•   
  •   
  •   

US5% chance of an even bigger earthquake in Southern California, scientists say

08:40  06 july  2019
08:40  06 july  2019 Source:   latimes.com

California earthquake: Searles Valley quake generates over 100 aftershocks

California earthquake: Searles Valley quake generates over 100 aftershocks The strongest earthquake to hit Southern California in nearly 20 years has prompted one city to declare a state of emergency Thursday, and shook residents from Las Vegas to Orange County. The quake, with a magnitude of 6.4, was centered near Ridgecrest, a community west of the Mojave Desert and about 150 miles north of Los Angeles. At least 159 aftershocks of magnitude 2.5 or greater were recorded after the earthquake, according to USGS Seismologist Robert Graves. It is a higher than normal number, but not unprecedented, he said. The largest of them were magnitude 4.6.

The 7.1 quake that struck Friday night was about 10 times larger than the 6.4 quake on Thursday morning, said Caltech seismologist Lucy Jones said she could not recall a pattern of earthquakes in California where a 6.4 foreshock was followed by a 7.1 event, only to be followed by an even bigger

The odds that Southern California will experience another earthquake of magnitude 7 or greater in the next week are now nearly 11%, according to preliminary estimates from seismologists. And the chances that a quake will surpass the 7.1 temblor that struck near Ridgecrest on Friday night are

5% chance of an even bigger earthquake in Southern California, scientists say© Irfan Khan / Los Angeles Times

The 7.1 quake that struck Friday night was about 10 times larger than the 6.4 quake on Thursday morning, said Caltech seismologist Lucy Jones. Given its size, it’s likely to be followed by more shaking that will be felt in Los Angeles.

“The largest aftershock, on average, to a 7.1 would be a magnitude 6,” Jones said. That means another quake on the order of Thursday’s 6.4 temblor “would not be surprising to anybody.”

Or it could be even bigger.

“There’s a 5% chance that this could be followed by an even larger quake,” said USGS seismologist Robert Graves.

Though such a quake would be more likely to occur in the next few days, the shaking could continue for quite some time.

July 4th earthquake won't delay the Big One. And it might have worsened quake strain

July 4th earthquake won't delay the Big One. And it might have worsened quake strain Does a good-size earthquake help relieve pent-up seismic stress? Does that postpone the day of reckoning when the Big One finally arrives? 

A major earthquake is going to hit the along the southern San Andreas fault. We don't know when, but we know what happens next. These mean different things when talking about the severity of an earthquake . Magnitude is a quake 's quantitative size. It's measured by how much seismic energy is

California could be hit with a series of large earthquakes after the 7.1 magnitude quake that “There is about a one-in-twenty chance that this location will be having an even bigger earthquake within the Friday’s earthquake was widely felt across Southern California , including greater Los Angeles

“A magnitude 7 usually has aftershocks that last for years,” Jones said.

Jones said she could not recall a pattern of earthquakes in California where a 6.4 foreshock was followed by a 7.1 event, only to be followed by an even bigger quake.

Get ready for a major quake. What to do before — and during — a big one »

But that doesn’t mean it can’t happen, she cautioned.

5% chance of an even bigger earthquake in Southern California, scientists say
5% chance of an even bigger earthquake in Southern California, scientists say
5% chance of an even bigger earthquake in Southern California, scientists say
5% chance of an even bigger earthquake in Southern California, scientists say
5% chance of an even bigger earthquake in Southern California, scientists say
5% chance of an even bigger earthquake in Southern California, scientists say
5% chance of an even bigger earthquake in Southern California, scientists say
5% chance of an even bigger earthquake in Southern California, scientists say
5% chance of an even bigger earthquake in Southern California, scientists say
5% chance of an even bigger earthquake in Southern California, scientists say
5% chance of an even bigger earthquake in Southern California, scientists say
5% chance of an even bigger earthquake in Southern California, scientists say
5% chance of an even bigger earthquake in Southern California, scientists say
5% chance of an even bigger earthquake in Southern California, scientists say
5% chance of an even bigger earthquake in Southern California, scientists say

Slideshow by photo services

“It is clearly a very energetic sequence, so there’s no reason to think we can’t have more large earthquakes,” she said.

No, the California earthquakes weren't along the San Andreas fault

No, the California earthquakes weren't along the San Andreas fault When a magnitude-7.1 earthquake struck a day after a 6.4 in Southern California, searches for "San Andreas fault" spiked. Ridgecrest is far from it.

Jones said it’s not likely that these quakes will trigger any activity on the San Andreas fault.

The 7.1 quake occurred on the same fault system as the 6.4 temblor that is now being considered a foreshock. It was further away from Los Angeles, though still in the Owens Valley.

“This happened at the end of the zone that moved previously,” Jones said.

It has already been followed by several aftershocks about 15 miles to the northwest, Jones said. She said the fault is now likely to be 25 to 30 miles long.

“The fault is growing,” Jones said.

Thursday’s 6.4 foreshock triggered shaking in Ridgecrest of intensity 8. With Friday’s 7.1 main shock, the shaking intensity reached a 9, Jones said.

“My expectation is that Ridgecrest is having a pretty difficult time tonight,” said Lucy Jones.

“We don’t get the 7s very often,” she added.

Why the quake warning system didn't work »

Read More

Southern California isn't doing enough to fix earthquake-vulnerable buildings, expert says.
"I don't want to frighten people," one expert said. "But I think it's important to be transparent. This is a real issue." O'Dell estimated that half a million people likely call these structures home. That estimate is drawn, in part, on a recent survey done in the city of Los Angeles that found roughly 12,000 soft-story structures built before 1978. Extrapolating out across a county that has dozens of cities and a population of more than 10 million, O'Dell said the area could easily have double that number.

Topical videos:

usr: 1
This is interesting!