blacksburg, VA BRBC 35-44.34 82-17.16 1976 8205- CERI Mt. Mitchell, NC BRTN 36-21.40 82-52.07 630 8606- TVA Brown Mtn., TN BVD 39-46.49 75-29.96 58 8502- DGS Bellevue State Park, DE BWD 39-47.96 75-34.60 63 8502- DGS Brandywine State Park, DE CBN 38-12.30 77-22.40 70 71 - USGS Corbin, VA CCK 35-01.37 82-59.49 701 9201- USC Bad Creek Res., SC CCVA 36-36.18 83-40.02 571 8211- CERI Cudjo Cave, VA CDG 34-36.65 84-40.00 332 - GIT Carters Dam, GA CEH 35-53.45 79-05.57 152 7508- UNC Chapel Hill, NC CFS 33-16.68 80-10.22 26 8805- USC -USGS Crossfire Tower, SC CNV 38-12.30 77-22.40 70 7807-9308 VTSO Corbin, VA COW 33-22.90 80-41.96 60 7710- USC Cow Castle Creek, SC CRTN 36-11.99 83-50.44 488 8408- TVA Comb Ridge, TN CVL 37-58.88 78-27.65 167 7807- VTSO Charlottesville, VA CVV 37-58.88 78-27.65 167 7404- VDMR Charlottesville, VA DALG 34-46.43 85-00.47 329 9103- GIT Dalton, GA DRC 33-06.45 80-23.30 20 8303- CSU -USGS Dorchester, SC ETT 35-19.56 84-27.30 588 8111- CERI Etowah, TN EVE 25-23.24 80-40.97 2 8910- UFL Homestead, FL FDKY 36-47.40 85-47.65 306 8703- TVA Freedom, KY FGTN 36-26.02 83-11.72 509 9112- CERI TN FKT 35-47.04 86-58.26 321 9310- TVA Franklin, TN FRV 37-12.18 78-21.56 216 7812-9312 VTSO Farmville, VA GAI 29-39.02 82-20.01 51 7711- UFL Gainesville, FL GBTN 35-39.96 84-12.66 326 8303- CERI Greenback, TN GBV 38-25.93 79-50.72 802 7711- NASA Green Bank, WV GFM 36-06.66 81-48.42 1726 8205- CERI Grandfather Mtn., NC GHV 37-47.65 78-06.44 107 7810- VTSO Goochland, VA GLT 36-21.72 86-29.88 159 8111- CERI-VCSS Gallatin, TN GMG 34-50.16 84-40.20 1097 8509- CERI Grassy Mtn., GA HAKY 37-06.34 86-35.10 169 8706- TVA Hadley, KY HBF 32-56.85 80-19.96 10 7303- USC Harts Bluff, SC HPKT 35-55.56 83-52.74 305 8003- GIT -TVA Knoxville, TN HWD 32-44.33 80-17.01 9 8303- CSU -USGS Hollywood, SC HWV 37-35.43 80-50.45 521 7804- VTSO Hinton, WV JSC 34-16.90 81-15.62 120 7405- USC Jenkinsville, SC JVW 34-59.54 82-59.86 554 9111- USC Bad Creek Res., SC LAL 34-26.20 87-20.23 320 8903- TVA Leola, Alabama LEX 37-47.36 79-26.50 311 7105- WAL Lexington, VA LHS 34-28.57 80-48.37 120 7405- USC Liberty Hill, SC LKGA 34-37.40 85-28.33 655 8512- TVA Lookout Mtn., GA MGS 32-53.87 80-08.46 9 7603- CSU -USC Middleton Gardens, SC MMC 34-46.79 82-54.91 280 8707- DPC Morgan Memorial Church, SC MOTN 36-37.08 87-59.20 177 8308- TVA Model, TN MRG 39-37.98 79-57.26 281 7511- WVU Morgantown, WV MR01 34-19.91 81-17.74 131 7711- USC -SCEG Monticello Res., SC MR02 34-11.58 81-13.81 84 7711- USC -SCEG Monticello Res., SC MR05 34-16.05 81-20.05 103 7807- USC -SCEG Monticello Res., SC MR07 34-22.32 81-19.50 134 7807- USC -SCEG Monticello Res., SC MR10 34-20.18 81-20.25 137 7807- USC -SCEG Monticello Res., SC MSAL 34-50.80 86-40.41 260 8307- TVA Monte Sano, AL MTT 33-45.02 81-38.40 182 7608- USC Monetta, SC NAV 37-18.94 80-47.61 610 7710- VTSO Narrows, VA NA2 38-07.62 77-44.82 82 7810-9308 VTSO North Anna, VA NA5 38-00.65 77-44.19 76 7808-9308 VTSO North Anna, VA NA12 37-58.98 77-52.77 125 7808- VTSO North Anna, VA NED 39-42.25 75-42.49 47 7211- DGS Newark, DE OLT 35-09.00 85-01.44 445 9306- TVA Ooltewah, TN ONTN 36-28.89 84-26.60 635 8402- TVA Oneida, TN ORT 35-54.57 84-18.29 370 75 - TVA Oak Ridge, TN PBV 36-58.94 77-31.87 49 7811- VTSO Petersburg, VA PDTN 35-16.40 85-50.97 335 8509- TVA Piedmont, TN PKNC 36-02.76 81-09.48 785 8211- CERI Pores Knob, NC PLVA 36-39.98 81-09.63 1353 8211- CERI Point Lookout, VA PRM 34-04.98 82-21.78 254 7507- USC Parsons Mtn., SC PWLA 34-58.80 88-03.84 204 8005- CERI- SLU Pickwick Lake, AL PWV 37-20.09 81-02.93 820 7803- VTSO Princeton, WV RBNC 35-21.42 82-59.16 1829 8205- CERI Richland Balsam, NC RCG 34-58.50 85-20.88 468 8110- CERI Rock City, GA RGR 32-54.45 80-11.65 -52 8606- CSU -USGS (Roger Stewart) SC RICH 35-55.20 82-49.20 967 8306- CERI Rich Mtn., NC SAR 27-10.53 82-27.94 4 8910- UFL Osprey, FL SGS 33-11.55 80-30.57 25 7303- USC St. George, SC SLTN 36-26.59 82-07.23 1280 8401- TVA Sullivan, TN SMLT 33-45.18 84-02.72 238 93 - GIT Norris Lake, GA (temporary) SMT 34-55.85 82-58.26 498 7704- USC Smeltzer Mtn. (Jocassee), SC SRAV 33-19.50 81-40.80 91 - WSRC Savannah River Lab, SC SRPD 33-09.30 81-42.75 31 7608- WSRC Savannah River Lab, SC SRPN 33-19.74 81-35.33 95 7608- WSRC Savannah River Lab, SC SRPW 33-12.14 81-34.69 77 7608- WSRC Savannah River Lab, SC SVS 32-58.10 80-14.89 3 7603- USC Slandsville, SC TCT 36-00.32 87-33.17 245 8803- TVA Tennessee City, TN TKL 35-39.48 83-46.44 350 78 - CERI-TVA Tuckaleechee Caverns, TN TQTN 35-30.96 84-43.55 