Tag Archives: Ridgecrest

California expanding early quake detection and warning system

FILE PHOTO - A house left destroyed by a powerful magnitude 7.1 earthquake, triggered by a 6.4 the previous day, is seen at night near the epicenter in Trona, California, U.S., July 6, 2019. REUTERS/David McNew

By Alex Dobuzinskis

LOS ANGELES (Reuters) – California officials are spending more than $40 million on an earthquake early warning system that in addition to alerting the public could also be used to automatically halt trains and open fire station doors moments before a major tremor actually strikes.

California Governor Gavin Newsom announced after a magnitude 7.1 quake shook Southern California on Friday that the state has already installed 70 percent of the 1,115 early detection sensors it needs to have the system in place statewide.

“I think the whole state’s on notice right now about the opportunity that’s in front of us,” said Ryan Arba, chief of seismic hazards under the governor’s Office of Emergency Services (OES).

Emergency management officials have said they intend to have the statewide warning system in place by mid-2021 to serve California’s roughly 40 million residents.

In a jolt that grabbed the attention of seismically jaded Californians, Friday’s magnitude 7.1 temblor ruptured gas lines and sparked numerous fires in Ridgecrest, a remote town of fewer than 30,000 people in the Mojave Desert, about 125 miles (200 km) northeast of Los Angeles. It came one day after a 6.4 quake in the same area.

The back-to-back quakes ended a period of relative seismic calm in Southern California and brought renewed awareness to development of the state’s early warning system for earthquakes.

Japan developed the world’s most advanced earthquake early warning system after the 1995 Kobe earthquake. It relies on more than 4,000 sensors and is based on the same principles of physics that California is using to build its system.

FAST-MOVING P-WAVES

Like in Japan, the California network is designed to detect the fast-moving seismic P-waves that are unleashed by earthquakes and can reach a sensor before the ground starts moving in a given area. Many animals are able to feel P-waves, according to the U.S. Geological Survey (USGS).

In general, communities farthest away from the epicenter of a quake would receive the most advance warning.

In a best-case scenario, a rupture of the San Andreas Fault near California’s border with Mexico would be far enough away from Los Angeles to give the nation’s second-largest city 60 seconds of warning before ground motion from the quake actually arrives, Arba said. Communities very close to a quake’s origin would receive little or no warning.

Officials in Los Angeles County in January introduced a “ShakeAlertLA” mobile phone application that can transmit an early warning to residents who have installed the app, giving them extra seconds to take cover before a major quake hits.

The “ShakeAlertLA” app was not activated for either of the Ridgecrest earthquakes because the projected intensity of shaking for Los Angeles County was below required thresholds, the U.S. Geological Survey said.

Officials plan to eventually expand the system statewide and to tie it into the operations of medical facilities, emergency responders, power companies, hazardous materials management, mass transit and other workplaces to minimize damage and injuries, according to OES.

Already, the Bay Area Rapid Transit (BART) system in and around San Francisco has connected the early detection network to its rail service to automatically slow down its trains, and hopefully reduce the risk of a derailment, if a major earthquake is about to strike, Arba said.

Southern California’s Metrolink commuter rail system halted service after Friday’s 7.1 earthquake in Ridgecrest, but orders to stop the trains only went out by radio when shaking was felt by officials at the operations center in Pomona, east of Los Angeles, Metrolink spokesman Scott Johnson said.

The Metrolink board has voted to spend $4.9 million in state funds to eventually automate the halting of its trains via the quake detection and warning system, Johnson said.

Two fire stations in the Silicon Valley community of Menlo Park in Northern California are likewise connected to seismic sensors so that detection of a large quake raises their doors, Arba said. Officials hope to have other fire stations take similar precautions.

In hospitals, an early warning system would allow doctors performing surgery to pause before shaking begins to prevent any harm to their patients, and in tall buildings elevators could be equipped to automatically descend to the ground floor, according to OES.

University of California at Los Angeles engineering professor John Wallace said the potential uses of the early warning system are widespread and have not all been mapped out.

“Once you provide the system, you’d be surprised how many ways people will find to use it to their benefit,” he said.

(Reporting by Alex Dobuzinskis; Editing by Sandra Maler)

Shaken communities take stock of damage after Southern California quakes

A house left destroyed by a powerful magnitude 7.1 earthquake, triggered by a 6.4 the previous day, is seen at night near the epicenter in Trona, California, U.S., July 6, 2019. REUTERS/David McNew

By Alan Devall

RIDGECREST, Calif. (Reuters) – High desert communities in Southern California on Saturday assessed damage and braced for potentially dangerous aftershocks from a major earthquake that shook buildings, ruptured gas lines and sparked fires near the remote epicenter of the second temblor in as many days.

A house is left destroyed by an earthquake, triggered by a previous day quake, near the epicenter in Trona, California, U.S., July 6, 2019. REUTERS/David McNew

A house is left destroyed by an earthquake, triggered by a previous day quake, near the epicenter in Trona, California, U.S., July 6, 2019. REUTERS/David McNew

The powerful magnitude 7.1 earthquake rocked the Mojave Desert town of Ridgecrest south of Death Valley National Park as darkness fell on Friday, jolting the area with eight times more force than a 6.4 quake that struck the same area 34 hours earlier.

