Mount Rainier is rattled by more than 300 earthquakes. It's the largest swarm in years.
More than 300 earthquakes have erupted at Washington's Mount Rainier this week, the largest earthquake swarm at the volcano since 2009.
As of Thursday, July 10, 334 earthquakes had been identified at Mount Rainier by the Pacific Northwest SeismicNetwork (PNSN), Cascades Volcano Observatory Public Information Officer Holly Weiss-Racine told USA TODAY. The swarm, a cluster of earthquakes occurring in the same area in rapid succession, began in the early morning of Tuesday, July 8.
Scientists do not have any concerns about the earthquakes, the Cascades Volcano Observatory states. The largest so far was recorded at a magnitude of 2.3 on Wednesday, July 9.
Weiss-Racine said the rate peaked at 26 earthquakes per hour on the morning of July 8 and has decreased to "a few" per hour on the morning of July 10.
The PNSN is continuing to locate earthquakes a part of the swarm. Updates are shared on the PNSN website at pnsn.org/volcanoes/mount-rainier.
Is the earthquake swarm dangerous?

The earthquake swarm is not dangerous to hikers on the mountain and has posed no indication for concern, the Cascades Volcano Observatory wrote in a news release.
As of July 10, the largest earthquake in the swarm was recorded at a magnitude of 2.3.
According to Michigan Technological University, earthquakes of a 2.5 or less magnitude are common – millions happen each year – and are not usually felt.
Earthquake guide: Earthquakes happen all the time, you just can't feel them.
What is Mount Rainier?
Mount Rainier is an active volcano and national park in the state of Washington. It rises more than 14,000 feet above sea level and sprawls over five major rivers, according to the National Park Service.
Are earthquakes common at Mount Rainier?
About nine earthquakes per month are common at Mount Rainier, according to the Cascades Volcano Observatory. Earthquake swarms typically occur one or two times a year at the volcano but are not as large.
When was the last sizeable earthquake swarm at Mount Rainier?
The last large earthquake swarm at Mount Rainier occurred in 2009 and lasted for three days. The swarm resulted in more than 1,000 earthquakes and the largest was of a 2.3 magnitude, according to the U.S. Geological Survey.
Can the earthquake swarm cause a volcanic eruption?
The Cascades Volcano Observatory states that Mount Rainier is not "due" for an eruption and no signs point to an eruption at this time.
But generally, earthquakes can be related to subsequent volcanic eruptions, according to the U.S. Geological Survey. However, the circumstances have to be just right.
For a volcano to be triggered into eruption by earthquakes, a volcano must have enough "eruptible magma" and significant pressure within its magma storage, the U.S. Geological Survey states.
When was the last time Mount Rainier erupted?
Mount Rainier hasn't had a major eruption, with strong geologic evidence, in the past 1,000 years, Weiss-Racine said.
This story has been updated to fix a typo.
Greta Cross is a national trending reporter at USA TODAY. Story idea? Email her [email protected].
This article originally appeared on USA TODAY: Mount Rainier experiences more than 300 earthquakes in 2 days