BULLETIN NO 8 TABLE OF CONTENTS Page Introduction 1 Southeastern United States Seismicity 9 List of Figures 1. Seismic Stations Operating During the Period January - June 1981 2 2. South Carolina Seismic Network 3 3. Virginia Tech Seismic Network 4 4. Georgia Tech Seismic Network 5 5. Alabama Seismic Network 6 6. Report Period Epicenter Map 10 7. Earthquake Epicenters for the Period July 1977 - June 1981 11 List of Tables 1. Seismic Stations Operating During Report Period 12 2. Earthquakes Located During Report Period 15 3. Earthquakes Detected But Not Located During Report Period 27 Acknowledgments 31 Errata - Late Data 32 Appendix - Station Information Seismic Stations in Florida 41 Seismic Stations in Georgia 42 Seismic Stations in North Carolina 48 Seismic Stations in South Carolina 52 Seismic Stations in Tennessee 64 Seismic Stations in Virginia 69 Seismic Stations in West Virginia 89 Mailing List 93 INTRODUCTION This report is the eighth semi-annual BULLETIN OF SEISMICITY OF THE SOUTHEASTERN UNITED STATES. It covers the period January through June, 1981. The organizations supplying data for this BULLETIN are the Carolina Power and Light Company, the E. I. DuPont de Nemours and Company, Inc. (Savannah River Laboratory), University of Florida, Georgia Institute of Technology, NASA (Goddard Space Flight Center- Geophysics Branch), University of North Carolina, Tennessee Earthquake Information Center, Union Carbide Corporation (Nuclear Division), United States Geological Survey, Virginia Division of Mineral Resources, Virginia Polytechnic Institute and State University, Washington and Lee University and West Virginia University. Table 1 is a listing, by state, of the 95 stations operating during the period January-June, 1981. The format of the information included in the table is as follows: 1). Three or four letter station code, 2). Station latitude in decimal degrees, north, 3). Station longitude in decimal degrees, west, 4). Station elevation, meters, 5). Geographic name of station, 6). Station operator. Figure 1 is a geographic map of the entire Southeastern United States Seismic Network (SEUSSN). Figures 2, 3, 4 and 5 show the South Carolina, Virginia, Georgia and Alabama Networks, respectively. Each of these networks has station spacings too close to be shown clearly on Figure 1. Table 2 is a listing of the hypocentral parameters, phase arrival times and magnitude estimates for earthquakes that occurred in the southeastern United States during the report period. Most items in the listing are self-explanatory and all times are Coordinated Universal Time. Some entries that might require definition are: AZ= Epicenter-to-station azimuth in degrees, DIST= Epicentral distance in degrees (Deg) or kilometers (Km), DPTH= Focal depth