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M 4.0 (NCSN), Mw 4.1 UCB

6.1 km (3.8 miles)

Mammoth Lakes is jolted by M 4.1 quake - first in nearly 4 years!

Seismo-Watch More Special Earthquake Reports

Saturday, March 8, 2003

An earthquake registering M 4.1 occurred this morning along the eastern Sierra near Mammoth Lakes, California. Early reports indicate it was widely felt in the region, but there have been no reports injuries at this time.

Seismo-Watch EQ Flash! Alert Bulletins notified subscribers of this earthquake within minutes after it happened. You should subscribe to the service too! It's FREE and Fast! NOW! Wireless EQ Flash! via pager, cell phone or PDA's! More info.

According to the Northern California Seismic Network (NCSN) the earthquake measured M 4.1 occurred at 15:35:01 GMT or 7:35 a.m. PST, Saturday, March 8, about 7 miles southeast Mammoth Lakes and 2 miles southwest of Convict Lake at Mount Laurel. See a Topozone topographic map or a MapQuest street map.

The focal depth was 6.1 km, a typical depth for earthquakes in this location. A preliminary fault plane solution by UC Berkeley indicated a complex oblique-normal movement (extension with some sideways slip) along a northwest trending plane.

UC Berkeley determined a Moment magnitude (Mw) of 4.1. See solution.

Earthquake activity at Mammoth Lakes has been relatively quite in recent years and this is the first M 4.0+ earthquake to strike the region in nearly four years, the last event happening on June 3, 1999 - 190 weeks ago!

Seismo-Watch produces a weekly earthquake of the Mammoth Lakes area and are considered to be experts of the activity. Be sure to sign up for free update notices for these reports! When in the area, be sure to pick up a Mammoth Times newspaper for all the local news and information.

Continued on Page 2

Report update: 11:18:06 AM, Saturday, March 8, 2003

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