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Sonntag, 7. Juli 2019

AFTER M 7.1 QUAKE SHAKEALERT SYSTEM REPORTED: NO SHAKING EXPECTED









Strongest earthquake since 20 years
rattles Southern California

After Ridgecrest earthquake:
NO SHAKING EXPECTED

Did ShakeAlert work or not?
It detected the quakes, but did not issue alerts:
Despite ‘Shake Alert’ Warning System,
Los Angeles Residents Did Not Receive Notification
Richard Allen @RAllenQuakes

Despite ‘Shake Alert’ Warning System,
Los Angeles Residents Did Not Receive Notification

By Scott Budman
Published Jul 4, 2019 at 5:00 PM | Updated at 6:29 PM PDT on Jul 4, 2019

Seismologists say a new warning system being tested gave them nearly a full minute warning that an earthquake was coming, but residents in Southern California said they did not receive the alert.
Bay Area residents have seen a "shake alert" in action as it was developed, and on Thursday, United States Geological Survey officials said the warning system worked during the Ridgecrest earthquake.
"The idea is to give you warning that an earthquake has occurred, and you're about to feel a strong shaking," said Dr. Angela Chung, an early warning expert with the UC Berkeley Seismology Lab.
Chung said the alert worked and gave the USGS about 48 seconds worth of warning Thursday. But the alert did not go out to the people in Los Angeles because it didn’t measure strong enough.
Ridgecrest On the Road to Recovery, Officials Urge Residents to Be Prepared for Natural Disasters
"We know that the system worked, but the app has parameters; it doesn't give a message if it’s below this level," said Dr. Lucy Jones, a seismologist with Caltech.
By the time the quake reached the big cities, it didn’t trigger the alert, Chung said. The alert has a limit so residents don’t receive a notification every time there is an earthquake.
"We don’t want to be a nuisance, to tell you about every little teeny, tiny earthquake because that’s not what the system is designed for," Chung said. "The system is designed to save lives and property and damage."
4 Shot in San Jose; Suspect Remains at Large: Police
Experts said it’s a fine line between providing an ample warning in advance of a strong earthquake or "over" warning residents ahead of the small ones.


**********

After big Southern California earthquake,
months of aftershocks to follow
UPDATED ON: JULY 6, 2019 / 4:40 PM / CBS NEWS

Crews in Southern California were assessing the damage Saturday after the region was rattled by another powerful earthquake late Friday evening. The magnitude 7.1 quake caused injuries, sparked fires and closed roadways but no deaths were reported.

The epicenter of Friday night's 7.1 magnitude earthquake was 11 miles from Ridgecrest in the same area where a 6.4 magnitude temblor hit just a day earlier. The latest earthquake happened just after 8 p.m. local time and was centered in the Mojave Desert near the town of Ridgecrest, which is still recovering from a 6.4 quake on the Fourth of July. Ridgecrest used to be known as the earthquake capital of the world because it had so many small quakes.

Social media posts showed restaurant lights swaying, items crashing from store shelves and vehicles shaking violently more than 100 miles from the center of the quake.

Friday night's quake is Southern California was most powerful one since a 7.1 quake struck near a U.S. Marine Corps base in the Mojave Desert in 1999. The last earthquake to cause major destruction in the region was in 1994 when a 6.7 magnitude quake in densely populated Northridge killed 57 people and caused billions of dollars in damage.

Scientists expect more shaking in region
A seismologist in California says scientists believe the sequence of earthquakes striking the Mojave Desert will produce more than 30,000 quakes of magnitude 1 or greater over six months.

Small town hit hard by earthquake
Fire officials say as many as 50 structures in the small town of Trona were damaged by the magnitude 7.1 earthquake Friday night in Southern California. In addition, San Bernardino County Supervisor Robert Lovingood said Saturday that damaged water lines prompted FEMA to deliver a tractor-trailer full of bottled water to the town, and firefighters were checking numerous reports of gas leaks.

In Trona, Calif. the town was temporarily cut off after the earthquake, when officials shut down a highway connecting Trona to Ridgecrest because of rockslides and cracks in the roadway. Julia Doss, who maintains the Trona Neighborhood Watch page on Facebook, said residents reported that chimneys and entire walls collapsed during the quake. She said the only food store in town has been shuttered.

Navy base "not mission capable" after quake
Multiple earthquakes that struck the Ridgecrest area left Naval Air Weapons Station China Lake "not mission capable until further notice," the base announced Saturday. In a Facebook post, the base said that Rear Admiral Bette Bolivar issued an evacuation order for non-essential active duty, drilling reservists, civilian employees, and dependents to evacuate to a radius of 100 miles from Naval Base Ventura County.

National Guard mobilized

The California National Guard was sending 200 troops, logistical support and aircraft, said Maj. Gen. David Baldwin. The Pentagon had been notified, and the entire California Military Department was put on alert, he said.

No deaths reported from quake
A fire official says there were no fatalities or major injuries in Ridgecrest after the earthquake on Friday night. Kern County Fire Chief David Witt also said Saturday there were no major building collapses but some structures could be weakened from the back-to-back quakes.

Amusement parks closed
The quake affected amusement parks across two states. Six Flags Magic Mountain in Santa Clarita and Disneyland in Orange County closed their rides while the Big Apple Coaster swayed at the New York-New York hotel in Las Vegas.

California governor issues emergency declaration
Governor Gavin Newsom issued an emergency declaration in response to the damage reported in Ridgecrest. "On behalf of all Californians, I offer my heartfelt support to those affected by tonight's earthquake near Ridgecrest. The State of California will continue to offer support to aid residents in the region," he said in a statement.

"I have also activated the State Operations Center in Mather, California to its highest level and the center is already working closely with state, federal and local emergency managers and first responders."


In Kern County, houses throughout the town were strewn with books, fallen televisions and broken glass, but most concerning is the structural damage and cracks that can be seen in foundations.

"I was inside the house and it started shaking," resident Randy Witcher said. "I was in my lounge chair and it started shaking and it continued."

"I fell down on the front porch," he said. "It was very loud. You talk about a train rumbling, and that is what it sounds like."

Dozens of aftershocks reported
Dozens of aftershocks have been reported following Friday evening's 7.1-magnitude earthquake that hit near Ridgecrest, just one day after a 6.4 magnitude quake rocked the area, CBS Los Angeles reports. Seismologists are anticipating as many as 410 quakes of magnitude 3 or higher.

​More aftershocks expected
There's a very good chance the region could get more 5 magnitude aftershocks. There is a 1 in 20 chance the region could get a bigger earthquake. Seismologist Lucy Jones said there have been more than a thousand aftershocks since a 6.4 magnitude quake rattled the same region on Independence Day. That tremor is now considered a foreshock to the much larger quake Friday night. If the 7.1 measurement sticks, it would be the largest earthquake to shake the region in two decades.

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