260 8607- TVA Tranquillity, TN TRYN 35-14.76 82-16.02 915 8303- CERI Tryon Peak, NC TWB 33-06.88 80-06.18 9 8803- CSU -USC Tillman's/White's Bay, SC VBV 36-47.12 76-06.48 5 7705- TCC Virginia Beach, VA VRN 33-02.19 80-56.39 30 7912- USC Varneville, SC VWV 37-27.96 80-23.50 963 8207- VTSO VA-WV Border WAK 30-14.83 84-17.90 5 9302- UFL Wakulla, FL WAS 32-50.81 80-16.30 9 8303- CSU -USGS West Ashley, SC WMTN 35-14.88 84-58.39 378 8507-9306 TVA White Oak Mtn., TN WMV 37-06.51 80-58.23 1157 8210- VTSO Walker Mtn., VA WSSR 35-16.68 83-34.68 1340 8510- CERI Wesser Bald, NC WYC 31-12.32 82-23.39 43 9304- UFL Waycross, GA CHANGES TO THE SEUSSN STATION LISTING Station Code Operator Locality Change CNV VTSO Corbin, VA Closed August 1993. EVE UFL Homestead, FL Opened October 1989. FKT TVA Franklin, TN Opened October 1993. FRV VTSO Farmville, VA Closed December 1993. GAI UFL Gainesville, FL New latitude and longitude. NA2 VTSO North Anna, VA Closed August 1993. NA5 VTSO North Anna, VA Closed August 1993. OLT TVA Ooltewah, TN Opened June 1993. SAR UFL Osprey, FL Opened October 1989. WAK UFL Wakulla, FL Opened February 1993. WMTN TVA White Oak Mtn., TN Closed June 1993. WYC UFL Waycross, GA Opened April 1993. TEMPORARY SEUSSN STATION LISTING Station Code Operator Locality Change SMLT GIT Norris Lake Opened (temporary) FIGURE 10. Seismic stations (triangles) operating in the SEUSSN during the report period. The SEUSSN monitoring area is outlined. FIGURE 11. Georgia Tech - Geological Survey Of Alabama Seismic Network. FIGURE 12. South Carolina Seismic Network. FIGURE 13. Center for Earthquake Research and Information - Southern Appalachian Regional Seismic Network. FIGURE 14. Tennessee Valley Authority Seismic Network. FIGURE 15. University of Florida Seismic Network. FIGURE 16. Virginia Tech Seismic Network. ACCESSING DIGITAL WAVEFORM DATA AND OTHER INFORMATION FROM THE VIRGINIA TECH SEISMOLOGICAL OBSERVATORY OVERVIEW: The Virginia Tech Seismological Observatory (VTSO) has established computer access to its catalog and digital data bases through gopher and anonymous ftp servers on node vtso.geol.vt.edu (128.173.184.38). Waveform data currently available include event data from the Virginia Regional Seismic Network and from the GSE (GSETT-2) short-period and broadband instruments located at Blacksburg, Virginia (co-sited with WWSSN station BLA). Network data files consist of 32 channels, digitized at 100 sps at the Blacksburg collection node from (currently) 10 sites in Virginia and West Virginia. This acquisition system is being upgraded from its current 40 dB of dynamic range to a system with over 100 dB of dynamic range. The GSE data consist of six channels recorded with a 24 bit digitizer. The three short-period channels are sampled at 40 sps and the three broadband channels at 10 sps. Both the network and GSE stations are calibrated. A brief description of the available data is given below. For further information, help files are provided on the ftp and gopher servers. If one has problems, or wants data in a format other than that provided, contact Matthew Sibol (sibol@vtso.geol.vt.edu or 703-231-4707). NEAR-REAL-TIME WAVEFORM DATA: Every 20 minutes, triggered event waveform data files from the Virginia Tech Seismic Network are transferred from the digital acquisition system to an anonymous ftp account on vtso.geol.vt.edu. Given processing time, the longest delay expected between the recording of an event and its availability via anonymous ftp is 30 minutes. These data are raw triggers with no event information. The data are in demultiplexed UNIX-SUDS-1 format. SELECTED DIGITAL WAVEFORM DATA SETS: For events of particular interest, processed waveform data sets from the network and/or the GSE are prepared and put in subdirectories accessible through ftp and/or gopher. Waveform data from the network will have the timing and digitizing rates double-checked against a satellite time code channel, and the traces will all be corrected to the Virginia Tech standard instrument response. The waveform data are in either the SAC or the Center for Seismic Studies (CSS) database structure binary formats. OTHER INFORMATION AVAILABLE: Other data and information available from the Virginia Tech Seismological Observatory (node: vtso.geol.vt.edu) include: o Updated overview of available information by finger, telnet, or e-mail from quake@vtso..geol.vt.edu. o Unprocessed data from the GSE station for selected events (in binary CSS format). o channel information