Southern California is earthquake country. But if you’ve lived in the area for the last couple of decades, you might not know it.

Despite Thursday’s wake-up call 6.4 magnitude in a remote desert area near the town of Ridgecrest, Southern California has been experiencing an earthquake drought, scientists said Thursday.

The relative inactivity did not go unnoticed by one high-profile expert on California’s shakers.

“I think this would be a good time to remind you that if you have been experiencing earthquakes for the last 20 years in California, you have been experiencing an extremely quiet time in California history,” Caltech scientist Lucy Jones said.

Take note of that history:

The last time there was an earthquake above magnitude 6 in Southern California was 1999, Jones said.

The previous decade leading up to that had about eight magnitude 6s.

“This has been an extremely quiet, abnormal time,” she said.

Jones said the quake that shook the region on Thursday was actually more “normal” for what we should be expecting in Southern California, based on historical averages.

A quake of the Ridgecrest size, based on long-term history, should be coming once every five or 10 years in Southern California.

Yet, you’d have to go back to Oct. 16, 1999, for anything bigger. That’s when a magnitude 7.1 quake hit about 32 miles north of Joshua Tree.

Until Thursday’s Ridgecrest quake, it was the largest tremor to have hit the area since the 7.3-magnitude Landers Earthquake struck on June 28, 1992. And just this year, the 25th anniversary of the 6.7-magnitude Northridge Earthquake was remembered, along with its tragic toll of 57 people killed.

Here’s a quick rundown on some others above 4.0 over the last 25 years:
• 6.4 magnitude earthquake in Southern California shakes social media with surprise reactions and videos
• LA has an earthquake warning system. It didn’t send an alert for the July 4th quake. So what does this all mean? Are we due? Is there energy building up on the faults throughout Southern California?

It may just come down to being aware.

Here’s what U.S. Geological Survey seismologist Robert Graves had to say about that: “Obviously any earthquake that occurs releases some of that tension. But there’s a tremendous amount that’s built up since the last major earthquake, which was in 1857 on the San Andreas.” </s> The magnitude-5.3 earthquake that rattled Southern California on Thursday was the strongest in the area several years.Though there were no immediate reports of damage, the quake was felt across a wide area and was a blunt reminder that California is earthquake country. The U.S. Geological Survey put the epicenter about 23 miles off the Channel Islands, about 85 miles west of Los Angeles.It was centered near the Eastern Santa Cruz Basin Fault Zone, Caltech seismologist Egill Hauksson said. "Earthquakes happen out there now and again. There's a major offshore fault system," he said.Seismologist Lucy Jones said on Twitter that the fault system "moves Southern California around a bend of the San Andreas fault."There is a slightly greater likelihood that the the temblor could trigger a larger earthquake, but that chance decreases with time, Hauksson said.The last big earthquake in the Channel Islands region before Thursday's temblor was in 1981, which was a magnitude 6.0, Hauksson said. A magnitude 4.8 quake struck near the islands in 2013.The last quake to be felt this widely in the L.A. area was a magnitude 4.4 in Encino in 2014. That quake also shook a wide area and was the largest in the Los Angeles area in four years. It was the strongest to hit directly under the Santa Monica Mountains in the 80 years.The Santa Barbara area is home to a number of earthquake faults, the largest of which is the Santa Ynez fault, which is 80 miles long and runs just north of the city. That fault is believed to be capable of triggering an earthquake as powerful as 7.5.The great Santa Barbara quake of 1925, recorded as a magnitude 6.8, destroyed a significant portion of the city's downtown area, damaged rail lines and caused extensive landslides on bluffs. It killed 13 people and was felt as far away as Orange County.Since the Easter Sunday earthquake of 2010 that hit along the California-Mexico border, there have been 14 earthquakes of magnitude 5 or greater in Southern California. Hauksson estimated that perhaps about half of them were felt in Los Angeles. </s> A 5.4-magnitude aftershock rattled Searles Valley Friday morning, less than 24 hours after a 6.4 magnitude quake in the area shook Southern California.

The aftershock occurred just after 4 a.m. about 10 miles west of Searles Valley, according to the United States Geological Survey. It was the strongest of the more than 200 aftershocks that followed Thursday morning's quake.

An aftershock of this magnitude was expected by experts following Thursday's temblor.

