Magnitude 4.3 Quake Strikes in Desert Area South of Border

In another earthquake in the volcanic zone of Baja California, a magnitude 4.3 temblor centered 35 miles south of the border town of Calexico struck early Wednesday, the U.S. Geological Survey reported.

The quake hit at 4:26 a.m. and was felt in the Imperial Valley and north along the coast as far as San Clemente. Neither damage nor injuries were reported.

There were three reported aftershocks, the strongest 2.7 at 1:02 p.m.

Wednesday’s quake was in sparsely populated desert territory in Mexico, along the road between Mexicali and San Felipe.

The area has seen significant seismic activity, and there is a geothermal field of heated underground magmatic sources on both sides of the border.

The strongest of these quakes in the last century occurred in 1915, 1934, 1940, 1979 and 1987, including the magnitude 7.1 quake in 1940 that killed nine people. There also have been frequent swarms of quakes, multiple jolts of about the same intensity that may last for days.

Residents who reported Wednesday’s quake to the Geological Survey’s Web site put the highest shaking intensity on the American side of the border near El Centro, at an intensity III on the modified Mercalli scale. That indicated that in those areas, the quake was felt indoors, caused hanging objects to swing.