estimate in Km; FXD indicates that the depth was held fixed during the epicentral determination, GAP= The largest sector, in degrees, where there were no observing stations (HYPO71), HOR SEMI-AXES (KM, DEG)= Lengths (km) and azimuths (deg) of principal axes (horizontal projection) of error ellipsoid (HYPOELLIPSE; J. C. Lahr, USGS Open File Report 79-431), MBN= Body wave magnitude determination using Nuttli's formulas for the Lg phase, MEUS= Body wave magnitude determination using Evernden's formula for the Pn phase, ML= Local magnitude; contact agency or group making the estimate for details on their specific procedure, MLD= Local magnitude determined from duration of vibrations, MSZ= Surface wave magnitude determined from the long period vertical seismogram, NO= Number of phases used in the hypocenter determination, Q= Solution quality of error ellipsoid based on length of largest semi-axis (HYPOELLIPSE), or Solution quality of the hypocenter (HYPO71), RES= P wave residual in seconds; observed arrival time - calculated arrival time, RMS= Root mean square error of time residuals in sec (HYPO71), VERT SEMI-AXIS (KM)= Length (km) of principal vertical axis of error ellipsoid (HYPOELLIPSE). *XXXX= Agency or group that made the hypocentral determination. Even-numbered BULLETINS have a Station Information Appendix that gives specific information on the operator, seismograph types, operating characteristics, recording formats, etc. Odd-numbered BULLETINS have an Appendix that presents the detection and location capability of the SEUSSN. SOUTHEASTERN UNITED STATES SEISMICITY Figure 6 is an epicenter map for the report period, while Figure 7 is a cumulative epicenter map for the 4 year period from July 1, 1977, through June 30, 1981. There were 54 earthquakes (-0.7 le M le 3.5) located in the southeastern United States during the first six months of 1981. Of those, 9 were felt events: 4 in North Carolina (2.8 le M le 3.5), 3 in Virginia (2.9 le M le 3.4), 1 in South Carolina (M= 2.3) and 1 in Kentucky (M= 1.5). Thus, the report period was the most seismically active six-month interval since the initiation of this BULLETIN on July 1, 1977. The 4 felt shocks in North Carolina are particularly noteworthy (there were also two additional not-felt events). It has been almost a century since a similar number of felt events were reported from that state (in 1884; see Reagor, B. G., C. W. Stover and S. T. Algermissen (1980), Seismicity Map of the State of North Carolina, U.S. Geol. Survey Misc. Field Studies, Map MF-1224.). TABLE 1 LIST OF OPERATING SEISMIC STATIONS BY STATE JANUARY - JUNE, 1981 STA LATITUDE LONGITUDE ELEVATION ID DEG. (N) DEG. (W) METERS LOCALITY OPERATOR ALABAMA BKA 33.6339 87.9690 122 KENNEDY GT-GSA HGA 34.2602 85.8464 384 COLLINSVILLE