Hi Todd. You have some thought provoking questions there. Using a center of 33.849N/116.796W (15 miles west of Palm Springs) and a radius of 200 miles I found some interesting quake patterns.

The first set of quakes are all quakes M>6.0 and larger that occurred inside that 200-mile radius. I used only the quakes that were larger then M>7.0 for the short lists (one year, or there about) except for the quake that occurred in 1992. The events leading up to that quake were different then the events prior to the other quakes.

As you can see there are some differences in the number of quakes leading to the main event. Enough so in my opinion that what might be true for one area may not be true for another area. What was seen for one quake may not be seen for another quake.

Something I learned about statistics a long time is that they mean only what the person with the statistics wants them to mean. Take Care…Don in creepy town

catalog=ANSS
start_time=1898/01/01,00:00:00
end_time=2004/08/29,12:52:11
minimum_magnitude=6.0
maximum_magnitude=10
event_type=E
delta=0 km to 320 km from (33.849,-116.796)
Date Time Lat Lon Depth Mag Magt Nst Gap Clo RMS SRC Event ID
----------------------------------------------------------------------------------------------
1933/03/11 01:54:07.80 33.6167 -117.9667 0.00 6.40 ML 0 0.00 CI š�
1934/12/30 13:52:00.00 32.2500 -115.5000 0.00 6.50 ML 0 0.00 CI š�
1934/12/31 18:45:00.00 32.0000 -114.7500 0.00 7.10 ML 0 0.00 CI š�
1935/02/24 01:45:00.00 31.9833 -115.2000 0.00 6.00 ML 0 0.00 CI 0
1937/03/25 16:49:01.83 33.4085 -116.2615 10.00 6.00 ML 0 0.00 CI 0
1940/05/19 04:36:40.90 32.7333 -115.5000 0.00 6.70 ML 0 0.00 CI 0
1940/12/07 22:16:27.00 31.6667 -115.0833 0.00 6.00 ML 0 0.00 CI 0
1942/10/21 16:22:13.00 32.9667 -116.0000 0.00 6.60 ML 0 0.00 CI 0
1946/03/15 13:49:35.90 35.7252 -118.0547 22.00 6.00 ML 0 0.00 CI 0
1947/04/10 15:58:06.00 34.9833 -116.5500 0.00 6.50 ML 0 0.00 CI 0
1948/12/04 23:43:17.00 33.9333 -116.3833 0.00 6.00 ML 0 0.00 CI 0
1952/07/21 11:52:14.00 35.0000 -119.0167 0.00 7.50 ML 0 0.00 CI 0
1952/07/21 12:05:31.00 35.0000 -119.0000 0.00 6.40 ML 0 0.00 CI 0
1952/07/23 00:38:32.00 35.3667 -118.5833 0.00 6.10 ML 0 0.00 CI 0
1952/07/29 07:03:47.00 35.3833 -118.8500 0.00 6.10 ML 0 0.00 CI 0
1954/03/19 09:54:29.00 33.2833 -116.1833 0.00 6.40 ML 0 0.00 CI 0
1954/10/24 09:44:08.00 31.5000 -116.0000 0.00 6.00 ML 0 0.00 CI 0
1954/11/12 12:26:47.00 31.5000 -116.0000 0.00 6.30 ML 0 0.00 CI 0
1956/02/09 14:32:38.00 31.7500 -115.9167 0.00 6.80 ML 0 0.00 CI 0
1956/02/09 15:24:26.00 31.7500 -115.9167 0.00 6.10 ML 0 0.00 CI 0
1956/02/14 18:33:34.00 31.5000 -115.5000 0.00 6.30 ML 0 0.00 CI 0
1956/02/15 01:20:38.00 31.5000 -115.5000 0.00 6.40 ML 0 0.00 CI 0
1966/08/07 17:36:26.70 31.8000 -114.5000 0.00 6.30 ML 0 0.00 CI 0
1968/04/09 02:28:59.06 33.1900 -116.1287 11.10 6.50 ML 0 0.00 CI 0
1971/02/09 14:00:41.83 34.4112 -118.4007 8.40 6.60 ML 0 0.00 CI 0
1979/10/15 23:16:53.44 32.6137 -115.3182 12.28 6.40 Mc 0 0.00 CI 0
1980/06/09 03:28:19.37 32.1853 -115.0758 5.00 6.10 Mc 0 0.00 CI 0
1987/11/24 01:54:14.66 33.0900 -115.7925 10.81 6.20 Mc 46 0.32 CI 134894
1987/11/24 13:15:56.71 33.0145 -115.8517 11.18 6.60 Mc 71 0.39 CI 628016
1992/04/23 04:50:23.22 33.9612 -116.3175 12.38 6.10 Mc 151 0.27 CI 3019681
1992/06/28 11:57:34.13 34.2002 -116.4367 0.97 7.30 Mc 109 0.19 CI 3031111
1992/06/28 15:05:30.72 34.2033 -116.8268 5.21 6.40 Mc 37 0.22 CI 3031425
1994/01/17 12:30:55.39 34.2130 -118.5370 18.39 6.60 Mw 195 0.31 CI 3144585
1999/10/16 09:46:44.13 34.5940 -116.2710 0.02 7.10 Mw 55 0.16 CI 9108652
-------------------------------------------------------------------------------