such as station locations, instrument responses (in both pole-zero and frequency-amplitude-phase formats), station calibration histories, etc. o Southeastern U. S. Seismic Network (SEUSSN) Bulletins. o SEUSSN earthquake catalog (for July 1977 through the current Bulletin) and a catalog of historic and instrumentally located earthquakes for the southeastern United States (for 1698 through the current Bulletin). DEFINITIONS AND NETWORK OPERATOR CODES Below are some entries in this Bulletin that might require definition. Also given is a detailed listing of agencies or groups (and their letter codes) that supply information to this Bulletin. AZM: Azimuthal angle from epicenter to station as measured from north (in deg), DEP: Focal depth estimate (in km); FXD indicates that the depth was held fixed during the epicentral determination, DIST (KM) Epicentral distance (in km) between the epicenter and a station, ERROR ELLIPSE: Semi-axes, expressed as lengths (km) and azimuths (deg), of the vertical projection of the error ellipsoid (Lahr, 1980). Horizontal axes are expressed as the semi-major axis (ERHMAX), it's azimuth (AZ), and the semi-minor axis (ERHMIN). The vertical axis (ERZ) is the largest vertical deviation of the error ellipsoid from the hypocenter. A quality measure (Q) for the ellipsoid based on the length of the largest semi-axis (ERHMAX, ERHMIN, or ERZ) may also be supplied. For this Bulletin the following statistics apply for error estimates: CERI, TVA, and VTSO: Error ellipse projected semi-axes from HYPOELLIPSE corresponding to a chi-square statistic (68%) with one degree of freedom, GIT: Error ellipse projected semi-axes from LOCA, and USC: Standard error estimates from HYPO71. NEIC and USGS: Unknown, GAP: The largest azimuthal separation (in deg) between recording stations, HYPOELLIPSE: Computer hypocenter location program (Lahr, 1980), HYPO71: Computer hypocenter location program (Lee and Lahr, 1974), LOCA: Computer hypocenter location program developed at the Georgia Institute of Technology, MBN or mb(Lg): Body wave magnitude determination using Nuttli's formulas for the Lg phase (Nuttli, 1973), MDB, MDL, MD: Duration/coda length magnitude that approximates either the mb, ML, or an unknown magnitude scale, respectively. As of June 1986 (SEUSSN Bulletin 17), those using a duration magnitude approximating mb(Lg) are CERI, DGS, GIT, TVA and VTSO. Specifically: CERI: MDB = -2.36 + 2.23 Log(D) + 0.12 Log(K) (MDB > 2.6) MDB = -3.38 + 2.74 Log(D) (MDB < 2.7) VTSO, TVA, and GIT: MDB = -3.45 + 2.85 Log(D) where D is signal duration measured from the P-wave arrival time to the time when the signal returns to background noise, and K is the epicentral distance in kilometers. Those using a duration magnitude approximating ML are USC and USGS. Specifically: USGS: MDL = -0.87 + 2.0 Log(D) + 0.0035 X where D is signal duration measured from the P-wave arrival time to the time when the signal returns to twice background noise, and X is the epicentral distance in kilometers. For more information please see SEUSSN Bulletin 17 (page 1) or contact the agency making the estimate for details on their specific procedure, ML: Local magnitude; contact the agency or group making the estimate for details on their specific procedure, NO: Number of P, S, and S-P readings used in locating the event, PHASE: Phase descriptions for either P or S waves, or S-P times. Included under this heading may also be the descriptors; 'i' for an impulsive arrival or 'e' for an emergent arrival. Preliminary first motions may also be given for P wave polarities. These include; 'u', 'c', or '+' for a compressional first arrival, and 'd' or '-' for a dilatational first arrival. '?' indicates that the arrival time is questionable. Q: Solution quality of the hypocenter (the average of the SQD quality measures, see below; Lee and Lahr, 1974), RES: Arrival time residual (the difference between the observed and the calculated arrival time, in seconds). An "X" following the value of the arrival time residual means that the arrival time was not used to compute the location of that event, RMS: Root-mean-square of the weighted arrival time residuals (in sec), S-P: Difference between the S and P wave arrival times (in sec), SQD: Measures of the statistical quality of the solution (S), and of the distribution of stations (D) around the hypocenter (Lee and Lahr, 1974), *XXXX: Code indicating the agency or group that made the hypocentral/magnitude determination; a listing of