There were two earthquakes early Wednesday morning with magnitudes over 5.0 that rumbled under the Pacific Ocean off the Northern California coast.

The first of the quakes, with a magnitude of 5.7 on the Richter Scale, struck at 3:53 am about 95 miles due west of the California-Oregon border. The USGS puts the epicenter at 154 kilometers WSW of Pistol River, Oregon.

The second earthquake, 5.1M, occurred at 5:45 am and its epicenter was further south, off the coast of Eureka. Its epicenter was about 40 miles off the coast, or 64 kilometers west of Petrolia, California, in Humboldt County.

This earthquake's depth was relatively shallow, just about a half-mile below the seafloor.

There was subsequently a 4.5M aftershock in the same area at 6:11 am.

Some shaking was likely felt in and around Humboldt County from the latter two quakes, but no damages have been reported. At least one or two people on Xitter in Humboldt County reported the shaking.

This area off the NorCal coast is known to be highly tectonically active, and the latter two earthquakes occurred near what's called a triple-junction, where the northern end of the San Andreas Fault intersects with the Mendocino Fracture Zone  and the Cascadia Subduction Zone. The earlier, larger quake appears to have occurred along the Cascadia Subduction Zone.

The most recent earthquakes off the San Francisco coast occurred on April 25, and had magnitudes of 3.0 and 2.7.

• The city of San Francisco plans to raise water and sewage rates by almost 25% over the next two years, as well as continually over the next decade. The average single-family household bill is expected to increase from $171 a month to $189 this summer and $212 a month next summer. [Chronicle]
• The attempt to persuade all Democratic candidates to drop out of the special election for former Representative Eric Swalwell’s vacant seat in favor of a caretaker candidate has fallen through. [Bay Area News Group]
• Two earthquakes with magnitudes of 3.0 and 2.7 struck off the coast near the San Francisco Zoo Saturday starting around 4:40 pm with weak shaking reported. [KPIX]
• BART’s Red line and Green Lines will be out of service all day Sunday for lighting work, and service will resume Monday. [KRON4]
• Around 75 addresses in Mountain View have been without water since Friday when the main water line was contaminated by a construction crew, and comprehensive drinking water safety testing will not be complete until at least Monday. [Bay Area News Group]
• Novato Police are searching for an older woman who is suspected of striking an eight-year-old on a bike and fleeing the scene Friday afternoon. [NBC Bay Area]

Image: Leanne Maxwell/SFist

• In addition to all the lightning and thunder, Humboldt County was struck by a 3.4 magnitude quake Saturday around 11:12 am. [NBC Bay Area]
• Amid the thunder, lightning, and ongoing conflict in Iran, residents in SF and the East Bay expressed concern Saturday night over a private 10-minute fireworks show displayed from a barge in the bay as part of an annual party for a local company. [SFGate]
• A warehouse worker in Southern California disgruntled with corporations allegedly started a fire at his workplace that caused $500 million in damages. [The Press-Enterprise]
• A small crowd of labor union and farmworker supporters braved the downpour Saturday to watch a scaled-down parade of dancers and performers at the 25th annual — newly labeled — Farmworkers Day Festivities in the Mission, despite all four of the event’s bands canceling due to the weather. [Chronicle]

• Cosplayers of all stripes converged on San Jose this weekend at Fandomcon Silicon Valley, a three-day convention celebrating multiple genres, including anime, comics, gaming, sci-fi, and popular culture. [KRON4]

Image: Leanne Maxwell/SFist

The Sacramento Bee, like many publications across the country, has been experimenting with AI-generated content for its website, particularly in the realm of real-time wildfire and earthquake updates. But it seems like they may need more human eyes on this stuff.

In the last few days, the Sacramento Bee's website has published several false earthquake reports — albeit falsely generated by the US Geological Survey's earthquake notification system, but quickly retracted — and one false wildfire report.

The earthquake reports on Monday evening are attributed to the McClatchy Company's CA Earthquake Bot — the one linked above reported on an offshore earthquake west of Bonny Doon, in Santa Cruz County, with a preliminary magnitude of 3.7.

