The relationship between the West Irian earthquake of October 10, 2002 (Mw 7.5) and the Grapevine earthquake today in southern California may be of some interest to readers of this board. Last month a message was posted on this board which stated (see link below for full text):

"Some seismic activity is possible in the southern California areas of Los Angeles/Northridge area and in the Joshua Tree/Baker/Hector Mine between November 4 and 10. A strong increase in seismicity in these areas is possible at this time.
This is based on relationships in which a moderate or strong earthquake in California follows large events in the Irian Jaya
region. These events often occur in the region west of Los Angeles or in the Imperial Valley area or both. Following are the relations for the past 5 large (Mw>=7.5) earthquakes in the Irian Jaya (130-140E) area and following events in the L.A. or Imperial Valley area:

Irian Jaya June 22, 1957
So. Calif. July 21, 1957 35.1N 119.1W Ml 3.6"
29 days (interevent time)

Today's event also occurred 29 days after the recent Irian Jaya earthquake. This is quite similar to the first example cited in interevent time and event magnitude in that post. Since the Grapevine event breaks a long quiet period in the SW California area, the relationship between these two earthquake might be considered significant by some.

29 days

• Earthquake forecast for So. Cal forwarded earlier to this board.