agencies and groups that operate seismographs in the SEUSSN and/or who supply information to this BULLETIN follows. OPERATOR CODES CERI - Center for Earthquake Research and Information, TN (formerly Tennessee Earthquake Information Center, TEIC, changed 7/1/87) CPL - Carolina Power and Light Company, NC CSU - Charleston Southern University, SC (formerly BCC, Baptist College at Charleston, SC, changed 1991) DGS - Delaware Geological Survey, DE DPC - Duke Power Company, SC GIT - Georgia Institute of Technology, GA GSA - Geological Survey of Alabama, AL GSW - Georgia Southwestern College, GA MGS - Maryland Geological Survey, MD NASA - National Aeronautics and Space Administration/ Goddard Space Flight Center, WV NEIC - National Earthquake Information Center, USGS, CO SCEG - South Carolina Electric and Gas Company, SC SLU - St. Louis University, MO TCC - Tidewater Community College, VA TVA - Tennessee Valley Authority, TN UFL - University of Florida, FL UNC - University of North Carolina, NC USC - University of South Carolina, SC USGS - United States Geological Survey, CO UTM - University of Tennessee at Martin, TN VDMR - Virginia Division of Mineral Resources, VA VP - Virginia Power, VA VTSO - Virginia Tech Seismological Observatory, VA VSCC - Volunteer State Community College, TN WAL - Washington and Lee University, VA WSRC - Westinghouse Savannah River Company, SC WVGS - West Virginia Geological and Economic Survey, WV WVU - West Virginia University, WV APPENDIX A: SUMMARY OF THE HOWARD COUNTY, MARYLAND, EARTHQUAKES OF 1993 James P. Reger Maryland Geological Survey The year 1993 will be long remembered by many residents of Howard County, Maryland, as a year for earthquakes. From March through November, a total of 21 confirmed and probable earthquakes occurred, most of which were centered near Columbia, Maryland, which lies approximately 20 km southwest of Baltimore (Fig. A1). All were very small earthquakes. The first instrumented and widely felt event occurred March 10, 1993, although there is some evidence that two small events occurred March 5. (The Office of Terrestrial Magnetism, Carnegie Institution of Washington, DC, announced at a meeting of the Washington Geological Society on April 14 that prior to March 10 its research seismograph detected small earthquakes of such distance from Washington that they could have originated in the Columbia area. There was also at least one credible firsthand report of two small events on March 5.) From March 5 through April 8, 1993, the community of Allview Estates (near Columbia) experienced 14 very small earthquakes (Table A1). Low-scale seismic activity continued sporadically through the end of November. None has been confirmed since November 27. The total number of small earthquakes in Howard County in 1993 now stands at 21 confirmed and/or probable, and all but two of these were apparently centered in the Allview Estates area. A single small earthquake was also reported and confirmed in March near Abingdon, Harford County, roughly 50 km northeast of Columbia. It is interesting to note that three small earthquakes occurred in 1990-1991 in the Randallstown-Granite-Hernwood area of southwestern Baltimore County, just a few kilometers north of the Columbia epicenters (Table A2, Figure A2). The largest events, mbLg 2.5 and 2.7, occurred on March 10 and 14. Other events were even smaller (0 < Mc < 2.0). Although most felt reports came from the immediate epicentral area, the overall felt area covered approximately 600 square km and followed a northwest trend for more than 55 km from Washington, DC, to Baltimore. Some very light cosmetic damage was reported near the epicenters (e.g., cracked plaster or concrete; light objects fell from shelves; bicycles fell over). However, there were no reports of structural damage, which includes things like collapsed walls and houses shifted on foundations, and there were no reports of injuries. The earthquake history of Maryland indicates small earthquakes do occasionally occur, but that there has never been a destructive earthquake centered in Maryland. The strongest Maryland earthquake for which a Richter magnitude is available was a 3.1 magnitude event in 1978 near Hancock, in western Maryland. As a rough approximation, in the Maryland area scattered minor structural damage (e.g., a cracked or toppled chimney) might occur around magnitude 4, significant structural damage would probably begin to occur at approximately a magnitude 5.0 event, and serious