THE VIRGINIA TECH SEISMOLOGICAL OBSERVATORY HISTORIC/INSTRUMENTAL SOUTHEASTERN U.S. EARTHQUAKE CATALOG Updated: March, 2008 For Questions, and additional information, contact Martin Chapman phone: 540-231-5036 email: mcc@vt.edu The current (1568-2006 version) of the SUSN catalog is contained in file susn2006cat.txt. The catalog is a synthesis of the U.S. Geological Survey State Seismicity Map Series (C. W., B. G. Reagor, and S. T. Algermissen, 1984, 'United States Earthquake Data File', U. S. Geological Survey Open-File Report 84-225, 123 pp.), and the Southeastern U. S. Seismic Network catalog for events after July 1977. DATA FORMAT The first and last 10 entries from the 1993 version of the catalog, sorted for the southeastern U.S. (i.e., using the SUSN polygon) are shown below. Comparing the last ten entries with the last ten events found in SEUSSN Bulletin 27 can be instructive. The definitions of some entries (for example, magnitude "T"ype or "S"ource) follow the listing below. ------------------------------------------------------------------------------- S CC H t oo y M M M a dd p a a a M Felt t ee o g g g M Area e 12YearMoDyHrMnSe.c Lat N Lon WDepth ERH ERZ LS 1 TS 2 TS 3 TS IS (mi2) S ------------------------------------------------------------------------------- SC 16980305 32.9 N 80.0 W 83.4 HG 2.7IM 3G NC 17350308 35.5 N 76.8 W 83.4 HG SC 1754051916 32.9 N 80.0 W 83.4 HG 2.7IM 3G SC 17551100 33.4 N 79.3 W 166.8 HG 2.7IM 3G SC 17570207 32.9 N 80.0 W 83.4 HG 2.7IM 3G MD 175804250230 38.9 N 76.5 W 166.8 HG VA 177402211911 37.2 N 77.4 W 83.4 HG 4.6CM 6G 58000.G VA 2177402211945 37.2 N 77.4 W 83.4 HG 3.5IM 5G VA 21774022219 37.2 N 77.4 W 83.4 HG 3.3IM 4G VA 177503161915 37.7 N 78.8 W 166.8 HG 3.3IM 4G SC 19921112135413.832.933N 80.138W 5.7 0.4 0.6IV 1.2DV TN 19921118093707.136.078N 83.793W 5.9 1.1 4.0IV 1.1DV SC 19921121054110.532.950N 80.003W 3.8 0.8 0.6IV 1.4DV WV 19921124022650.737.457N 80.884W 12.3 0.5 1.1IV 1.2DV GA 19921211043933.334.763N 85.330W 7.4 1.1 1.8IV 1.0DV SC 19921212065331.333.295N 81.837W 10.7 1.2 1.3IV 1.2DV TN 19921214085502.035.122N 85.548W 7.4 1.0 1.7IV 1.5DV TN 19921218024455.435.357N 84.683W 20.3 1.6 1.5IV 0.8DV VA 19921225183313.936.769N 80.731W 6.5 1.0 3.3IV 2.2DV 2V TN 19921230082824.935.560N 84.393W 10.8 0.5 1.2IV 1.2DV ------------------------------------------------------------------------------- SOURCE "S" CODES FOR HYPOCENTERS, MAGNITUDES, INTENSITIES, AND FELT AREAS: B - Bollinger, 1975, Southeastern U. S. Catalog 1754-1974, E - Earth Physics Branch, Canadian catalog, G - USGS - State Seismicity Maps (Stover/Reagor et al.), I - EPRI Catalog (8 July 1986), M - Sibol, Bollinger, and Birch, BSSA, 77, pp. 1635-1654, N - Neilsen, 1982 (Stanford Data Base...), O - Nuttli, 1974, BSSA, 64, pp. 1189-1207, R - Barstow et al., 1981 (Rondout Asso.), NUREG/CR-1577, S - Street and Turcotte, 1977, BSSA, 67, pp. 599-614, T - Reinbold and Johnston (TEIC), 1986, USGS Final Rept., U - Earthquake History of the U.S./U.S. Earthquakes, V - SEUSSN Bulletins (Va. Tech Publication), W - Nuttli, et al., 1979, BSSA, 69, pp. 893-909, Y - Felt area only, value is the average of those found in G and R above, Z - Felt area only, value is the average of those found in U and R above, ? - Some discrepancy exists for the event (Follows State), HYPOCENTER CODES H - Historical Location (from intensity/felt area data), I - Instrumental Location, MAGNITUDE TYPE CODES (FOLLOWS MAGNITUDE VALUE, THAT IS, THE T IN MAGTS) B - mb from Baysian estimate (Veneziano & VanDyck, 1984), C - mb from intensity and felt area (Sibol et al., 1987) D - Md from duration or coda length, F - mb from felt area or attenuation data, I - mb from intensity data L - ML (Richter, 1958), M - mb determined from modified instruments/formuli, N - mb from Lg wave data (Nuttli, 1973), O - m3Hz (Lawson, et al., 1979 - Oklahoma earthquakes), P - mb from P wave data (Gutenberg and Richter, 1956), S - MS (Bath, 1966, Gutenberg, 1945), X - Magnitude of unknown type.