GT-GSA HVA 34.0264 86.7692 195 HANCEVILLE GT-GSA MLA 32.7055 87.6936 55 SAWYERVILLE GT-GSA OCA 34.6138 86.4352 250 OWENS CROSSROADS GT-GSA TDA 33.5417 86.0247 181 TALLADEGA GT-GSA TSA 33.2561 87.0675 180 TANNEHILL STATE PARK GT-GSA FLORIDA GAI 29.6458 82.3394 51 GAINESVILLE UFL GEORGIA AMG 32.0594 84.2177 122 AMERICUS GSW ATL 33.4333 84.3375 272 ATLANTA GIT BEV 34.0893 82.7334 158 CLARK HILL RESERVOIR GIT CDG 34.6108 84.6713 332 CARTERS DAM GIT CH5 33.7332 82.3118 114 CLARK HILL RESERVOIR GIT CH6 33.8792 82.5194 130 CLARK HILL RESERVOIR GIT CRG 34.6581 84.5781 418 CARTERS DAM GIT EP1 33.9514 82.5136 134 CLARK HILL RESERVOIR GIT ETG 33.2912 83.3507 137 WALLACE DAM NET GIT GBG 33.4994 83.2112 174 WALLACE DAM NET GIT IVA 34.2721 82.7460 168 CLARK HILL RESERVOIR GIT LDV 34.1479 82.6833 162 CLARK HILL RESERVOIR GIT REG 33.4421 83.3371 178 WALLACE DAM NET GIT RMG 34.3359 85.3160 337 ROCKY MOUNTAIN NET GIT SMG 34.3495 85.3463 314 ROCKY MOUNTAIN NET GIT TVG 34.3771 85.3023 323 ROCKY MOUNTAIN NET GIT WDG 33.3440 83.1752 177 WALLACE DAM NET GIT NORTH CAROLINA AVNC 35.624 82.531 ASHEVILLE TEIC CEH 35.8908 79.0928 152 CHAPEL HILL UNC RNC 35.63 78.98 85 RALEIGH CPL SOUTH CAROLINA BCS 32.9812 80.0717 12 BAPTIST COLLEGE USGS BOW 33.3736 80.6431 35 BOWMAN USGS CCS 32.8162 80.2553 9 CAWCAW SWAMP USGS CHF 34.0247 82.5867 152 CALHOUN FALLS USGS COW 33.3842 80.7008 33 COW CASTLE CREEK USGS HBF 32.9330 80.3780 10 HARTS BLUFF USGS JSC 34.2790 81.2580 120 JENKINSVILLE USGS LHS 34.4790 80.8080 120 LIBERTY HILL USGS MGS 32.8970 80.1408 9 MIDDLETON GARDENS USGS MTT 33.7513 81.6362 182 MONETTA USGS MR01 34.3319 81.2957 131 MONTICELLO RESERVOIR SCEG MR02 34.1930 81.2301 84 MONTICELLO RESERVOIR SCEG MR03 34.3514 81.4569 125 MONTICELLO RESERVOIR SCEG MR04 34.4287 81.2166 145 MONTICELLO RESERVOIR SCEG MR05 34.2675 81.3342 103 MONTICELLO RESERVOIR SCEG MR06 34.3517 81.1962 137 MONTICELLO RESERVOIR SCEG MR07 34.3705 81.3250 134 MONTICELLO RESERVOIR SCEG MR08 34.4088 81.4092 112 MONTICELLO RESERVOIR SCEG MR09 34.3008 81.4030 122 MONTICELLO RESERVOIR SCEG MR10 34.3363 81.3375 137 MONTICELLO RESERVOIR SCEG NHS 33.0720 79.7560 10 NORTH HAMPDEN USGS 0SB 33.5472 80.8444 91 ORANGEBURG USGS PBS 33.2790 80.2640 25 PIGEON BAY USGS PPS 32.8237 80.0400 4 PIERPONT USGS PRM 34.0833 82.3633 254 PARSONS MOUNTAIN USGS ROW 33.3650 80.7944 35 ROWESVILLE USGS SGS 33.1930 80.5120 25 ST GEORGE USGS SRPD 33.1550 81.7125 31 SAVANNAH RIVER LAB DUP SRPN 33.3290 81.5888 95 SAVANNAH RIVER LAB DUP SRPW 33.2023 81.5782 77 SAVANNAH RIVER LAB DUP SVS 32.9688 80.2487 3 SLANDSVILLE USGS VSC 32.8792 81.0500 30 VARNEVILLE USGS WMS 33.4358 80.7408 34 W MIDDLE SCHOOL USGS ZIN 33.1072 80.1628 30 MT ZION CHURCH USGS TENNESSEE HPK 35.926 83.879 305 KNOXVILLE GIT/TEIC HWR 35.758 83.938 311 MARYVILLE TEIC