Earthquake rocks Southern California

1:49 p.m. ET, July 6, 2019

There have been more than 4,700 quakes since Thursday

A cinderblock wall partially destroyed in Ridgecrest, California, on Saturda, following a magnitude 7.1 earthquake on Friday
A cinderblock wall partially destroyed in Ridgecrest, California, on Saturda, following a magnitude 7.1 earthquake on Friday ROBYN BECK/AFP/Getty Images

There have been more than 4,700 earthquakes since Thursday’s 6.4-magnitude event, according to John Bellini, a geophysicist with the USGS. 

“They are coming in every 30 second, every minute," he said.

Since Friday night's 7.1-magnitude quake, there have been three quakes with magnitudes of 5 or greater. Those three all occurred within the first hour after the 7.1 quake; one was a 5.5 magnitude and there were two 5.4 quakes.

1:27 p.m. ET, July 6, 2019

SOON: Officials give and update on the earthquake

Officials in Ridgecrest, California, will hold a news conference at 1:30 p.m. ET (that's 10:30 a.m. PT) to give an update on last night's earthquake.

If you're just catching up on the news, here's what we know so far about the Friday night quake:

  • Where it hit: The Friday night earthquake struck 11 miles northeast of Ridgecrest, according to the US Geological Survey.
  • Its power: It was 11 times stronger than Thursday's 6.4-magnitude earthquake, also centered near Ridgecrest. That means Thursday earthquake was a foreshock to last night's quake.
  • The damage: Gas leaks caused structure fires throughout Ridgecrest, residents reported water main breaks, and the power and communications were out in some areas, Mark Ghilarducci, Director of California Governors' Office of Emergency Management, said. Several injuries were reported.
  • What happens next: A state of emergency is declared in Ridgecrest and San Bernardino County and seismologists are expecting more aftershocks.
12:46 p.m. ET, July 6, 2019

There have been more than 2,300 earthquakes since the Fourth of July

There have been more than 2,300 earthquakes since the 6.4-magnitude quake that rattled Southern California on Thursday.

There were around 1,500 quakes in the area between the Thursday earthquake — which we now know was a foreshock — and the 7.1-magnitude quake last night, according to USGS.

Of the 2,300 quakes since the Fourth of July, 300 had magnitudes of 3 or more, which means they were strong enough to be felt. And 50 of them have been had magnitudes of 4 or more. Quakes with that strength have enough power to cause damage.

12:02 p.m. ET, July 6, 2019

Fire chief: We think there is damage, "but we don’t know the extent of it yet"

Kern County Fire Chief David Witt said there are no known fatalities from the earthquake. And while officials believe there is damage, they're not sure how bad it is yet.

“We do feel like there is damage, but we don’t know the extent of it yet,” Witt said at a news conference moments ago. “Nobody was trapped, no major collapses that we know of, but we are out there searching.”

Witt said everybody wants information quickly, but “it’s hard to gather intel in darkness.”

Fire officials are inspecting buildings and the Army Corps is doing a detailed inspection of the dam, he said.

Witt said all of the fire stations are up and running and everybody has power. They are prepared to handle any vegetation or structure fires in Kern County, Witt said.

11:47 a.m. ET, July 6, 2019

Why Friday’s quake was 11 times stronger but only 5 times bigger than Thursday’s

Broken bottles cover the floor of a liquor store in Ridgecrest, California, following an earthquake on Friday
Broken bottles cover the floor of a liquor store in Ridgecrest, California, following an earthquake on Friday ROBYN BECK/AFP/Getty Images

Experts have been comparing last night's 7.1-magnitude earthquake to the 6.4-magnitude quake that hit on Thursday. (Technically, the Thursday quake was a foreshock leading up to Friday's).

The Friday quake has been described as both five times bigger and 11 times stronger than the Independence Day earthquake.

That's not a typo — here's how both those figures are possible:

  • "Five times bigger" refers to the scientific measure of the earthquake. On the seismograph, Friday’s quake is technically five times stronger than Thursday’s quake.
  • "11 times stronger" refers to the intensity of the quake. Friday’s quake released 11 times the amount of energy than Thursday’s quake.

But the strength — not the size — is the more important figure. The energy released in a quake is what causes damage. Or, as the USGS puts it: "It is really the energy or strength that knocks down buildings."

11:34 a.m. ET, July 6, 2019

There's a 3% chance that another quake as strong as last night's will hit

There's a 27% chance that there will be another earthquake with a magnitude of 6 or more within the next week, according to the United States Geological Survey.

The possibility that another 7-magnitude quake will strike is 3%. Friday's earthquake measured 7.1 and Thursday's was a 6.4.

On their website, the USGS broke down the possibility of more aftershocks in the next week (until July 13). Here's the forecast:

  • The chance of an earthquake of magnitude 3 or higher is more than 99%.
  • The chance of an earthquake of magnitude 5 or higher is 96%.
  • The chance of an earthquake of magnitude 6 or higher is 27%.
  • The chance of an earthquake of magnitude 7 or higher is 3%.

Remember:  These probabilities will continue to decrease as time goes on.

11:17 a.m. ET, July 6, 2019

Some California residents took their mattresses outside because it was safer than sleeping in their homes

CNN's Sara Sidner is in Ridgecrest, California, close to where last night's 7.1-magnitude earthquake was centered.

She said several residents took their mattresses outside and slept in their driveways in case more quakes struck overnight.

"They simply did not feel safe enough in their homes with stuff coming down," Sidner said. "They were so concerned that more of it was going to come down on them. They decided that it would be safer to sleep outside."

Sidner said the people she's spoken to are not physically hurt — but they are scared.

"When you lose all ability and sense of — sort of your own control of your surroundings, it is scary. When the Earth is literally moving underneath you and things are falling off the walls and you don't know how much longer it's going to go on, it feels like eternity as one of these earthquakes roll through."

Watch for Sidner more: