Earthquake In LA? Nope, That Was A Sonic Boom That Rattled Your Home's Windows This AM

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LAist 09 July, 2021 - 01:20pm 70 views

People have been asking about the "earthquake" in LA around 9:20 this morning. Many people report feeling it but the seismograms clearly show the earth was not moving, only the air. So it was a sonic boom. https://t.co/OmoIoikKdv

Even though it wasn’t a quake, now’s still a good time to prepare for one.

Read full article at LAist

Sonic boom felt in Los Angeles area

FOX 11 Los Angeles 10 July, 2021 - 01:00am

That Was No Earthquake — Mysterious Sonic Boom Rattles SoCal

Patch.com 09 July, 2021 - 06:13pm

LOS ANGELES, CA — What thousands of people across the Southland thought was an earthquake Friday morning turned out to be a sonic boom that rattled windows over hundreds of miles. What caused the sonic boom, however, is a mystery.

The jarring boom occurred at about 9:20 a.m., prompting hundreds of people from Thousand Oaks to Huntington Beach to report an earthquake to the U.S. Geological Survey. The bulk of the reports came in from the Los Angeles and San Gabriel Valley areas.

But it was no quake, confirmed seismologist Dr. Lucy Jones. Seismograms showed no earth movement at the time.

"People have been asking about the 'earthquake' in LA around 9:20 this morning. Many people report feeling it, but the seismograms clearly show the earth was not moving, only the air. So it was a sonic boom," tweeted Jones. "The distribution of people who felt the sonic boom from strongly suggests the source was a supersonic aircraft over the ocean."

Most military bases in Southern California don't operate supersonic aircraft. Edwards Airforce Base in Kern County is home to the Air Force Test Center.

"Our air space is the only supersonic flight corridor in the nation," said Edwards Airforce Base Public Affairs Specialist Grady Fontana.

"Sonic booms are caused by an object moving faster than sound -- about 750 miles per hour at sea level. An aircraft traveling through the atmosphere continuously produces air-pressure waves similar to the water waves caused by a ship's bow," according to the Base's website. "When the aircraft exceeds the speed of sound, these pressure waves combine and form shock waves which travel in all directions and eventually reach the ground. The sound heard on the ground is the sudden onset and release of pressure after the buildup by the shock wave."

Fontana confirmed aircraft did pass through the Edwards Airforce Base airspace Friday morning, but that activity didn't appear to coincide with the sonic boom that rattled the region.

A sonic boom can carry for hundreds of miles, and it's possible the supersonic jet took off from an aircraft carrier out to sea. Patch checked in with NASA, Camp Pendleton, Marine Corps Air Station Miramar, the Seal Beach Naval Weapons Station, the Los Alamitos Joint Forces Training Base, the Marine's 3rd Marine Aircraft Wing and the Naval Base Coronado. None said they were involved with supersonic flight operations in the area Friday.

The military doesn't always fess up to noisy operations. However, after startling residents across San Diego last month with an unanticipated sonic boom, Marine Corps Air Station Miramar sent out a cheeky tweet, "So, about the other night...#SanDiegoBoom."

No, that wasn’t a quake SoCal — it was a sonic boom

KTLA Los Angeles 09 July, 2021 - 03:08pm

A sonic boom was recorded at about 9:20 a.m. on July 9, 2021, near San Dimas, according to the U.S. Geological Survey.

A day after a 6.0 magnitude earthquake jostled a wide swath of Northern California, residents in Southern California got a jolt Friday morning.

But what some thought was another quake turned out to be a sonic boom that was recorded about 9:20 a.m., according to the U.S. Geological Survey.

The blast of sound energy occurred about one mile south of San Dimas, the USGS reported. But the effects rippled out toward the coast, where several people reported feeling an earthquake-like rumble.

A sonic boom is a thunder-like noise that can be heard when an aircraft flies faster than the speed of sound, according to NASA.

People have been asking about the "earthquake" in LA around 9:20 this morning. Many people report feeling it but the seismograms clearly show the earth was not moving, only the air. So it was a sonic boom. https://t.co/OmoIoikKdv

Copyright 2021 Nexstar Media Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

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A quake in SoCal? No — a sonic boom, seismologists say

Los Angeles Times 09 July, 2021 - 02:37pm

But what some thought was another quake turned out to be a sonic boom that was recorded about 9:20 a.m., according to the U.S. Geological Survey.

The blast of sound energy occurred about one mile south of San Dimas, the USGS reported. But the effects rippled out toward the coast, where several people reported feeling an earthquake-like rumble.

A sonic boom is a thunder-like noise that can be heard when an aircraft flies faster than the speed of sound, according to NASA.

“Many people report feeling it but the seismograms clearly show the earth was not moving, only the air,” earthquake expert Dr. Lucy Jones said in a tweet. “So it was a sonic boom.”

According to the USGS, one way seismologists can detect a sonic boom is when it is felt in a wide area, indicative of a large earthquake — except seismic instruments don’t register the disturbance as an earthquake.

Residents from Huntington Beach to Highland Park reported feeling their house shudder, the ground rumble and hearing a loud sound.