damage at about magnitude 6.0. The National Earthquake Hazards Reduction Program (NEHRP) categorizes the Maryland-Delaware area of the eastern United States as having the lowest earthquake hazard of any state between Georgia and Maine. The best available records indicate that Maryland has been the site of 25 small earthquakes from 1758 to 1991, about a third of which occurred in central Maryland since 1900 (Table A2, Fig. A2). The strongest earthquake in Maryland history may have been a 1939 earthquake near Phoenix, Baltimore County. A newspaper reported the quake was felt "in surrounding states." Shortly after the earthquakes began in March, seismologists from Columbia University's Lamont-Doherty Earth Observatory installed several portable seismographs to monitor seismic activity in the Columbia area. Their findings are described below and illustrated in Figure A3. In early April, they established a telephone link between their Palisades, New York, headquarters and a digital seismograph in the Columbia area, thereby enabling the scientists to obtain a more or less continuous record of seismic activity without the need to be in Columbia. However, an assortment of technical and communications problems (including being struck by lightning) have prevented the seismograph from functioning properly much of the time. Lamont-Doherty's preliminary analysis of data from the portable seismographs identified a small fault (perhaps a few hundred meters in length) lying beneath US 29 in the Allview Estates-Arrowhead area of Howard County (Fig. A3). The fault is oriented approximately northwest-southeast and dips about 45 degrees to the northeast. Movement along the fault is primarily "reverse," meaning the bedrock on the northeast side of the fault is moving "up and over" the material to the southwest (Fig. A3 inset). There also seems to be a small amount of left-lateral slippage along the fault. The fault resolution is consistent with known regional stress patterns in the earth's crust, which is essentially compression from the northeast toward the southwest in this part of North America (roughly parallel to the coastline). Field examination of the area and interviews of local residents by the Maryland Geological Survey failed to find any signs of surface rupture in the area where the fault would project to the surface, although some newly formed small cracks in interior floors and walls were observed. These were probably caused by the 2.7-magnitude earthquake on March 14. The Howard County earthquake swarm was unusual in several respects. For one thing, it marked the first time in recorded history that Maryland experienced multiple events. Previous events were known to have occurred singly or in pairs. Secondly, Lamont-Doherty seismologists noticed that the magnitudes did not display the typical log-normal distribution, in that there were no M < 0 events. And a third unusual characteristic of the Columbia earthquakes is that they were extremely shallow, with hypocenters on the order of 500 to 600 meters deep. The shallow depths were the chief, if not sole, reason why the earthquakes were so strongly felt. Based on some general similarities in geologic setting between the Columbia earthquakes and the Marticville earthquakes near Lancaster, Pennsylvania, in 1984, both the Maryland Geological Survey and seismologists from Lamont-Doherty Earth Observatory initially hypothesized that this recent spate of earthquakes might be caused by movement along a fault or faults associated with a diabase dike 2 km west of the epicenters (Figs. A2 and A3). This dike appears to continue, somewhat sporadically, northeast into Pennsylvania, where it is known as the Rockhill dike and where in 1984 a series of small earthquakes occurred near Lancaster (maximum magnitude 4.1). At this time, it is not known with certainty whether the fault in Howard County is physically related to the diabase dike, although the fault may extend to and even offset the dike. A team of four geoscientists from the Maryland Geological Survey and Millersville (Pennsylvania) State University conducted a magnetometer survey of the diabase dike that has been the center of much speculation in regard to the earthquake occurrences. The team conducted foot traverses across the dike at known, inferred, or speculated locations in several areas of Baltimore and Howard Counties. The survey should delineate the location of the dike in the area, but it is not known whether results will improve