Quake swarm near the border has residents on edge
Residents of the Imperial Valley are living on shaky ground these days.
Since Friday, cities such as Calexico and El Centro, as well as Mexicali across the border, have been rocked by hundreds of earthquakes, from tiny to teeth-rattling -- three have registered a magnitude of 5.0 or more.
The onslaught of temblors is known as a swarm, in which quakes of varying sizes can strike every few minutes, said Kate Hutton, a staff seismologist at the California Institute of Technology. The Imperial Valley and Baja are prone to the swarms, she said; they can last a few days to a week.
Though the quakes aren't breaking any geologic records, they've caused several sleepless nights for Calexico resident Barbara Lopez.
"It's been scary," said Lopez, a 27-year-old apartment leasing agent, of what she describes as nonstop quakes. "You're like constantly thinking: 'Is the big one going to hit? Are we prepared?' Of course we're not."
Lopez has already stashed her $300 mirror between the couch and the wall, along with her computer and breakable family photos. She and co-workers at Desert Properties in El Centro spent part of Tuesday running through earthquake drills in the office.
Firefighters in the region say that although the quakes are jangling people's nerves, they have not caused any structural damage or injuries.
"In the grand scheme of California earthquakes, they've been pretty mild," said Richard Burns, a battalion chief in the El Centro Fire Department. The Calexico Fire Department sent a mutual assistance team to Mexicali recently to check for damage to the city's downtown but didn't find anything serious, said Calexico firefighter Joe Guerra.
The region sits atop a geothermal area, where past volcanic activity has kept underground rocks hot, Hutton said. That heats the groundwater, which could lubricate local fault lines.
El Centro coffee shop cashier Gloria Estrada has been running for cover in doorways at home and work over the last few days. Although her radio crashed to the floor on a recent night, in her opinion the locals "are used to it."
Lopez describes the tremors, which scare her young daughters, "like a big rumble, then all of a sudden the house starts moving."
"Right when you're like going back to sleep, it starts shaking."
Fortunately she has a built-in earthquake alarm: Her two basset hounds, Tiny and Tubby, start barking each time the earth's about to move.
susannah.rosenblatt@latimes.com
