Another indication of Don's accuracy occurred this afternoon when a Ml 3.0 occurred
near Clear Lake CA within 20 km of Don's predicted epicenter and within the
prescribed window. This is only the second earthquake in the past 7 days
of Ml>=3 in the western U.S.
The background seismicity rate within 40 km of the predicted epicenter includes
46 events of Ml>=3 from 8/31/98 to 8/31/01. This is a period of 1095 days, 44 of which
had at least one event of Ml>=3. So the background rate per day is about 0.04, over
a 6-day period, the rate is about 0.24, or odds of about 1 in 4. Not a terribly impressive
accomplishment, but still the forecast would have been wrong 3 out of 4 times.

The event parameters were listed by NCSN as:
18SEP2001 20:48:01 38.8N 122.8W ML=3.0 NCSN ESE of The Geysers, CA

Don Had said:
13-18SEP 2001 +/-40 km 38.9N 122.7W Ml 2.3-3.5 Clear Lake CA
The event lies about 14 km from the predicted epicenter in the windowed time,
and within the magnitude limits. Although the probability of getting this right
by chance is higher than Don's normal predictions, it is still only 1 in 4 odds
of a chance success, so the grade for this prediction is another A.

Congratulations Don.