Dr. Lucy Jones, a seismologist and founder of the Dr. Lucy Jones Center for Science & Society, estimated during a news conference hours after Thursday's earthquake that there was a 50 percent chance an aftershock of 5.0 magnitude would strike Thursday afternoon.

More: One of the strongest earthquakes in years rattles Southern California, damaging areas of Kern County

"It’s certain this area is going to be shaking a lot today," Jones said on Thursday. "Some of those aftershocks will exceed magnitude five."

The last time Southern California had an earthquake greater than magnitude 6.0 was in October 1999. The magnitude-7.1 quake was centered about 30 miles north of Joshua Tree National Park headquarters and was felt in Nevada, Arizona and Mexico.

Both Thursday's earthquake and its strongest aftershock occurred about 170 miles northwest of Palm Springs. Local experts said there's no need for additional concern in the Coachella Valley.

“In general, the earthquake hazard is high in the Coachella Valley, but this particular earthquake is not a cause of additional concern for people in the Palm Springs area,” said Abhijit Ghosh, a professor of geophysics at the University of California, Riverside, on Thursday afternoon.

This article will be updated as more information becomes available. </s> A magnitude 7.1 quake hit about 230 kilometres east of Tadine in New Caledonia's Loyalty Islands.

A strong earthquake has struck in the Pacific Ocean near New Caledonia but experts say there isn't a tsunami threat.

According to the United States Geological Survey (USGS), the magnitude 7.1 quake hit Wednesday afternoon about 230 kilometres east of Tadine in New Caledonia's Loyalty Islands.

The quake was about 290km from Isangel in Vanuatu. The USGS says it was about 26km deep.

There are no immediate reports of damage or injuries.

READ MORE:

* Tsunami waves hit alert New Caledonia and Vanuatu after big quake hits Pacific

* 6.8m earthquake near Tonga and Samoa

* Deep 6.8 magnitude earthquake strikes cyclone-affected Vanuatu

* Magnitude 5.7 quake hits north of Vanuatu

The Pacific Tsunami Warning Center says it does not expect a destructive Pacific-wide tsunami and there is no threat to Hawaii.

New Caledonia and Vanuatu sit on the Pacific's 'Ring of Fire', an arc of seismic faults around the Pacific Ocean where earthquakes and volcanoes are common.

The New Zealand Ministry of Civil Defence & Emergency Management have said there is no tsunami threat to New Zealand.

Earlier in the same day, a magnitude 4.4 earthquake rattled a wide area of Southern California. But there were no immediate reports of damage or injuries.

The temblor struck about 7.33pm (local time) and was centered about 4.8km north of La Verne, a San Gabriel Valley city about 40km east of downtown Los Angeles, according to a preliminary report by the US Geological Survey.

It was followed a minute later by a magnitude 3.4 quake.

The quake was about four miles deep, but it was felt sharply near the epicentre.

Vickie Carillo and her son were sitting on the couch of their La Verne home, watching Jaws 2, when the quake struck. "It was like if somebody had grabbed it and was shaking the house," Carillo told the Los Angeles Times.

Carillo said she screamed. Her family picked up their two Jack Russell terriers and ran outside, where they joined about a dozen neighbours.

STUFF Victor Flores said the California earthquake moved his whole house and sounded "like thunder".

Victor Flores said the temblor violently shook his two-story house in the hills.

"It was moving the whole house," he told the Times. "It shook hard for what seemed like 10 to 20 seconds, and then it just kept going. It was really loud too, kind of like thunder. It just hit really hard and quick."

The temblor made the water slosh in his swimming pool, Flores added.

The quake shook buildings for several seconds in downtown Los Angeles. It was also felt as a rolling motion dozens of miles away and as far away as the San Diego area, about 160km south. </s> Earthquake hits off Fukushima in Japan; no tsunami warning

TOKYO — A strong earthquake has shaken the same area in Japan hit by a magnitude-7.4 earthquake two days ago. No tsunami warning was issued.

The Japan Meteorological Agency says a magnitude-6.1 earthquake struck Thursday morning off the shore of southern Fukushima prefecture.

It said that there may be slight changes in sea levels, but there is no risk of damage from a tsunami.

The U.S. Geological Survey recorded the magnitude at 5.6.

