500 aftershocks and counting from Mexicali earthquake
“People who live near [the epicenter] are getting no sleep,” said Kate Hutton, a Caltech seismologist.
Most of the aftershocks have been minor -- in the 3 magnitude or less. But there have been six aftershocks that registered more than 5.0, and dozens in the 4 range, according to the U.S. Geological Survey.
There was a 4.6 temblor on the border early Tuesday morning. But the last magnitude 5 quake occurred Monday morning.
Hutton said there’s about a 56% chance that another magnitude 5 aftershock will occur sometime today. She said that over the next week, there might be as many as 22 magnitude 4 aftershocks and maybe two magnitude 5 aftershocks.
“The good news is that the aftershocks do become less frequent with time,” Hutton said. “After a week or two, it will only be an occasional jolt.”
The aftershocks are being felt most acutely in Mexicali, El Centro, Calexico and other border towns hit hardest by the temblor.
On Monday, assessment teams inspected buildings and cleanup crews swept up broken glass in Mexicali and its smaller California neighbor, Calexico, both of which sustained modest damage. The death toll rose to two from the quake, which also left more than 230 people injured. The quake, centered about 30 miles south of the border, caused 45 buildings in Baja California to collapse or partly collapse, authorities said.
On the U.S. side of the border, a 12-square-block historic section of Calexico was closed for inspection and several buildings were red-tagged as unsafe, City Manager Victor M. Carrillo said. Calexico also lost the use of its main water tank, prompting city officials to call for strict conservation.
Two people were injured in surrounding Imperial County, one critically, according to Maria Peinado, a spokeswoman for the county Office of Emergency Services. It wasn't clear how or where they were hurt.
--Ching-Ching Ni and Shelby Grad
Photo: Residents of the Mexicali Valley show the fatigue of a sleepless night and having walked more than seven miles from Ejido Cucapah to an aid distribution center on Highway 5. Next to them is a roadside light fixture that nearly toppled during Sunday's magnitude 7.2 quake. (Don Bartletti / Los Angeles Times / April 5, 2010)