Monday, April 5, 2010
A magnitude 7.2 earthquake struck on Easter Sunday in Baja California. People in San Diego felt the quake which was centered about 19 miles southeast of Mexicali. Mexican authorities say at least one person died and several buildings have collapsed. In San Diego the damage was minimal.
SAN DIEGO A magnitude 7.2 earthquake struck on Easter Sunday in Baja California. People in San Diego felt the quake which was centered about 19 miles southeast of Mexicali. Mexican authorities say at least one person died and several buildings have collapsed. In San Diego the damage was minimal.
The fire departments in Tijuana and Rosarito both pitched in to help Mexicali. Multiple fires broke out when gas lines split and propane tanks ruptured. A parking garage under construction at the Baja California state capitol also collapsed. People who felt the quake describe a rolling sensation and the land shifting back and forth. Seismologist Kim Bak Olsen says that’s because the epicenter for the quake was just over six miles below the earth’s surface.
“Such a shallow earthquake tends to generate what we call surface waves, which are shaking waves which travel very close to the surface,” he said.
He says the seismic waves also travel farther. This quake was felt as far north as Santa Barbara and east toward Phoenix. In San Diego people described a significant amount of shaking.
“My TV almost fell off, I had mirrors falling down, pictures falling down, drawers opening,” said Evan from University City. She was one of many who called into KPBS to share their experience.
Jeremy was walking near a pool at the Sheraton Harbor Island hotel when the quake hit. “After it stopped I kept on walking to the smaller pool and there were waves washing water outside of the pool to one side. And then the wave would come to the other side and it would wash water clear out of the pool on the other side,” he said.
The Sheraton had to evacuate guests after the quake caused a crack in the hotel’s floor. An inspection later determined there were no major problems. Guests at another hotel, the Hotel Del Coronado also felt the quake. Jon was at the Del when it struck. He called into KPBS and says it felt like he was on a ship because of the rolling.
“And then next thing I know, there’s hundreds and hundreds of people pouring out of the ball room and the crown room and the main lobby,” he said. “I had a guest who said the chandelier was just swaying back and forth.”
Riding out the earthquake’s waves was just the beginning for people in charge of maintaining San Diego’s infrastructure. Ron Lane is the Director of the San Diego County Office of Emergency Services.
“They check the major facilities like the Coronado-Bay Bridge,” he said. “Places like the airport and San Onofre Nuclear Power plant all have procedures that they go through to make sure their facilities are fully operational.”
But what was an unwelcome interruption to Easter for many people was an interesting research opportunity for earthquake experts. Seismologist Olsen says the quake may have occurred at the southern end of the San Andreas Fault which runs nearly the length of California.
“I was definitely looking very carefully at the activity right after the 7.2,” Olsen said. “Because that’s the kind of triggers that potentially could set off a large earthquake if that indeed was connected to the San Andreas Fault.”
However Olsen said enough time has passed since the Easter quake that larger related quakes on the fault aren’t a big concern. He said the data gathered from Sunday’s earthquake will be valuable.
“These patterns of seismic activity are really important to understand if we’re every going to be able to predict earthquakes in the future,” he said.
That’s something San Diegan’s may be able to appreciate after having their quiet Easter Sunday unexpectedly rattled.