A magnitude-4.5 earthquake rattled the San Francisco Bay Area — days before the 30th anniversary of a monster quake that killed dozens and wounded thousands.
The quake shook the northeast San Francisco region, near Walnut Creek, just after 10:30 p.m. Monday — just three days before the anniversary of the massive Loma Prieta shaker that rocked the region in 1989, the local National Weather Service branch said.
Moderate shaking could be felt in the Walnut Creek, Pleasant Hill and Concord areas — of an intensity that could overturn unsecured objects like books and picture frames, and break dishes and windows, according to the Los Angeles Times. Weaker shaking could be felt in San Francisco, Oakland and San Jose.
No injuries were immediately reported, the Contra Costa Sheriff’s Office tweeted.
The quake’s preliminary depth was about 9 miles beneath the Earth’s surface, fairly deep for that part of the world, USGS geologist Keith Knudsen told the Times. As a result, the quake could be felt over a broad area, but the intensity of the shaking felt on the ground was less than if it had been a shallow quake, he said.
The quake was not directly on top of any of the main faults in the region — with its epicenter about 3 miles west of the Concord fault and even farther off the northern end of the northern Calaveras fault, he added.
The epicenter did fall just northwest of Mt. Diablo, one of the tallest peaks in the area — which is known as “a region of uplift, folding and thrusting,” USGS scientist emeritus David Schwartz told the outlet.
A smaller, 2.5-magnitude earthquake occurred in the city of Pleasant Hill about 10 minutes earlier, the weather service said.
Seismologist Dr. Lucy Jones said a larger earthquake isn’t out of the question for the area.
“Because any quake can be a foreshock, there’s a slight increase in the chance of a bigger quake for the next few days, at the same location near the Calaveras fault,” she tweeted.
Doug Sovern, a reporter for local KCBS Radio, said the quake is keeping locals on their toes as the anniversary of the 6.9-magnitude Loma Prieta quake approaches.
“Looks like Mother Nature wanted to make sure everyone paid attention to Thursday’s 30th anniversary of the Loma Prieta earthquake, and remind everyone to up their preparedness game,” he tweeted.
The 1989 quake killed 67 people, injured more than 3,500 and created about $5 billion in property damage in the Bay Area.
