Seismo-Watch

More Special Earthquake Reports

February 22, 2002

An earthquake measuring ML 5.2 (SCSN), Mw 5.7 (NEIC) occurred at 11:32 PST late this morning along the Southern California-Mexico border. Although the quake shook the epicentral region hard and was felt over a wide area, there have been no reports of significant damage or injuries at this time.

Subscribers to the Seismo-Watch EQ Flash! Alert Bulletins received a notification of this earthquake within minutes after it happened. See alert bulletin. 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 Southern California Seismic Network (SCSN) the earthquake measured a Local magnitude (ML) of 5.2 and occurred at 19:32:40 GMT, February 22, about 28 miles south of Calexico and about 12 miles southwest of Delta in a remote area of southern Mexicali Valley, Baja California, Mexico, near the junction of Mexico Highway 5 and the Ejido Durango Road. See locations maps by Expedia or MapQuest. SCSN determined a focal depth to be at or very close ground surface.

Because the earthquake was centered rather south of the SCSN network, the quality of data analysis may not be as accurate and further data processing shall be necessary to resolve better information.

Meanwhile, the National Earthquake Information Center (NEIC) reported a Moment magnitude (Mw) of 5.7 and thier analysis will be the authoritive result. They determined a focal point at 10 km below the surface and their fault plane solution indicated strike-slip motion along a west-northwest trending plane. See their preliminary Moment Tensor analysis.

Foreshocks and aftershocks
Three foreshocks were recorded, two registering M3.3 and M3.0 two days ago on Wednesday afternoon, February 18, and a M3.2 at 10:27 a.m. yesterday morning.

A robust aftershock sequence has followed and has included several dozen events thus far. See partial list. More than 20 aftershocks have registered M3.0 or stronger, the largest of which measured M4.1 and came at 12:33 p.m. on February 22.

Seismo-Cam
The NBC Channel 4 Newsroom in Burbank, California has a continuous image recorder of a seismometer (Seismo-Cam). See the current and past Seismo-Cam images of the earthquake series.

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