Baja, Calif., Rocked By 7.2 Magnitude Earthquake

A 7.2-magnitude quake struck at 3:40 p.m. on April 4, 2010 about 19 miles southeast of Mexicali, about 16 miles from Baja, Calif., according to the U.S. Geological Survey. The epicenter was located about 75 kilometers south of the Mexico-USA border, and the earthquake occurred at shallow depth along the boundary zone between the North American and Pacific plates.

Only two similar sized earthquakes have been recorded in the area, USGS said. The first was the 1892 earthquake estimated at magnitude 7.0-7.2 along the Laguna Salada fault just south of the USA-Mexico border. The second was the 1940 Imperial Valley magnitude 6.9 earthquake which occurred in southernmost California.

Sunday’s earthquake was followed by several aftershocks, one with a magnitude as high as 5.4.

According to the USGS ShakeMap, the strongest shaking reached up to intensity VIII to IX (severe to violent) near the epicenter region, however this region is very sparsely populated. The closest city to the epicenter is Mexicali, with a population of close to 600,000, which seems to have been subject to shaking of intensity VII (very strong) which has the potential to cause moderate damage to resistant structures and moderate to heavy damage to vulnerable structures, risk modeling firm RMS said.

Preliminary media reports indicate that there has been damage to some buildings and infrastructure in Mexicali, and rescue teams have been deployed to the city. In Tijuana, which has a population of around 1.3 million, shaking is estimated to be of intensity V (moderate) by the USGS and damage reports are very sparse. There are very few reports emerging from other towns or cities in Baja California at this time, however power outages are reported to be widespread at this time and it is possible communications could be affected. Two fatalities and at least 100 injuries have been reported in Mexicali, RMS said.