Largest quake yet hits WA's Mount Rainier in ongoing 'earthquake swarm'

FOX 13 Seattle ^ | July 9, 2025 | Lauren Donovan

[SunkenCiv]

Seismologists are closely monitoring Mount Rainier after a swarm of earthquakes struck the Pacific Northwest’s tallest volcano this week. The U.S. Geological Survey (USGS) reports that hundreds of small quakes have occurred since the swarm began, making it the largest such event at the mountain since 2009.

Wes Thelen, a seismologist with the Cascades Volcano Observatory, told FOX 13 Seattle that the quakes began as a concentrated group of seismic events happening in quick succession...

"We had an increase in activity in seismic activity up to about 26 events an hour, which is a pretty good event rate for a quiet volcano," explained Thelen. "Since then, it's tailed off."

He added that while the swarm has calmed slightly, the activity could intensify again.

"We don’t necessarily have a crystal ball to understand what is happening under there," he said...

As of Wednesday morning, seismic instruments had recorded a magnitude 2.3 earthquake among the latest in the sequence. Thelen said the swarm is believed to be caused by hot fluids moving through pre-existing faults beneath the volcano...

Though Rainier last erupted roughly 1,000 years ago, Thelen noted that the volcano is not unusually active when viewed on a longer timescale.

[SunkenCiv]

Mount Rainier Earthquake [Brave results]

A significant earthquake swarm has been detected beneath Mount Rainier in Washington State, with hundreds of small quakes recorded since early Tuesday morning.

The activity, which began around 1 a.m. on July 8, involves quakes occurring at a rate of several times per minute, with the largest measuring 1.7 in magnitude. Geologists emphasize that there is no cause for concern, and the volcano remains at Alert Level Green/Normal.

Earthquake Swarm Details: The swarm includes hundreds of small earthquakes, with the largest measuring 1.7 on the Richter scale. The quakes are occurring between 1.2 and 3.7 miles beneath the summit and have not been felt at the surface.

Volcanic Activity: The USGS attributes the tremors to hydrothermal fluids interacting with preexisting faults beneath the volcano. This type of activity is not unusual for Mount Rainier, which experiences a few swarms each year.

Monitoring and Safety: The volcano is closely monitored by the USGS and the Pacific Northwest Seismic Network. No signs of ground deformation or anomalous signals have been detected, and the alert level remains at Green/Normal.

Historical Context: This is the largest earthquake swarm at Mount Rainier since 2009, when over 1,000 quakes were recorded over three days. The current swarm is considered part of natural volcanic processes.

AI-generated answer. Please verify critical facts.

[HIDEK6]

Is that the one we’re calling Mt. Trump now?

[SunkenCiv]

---

join or quit view topics view or post blog bookmark post new topic subscribe

---

• 38 Volcanoes Have Recently Erupted, And Here Are 3 More Inside U.S. Territory That Everyone Should Be Watching Very Carefully [02/23/2025]
• Scientists say recent quake swarm at Rainier is not unusual [09/21/2017]
• Mount Rainier Could Be On The Brink Of A Monstrous Eruption [07/24/2014]
• New View of Rainier's Volcanic Plumbing [07/18/2014]
• Scientists use 'metal-detector' instruments to trace activity of magma under Mount Rainier [07/17/2014]
• Geology Pictures of the Week, Sep 25-Oct 1, 2005: Mount Rainier and SD Badlands from Space [09/26/2005]
• Geology Pictures of the Week, July 10-16, 2005: Landslides, Ash Layers, and Property Values [07/12/2005]
• Geology Pictures of the Week, July 10-16, 2005: Landslides, Ash Layers, and Property Values [07/12/2005]
• Mount Ranier Called A Threat [08/14/2003]

[sit-rep]

https://youtu.be/Sn3Xhq6S30M?list=RDSn3Xhq6S30M&t=46

[Zathras]

They must be all below 1.x.
My app says only 2 in the 2.5 range in the last week.

[Carry_Okie]

From Brave AI searchMount Rainier's last significant eruption occurred approximately 1,000 years ago, with the most recent recorded volcanic activity between 1820 and 1854, though many eyewitnesses reported eruptive activity in 1858, 1870, 1879, 1882, and 1894 as well.

The last major eruptive period for Mount Rainier was around 1,000 years ago, but even in that incident, there were no lava flows. More recently, in 1894-95, there were small summit explosions reported by observers in Seattle and Tacoma. It is important to note that while Mount Rainier has not had a magmatic eruption in over a millennium, it is still considered an active volcano, and scientists continue to monitor it for any signs of reawakening.

I guess AI is prone to redundancy.

[Zathras]

A fair amount of activity at what I call The Keystone offshore just south of Eureka.

[Billthedrill]

A federal judge has just laid down a temporary injunction against an eruption. We’re saved.

[nwrep]

2.2.

[Theophilus]

Got to visit Mount Rainier last year. It is one of the most beautiful places I've ever been. Maybe the most.

Watch out for lahars!

[struggle]

Sorry, but a district judge just allowed the eruption to continue.

[BenLurkin]

There’s a great many small temblors inside (or under) just the mountain itself per USGS

https://earthquake.usgs.gov/earthquakes/map/?extent=46.7742,-122.05055&extent=46.93573,-121.52596&range=week&magnitude=all&baseLayer=satellite&list=false

[dpetty121263]

Good way to clear Washington St of Liberals...

[algore]

There have been no major earthquakes or eruptions in Wa state in recent history, except for St Helens.

No one even died in that eruption except Harry Truman

[algore]

look up the history of Washington State.

A kind and considerate black man by the name of George W. Bush with a bunch of other families took the Oregon Trail and ended up in Oregon, but in 1845 after they arrived the racist people in Portland chased him across the river to the Washington territory cause they were scared of his blackness.

The Bush family, along with some other settlers who told the Portland racists to F- off, established a settlement there, becoming the first Americans to settle north of the Columbia River in what is now Washington.

IIRC the oldest apple tree from seeds provided by Johnny is still growing on that property

[HartleyMBaldwin]

No one even died in that eruption except Harry Truman

Not true.

[Peter ODonnell]

The death toll from the Mt St Helens eruption in May 1980 was 57.

[algore]

Sorry Hartley, you are right, on further research I see that there were a claimed 57 people who died.

The only one I remembered was Harry.

but to put this into perspective

The Oso landslide, which occurred on March 22, 2014, resulted in 43 deaths.

[cherry]

They’re doing rock blasting tonite near Cle elum on Interstate 90.

[Myrddin]

I personally experienced a 5.5 in Federal Way, WA in 1964. It was pretty "exciting". A few chimneys collapsed on the street behind mine. Mom was holding the dishes back from the cabinet doors.

It was a lovely place to live in 3rd grade. The political landscape changed by the time I was an adult. No thanks.