California Governor Gavin Newsom placed the state Office of Emergency Services (OES) on its highest alert and requested federal assistance.

He told a news conference in Ridgecrest on Saturday that he had just got off a phone call with U.S. President Donald Trump, seeking a presidential emergency declaration.

“I have full confidence that the president will be forthcoming, in immediate terms, with the formal declaration,” Newsom said, flanked by first responders.

Cracks emerge on a road after an earthquake broke in Trona, California, U.S., in this photo from the USGS posted on July 6, 2019. USGS/Handout via REUTERS

Cracks emerge on a road after an earthquake broke in Trona, California, U.S., in this photo from the USGS posted on July 6, 2019. USGS/Handout via REUTERS

There were several minor to moderate injuries, OES Director Mark Ghilarducci told reporters.

“No reports of any fatalities, so I think we’re very lucky there,” he said.

There were reports of building fires, mostly as a result of gas leaks or gas-line breaks, Ghilarducci said.

State officials said all roads damaged by the quakes had been repaired and reopened.

Violent shaking also caused water-main breaks and knocked out power and communications to parts of Ridgecrest, home to about 27,000 people some 125 miles (200 km) northeast of Los Angeles.

Officials warned there was sure to be a significant number of aftershocks, including possible powerful ones, and advised residents to ensure they had necessary supplies.

“I’ve said this ad nauseam: be prepared for the worst,” said Newsom, who on Saturday met victims in the hospital and visited a hardware store where the earthquake hurled products from shelves and left ceiling tiles scattered across the aisles.

Standing outside her damaged home in Ridgecrest, life-long resident Sierra Wood said it was heartbreaking and scary.

“This is the first time I’ve ever seen anything like this,” she said. “I mean – they say that it’s happened and you’ve heard about it. But once you’re in it, it’s completely different, it’s terrifying. It’s terrifying.”

Her husband, Keith Wood, said the aftershocks were grueling.

“It’s like when, when do we get a break from it?” he said. “When is enough enough? Mother Nature has had her way. Give us a break now, OK?”

Evacuees leave a fire station with their belongings after an earthquake near Trona, California, U.S. July 6, 2019. REUTERS/Gene Blevins

Evacuees leave a fire station with their belongings after an earthquake near Trona, California, U.S. July 6, 2019. REUTERS/Gene Blevins

The sprawling U.S. Naval Air Weapons Station China Lake just northwest of Ridgecrest was evacuated of all non-essential personnel following the quake.

The facility, which at more than 1.1 million acres (445,000 hectares) is larger than the state of Rhode Island, reported no injuries. Authorities were assessing any damage to buildings or other infrastructure, according to a post on the base’s Facebook page.

MORE TO COME

Friday’s earthquake was widely felt across Southern California, including greater Los Angeles, where shaking in some areas lasted about 40 seconds. Low-level rumbling extended as far north as the San Francisco Bay area and beyond to Reno, Nevada, and as far east as Phoenix, Arizona.

Seismologists said the initial quake on Thursday, and scores of smaller ones that followed it, proved to be foreshocks to Friday’s larger temblor, which now ranks as Southern California’s most powerful since a 7.1 quake that struck near a U.S. Marine Corps base in the Mojave Desert in 1999.

The U.S. Geological Survey said Friday’s quake was immediately followed by at least 16 aftershocks of magnitude 4 or greater and warned of a 50 percent chance of another magnitude 6 quake in the coming days. Geologists put the chance of another magnitude 7 tremor at 10 percent over the next week.

There were hundreds of aftershocks of 2.5 magnitude or greater in the area surrounding the epicenter, according to USGS data.

Victor Abdullatif was helping clean up broken bottles and other debris inside his father’s liquor store, the Eastridge Market, which sustained damage to its ceiling, and found the periodic aftershocks unnerving.

“They’re still scary because you almost don’t know, ‘Is this going to be a full earthquake?’ You have to kind of have faith that it’s just an aftershock,” he told Reuters.

The last major destructive quake to hit Southern California was the 6.7 magnitude Northridge quake in 1994, which struck a densely populated area of Los Angeles. It killed 57 people and caused billions of dollars in property damage.

The comparatively limited damage from Friday’s quake, which packed greater force than the Northridge event, was a function of its location in a remote, less developed area.

Its ground motion, however, startled seismically jaded Southern Californians over a wide region.

Pools in Los Angeles sloshed wildly, and TV cameras at Dodger Stadium were shaking as they filmed the night Major League Baseball game between the Los Angeles Dodgers and San Diego Padres.

A television anchorwoman ducked out of sight during a local newscast as shouts of “get under a desk” were heard in the background.

(Reporting by Alan Devall; Additional reporting by Bill Tarrant, Steve Gorman, Alex Dobuzinskis, Joseph Ax and Keith Coffman; Writing by Steve Gorman; Editing by Toby Chopra, Will Dunham and David Gregorio)