Electronic Supplement to
Semiannual Earthquake Periodicity

by Patrick H. McClellan

Table S13. Solar Semiannual (Ssa) Phase of M ≥ 4.3 Earthquakes in the New Madrid Seismic Zone from 1 January 1900 to 1 April 2014, with Notable Mainshocks back to 1800

Date Time, UTC (hh:mm:ss.sss)* Latitude (°) Longitude (°) Magnitude Phase
16 December 1811§ 08:15:99 7.7 0.462
31 October 1895§ 23:08:99 6.6 0.211
5 January 1843§ 02:45:99 6.3 0.581
27 March 1974 16:10:56.300 38.55 −90.13 5.6 0.036
18 April 2008 09:36:59.110 38.45 −87.89 5.4 0.156
9 November 1968§ 17:02:99 36 −93 5.4 0.264
3 January 1977 22:56:48.500 37.55 −89.79 5 0.579
25 March 1976 00:41:21.000 35.64 −90.33 5 0.024
10 June 1987 23:48:54.880 38.71 −87.95 4.9 0.439
26 September 1990 13:18:51.330 37.17 −89.58 4.7 0.018
18 June 2002 17:37:15.170 37.99 −87.78 4.6 0.482
29 September 1987 00:04:56.130 36.88 −89.15 4.6 0.030
27 April 1989 16:47:49.850 36.01 −89.77 4.6 0.204
4 May 1991 01:18:54.910 36.56 −89.82 4.4 0.236
13 May 1974 06:52:18.800 36.71 −89.39 4.3 0.286
13 June 1975 22:40:27.200 36.54 −89.68 4.3 0.454
29 November 1996 05:41:33.680 35.92 −89.93 4.3 0.375

* 99 denotes the time unit value is unavailable.

† Magnitude type as given in the ANSS catalog or by Dart and Volpi (2010).

‡ Phase is the fraction of the cycle elapsed between bounding equinoxes.

§ Notable mainshocks back to 1800 (Dart and Volpi, 2010).

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