The earthquake was felt in Tokyo, 225 kilometers (140 miles) southwest of the epicenter.

There were no immediate reports of damage or injuries. </s> A magnitude 5.3 earthquake struck near the Channel Islands on Thursday afternoon, the U.S. Geological Survey said. The quake was the strongest in Southern California in several years.

The temblor occurred just before 12:30 p.m. and was centered south of Santa Cruz Island. It was felt as far away as Bakersfield, Palmdale and the city of Orange, according to witnesses and the USGS.

The Los Angeles Police Department said it had not received any reports of injuries or damage since the earthquake struck.

The Los Angeles Fire Department said it went into “earthquake mode” in which firefighters deploy and check all major areas of concern, such as freeway overpasses, large buildings and infrastructure for damage. Firefighters said about an hour later that the city was not damaged.

Sgt. Eric Buschow, public information officer for the Ventura County Sheriff's Office, said the office had also received no reports of significant injuries or damage and no large influx of 911 calls.

The L.A. area feels an earthquake of this magnitude on average about once a year, said John Vidale, director of the Southern California Earthquake Center at USC.

There is a 1-in-20 chance that Thursday’s quake will lead to a larger one in the next few weeks, he said. But, more than likely, smaller aftershocks that may not even be felt will follow, he said.

The quake was too small and far away from the coast to trigger any tsunami concerns.

“It would never make a wave that you could see,” he said.

But it was large enough to active the state’s developing earthquake early-warning system.

Vidale said he and colleagues at USC heard beeping 10 to 15 seconds before the quake’s shaking reached their campus.

“We all felt it pretty well. It was small and distinct,” he said. “We heard the warning go off and then we heard the shaking.”

The early-warning system is under development by the USGS and is available only to a limited array of testers, but it is expected that more people will be eligible to test the system later this year.

One person said on Twitter that the warning gave them more than half a minute to prepare.

“I had 34 seconds warning — enough time to drop, cover, and hold on, which I would have done if I knew shaking was going to be strong,” wrote Alissa Walker.

The quake was initially reported as a magnitude 5.0 and upgraded later to 5.3.

Though there were no reports of damage, the quake was felt across a wide area and was a blunt reminder that California is earthquake country.

Earthquake that rattled L.A. area was strongest in years>>

“A 5.3 could be damaging if it was right under our feet,” Vidale said. “It’s right on the edge of being an earthquake that could be dangerous. It’s a reminder that we need to be ready in the future.”

The temblor was located near the Eastern Santa Cruz Basin Fault Zone, said Caltech seismologist Egill Hauksson, and seismologist Lucy Jones said on Twitter that the fault system "moves Southern California around a bend of the San Andreas fault."

"Earthquakes happen out there now and again. There’s a major offshore fault system," Hauksson said.

When asked why some people felt the earthquake but others nearby didn't, Hauksson said where a person is matters a lot. "People in high rises probably felt it pretty well," he said. People on softer soils might also feel stronger shaking.

The last quake to be felt this widely in the L.A. area was a 4.4 quake in Encino in 2014. That quake also shook a wide area and was the largest in the Los Angeles area in four years. That temblor was noted by seismologists as the strongest to hit directly under the Santa Monica Mountains in the 80 years.

The epicenter of Thursday’s quake was south of the Channel Islands. A 4.8 magnitude quake in the same area rattled the region in 2013.

The Santa Barbara area is home to a number of earthquake faults, the largest of which is the Santa Ynez fault, which is 80 miles long and runs just north of the city. That fault is believed to be capable of triggering an earthquake as powerful as magnitude 7.5.

The great Santa Barbara quake of 1925, recorded at a magnitude 6.8, destroyed much of the city’s downtown on State Street, damaged rail lines, caused extensive landslides and was felt as far away as Orange County. It killed 13 people.

Since the Easter Sunday earthquake of 2010 that hit along the California-Mexico border, there have been 14 earthquakes of magnitude 5 or greater in Southern California. Hauksson estimated that perhaps about half of them were felt in Los Angeles.

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

2:20 p.m.: This article was updated with reports that there was no damage in Los Angeles.

1:45 p.m.: This article was updated with comments from seismologists and the Los Angeles Fire Department.

1:05 p.m.: This article was updated with comments from John Vidale, director of the Southern California Earthquake Center, and information on past Southern California earthquakes.