LGAR 34.6514 90.6581 107 LA GRANGE TEIC* ORT 35.9095 84.3048 370 OAK RIDGE UCC PGM 34.4667 90.1167 TEIC* SFTN 35.3575 90.0188 -23 SHELBY FOREST TEIC* TKL 35.6582 83.7744 355 TUCKALEECHEE CAVERNS TEIC *In easternmost Tennessee near New Madrid, Missouri - not in southeastern United States VIRGINIA BAV 37.2220 80.4250 622 BLACKSBURG VPI BLA 37.2114 80.4211 634 BLACKSBURG VPI BV1 38.1781 79.6611 768 BATH COUNTY VPI BV2 38.1367 79.9194 610 BATH COUNTY VPI BV3 38.2383 79.7667 750 BATH COUNTY VPI CBN 38.2050 77.3733 70 CORBIN USGS CNV 38.2050 77.3733 70 CORBIN VPI CVL 37.9813 78.4608 167 CHARLOTTESVILLE VPI CVV 37.9814 78.4608 167 CHARLOTTESVILLE DMR FRV 37.2030 78.3593 216 FARMVILLE VPI FTV 38.8661 78.1688 341 FRONT ROYAL DMR GHV 37.7942 78.1073 107 GOOCHLAND VPI LEX 37.7894 79.4417 311 LEXINGTON WAL NAV 37.3167 80.7931 610 NARROWS VPI NA2 38.1270 77.7470 82 NORTH ANNA VPI NA5 37.9930 77.7470 76 NORTH ANNA VPI NA11 37.9830 77.6850 84 NORTH ANNA VPI NA12 37.9830 77.8795 125 NORTH ANNA VPI PBV 36.9823 77.5312 49 PETERSBURG VPI PUV 37.0235 80.8158 652 PULASKI VPI VBV 36.7853 76.1080 5 VIRGINIA BEACH TCC WEST VIRGINIA BV4 38.3572 79.8278 814 POCAHONTAS COUNTY VPI GBV 38.4321 79.8453 802 GREEN BANK NASA HWV 37.5905 80.8408 521 HINTON VPI MRG 39.6331 79.9544 281 MORGANTOWN WVU PWV 37.3348 81.0488 820 PRINCETON VPI OPERATOR CODE CPL - Carolina Power and Light Company DMR - Virginia Division of Mineral Resources DUP - E. I. DuPont de Nemours and Company, Inc. GIT - Georgia Institute of Technology GSA - Geological Survey of Alabama GSW - Georgia Southwestern College NASA - NASA/Goddard Space Flight Center SCEG - South Carolina Electric and Gas Company TCC - Tidewater Community College (Va) TEIC - Tennessee Earthquake Information Center UCC - Union Carbide Corporation UFL - University of Florida UNC - University of North Carolina USGS - United States Geological Survey VPI - Virginia Tech WAL - Washington and Lee University WVU - West Virginia University TABLE 2 LIST OF LOCATED SOUTHEASTERN UNITED STATES EARTHQUAKES FOR THE TIME PERIOD 1 JANUARY 1981 THROUGH 30 JUNE 1981 3 FEBRUARY 1981 TELLICO PLAINS, TENNESSEE ML= 2 (GIT) *GIT LAT= 35.449N LONG= 84.828W H= 14-26-46.9 DPTH= 0.0, FXD STA PHASE TIME STA PHASE TIME BEV PN 14-27-24.5 IVA PN 14-27-22.8 SN 27-50.0 SV 27-46.9 TVG PN 27-10.0 RMG PN 27-10.9 SN 27-24.1 SN 27-25.9 REG PN 27-28.0 ETG PN 27-30.5 SN 27-55.7 SN 27-58.2 GBG PN 27-27.6 TKL PN 27-03.5 SN 27-54.6 SN 27-13.4 ORT PG 27-02.0 CH5 PN 27-34.5 S 27-10.5 SN 28-06.8 Additional Data STA PHASE TIME PWLA EPN 14-27-38.5 ESN 28-14.2 IS 28-16.6 ILG 28-18.4 21 FEBRUARY 1981 BOWMAN, SOUTH CAROLINA MLD= 2.0 *USGS LAT= 33.604N LONG= 81.171W H= 04-48-26.5 DPTH= 1.0, FXD (NO= 13, RMS RES= 0.13 SEC, GAP= 156 DEG, ERH= 1.0 KM, ERZ= 4.3 KM, Q= C) (HYPOELLIPSE