our understanding of the earthquakes. In summary, analysis of seismic data for several of the small earthquakes shows the activity occurred along a small reverse fault near the intersection of US 29 and Md Route 32. However, the cause of the movement along the fault (i.e., the cause of the earthquakes) is not known, and may never fully be known. These recent events may increase to an unknown degree the probability of a larger earthquake. The geoscientists tend to see these events as an opportunity to learn a little more about eastern U.S. seismicity, rather than a cause for alarm. It is still widely believed that Maryland is more likely to feel a "big" earthquake (e.g., magnitude 4.5-5.5 or more) that originates elsewhere in the region than it is to feel one that originates inside the State. Due to the scarcity of historical earthquake activity in the region and the absence of any detailed seismological studies in the region, one must be very careful in forecasting future seismic activity -- or the lack thereof. Figure A1. Map of eastern Howard County, showing general epicentral areas of 19 very small earthquakes at Allview Estates and 2 very small earthquakes near Ilchester. Table A1. Confirmed and Probable Earthquakes in the Columbia, Maryland, Area During 1993. Data from the Maryland Geological Survey, Delaware Geological Survey, U.S. Geological Survey National Earthquake Information Center, and Lamont-Doherty Earth Observatory. MM Intensities are preliminary and subject to change. November 28 events were not instrumented, but widely felt, and are considered probable. ------------------------------------------------------------------------ No. DATE ORIGIN TIME EPICENTER MODIFIED RICHTER MERCALLI MAGNITUDE INTENSITY ------------------------------------------------------------------------ 1 Mar 5 -- Allview Estates* I-II? approx. 1-1.4? 2 Mar 5 -- " I-II? approx. 1-1.4? 3 Mar 10 09:32 EST " II-IV 2.5 4 Mar 11 19:54 EST " II-III 2.0 5 Mar 14 23:30 EST " III-V 2.7 6 Mar 16 02:59 EST " II-III < 2 7 Mar 16 11:59 EST " II-III 1.8 8 Mar 17 06:54 EST " I-II le 1 9 Mar 19 00:50 EST " I-II approx. 1 10 Mar 19 14:26 EST " I-II < 1 11 Mar 22 05:26 EST " (no felt reports) approx. 0 12 Apr 4 13:32 EDT " I-III approx. 1.5 13 Apr 4 13:33 EDT " I-III approx. 1.5 14 Apr 8 05:10 EDT " I-II approx. 1-1.5 15 Jul 9 02:30 EDT " II-III 1.9 16 Jul 12 17:25 EDT " II-III 2.1 17 Oct 28 02:00 EDT Ilchester** IV 2.1 18 Oct 28 02:01 EDT " III-IV 1.8 19 Nov 17 11:35 EST Allview Est. II-III 1.5-1.8? 20 Nov 27 10:26 EST " I-II < 1.5 21 Nov 27 13:43 EST " I-II approx. 1.5 ------------------------------------------------------------------------ * 39.19 degrees North / 76.87 degrees West ** 39.25 degrees North / 76.77 degrees West Note: On March 21, 1993, the Delaware Geological Survey confirmed a small earthquake roughly 25 km northeast of Baltimore (approx. 39.4 degrees North / 76.3 degrees West; MM Intensity I- II; mbLg approx. 1.5). Table A2. Earthquake Chronology of Maryland, 1758-1991. (Data primarily from the U.S. Geological Survey) No. DATE APPROXIMATE LOCATION MODIFIED RICHTER (NEAREST TOWN, COUNTY) MERCALLI MAGNITUDE INTENSITY ---------------------------------------------------------------------- 1 1758 Apr 25 Annapolis, Anne Arundel Co. -- -- 2 1828 Feb 24 Bowie, Prince George's Co. -- -- 3 1876 Jan 30 Annapolis, Anne Arundel Co. -- -- 4 1876 Apr 10 Prince Frederick, Calvert Co. III -- 5 1877 Sep 01 Brandywine, Prince George's Co. III -- 6 1883 Mar 11 Fallston, Harford Co. IV -- 7 1883 Mar 12 Fallston, Harford Co. III -- 8 1902 Mar 10 Union Bridge, Carroll Co. III -- 9 1902 Mar 11 Union Bridge, Carroll Co. III -- 10 1903 Jan 01 Union Bridge, Carroll Co. III -- 11 1903 Jan 01 Union Bridge, Carroll Co. II -- 12 1906 Oct 13 Catonsville, Baltimore Co. III -- 13 1910 Jan 24 Westminster, Carroll Co. II -- 14 1910 Apr 24 Catonsville, Baltimore Co. III -- 15 1928 Oct 15 Ocean City, Worcester Co. IV -- 16 1930 Nov 01 Round Bay, Anne Arundel Co. IV -- 17 1930 Nov 01 Round Bay, Anne Arundel Co. III -- 18 1939 Jun 22 Phoenix, Baltimore Co. III -- 19 1939 Nov 18 Phoenix, Baltimore Co. IV -- 20 1939 Nov 26 Phoenix, Baltimore Co. V 3-4? 