This was one of several false alarms registered by the USGS's automated earthquake notification system in Northern California Monday night, as we previously reported, and the USGS quickly noted the errors and removed the erroneous earthquake notices from its website. The Sacramento Bee post about the earthquake, along with several others like this 3.2M quake near Shaver Lake that did not happen, remain live on the site.

A correction does appear on this post from Wednesday afternoon, regarding a Ventura County wildfire that turned out not to exist. That story was attributed to "CA Wildfire Bot."

"A previously published report about a wildfire in Ventura County was published in error and has been removed. No such fire existed," the post now reads. "The report was generated due to a system error from data provided by the National Interagency Fire Center. We apologize for the error."

That automated error appears to have mistaken a 500-acre wildfire in Valencia County, New Mexico, called the United Fire, which broke out Wednesday, for a fire in SoCal's Ventura County. And Cal Fire quickly saw the erroneous report, and notified the Sacramento Bee.

The CA Wildfire Bot and Earthquake Bot, by the way, are now producing dozens of posts per day, one for every wildfire or earthquake notification, the former based on Cal Fire or INCI web data — and/or the NIFC, which appears to be blamed for the erroneous post.

The earthquake posts linked to retracted USGS posts continue to link to pages on the USGS site that have since been deleted.

These AI-generated posts at the Sacramento Bee previously had a joke-y disclaimer on them saying, "This article was generated by the CA Earthquake Bot, software that analyzes structured information, such as data, and applies it to articles based on templates created by journalists in the newsroom. No human journalist was harmed in this experiment."

But that disclaimer has now changed to say, "The creation of this content included the use of AI based on templates created, reviewed and edited by journalists in the newsroom."

Photo by Fachy Marin

For the second time in four months, a false-alarm alert about an earthquake was triggered in Northern California, and this was actually multiple alerts, but this time there thankfully were no loud alarms on cellphones rattling Bay Area residents awake.

The US Geological Survey has some questions to answer about a series of false alerts that were somehow triggered on its automated earthquake detection system Monday night in multiple locations. As the Chronicle reports, these included two off-shore earthquakes west of the Bay Area, as well as locations near Bonny Doon in Santa Cruz County, near Point Reyes, near Yreka, and near Shaver Lake in Fresno County.

The false alerts were for quakes ranging in size from 3.2M to 3.8M.

The Sacramento Bee, for instance, has this report, via the CA Earthquake Bot, showing an earthquake with a preliminary magnitude of 3.7 having struck offshore, 53 miles west-southwest of Bonny Doon, at 8:48 pm. If you look at the USGS earthquake site today, however, no such quake appears, and the only Bay Area quake in the last 24 hours was a 2.8M that struck just after midnight near San Ramon — the site of an ongoing earthquake swarm that began last fall.

As the Chronicle notes, the USGS's automated earthquake detection system can "occasionally produce erroneous readings due to signal interference or processing errors," but these instances are reportedly supposed to be "rare."

In early December, Bay Area residents were alarmed by an 8:06 am "Critical" earthquake warning about a 5.9M quake, pushed out to cellphones that subscribe to the ShakeAlert system with a blaring alarm sound, however the warning seemed immediately suspect because of the location of the false quake — which was centered in Lyon County, Nevada.

Even an earthquake of that size likely would not have been felt over 200 miles away in the Bay Area.

The USGS quickly retracted the report and issued an apology on X, saying "There was no M5.9 earthquake," and "We are currently looking into why the alerts were issued."

The incident prompted a rebuke from California politicians the following week, with Representative Kevin Mullin and four other Democratic House members writing to the USGS and saying, "The public relies on USGS for authoritative, real-time information during earthquakes," and this public trust is "essential." Governor Gavin Newsom also said that the error put a spotlight on the Trump administration's cuts to federal agencies like the USGS.

Per the New York Times, Christie Rowe, director of the Nevada Seismological Laboratory at the University of Nevada, Reno, put out a statement suggesting that "a faulty power system" at one of the seismic monitoring stations in Nevada was likely to blame for the false alarm.

The malfunction at that one station reportedly caused data transmission issues throughout the ShakeAlert system.

And this system is gaining a reputation for unfortunate glitches that can lead to widespread, if brief, panic. You'll recall that after the system went online, there was an earthquake drill scheduled for 10:19 am on October 19, 2023, but the loud alert instead went out seven hours early, at 3:19 am, to cellphones around the Bay Area.