SEMI-AXES (LENGTH IN KM, AZIMUTH IN DEG): HORIZONTAL IS 0.5, -57; 1.0, 33 AND VERTICAL IS 4.3 KM. QUALITY= B) STA PHASE TIME DIST (KM) AZ (DEG) RES (SEC) OSB IPC 04-48-32.35 31.0 102 0.27 ES 48-36.00 0.07 ROW IPD 48-34.61 43.9 127 -0.13 WMS IPC 48-34.57 44.6 116 -0.09 ES 48-39.80 -0.50 MTT EP 48-34.70 46.1 291 0.07 ES 48-40.20 -0.05 COW EP 48-35.60 50.0 119 -0.11 ES 48-42.30 0.23 BOW EP 48-36.35 55.3 118 -0.17 JSC IPC 48-39.60 75.3 354 -0.02 ES 48-48.70 0.02 SGS EP 48-40.40 76.4 127 0.45X VSC EP 48-38.55 81.2 172 -2.06X ES 48-46.50 -3.85X LHS EP 48-44.00 102.7 19 0.02 ES 48-55.90 -0.15 HBF EP 48-44.75 104.8 135 0.28 ES 48-57.10 0.21 PRM IPC 48-47.30 122.5 296 0.03 ES 49-01.70 0.09 CHF EP 48-50.10 139.1 290 0.30 ES 49-06.20 0.30 STA PHASE TIME MLD SRPN IP 04-48-35.1 2.4 (SRPN) S 48-40.6 SRPW IP 48-36.8 S 48-43.8 TKL EP 49-20.4 2.2 (TEIC) ES 49-57.2 19 MARCH 1981 MIDDLETON PLACE, SOUTH CAROLINA MLD= 2.3 (USGS) *USGS LAT= 32.960N LONG= 80.188W H= 04-33-55.4 DPTH= 5.9 KM (NO= 16, RMS RES= 0.16 SEC, GAP= 70 DEG, ERH= 1.2 KM, ERZ= 2.4 KM, Q= B) (HYPOELLIPSE SEMI-AXES (LENGTH IN KM, AZIMUTH IN DEG): HORIZONTAL IS 0.8, -47; 1.2, 43 AND VERTICAL IS 2.4 KM. QUALITY= A) (FELT IN THE SUMMERVILLE AREA) STA PHASE TIME DIST (KM) AZ (DEG) RES (SEC) SVS IPC 40-33-56.90 5.8 280 0.15 MGS IPD 33-57.06 8.3 148 0.10 ES 33-57.80 -0.34 BCS IPD 33-57.45 11.1 78 0.00 ES 33-58.26 -0.74 AIN IPD 33-58.39 16.5 8 0.12 ES 33-59.83 -0.60 CCS IPC 33-58.50 17.2 202 0.12 HBF IPD 33-57.98 18.1 260 -0.04 PPS IPC 33-58.95 20.5 138 0.04 ES 34-01.45 -0.09 SGS IPC 34-02.16 39.8 310 -0.03 BOW IPC 34-05.95 62.5 317 0.09 COW IPC 34-06.50 67.1 314 -0.02 ROW IPD 34-07.30 72.2 308 -0.02 ES 34-16.80 0.59 OSB IPC 34-09.75 89.3 317 -0.43 MTT EP 34-21.35 160.8 303 0.54 JSC EP 34-24.10 176.8 326 1.55 ES 34-43.35 0.55 PRM EP 34-31.25 237.5 302 1.33 ES 35-00.40 4.74 Additional Data STA PHASE TIME MLD SRPN IP 04-34-17.8 2.3 (SRPN) S 34-33.1 BEV P 34-36.0 S 35-04.0 REG SLG 35-11.9 GBG SLG 35-15.4 ETG SLG 35-17.5 4 MARCH 1981 ASHEBORO, NORTH CAROLINA MBN= 2.8 (VPI) *CPL PRELIMINARY LOCATION: 35.8N-79.7W (SEE PAGE 30) FELT IN ASHEBORO LOCALE 26 MARCH 1981 MIDDLETON PLACE, SOUTH CAROLINA MLD= 1.4 (USGS) *USGS LAT= 32.975N LONG= 80.217W H= 09-12-50.9 DPTH= 9.8 KM (NO= 7, RMS RES= 0.15 SEC, GAP= 173 DEG, ERH= 2.9 KM, ERZ= 4.8 KM, Q= C) (HYPOELLIPSE SEMI-AXES (LENGTH IN KM, AZIMUTH IN DEG): HORIZONTAL IS 1.6, 31; 2.9, -59 AND VERTICAL IS 4.8. QUALITY= B) STA PHASE TIME DIST (KM) AZ (DEG) RES (SEC) SVS IPC 09-12-52.40 3.1 257 -0.17 ES 12-52.80 -1.04 AIN IPC 12-54.00 15.5 19 0.11 ES 12-56.20 0.06 HBF IPD 12-53.68 15.8 253 0.24 ES 12-55.40 0.05 CCS EP 12-54.20 18.0 192 -0.05 ES 12-56.00 -0.78 SGS EP 12-57.10 36.7 311 -0.18 2 APRIL 1981 SOUTHEAST TENNESSEE ML= 2.1 (GIT), MLD= 2.6 (TEIC) *GIT LAT= 