21 1962 Sep 07 Hancock, Washington Co. -- -- 22 1978 Apr 26 Hancock, Washington Co. -- 3.1 23 1990 Jan 13 Randallstown, Baltimore Co. III-V 2.5-2.6 24 1990 Apr 04 Randallstown, Baltimore Co. II 1.6-1.7 25 1991 Sep 28 Randallstown, Baltimore, Co. III 2.4 ---------------------------------------------------------------------- Figure A2. Approximate locations of diabase dikes and earthquake epicenters in central Maryland since 1900. Figure A3. Map of Allview Estates-Arrowhead area showing locations of seven epicenters (circles), projected location of fault at surface (dashed line), sites where diabase dike rock has been found (filled circles), and one possible trend of dike (solid line). Map scale 1 inch = 2,000 feet. (Source: Maryland Geological Survey and Lamont- Doherty Earth Observatory) Inset: Block diagram illustrating a reverse fault with a left-lateral component; striking to the northwest and dipping to the northeast. APPENDIX B: AUGUST 08, 1993 AIKEN, SOUTH CAROLINA EARTHQUAKE Talwani, Pradeep, Department of Geological Sciences, University of South Carolina, Columbia, SC 29208; and Donald A. Stevenson, Westinghouse Savannah River Company, Aiken, SC 29802 On August 08, 1993 at 09:24 (UTC), a felt earthquake of duration magnitude 3.2 occurred in south central South Carolina. The earthquake was located approximately 13 km east northeast of Aiken using data from stations of the South Carolina and the Savannah River Site Seismic Networks. A small aftershock occurred at 1600 (UTC) on the same day. The earthquake was widely felt (with over 100 felt reports), and awoke several residents. Felt effects included small articles falling from shelves in the epicentral area (estimated maximum MMI V). The most common description was that of an explosion. Felt reports were reported from Windsor, Montmorenci, Aiken, New Ellenton, Clearwater, Eureka and Edgefield County. The focal mechanism shows left lateral strike slip on a steeply dipping northwest striking fault plane. The epicentral location lies on the flanks of a local gravity high with the same strike, suggesting possible causal association. This event is similar in character to small events that occurred in Neeses and Jackson, South Carolina, in 1992. NOTE: The above abstract appeared in Seismological Research Letters, Vol. 64, No. 3-4, July-December, 1993, p. 264, and was presented at the 65th Annual Eastern Section-Seismological Society of America meeting in Weston, Massachusetts. Figure B1. Isoseismal map for the August 8, 1993, Aiken, South Carolina earthquake. This map was produced using phone and personal interviews of felt reports from over 125 individuals. The map was submitted by the Westinghouse Savannah River Company and is a result of a cooperative effort between them and the University of South Carolina. APPENDIX C: PROBABILISTIC SEISMIC HAZARD ANALYSIS FOR VIRGINIA Martin C. Chapman Virginia Polytechnic Institute and State University A probabilistic seismic hazard analysis has been performed on a county-by-county basis for Virginia (Chapman and Krimgold, 1994). The objective of the study is to provide a consistent representation of the hazard, organized along jurisdictional boundaries useful to regulators and planners in the state and local governments as well as the engineering community. The chief products are maps and tables depicting the 1 Hz and 3.3 Hz pseudo-relative acceleration response (5% damping) with 10% probability of exceedance in 50 and 250 years, analogous to the preliminary spectral response maps of the 1991 edition of the NEHRP recommended provisions for the development of seismic regulations for new buildings. Motions for both rock and deep soil site conditions are developed. Additionally, information necessary for the construction of simulated ground motion time series compatible with the chosen hazard level at various localities within Virginia is derived. Hazard functions were calculated for the largest population center in each Virginia county. Seismic source zones and earthquake frequency-magnitude recurrence relationships were defined on the basis of the historical record and the results of 15 years of network monitoring and several recent geological and geophysical investigations. Ground motions were computed using recently developed ground motion models for both rock and deep soil sites in the eastern United States. This hazard model is used to directly identify the magnitude-distance combination(s) compatible with the mapped oscillator response values and their associated probabilities of exceedance. This is accomplished by determining the maxima of the hazard density functions for the 1 Hz and 3.3 Hz oscillator responses at the 475 and 2375 year return period hazard levels. The "most likely" events (in terms of magnitude and distance) contributing to hazard are defined by