The USGS blamed that one on a time-zone mix-up.

Previously: That 5.9M Earthquake Warning Out of Nevada Was Fake News

Small earthquakes centered near San Ramon continued to rattle the East Bay as they have for months Monday morning. And the largest, a 4.2M, was felt in parts of San Francisco.

San Ramon has been feeling the effects of another earthquake swarm, this one producing 17 earthquakes and counting, starting at 6:27 am. That first one in the series was a 3.8 magnitude, according to the US Geological Survey, but then several more smaller quakes were followed by a 4.2M at 7:01 am.

Another 3.8M quake came at 7:27 am, and the most recent was a 2.8M at 7:42 am.

The largest of the swarm, the 4.2M quake, was felt mildly in SF, with the Chronicle reporting on rattling windows and shaking in Glen Park and NoPa.

BART has issued an alert telling riders to expect delays throughout the system as trains are running at reduced speeds due to the quakes.

The San Ramon area has been rumbling with small earthquakes since mid-November, with a historic swarm that is apparently continuing up to today.

Photo by Jens Aber

• The coyote that made it onto Alcatraz Island earlier this month appears to be thriving there, as rangers reported seeing carcasses from prey that it caught. Authorities were worried about the safety of the visitors the coyote was attracting due to the media attention, but local expert Janet Kessler said the coyote is used to humans, as it was born and raised in SF. [Coyote Yips/Instagram]

• A cute, new mascot called “Maverick,” who’s a descendant of Ma Sheng, the Horse God, has been unveiled for the 2026 Chinese New Year Parade in celebration of the rare Year of the Fire Horse, which only comes around every 60 years. [KGO]

• The ongoing swarm of earthquakes near San Ramon, which have been striking in clusters for over a month, hit the region again Friday with a 3.4M quake, followed by a 2.9. [KPIX]
• The National Football League reportedly told San Jose officials, including Mayor Matt Mahan, that ICE agents will not be targeting Super Bowl events, but leaders are remaining vigilant in case of a surge. [NBC Bay Area]

• San Mateo County authorities are investigating the death of a 31-year-old woman who was found inside a detached garage that was on fire early Friday morning in Fair Oaks and was pronounced dead at the scene. [KRON4]
• Check out this aerial view showing the massive turnout at Friday's walkout and anti-ICE rally at SF's Dolores Park, with more protests to come over the weekend.

Image: Leanne Maxwell/SFist

Image: Leanne Maxwell (2017)/SFist

Cellphones across the Bay Area rang out with another earthquake alarm Sunday afternoon, but this time it was not a false alarm.

An earthquake with a magnitude of 4.0 shook under Sonoma County at 3:30 pm Sunday, with an epicenter about 3 miles west of Glen Ellen.

That was followed by a 3.1M aftershock at 3:38 pm, and another 3.4M quake centered closer to Kenwood occurred just before 4:05 pm.

The Shake Alert message that came through cellphones in San Francisco said that the initial earthquake was a 4.9M, and said to take cover and expect shaking, though no significant shaking was felt in the city. And a preliminary magnitude assigned to the quake was 4.2.

A friend of SFist in Glen Ellen said that significant shaking was felt there.

No damages have been reported.

This follows a false alarm from the Shake Alert system that was sent out to phones in the Bay Area about an earthquake in Nevada that did not actually occur on December 4.

This story has been updated with news of the third earthquake.

Photo by Georg Eiermann

It's Great ShakeOut Day in California, and just as preparations were being made for the annual earthquake drill, a 3.1M quake struck near Berkeley.

On Thursday morning at 9:23 am, an earthquake rattled under the East Bay, with an epicenter about one mile east of Berkeley, a magnitude of 3.1, and a depth of about four miles. The quake appears to have occurred on the Hayward Fault.

Shaking may have been felt in San Francisco — though I didn't feel it. The USGS has not yet updated their Shake Map for the quake.

The earthquake arrived just under an hour before the annual Great California ShakeOut drill, which was scheduled for 10:16 am Thursday. Your MyShake app, if it was activated, should have buzzed at that time with the drill.