1933/10/14 20:03:23.00 32.0000 -115.0000 0.00 3.70 ML 0 0.00 CI 0
1934/04/02 07:01:00.00 32.0000 -115.0000 0.00 3.50 ML 0 0.00 CI 0
1934/04/03 17:53:00.00 32.0000 -115.0000 0.00 4.00 ML 0 0.00 CI 0
1934/04/21 01:20:00.00 32.0000 -115.0000 0.00 3.50 ML 0 0.00 CI 0
1934/07/17 11:38:00.00 32.0000 -115.0000 0.00 4.00 ML 0 0.00 CI 0
1934/12/31 18:45:00.00 32.0000 -114.7500 0.00 7.10 ML 0 0.00 CI 0

1951/11/17 04:20:28.00 34.9167 -119.0333 0.00 3.40 ML 0 0.00 CI 0
1951/12/15 05:41:59.00 35.2500 -119.1167 0.00 3.40 ML 0 0.00 CI 0
1951/12/28 08:23:57.00 34.9667 -118.6333 0.00 3.10 ML 0 0.00 CI 0
1952/03/15 06:44:47.00 34.8167 -119.0667 0.00 3.00 ML 0 0.00 CI 0
1952/07/21 09:43:03.00 35.0000 -119.0833 0.00 3.10 ML 0 0.00 CI 0
1952/07/21 11:52:14.00 35.0000 -119.0167 0.00 7.50 ML 0 0.00 CI 0

1986/02/17 02:12:33.48 34.1157 -116.0298 11.28 4.00 Mc 72 0.36 CI 116008
1986/07/08 09:20:44.56 33.9992 -116.6085 10.35 5.60 Mc 162 0.09 CI 700917
1986/07/08 09:24:12.79 34.0317 -116.6542 9.12 4.40 Mc 13 0.04 CI 700919
1986/07/08 09:28:13.75 33.9503 -116.5328 17.77 4.00 Mc 11 0.20 CI 127338
1986/07/08 10:09:02.90 33.9772 -116.5790 8.07 4.40 Mc 113 0.10 CI 700934
1986/07/08 10:11:00.17 34.0228 -116.6697 3.92 4.10 Mc 56 0.15 CI 700935
1986/07/08 10:22:39.43 34.0282 -116.6267 10.91 4.40 Mc 27 0.08 CI 748481
1986/07/08 19:36:20.08 34.0163 -116.6145 11.68 4.00 Mc 90 0.09 CI 701105
1986/07/09 00:12:32.14 33.9758 -116.5673 8.70 4.20 Mc 113 0.10 CI 701181
1986/07/12 05:45:27.51 33.9857 -116.6520 6.63 4.00 Mc 103 0.13 CI 701985
1986/07/17 20:35:14.97 33.9890 -116.6473 6.65 4.60 Mc 112 0.10 CI 702983
1986/07/17 21:54:45.14 33.9930 -116.6473 7.26 4.40 Mc 145 0.11 CI 702997
1986/08/29 07:46:54.48 33.9545 -116.5985 5.33 4.00 Mc 89 0.09 CI 606616
1986/10/15 02:28:47.76 33.9482 -116.5768 6.58 4.10 Mc 80 0.09 CI 710934
1988/12/16 05:53:05.00 33.9788 -116.6813 8.12 4.90 Mc 169 0.11 CI 651401
1992/04/23 02:25:29.87 33.9562 -116.3175 11.53 4.60 Mc 121 0.23 CI 2047709
1992/04/23 04:50:23.22 33.9612 -116.3175 12.38 6.10 Mc 151 0.27 CI 3019681
1992/04/23 05:10:10.39 34.0098 -116.3242 3.04 4.30 Mc 112 0.25 CI 2047719
1992/04/23 05:10:28.09 33.9577 -116.3297 3.18 4.40 Mc 32 0.17 CI 3027826
1992/04/23 11:32:33.22 33.9710 -116.3217 0.84 4.00 Mc 16 0.19 CI 3122460
1992/04/24 12:36:05.74 33.9460 -116.3790 10.00 4.20 Mb 28 0.94 NEI 199204244040
1992/05/02 12:46:41.42 33.9893 -116.2868 3.97 4.10 Mc 85 0.20 CI 2050243
1992/05/04 01:16:02.56 33.9393 -116.3408 5.80 4.10 Mc 96 0.21 CI 2050538
1992/05/04 16:19:49.72 33.9412 -116.3042 12.41 4.80 Mc 105 0.22 CI 2050647
1992/05/06 02:38:43.35 33.9427 -116.3145 6.85 4.70 Mc 124 0.23 CI 2050937
1992/05/12 02:31:11.01 33.9815 -116.2597 6.65 4.50 Mc 96 0.22 CI 2051863
1992/05/12 02:31:27.94 33.9795 -116.2592 0.21 4.40 Mc 23 0.28 CI 3024922
1992/05/12 02:32:52.54 33.9848 -116.2582 4.89 4.00 Mc 54 0.22 CI 3024923
1992/05/18 15:44:17.97 33.9510 -116.3375 6.57 5.00 Mc 137 0.25 CI 2052730
1992/06/11 00:24:19.18 34.1743 -116.3498 0.79 4.40 Mc 100 0.19 CI 2055346
1992/06/28 11:57:34.13 34.2002 -116.4367 0.97 7.30 Mc 109 0.19 CI 3031111

1998/07/04 11:15:48.32 34.6360 -116.6870 1.10 3.71 ML 88 0.22 CI 9059472
1999/04/16 15:53:51.58 34.4840 -116.5110 3.31 3.15 ML 83 0.20 CI 9083778
1999/08/18 07:50:05.64 34.3960 -116.4690 4.02 3.09 ML 84 0.15 CI 9101425
1999/10/16 02:41:04.69 34.5940 -116.2700 0.01 3.70 ML 75 0.18 CI 9108606
1999/10/16 09:46:44.13 34.5940 -116.2710 0.02 7.10 Mw 55 0.16 CI 9108652