the maxima (mode) of the density function. By providing information on duration and character of ground motion, the modal events greatly expand the utility of the hazard analysis. Figure C1 shows the hazard maps of 1.0 and 3.3 Hz PSA for a deep soil site condition, with 10% probability of exceedance during a 50 year exposure period. Reference Chapman, M. C. and F. Krimgold, 1994, Seismic hazard assessment for Virginia, report prepared for the Virginia Dept. of Emergency Services and the Federal Emergency Management Agency, Virginia Tech Seismological Observatory, Blacksburg, VA, 62 p. Figure C1. Probabilistic seismic hazard maps for Virginia. The upper plot shows the 1.0 Hz pseudo-relative acceleration response (5% damping) for a deep soil condition, expressed as a percentage of gravity, with 10% probability of exceedance in 50 years. The lower plot shows similar results for 3.3 Hz pseudo-relative acceleration response. APPENDIX D: EARTHQUAKE STRONG MOTION RECORDING IN THE SOUTHEASTERN UNITED STATES Jeffrey W. Munsey Tennessee Valley Authority The plot of earthquake strong motion recording sites shown in Figure D1 is a subset of a station listing compiled by the Tennessee Valley Authority (TVA) in 1991. The original TVA listing was included in a report for TVA's Hydro Board of Consultants to document the number and location of all types of earthquake monitors within or near the Tennessee Valley. The primary source of information for the strong motion stations was NCEER report 90-0004, "Catalog of Strong Motion Stations in Eastern North America". Most of the strong motion monitoring sites are at dams or nuclear facilities. The major operators of strong motion sites within the SEUSSN area are (1) U.S. Army Corps of Engineers, (2) U.S. Department of Energy, (3) TVA, and (4) Veterans Administration. The Veterans Administration (VA) was required to install strong motion equipment at all VA hospitals following the 1971 San Fernando earthquake. This compilation of stations is admittedly dated and very likely incomplete. It is provided for distribution in the SEUSSN bulletin with the hopes that it will be a stimulus for tracking strong motion instrumentation efforts in the southeastern United States. References Busby, R. W., 1990, Catalog of strong motion stations in eastern North America, National Center for Earthquake Engineering Research, NCEER-90-0004, 54 p. Chiu, S. C. (editor), 1990, Center for Earthquake Research and Information Quarterly Seismological Bulletin, v. XI, no. 2, Memphis State University, 40 p. Sibol, M. S., 1991, Southeastern U.S. Seismic Network Bulletin No. 25, Virginia Polytechnic Institute and State University, 60 p. Stauder, William, 1990, Central Mississippi Valley Earthquake Quarterly Bulletin No. 62, St. Louis University, 35 p. Figure D1. This map shows the location of strong motion instruments operating in the southeastern United States. APPENDIX E: DETERMINATION OF THE COEFFICIENT OF SEISMIC ATTENUATION IN FLORIDA Bellini, John J., Tony J. Bartolini, Kenneth M. Lord, and Douglas L. Smith, Department of Geology, University of Florida, Gainesville, Florida 32611 Data from the recently completed six-station University of Florida Seismic Network (UFL), as well as that from an extensive review of record archives from station GAI, have yielded preliminary models of seismic attenuation for the Florida Plateau. Based on calculations of surface particle velocity, attenuation values suggest a pattern that deviates somewhat from that established for the remainder of the eastern United States. Models using data derived from local quarry blasts and from eight seismic events occurring in the continental United States yield a coefficient of seismic attenuation (alpha) equal to 0.10 per degree. Data from 22 events originating from the Caribbean, Central America, and South America yield coefficients approaching 0.20 per degree. Both coefficients support the idea that seismic attenuation in the Florida Plateau exceeds that of the eastern United States. These results have important implications for seismic hazard assessments in Florida and may be indicative of the unique lithospheric identity of the Florida basement as an exotic terrane. NOTE: The above abstract was for a poster session presented at the National Geological Society of America Meeting in October, 1993. APPENDIX E: Errata VTSO The Monticello Reservoir event on 19 July 1988 (19:31Z) listed in SEUSSN Bulletin 23 (page 23) had a latitude of 34.334N (not 32.334N).