35.407N LONG= 84.711W H= 06-32-37.9 DPTH= 6.5 KM STA PHASE TIME STA PHASE TIME BEV PN 06-33-13.9 RMG PN 06-33-01.1 SV 33-38.0 SV 33-16.1 LDV PN 33-13.6 GBG PN 33-16.9 SN 33-37.9 SV 33-43.4 WDG PN 33-18.1 TKL PLG 32-52.2 SN 33-48.3 SLG 33-01.1 HPK PLG 32-54.5 ORT PLG 32-51.1 SLG 33-04.0 SLG 32-59.7 -17- HWR PLG 32-51.3 REG PN 33-16.7 SLG 33-00.2 SN 33-44.5 EP1 PN 33-17.0 TVG PN 33-00.1 SN 33-44.9 SN 33-15.0 SMG PN 33-01.0 SN 33-16.3 NOTE: The provisional hypocenter for this shock from the TEIC using arrival-time data from six stations (ORT, HWK, TKL, HPK, AVNC, PWLA) is: LAT= 35.43N, LONG= 84.38W, H= 06-32-40.9, MLD= 2.6, DPTH= 3 KM, FXD, RMS= 0.6 SEC, GAP= 179 DEG Additional Data STA PHASE TIME HWK EP 06-32-51.5 ES 33-00.0 AVNC EP 33-08.8 ES 33-29.7 PWLA IP 33-31.0 ES 34-09.8 9 APRIL 1981 UNION MILLS, NORTH CAROLINA MBN= 3.0 (USGS), MLD= 3.1 (SRPN) *USGS LAT= 35.476N LONG= 82.073W H= 07-10-31.5 DPTH= 5.0 KM, FXD (STD DEV RES= 0.6 SEC (14 STA)) (FELT (IV) AT FOREST CITY, OLD FORT, MARION, MILL SPRING, SPINDALE AND UNION MILLS. ALSO FELT AT DYSORTVILLE, GLENWOOD AND SUGAR HILL) STA PHASE TIME DIST (DEG) AZ (DEG) RES (SEC) AVNC IP 07-10-39.5 0.4 292 0.0 IS 10-43.9 JSC EP 10-57.3 1.4 150 0.1 LHS PN 10-57.8 1.4 133 -0.4 S 11-17.9 PRM PN 10-58.0 1.4 190 0.2 TKL IP 10-57.4 1.4 278 -0.3 IS 11-16.0 ORT EP 11-05.3 1.9 284 0.9 S 11-29.8 PUV IPD 11-04.1 1.9 33 0.0 ES 11-28.2 PWV EP 11-07.2 2.0 24 0.4 ES 11-33.6 NAV EP 11-07.5 2.1 29 -0.4 ES 11-35.4 BLA EPN 11-09.7 2.2 37 0.7 PG 11-13.0 ES 11-40.4 HWV EP 11-11.1 2.3 25 0.0 ES 11-43.5 CEH EP 11-13.2 2.5 80 0.0 BV2 PN 11-22.0 3.2 32 -0.9 PG 11-25.6 ES 12-06.8 BV3 EP 11-22.0 3.3 33 -3.2X ES 12-11.7 BV4 EP 11-29.6 3.4 31 3.4X ES 12-12.8 FRV EP 11-33.8 3.5 59 6.7X ES 12-16.8 GHV EP 11-35.6 3.9 53 1.7X ES 12-30.8 PWLA IP 11-47.3 4.9 266 -0.7 ES 13-03.2 NOTES: The Tennessee Earthquake Information Center has issued a SPECIAL REPORT #4 on this and the May 5, North Carolina earthquakes. The Georgia Institute of Technology's epicenter for this event from their network data (listed below) is: 35.441N, 82.090W, H= 07-10-32.3, DPTH= 0.0 KM, FXD, MD= 2.6. Additional Data STA PHASE TIME STA PHASE TIME CH5 PLG 07-11-03.8 BEV PLG 07-10-59.1 SLG 11-27.5 SLG 11-19.0 EP1 PLG 11-00.4 LDV PLG 10-58.0 SLG 11-21.5 SLG 11-17.4 REG PLG 11-13.1 WDG PLG 11-14.2 SLG 11-42.3 SLG 11-43.2 ETG PLG 11-14.8 GBG PLG 11-12.6 SLG 11-46.4 SLG 11-40.1 TVG PLG 11-25.1 CRG PLG 11-15.5 SLG 12-00.9 SLG 11-41.8 RMG PLG 11-24.9 SRPN EP 11-08.6 SLG 12-01.2 S 11-33.2 SRPW EP 11-13.1 SRPD EP 11-13.7 S 11-36.3 S 11-43.8 LEX ES 12-00.0 3 MAY 1981 MIDDLETON PLACE, SOUTH CAROLINA MLD= 1.0 (USGS) *USGS LAT= 32.976N LONG= 80.248W H= 04-05-39.5 DPTH= 13.0 KM (NO= 4, RMS RES= 0.15 SEC, GAP= 360 DEG, ERH= 99.0, ERZ= 27.4, Q= D) (HYPOELLIPSE SEMI-AXES (LENGTH