There have been more than 500 aftershocks from Sunday’s 7.2 Mexicali earthquake, and experts said residents in the region can expect many more.
“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)