12:50 p.m.: This article was updated with a comment from the Los Angeles Police Department.

12:40 p.m.: This article was updated with an upgrade to the quake’s magnitude and comments from the Ventura County Sheriff’s Office.

This article was originally published at 12:35 p.m. </s> Southern California was rattled Thursday by a magnitude 5.3 earthquake that struck near the Channel Islands.

The quake was the strongest in Southern California in several years, jangling some nerves but causing no major damage because it occurred offshore in the Pacific Ocean and not on land.

The quake did cause some minor landslides and earth movement on Santa Cruz Island, which was close to the epicenter, and rattled a bald eagle whose livestreamed reaction to the temblor went viral.

“A 5.3 could be damaging if it was right under our feet,” said John Vidale, director of the Southern California Earthquake Center at USC. “It’s right on the edge of being an earthquake that could be dangerous. It’s a reminder that we need to be ready in the future.”

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The temblor occurred just before 12:30 p.m. and was centered south of Santa Cruz Island, about 90 miles west of downtown Los Angeles. It was felt as far away as Bakersfield, Palmdale and the city of Orange, according to witnesses and the U.S. Geological Survey.

Earthquake early-warning system gave heads-up before 5.3 magnitude temblor hit L.A. area »

The L.A. area feels an earthquake of this magnitude on average about once a year, Vidale said.

There is a 1-in-20 chance that Thursday’s quake will lead to a larger one in the next few weeks, he said. But, more than likely, smaller aftershocks that may not even be felt will follow, he said.

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The quake was too small and too far away from the coast to trigger any tsunami concerns.

“It would never make a wave that you could see,” Vidale said.

(Los Angeles Times )

But it was large enough to activate the state’s developing earthquake early-warning system.

Vidale said he and colleagues at USC heard beeping 10 to 15 seconds before the quake’s shaking reached their campus.

“We all felt it pretty well. It was small and distinct,” he said. “We heard the warning go off and then we heard the shaking.”

The early-warning system is under development by the USGS and is available only to a limited array of testers, but it is expected that more people will be eligible to test the system later this year.

It works on a simple principle: The shaking from an earthquake travels at the speed of sound through rock — which is slower than the speed of today’s communications systems.

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For example, it would take more than a minute for a magnitude 7.8 earthquake that starts at the Salton Sea and travels up the state’s longest fault, the San Andreas, to shake Los Angeles, 150 miles away. An early-warning system would give L.A. residents crucial seconds, and perhaps even more than a minute, to prepare.

It got a significant boost in the federal budget signed into law in March, defying an earlier proposal by President Trump to end federal funding for the program.

As part of the $1.3-trillion budget bill approved by Congress and signed by Trump, officials approved $22.9 million for the project. That more than doubles the $10.2 million it got in the previous year’s budget.

The USGS has said it planned to begin issuing limited public alerts from the system by the end of this year, as long as funding wasn’t cut. Southern California is one area where the network of seismic sensors is dense enough at present to begin early warnings.

That was the first earthquake I’ve felt since I got access to the @EarlyWarningLab beta app. I had 34 seconds warning—enough time to drop, cover, and hold on, which I would have done if I knew shaking was going to be strong. pic.twitter.com/Bx4Sn2imUW — Alissa Walker (@awalkerinLA) April 5, 2018

Earthquake that rattled L.A. area was strongest in years »

The temblor was located near the East Santa Cruz Basin fault zone, said Caltech seismologist Egill Hauksson, and seismologist Lucy Jones said on Twitter that the fault system “moves Southern California around a bend of the San Andreas fault.”

“Earthquakes happen out there now and again. There’s a major offshore fault system,” Hauksson said.

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When asked why some people felt the earthquake but others nearby didn’t, Hauksson said where a person is matters a lot. “People in high rises probably felt it pretty well,” he said. People on softer soils might also feel stronger shaking.

Among those creatures startled by the quake were the feathered inhabitants of a bald eagle’s nest high above Santa Cruz Island.

A National Park Service live web camera trained on the nest shows a parent eagle and three chicks as their tree begins shaking. The parent flies off as the chicks look around bewildered. The parent eagle returns moments later, after the shaking.