IN KM, AZIMUTH IN DEG): HORIZONTAL IS 4.4, 2; 99, -88, VERTICAL IS 27.4. QUALITY= D) STA PHASE TIME DIST (KM) AZ (DEG) RES (SEC) SVS IPD 04-05-41.80 0.9 182 0.14 ES 05-43.10 -0.16 CCS IPC 05-43.00 17.8 182 -0.14 ES 05-46.00 0.16 5 MAY 1981 HENDERSONVILLE, NORTH CAROLINA MBN= 3.5 (BLA), MLD= 2.8 (SRPN) *USGS LAT= 35.290N LONG= 82.476W H= 21-21-56.4 DPTH= 5.0 KM, FXD (STD DEV RES= 0.5 SEC (15 STA)) (FELT (V) IN PARTS OF BUNCOMBE, HENDERSON AND TRANSYLVANIA COUNTIES, NORTH CAROLINA. ALSO FELT IN THE GREENVILLE-SPARTANSBURG AREA OF SOUTH CAROLINA) STA PHASE TIME DIST (DEG) AZ (DEG) RES (SEC) AVNC IP 21-22-02.9 0.3 352 -0.3 ES 22-07.3 TKL IP 22-17.4 1.1 290 -0.5 ES 22-32.5 PRM IP 22-19.4 1.2 176 0.0 JSC IP 22-23.0 1.4 135 0.1 ORT EP 22-25.9 1.6 293 0.2 S 22-47.0 PUV P 22-34.43 2.2 37 0.3 PWV P 22-36.85 2.3 29 0.6 NAV P 22-37.93 2.4 33 0.3 BLA IPN 22-39.20 2.5 40 0.2 IPG 22-43.10 IS 23-14.50 HWV P 22-41.04 2.6 29 0.5 RNC IP 22-42.95 2.9 82 -0.8 BV3 P 22-54.30 3.7 36 -0.7 PG 23-46.30 ES 24-47.80 CVL P 23-03.10 4.2 49 0.6 S 24-06.80 PWLA P 23-08.4 4.6 268 0.3 S 24-16.8 NOTES: The Tennessee Earthquake Information Center has issued a SPECIAL REPORT #4 on this and the April 9, North Carolina earthquakes. The Georgia Institute of Technology's epicenter for this event from their network data (listed below) is: 35.398N, 82.352W, H= 21-21-52.5, DPTH= 0.0 KM, FXD. Additional Data STA PHASE TIME STA PHASE TIME BEV PLG 21-22-20.0 IVA PLG 21-22-16.5 SLG 22-36.8 SLG 22-28.9 LDV PLG 22-18.6 WDG PLG 22-31.8 SLG 22-33.9 SLG 22-55.8 GBG PLG 22-32.8 ETG PLG 22-34.9 SLG 22-54.6 SLG 23-01.6 EP1 PLG 22-21.2 TVG PLG 22-42.6 SLG 22-39.1 SLG 23-14.1 AVN PN 22-02.9 TKL PLG 22-17.4 SN 22-07.3 SLG 22-32.5 ORT PLG 22-26.0 HPK PLG 22-21.1 SLG 22-47.0 SLG 22-38.0 PWL PLG 23-08.4 SRPN EP 22-32.6 SRPD EP 22-37.3 S 22-47.5 S 22-55.5 7 MAY 1981 CULLMAN, ALABAMA MLD= 2.1 (TEIC) *GIT LAT= 34.227N LONG= 86.745W H= 09-58-44.0 DPTH= 0.0 KM, FXD STA PHASE TIME STA PHASE TIME TVG PLG 09-59-06.6 TSA PLG 09-59-03.0 SLG 59-22.8 SLG 59-16.5 PWL PLG 59-08.9 SLG 59-26.5 Additional Data STA PHASE TIME PWLA IP 09-59-08.7 ES 59-22.0 TKL E(P) 59-37.2 ES 10-00-10.3 8 JUNE 1981 MIDDLETON PLACE, SOUTH CAROLINA MLD= 1.2 (USGS) *USGS LAT= 32.924N LONG= 80.156W H= 05-10-46.7 DPTH= 3 KM, FXD (NO= 6, RMS RES= 0.17 SEC, GAP= 194 DEG, ERH= 14.4 KM, ERZ= 16.7 KM, Q= D) (HYPOELLIPSE SEMI-AXES (LENGTH IN KM, AZIMUTH IN DEG): HORIZONTAL IS 0.8, 41; 14.4, -49 AND VERTICAL IS 16.7 KM. QUALITY= D) STA PHASE TIME DIST (KM) AZ (DEG) RES (SEC) MGS IP 05-10-46.4 3.4 154 0.07 ES 10-46.8 -0.03 BCS IP 10-47.5 10.1 51 0.07 ES 10-48.5 -0.24 CCS IP 10-48.4 15.2 218 0.17 ES 10-49.8 -0.35 NOTE: Another event at 07-14 on this date was recorded by the MGS station only; MLD= 0.6. Following is a listing of earthquakes that