You can report whether or not you felt the sonic boom to the U.S. Geological Survey.

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Friday Morning L.A. 'Earthquake' Was Actually A Sonic Boom - LA Weekly

L.A. Weekly 09 July, 2021 - 02:20pm

L.A. County residents may have felt a rumble Friday morning, but it was not a reported earthquake— instead a “sonic boom” that traveled through the air.

The Southern California Earthquake Data Center (SCED) reported that a micro “sonic” shake occurred at 9:20 a.m., a mile from San Dimas, but logging in at 0.0 magnitude suggests it was not an earthquake.

“People have been asking about the ‘earthquake’ in LA around 9:20 this morning,” seismologist Dr. Lucy Jones said on Twitter Friday.  “Many people report feeling it but the seismograms clearly show the earth was not moving, only the air. So it was a Sonic Boom.”

Jones suggested the shake may have been caused by an aircraft, but as of this writing, there has been no indication of what caused the sonic activity.

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Sonic boom - not earthquake - caused jolt felt widely across SoCal, expert says

KABC-TV 09 July, 2021 - 01:51pm

Jolt felt across SoCal attributed to sonic boom, expert says

Dr. Lucy Jones: No, it wasn't an earthquake LA residents felt, it was a 'sonic boom'

FOX 11 Los Angeles 09 July, 2021 - 01:18pm

No, it wasn't an earthquake that residents in the Los Angeles area felt on Friday morning, it was a "sonic boom," according to Seismologist Dr. Lucy Jones.

"People have been asking about the ‘earthquake’ in LA around 9:20 this morning. Many people report feeling it but the seismograms clearly show the earth was not moving, only the air. So it was a sonic boom," Jones wrote on Twitter.

The distribution of people who felt the sonic boom strongly suggests the source was a supersonic aircraft over the ocean, according to the U.S. Geological Survey and Dr. Jones.

The sonic boom was reported at 9:20 a.m. a little over a mile south of San Dimas, USGS reported.

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According to NASA, a sonic boom is a thunder-like noise a person on the ground hears when an aircraft or other type of aerospace vehicle flies overhead faster than the speed of sound, or "supersonic."

At this time, there was no word on what aircraft flew over the area that caused the sonic boom.

This material may not be published, broadcast, rewritten, or redistributed. ©2021 FOX Television Stations

The 'Earthquake' Some Angelenos Felt Was Actually a Sonic Boom

NBC Southern California 09 July, 2021 - 12:52pm

Some Angelenos reported feeling an earthquake in the Los Angeles area Friday morning around 9:20 a.m.

But according to the United States Geological Survey, which tracks recent earthquakes, there was no geologic activity in the Los Angeles area.

According to the USGS Earthquake map, there was a sonic boom event about two kilometers, or 1.2 miles, south of San Dimas.

A sonic boom, according to NASA, is a "thunder-like" noise that someone on the ground can hear when an aircraft moves faster than the speed of sound.

Because sound is just waves of air or other particles bumping into each other, if something moves faster than the speed of sound, it pushes those particles against each other with enough force to create a shock wave of pressurized air molecules.

That shock wave can rattle things like windows and houses, and often feels much like an earthquake.

People have been asking about the "earthquake" in LA around 9:20 this morning. Many people report feeling it but the seismograms clearly show the earth was not moving, only the air. So it was a sonic boom. https://t.co/OmoIoikKdv

Most sonic booms don't register on seismic instruments, the USGS said, because the wave doesn't usually translate into the seismic energy those instruments pick up from the earth.

But if multiple reports come in anyway, from people over a wide area claiming to feel an earthquake, the agency can be "fairly sure" that the cause was something in the atmosphere.

In this case, reports of the "earthquake" came from San Dimas, Los Angeles, Long Beach and up towards Santa Clarita.

NBC4 is looking for the source of the sonic boom, and will update here if and when we find out.

USGS: Sonic Boom Felt Across Southern California Mistaken For Earthquake

CBS Los Angeles 09 July, 2021 - 09:27am

LOS ANGELES (CBSLA) — A shudder felt across most of Southern California wasn’t an earthquake – it was a sonic boom, according to the U.S. Geological Survey.

The sonic boom was felt at about 9:20 a.m. Friday across a wide swath of Southern California. And even though it wasn’t an earthquake, the USGS created an event page for it that indicated it was felt from Huntington Beach to Thousand Oaks along the coast, and as far inland as Lake Elsinore.

Hey SoCal – if you felt or heard something this morning ~9:20 AM local time that seemed like a quake it may have been a sonic boom – see the event page for more details https://t.co/F1DRFhkt5N and read more on sonic booms here https://t.co/R5kN5LTZ0w.

— USGS Earthquakes (@USGS_Quakes) July 9, 2021

Earthquake expert Dr. Lucy Jones said that seismograms clearly showed the earth did not move – just the air, which suggests the source was a supersonic aircraft over the ocean.

— Dr. Lucy Jones (@DrLucyJones) July 9, 2021

It’s unclear what aircraft may have caused the sonic boom.

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