The coincidence apparently excited an editor at the New York Times, because despite the minor nature of the quake, they went with a blaring headline and an interactive feature. (Maybe this was like a drill for them, to see how fast they could get one of these things published in the event of a real, significant, California earthquake?)

This morning's earthquake was significantly smaller than the one that also occurred on the Hayward Fault, centered in Berkeley, on September 22. That was a 4.3M, and jolted people awake across the Bay in San Francisco at 2:56 am.

Tomorrow, October 17, is the 36th anniversary of the Loma Prieta Earthquake, a 6.9M quake that took the lives of 63 people across the Bay Area.

According to the UC Berkeley Seismology Lab, the Hayward Fault currently holds the most potential dangers for the Bay Area, with a 33% chance of rupturing in a 6.7 magnitude earthquake or greater before 2043.

The Bay Area at large has a 72% chance of seeing a 6.7M or greater quake before 2043, taking into account other fault systems.

Given it's drill day and all, let this be another reminder to have your emergency plans in place with friends or family, make sure to have some cash on hand in small denominations just in case electronic payment systems go down, and get a Go Bag together containing essential items like prescriptions, water, first aid, things you need for your pet, etc.

You may have been rudely awoken by an earthquake just before 3 am Monday morning, which turns out to have been a 4.3-magnitude quake on the Hayward Fault, centered in Berkeley.

The earthquake struck at 2:56 am, and a short and sudden jolt was felt across San Francisco. Initial magnitude reports had the quake between 4.6M and 4.8M.

No major damages were reported, but KTVU found some businesses in in Berkeley that suffered some minor damage — including a butcher shop whose front display window shattered, and the owner said the same thing had happened during the Loma Prieta quake.

SF's Department of Emergency Management said no injuries had been reported, though it received "an increase in [911] calls from people who felt shaking."

BART announced early Monday that it would be running trains at reduced speeds during the morning commute while it assessed any possibly track damage across the system.

The epicenter of the earthquake was directly under College Avenue, about four blocks south of the UC Berkeley campus.

The US Geological Survey forecasts an 18% chance of aftershocks of 3.oM or less in the next week, and a 2% chance of aftershocks greater than 4.0M.

• Over 10,000 Air Canada flight attendants went on strike early Saturday, prompting the Canadian government to force the airline into arbitration. The shutdown of the airline, which operates about 700 flights a day, has left over 100,000 travelers stranded worldwide. [Associated Press]

• Mayor Lurie claimed his office secured $3.4 million in immigrant legal defense funding, which was actually awarded to the public defender’s office. Additionally, he neglected to renew $878,000 in grant funding that London Breed was awarded last year. [Mission Local]
• The Golden State Valkyries won their fourth game in a row Friday, scoring 90-59 against the Chicago Sky. [Bay Area News Group]
• The second bird in a month has been found to be infected with the West Nile virus — a crow from Walnut Creek tested positive on Friday. [KRON4]

• There have been 117 tiny earthquakes since Thursday’s 4.0-magnitude quake near the Geysers geothermal field in Mendicino, northeast of Healdsburg. [SFGate]

Image: Leanne Maxwell/SFist

An earthquake with a preliminary magnitude of 3.0 rattled parts of the South Bay Tuesday afternoon, and its epicenter was in a somewhat unusual spot on the San Andreas Fault.

Tuesday saw a 3.0M earthquake rumbling with an epicdenter 4.3 miles south-southwest of Los Altos and 5.4 miles west of Cupertino, which employees at Apple's spaceship campus likely felt. The earthquake struck at 2:17 pm according to the USGS, and the agency suggests that shaking may have been felt as far north as Palo Alto, and east in parts of San Jose.

The epicenter is directly along the Peninsula segment of the San Andreas Fault.

No damage has been reported, and there was not much anecdotal evidence on X, as historically there has been — the #earthquake hashtag this after noon was dominated with posts about a larger, 5.6M quake that struck in Guatemala about a half hour later, at 2:41 pm, and an earlier 4.8M quake there that struck at 2:11 pm.

A third 4.8M quake or aftershock occurred there at 2:54 pm.

The Bay Area hasn't experienced an earthquake with greater than 3.5M since January, when a pair of 3.7M quakes rattled San Francisco and the East Bay over the course of two days.

And here's your reminder to get that kit and go bag together!