Earthquake Magnitude Revised to 7.4M in Mexico's Acapulco-Oaxaca Region

Update 1:48 p.m. The U.S. Geological Survey has revised the magnitude of a significant earthquake that struck the Acapulco-Oaxaca region of Mexico Tuesday to 7.4M.

Preliminary reports indicated a magnitude-7.6 quake was recorded before noon Pacific Time, the USGS reported.

The depth of the quake was also revised from 10.9 miles to 12.4 miles below the Earth's surface.

The epicenter was 200 miles south-southeast of Mexico City, 115 miles east of the resort city of Acapulco, and 100 miles west-southwest of Oaxaca, according to the USGS.

Posted 11:58 a.m. A magnitude 7.6 earthquake was recorded Tuesday before noon Pacific Time in the Acapulco-Oaxaca region of Mexico, south of Baja, according to the U.S. Geological Survey.

"The preliminary report is a 7.6 magnitude event," said Ryan Gold, a research geologist with the National Earthquake Information Center in Golden, Colorado. "The way these things work magnitude will likely be revised as more stations report."

The quake was measured at 10.9 miles below the Earth's surface at 12:02 p.m. local time in Acapulco. That would be 11:02 a.m. Pacific Time in the San Gorgonio Pass.

"It looks like it's a reverse faulting, thrust-fault event, and that could be refined as more information comes in," Gold said. "This area is a convergent margin where one plate is subducting under Mexico."

Gold said he and other scientists were alerted before noon Pacific Time.

"We were just alerted 15 to 20  minutes ago," Gold told Banning-Beaumont Patch in a phone interview.

The San Gorgonio Pass is astride the San Andreas Fault, where the North American Plate and Pacific Plate meet.