Hi All. Today�s M=3.7 quake near Alum Rock is close to the quake that occurred on 01/15/2006. That quake was an M=3.6. Quakes at today�s magnitude are not that common in the area, but there does appear to be a marked increase in M=3.0+ quakes in the area as this is the 4th quake in the last 2 years. This is equal to the same number of quakes in the previous 28 years.

On July 1, 1911, a strong earthquake measuring M=6.6??? shook the Santa Clara Valley region of Central California. It is believed to have been centered on the Calaveras fault near Morgan Hill. No surface rupture was ever found. This was the last quake of a considerable magnitude in the area until the M=5.9 quake near Morgan Hill in August of 1979. Most seismologists think this quake indicated the Bay Area was coming out of the stress shadow created by the 1906 earthquake.

On June 20, 1897, an earthquake measuring M=6.2 occurred along the Calaveras fault in the South San Francisco Bay Area. The quake was centered in Santa Clara Valley near Gilroy.

Surface ruptures along the trace of the Calaveras fault were observed southeast of Gilroy near Pacheco Pass Road and in San Felipe Valley north of Morgan Hill.

It could be said that the quake that occurred on 01/15/2006 was a foreshock to today�s M=3.7 quake, or both quakes are foreshocks to a bigger event, but there is no way of knowing this until the next quake occur, or doesn�t occur.

Three quakes have registered in the M6.0 range and each along the Calaveras fault in Santa Clara Valley: Gilroy M=6.2 1897; and two near Morgan Hill 1911 M=6.5 and 1984 M=6.2. Don in creepy town

catalog=ANSS
start_time=1898/01/01,00:00:00
end_time=2006/01/25,18:16:13
minimum_magnitude=3.0
maximum_magnitude=10
event_type=E
delta=0 km to 16 km from (37.389,-121.485)
Date Time Lat Lon Depth Mag Magt Nst Gap Clo RMS SRC Event ID
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1943/03/10 18:05:22.00 37.3700 -121.4500 3.10 ML BK ��
1946/12/24 01:39:50.00 37.4800 -121.5300 3.40 ML BK
1948/04/21 10:55:01.00 37.4000 -121.5500 3.00 ML BK
1949/11/27 14:06:46.00 37.3800 -121.6000 3.00 ML BK
1951/11/30 07:54:45.00 37.4200 -121.3300 3.30 ML BK
1953/02/13 22:10:06.00 37.3800 -121.6500 3.20 ML BK
1953/05/23 21:16:22.00 37.3000 -121.6200 3.60 ML BK
1953/10/19 23:35:25.00 37.3500 -121.5800 3.80 ML BK
1954/07/29 08:51:36.00 37.4200 -121.3300 4.20 ML BK
1957/05/24 13:01:53.00 37.2800 -121.5700 3.10 ML BK
1958/05/07 16:20:12.00 37.2800 -121.6000 3.00 ML BK
1958/09/20 23:37:57.00 37.3000 -121.6200 3.30 ML BK
1960/01/26 05:52:23.00 37.3500 -121.6500 3.30 ML BK
1961/09/13 11:54:44.00 37.4000 -121.5000 3.00 ML BK
1969/09/07 16:32:24.56 37.5002 -121.4610 4.77 3.01 Md 18 218 18 0.08 NC -1003046
1973/03/17 03:30:27.40 37.3487 -121.6082 6.08 3.58 Md 46 95 3 0.07 NC -1014893
1974/09/09 08:06:18.12 37.3798 -121.6025 5.83 3.12 Md 52 126 7 0.09 NC -1020887
1977/03/19 22:56:47.30 37.4237 -121.6178 6.96 4.02 Md 81 137 9 0.08 NC -1034469
1978/08/24 21:04:25.63 37.4932 -121.5507 5.01 3.02 Md 65 156 14 0.09 NC -1041854
1979/11/15 15:08:56.86 37.4205 -121.6330 5.58 3.10 Md 46 144 13 0.08 NC -1048849
1984/10/31 14:12:26.81 37.3010 -121.6245 7.62 3.32 Md 88 67 10 0.07 NC 31010
1991/10/07 12:11:14.54 37.5167 -121.4102 0.48 3.12 Md 88 177 10 0.10 NC 233458
2005/02/05 18:43:30.31 37.4003 -121.4833 8.10 4.42 ML 101 69 6 0.10 NC 21437727
2005/04/21 16:19:50.24 37.4093 -121.3623 0.61 3.11 Md 7 114 33 0.29 NC 40173993
2006/01/15 10:42:06.98 37.3857 -121.5118 3.35 3.62 ML 105 59 5 0.15 NC 21502994
2006/01/25 15:29:57.15 37.3890 -121.4850 6.58 3.74 ML 87 67 6 0.14 NC 51167903