occurred in the vicinity of two reservoirs as reported by the Georgia Institute of Technology. CLARK HILL RESERVOIR AREA DATE (YR-MO-DAY) ORIGIN MLD 810310 01-21-29.6 0.0 810310 05-07-03.6 0.0 810312 07-49-51.3 0.0 810509 06-25-15.2 0.0 810513 17-42-38.3 -0.3 810522 21-45-43.4 -0.2 810529 18-27-55.5 -0.3 810529 20-54-41.5 -0.3 NOTE: All events are within 2 km of the EP1 location (33.9514N, 82.5136W). LAKE SINCLAIR AREA 810404 09-19-38.3 2.5 NOTE: This event was located at 33.2533N, 83.2105W. Following is a listing of Piedmont (non-Charleston seismic zone) South Carolina events from January-June 1981 reported by the United States Geological Survey, South Carolina Network. These events were located using HYPO71 and many of them occur near reservoirs in the state. Some may be blasts. A full report will be issued by the USGS at a later date. (A paper "Results of Recent South Carolina Seismological Studies" by A. Tarr, P. Talwani, S. Rhea, D. Carver and D. Amick is scheduled to appear in the December, 1981, issue of the Bulletin of the Seismological Society of America.) ORIGIN TIME LAT LONG ERH DPTH ERZ RMS (MO-DAY HR-MIN-SEC) (N DEG) (W DEG) (KM) (KM) (KM) MLD (SEC) Q 01 14 17-06-41.9 33.876 82.508 21 5.0 106 2.0 0.12 D 01 19 19-01-39.5 34.281 82.166 30.7 1.4 0.32 D 02 07 17-51-32.0 34.026 82.569 1.8 1.4 1.8 2.1 0.33 C 02 18 20-02-02.5 34.134 82.093 0.1 5.0 1.1 2.1 0.01 C 03 12 17-32-09.4 34.541 82.365 5.0 2.0 0.16 C 03 25 22-23-06.2 34.158 82.612 5.0 1.7 0.08 C 04 08 20-24-09.3 33.729 82.270 28.6 2.2 0.21 C 04 09 07-10-34.7 35.316 81.996 7.2 5.0 6.6 2.8 0.30 D 04 09 12-02-53.8 34.232 81.797 5.0 2.4 0.00 C 04 12 13-07-30.6 34.281 81.349 8.4 2.1 0.54 D 05 19 09-46-11.3 35.174 82.127 5.6 2.3 0.58 D 06 16 12-19-20.4 34.026 82.517 5.0 1.9 0.02 C 06 19 20-01-06.6 34.281 81.145 22.1 1.8 0.44 D Additional Data (May 19) STA PHASE TIME STA PHASE TIME LDV PLG 09-46-35.0 BEV PLG 09-46-36.0 SLG 46-43.0 SLG 46-44.0 GBG PLG 46-48.0 ETG PLG 46-53.0 SLG 47-05.0 SLG 47-12.5 CH6 PLG 46-35.2 EP1 PLG 46-34.4 SLG 46-43.8 SLG 46-42.1 CH5 PLG 46-35.3 SLG 46-44.6 NOTE: The GIT epicenter using the above arrival time is: LAT= 34.311N, LONG= 82.034W, H= 09-46-24.2, DPTH= 0.0 KM, FXD. Additional Data (April 9, 12-02-53.8) STA PHASE TIME STA PHASE TIME EP1 PLG 12-03-06.1 CH5 PLG 12-03-09.4 SLG 03-26.7 SLG 03-31.6 BEV PLG 03-05.0 LDV PLG 03-04.1 SLG 03-24.5 SLG 03-22.1 Following is a listing of hypocenters for events located in the southeastern United States region (east of longitude 88 deg W) by the Tennessee Earthquake Information Center during the period April-June, 1981. These data appear in complete detail in the TEIC PRELIMINARY SEISMOLOGICAL BULLETIN, APRIL-JUNE 1981, Volume II, Numbers 1, 2, 4. DATE AZI 1981 ORIGIN LAT LONG DPTH ST/PH GAP RMS (MO-DAY) TIME (