WATCH: Eagle and chicks on Santa Cruz Island react to 5.3 Channel Islands earthquake https://t.co/Tm7D67mSgP pic.twitter.com/AwvVf6823b — CBS Los Angeles (@CBSLA) April 5, 2018

One of the last quakes to be felt this widely in the L.A. area was a magnitude 4.4 in Encino in 2014. That quake also shook a wide area and was the largest in the Los Angeles area in four years. It was noted by seismologists as the strongest to hit directly under the Santa Monica Mountains in 80 years.

Another widely felt earthquake came later that same month, a magnitude 5.1 centered in La Habra. Residents close to the epicenter reported toppled furniture, broken glass and fallen pictures; several water mains broke, a rock slide caused a car to overturn, and more than a dozen homes and apartments were declared uninhabitable because of possible structural damage.

The last time an area earthquake produced more energy than Thursday’s temblor was in 2012, when a magnitude 5.4 earthquake struck the border town of Brawley in Imperial County. Local officials reported 20 mobile homes shifted from their foundations and cosmetic damage to downtown buildings.

The epicenter of Thursday’s quake was south of the Channel Islands. A magnitude 4.8 quake in the same area rattled the region in 2013, but that epicenter was much closer to the coast, three miles away from Isla Vista, and produced moderate shaking enough to knock down a few photo frames.

A park service spokeswoman told KEYT that Thursday’s quake sent some bricks toppling off a chimney from a historic ranch property built in the 1860s on one of the islands.

The Santa Barbara area is home to a number of earthquake faults, the largest of which is the Santa Ynez fault, which is 80 miles long and runs just north of the city. That fault is believed to be capable of triggering an earthquake as powerful as magnitude 7.5.

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

The great Santa Barbara quake of 1925, recorded at a magnitude 6.8, destroyed much of the city’s downtown on State Street, damaged rail lines, caused extensive landslides and was felt as far away as Orange County. It killed 13 people.

Since the magnitude 7.2 Easter Sunday earthquake of 2010 that hit along the California-Mexico border, there have been 14 earthquakes of magnitude 5 or greater in Southern California. Hauksson estimated that perhaps about half of them were felt in Los Angeles.

Seismologist Lucy Jones said she received a complaint Thursday about her calling earthquake activity like this normal. Some people on Twitter asked her what the larger meaning was behind the earthquake. But there isn’t any larger meaning nor a clue of when the next big earthquake will come or where it will hit, she said.

“There’s a human need for creating patterns,” Jones said. “It doesn’t make us safer or less safe. It’s a reminder of our reality.”

Earthquake activity in the Channel Islands shouldn’t be all that surprising. After all, earthquakes created the Channel Islands.

In fact, mountains throughout California are generally creations of earthquakes, Jones said.

Earthquakes pushed up the Santa Ynez Mountains in Santa Barbara and Ventura counties. The Santa Monica and Hollywood faults were responsible for creating the Santa Monica Mountains. The Sierra Madre fault is pushing up the San Gabriels. The Chino Hills were thrust upward by the Chino Hills fault.

“If you see mountains in California, that means something is moving up those mountains faster than erosion is wearing them down,” Jones said in an interview. “Basically, when you see mountains, think earthquakes in California.”

Staff writer James Queally contributed to this report.

joseph.serna@latimes.com

Twitter: @JosephSerna

ron.lin@latimes.com

Twitter: @ronlin

UPDATES:

12:05 p.m., April 6: This article was updated to include another recent earthquake widely felt in L.A. in recent years, the magnitude 5.1 earthquake centered in La Habra.

6:10 p.m.: This article was updated with additional information about the early-warning system and seismic history.

3:50 p.m.: This article was updated with reports of a damaged chimney on a historic property near the quake epicenter.

3:15 p.m.: This article was updated with details on a bald eagle nest on Santa Cruz Island.

2:20 p.m.: This article was updated with reports that there was no damage in Los Angeles.

1:45 p.m.: This article was updated with comments from seismologists and the Los Angeles Fire Department.

1:05 p.m.: This article was updated with comments from John Vidale, director of the Southern California Earthquake Center, and information on past Southern California earthquakes.

12:50 p.m.: This article was updated with a comment from the Los Angeles Police Department.

12:40 p.m.: This article was updated with an upgrade to the quake’s magnitude and comments from the Ventura County Sheriff’s Office.

