Millions of residents in the Los Angeles area were rattled by a 4.7 magnitude earthquake that hit early on Thursday morning and came as the region continues to battle multiple wildfires that yet to be brought under control.
The quake’s epicenter was 4 miles north of Malibu, according to the US Geological Survey. The tremor unleashed boulders on to a Malibu road, visibly shook Santa Monica’s historic 1909 wooden pier and jolted people from bed. No injuries or damages were immediately reported.
The shaking was felt as far as 45 miles (72km) away in Orange county, where people reported items moving in their homes, and was followed by several smaller aftershocks. A live camera at the 115-year-old Santa Monica Pier, about 10 miles away from Malibu, showed several seconds of intense shaking. Bruce Silverstein, the Malibu councilmember, said he has lived in the community for 13 years and this was the hardest quake he’d felt yet.
“Our house shook for about two or three seconds. I was concerned the windows were going to pop,” Silverstein said.
Some of LA’s celebrity residents including Paris Hilton, took to social media shortly after. “That #Earthquake was scary,” the heiress and media personality wrote on X. Reality TV star Khloe Kardashian posted: “Damn that was a big one.”
Thursday’s tremor was one of many smaller earthquake that have recently hit the region, including a 4.4 magnitude quake that rattled nerves and swayed building last month. There have now been 14th earthquake with a magnitude of 4.0 or higher in southern California this year. While this is above the average of eight to 10 a year in the past few decades, it’s too soon to tell whether the increased activity is statistically significant, said Lucy Jones, a seismologist at the California Institute of Technology. The previous highest number was 13 earthquakes of this size in 1988.
The quake happened as the greater LA area has been dealing with three major wildfires that torched dozens of homes and forced thousands to evacuate. The blazes erupted during a blistering heat wave that has only just begun to ease.
Firefighters hoped to take advantage of cooler weather as they slowly gained the upper hand, but not before dozens of homes were destroyed and thousands of people were forced to evacuate.
California is only now heading into the teeth of the wildfire season but already has seen nearly three times as much acreage burn than during all of 2023. The wildfires have threatened tens of thousands of homes and other structures across southern California since they accelerated during a triple-digit heatwave over the weekend.
No deaths have been reported, but at least a dozen people, mainly firefighters, have been treated for injuries, mostly heat-related, authorities said.
In the small community of Wrightwood, about 90 minutes outside Los Angeles, authorities implored residents to flee the exploding Bridge fire, which grew tenfold in a day and has burned more than 50,000 acres and torched at least 33 homes.
Quick Guide
US wildfire terms, explained
Show
Acres burned
US wildfires are measured in terms of acres. While the size of a wildfire doesn’t necessarily correlate to its destructive impact, acreage provides a way to understand a fire’s footprint and how quickly it has grown.
There are 2.47 acres in a hectare, and 640 acres in a square mile, but this can be hard to visualise. Here are some easy comparisons: one acre equates to roughly the size of an American football field. London’s Heathrow airport is about 3,000 acres. Manhattan covers roughly 14,600 acres, while Chicago is roughly 150,000 acres, and Los Angeles is roughly 320,000 acres.
Megafire
A megafire is defined by the National Interagency Fire Center as a wildfire that has burned more than 100,000 acres (40,000 hectares).
Containment level
A wildfire’s containment level indicates how much progress firefighters have made in controlling the fire. Containment is achieved by creating perimeters the fire can’t move across. This is done through methods such as putting fire retardants on the ground, digging trenches, or removing brush and other flammable fuels.
Containment is measured in terms of the percentage of the fire that has been surrounded by these control lines. A wildfire with a low containment level, such as 0% or 5%, is essentially burning out of control. A fire with a high level of containment, such as 90%, isn’t necessarily extinguished but rather has a large protective perimeter and a rate of growth that is under control.
Evacuation orders and warnings
Evacuation warnings and orders are issued by officials when a wildfire is causing imminent danger to people’s life and property. According to the California office of emergency services, an evacuation warning means that it’s a good idea to leave an area or get ready to leave soon. An evacuation order means that you should leave the area immediately.
Red flag warning
A red flag warning is a type of forecast issued by the National Weather Service that indicates when weather conditions are likely to spark or spread wildfires. These conditions typically include dryness, low humidity, high winds and heat.
Prescribed burn
A prescribed burn, or a controlled burn, is a fire that is intentionally set under carefully managed conditions in order to improve the health of a landscape. Prescribed burns are carried out by trained experts such as members of the US Forest Service and Indigenous fire practitioners. Prescribed burns help remove flammable vegetation and reduce the risk of larger, more catastrophic blazes, among other benefits.
Prescribed burning was once a common tool among Native American tribes who used “good fire” to improve the land, but was limited for much of the last century by a US government approach based on fire suppression. In recent years, US land managers have returned to embracing the benefits of prescribed burns, and now conduct thousands across the country every year.
Erin Arias, a resident, said she was racing up the mountain when she received the order to leave and did so, grabbing her passport and dog. On Wednesday, she and her husband doused water on the roof of their still-standing home. Their cat was missing, she said.
“It’s absolutely scary,” Arias said, looking at the burned embers of her neighbor’s home. “We’re really lucky.”
The UCLA climate scientist Daniel Swain said the fire moved extraordinarily fast across complex terrain, probably giving residents less time to evacuate than usual and surprising even seasoned fire officials.
“[The fire] had to go up mountain sides, burn down slope, jump across valleys, burn across new ridges, and then make it down slope again at least two other times in effectively one burning period,” Swain said.
The governor, Gavin Newsom, sent national guard troops in to help with evacuations, and the White House said Joe Biden was monitoring the situation.
Elsewhere, more than 5,500 homes in Riverside county were under evacuation orders due to the so-called Airport fire, affecting more than 19,000 residents. Several recreational cabins and structures in the Cleveland national forest have been damaged.
In San Bernardino county, some 65,600 homes and buildings were under threat by the Line fire, and residents along the southern edge of Big Bear lake, a mountain town popular for winter sports and lake recreation, were told to leave on Tuesday.
On the Nevada border with California near Reno, the Davis fire forced thousands of people to evacuate over the weekend, destroyed one home and a dozen structures and charred nearly 9 sq miles (23 sq km) of timber and brush along the Sierra Nevada’s eastern front.