This article was originally published at 12:35 p.m. on April 5, 2018. </s> RIDGECREST, Calif. -- A magnitude 5.4 earthquake hit near Searles Valley Friday morning, one day after a powerful 6.4 quake hit the region The quake is one in a series of aftershocks to hit the area since Thursday's 6.4 earthquake. It struck at approximately 4:07 a.m. local time and was centered about 9.7 miles from west of Searles Valley and 10.8 miles north-northeast of Ridgecrest, according to the U.S. Geological Survey.There were no immediate reports of damage in the surrounding area. People felt the quake in various parts of Los Angeles and Orange counties.About an hour and a half after the Friday quake, Los Angeles Fire Department tweeted that it had completed earthquake mode and gone back to normal operations.Thursday's earthquake was the strongest earthquake in the Southern California region since 1999, with people throughout Southern California reported feeling it. Minor cracks, multiple water mains ruptured and several power lines were down after the quake hit, according to the San Bernardino County Fire Department.Firefighters in Kern County responded to nearly two dozen incidents including medical emergencies and reports of a burning home.Kern County Fire Chief David Witt said emergency responders also contended with small vegetation fires, gas leaks and reports of cracked roadways in Ridgecrest, a city with a population of 28,000. Twenty patients were evacuated from Ridgecrest Regional Hospital as a precaution amid a slew of aftershocks, nine of which were measured at magnitude 4.0 or above. </s> LOS ANGELES (AP) — A strong earthquake rattled a large swath of Southern California and parts of Nevada on Thursday morning, making hanging lamps sway and photo frames on walls shake. There were no immediate reports of damage or injuries but a swarm of aftershocks were reported.

The 6.4 magnitude quake struck at 10:33 a.m. in the Mojave Desert, about 150 miles (240 kilometers) northeast of Los Angeles, near the town of Ridgecrest, California. It is the strongest quake to hit the region in 20 years.

The United State Geological Survey initially said it measured at a 6.6 magnitude.

"It almost gave me a heart attack," said Cora Burke, a waitress at Midway Cafe in Ridgecrest, a town of 28,000 people. "It's just a rolling feeling inside the building, inside the cafe and all of a sudden everything started falling off the shelf, glasses, the refrigerator and everything in the small refrigerator fell over."

Video posted online of a liquor store in Ridgecrest showed the aisles filled with broken wine and liquor bottles, knocked down boxes and other groceries strewn on the floor. There was at least one house on fire in Ridgecrest.

Veteran seismologist Lucy Jones said the earthquake Thursday was the strongest to hit Southern California in 20 years.

The previous large quake was a 7.1 on that struck in the area on October 16, 1999, she said.

Jones told reporters at the California Institute of Technology in Pasadena, California, that the 6.4 quake centered in the Mojave Desert near the town of Ridgecrest was preceded by a magnitude 4.3 temblor about a half hour earlier.

She says it was vigorous aftershock sequence occurring and that she wouldn't be surprise if a magnitude 5 quake occurred during the aftershocks.

"We should be expecting lots of aftershocks," she said.

People from Las Vegas to the Pacific Coast reported feeling a rolling motion and took to social media to report it.

Local emergency agencies also took to social media to ask people to only call 911 for emergencies.

"We are very much aware of the significant earthquake that just occurred in Southern California. Please DO NOT call 9-1-1 unless there are injuries or other dangerous conditions. Don't call for questions please," the LAPD said in a statement published on Twitter.

Ashleigh Chandler, a helicopter rescue EMT at Fort Irwin, California, said the quake happened as she was getting ready for a July 4th party.

"I was just in the living room getting everything ready, we start to feel the shaking, so then I look up and then the wine bottles start rattling and I thought, 'They're going to fall.'

"My stepson was in the house and my dog, so we just got everyone outside and then it ended. It was like 15, 20 seconds, maybe. It was pretty good shaking, so I'm out of breath."

Rodriguez reported from San Francisco. Associated Press writer Rachel Lerman in San Francisco and AP Radio reporter Shelly Adler in Washington, D.C., contributed.

The quote in the story from Ashleigh Chandler has been corrected to say stepson, not sister.
A magnitude 7.1 earthquake hits Southern California just a day after a magnitude 6.4 earthquake in the same area.