Mount Rainier rattled by hundreds of small earthquakes with no eruption threat
- A swarm of hundreds of small earthquakes has been detected beneath Mount Rainier, starting early Tuesday morning.
- The largest magnitude recorded was 1.7, and none of these earthquakes have been felt at the surface.
- Officials confirm there is no threat of eruption, keeping the alert level at Green/Normal.
In the early hours of Tuesday, July 8, 2025, a swarm of hundreds of small earthquakes occurred beneath Mount Rainier, Washington's highest volcano, located approximately 59 miles southeast of Seattle. The U.S. Geological Survey (USGS) reported that the seismic activity began just before 1:30 a.m. and was registered at a depth of 1.2 to 3.7 miles beneath the summit. Although the earthquakes were frequent and of low magnitude, with the largest measuring 1.7, they were not felt at the surface. Such quakes are typical for the region, happening a couple of times yearly, but this particular swarm was noted for its increased frequency. The USGS officials have reassured the public that there is currently no cause for concern regarding an eruption. The volcanic alert remains at a green status, indicating normal activity. Monitoring instruments detected no remarkable ground deformation or unusual seismic signals that would suggest potential eruptive behavior. The level of seismic activity recorded since the swarm began has led experts to emphasize that Mount Rainier's response remains within expected parameters, as it normally sees about nine quakes per month. Historical data indicates that Mount Rainier experiences swarm patterns due to fluid circulation interacting with pre-existing faults underground rather than indicators of imminent volcanic eruptions. The last significant swarm in 2009 saw over 1,000 earthquakes, peaking at magnitudes of 2.3 over a three-day period. The USGS highlighted that the current swarm, while larger than average, aligns with the expected geological behavior of the area, collectively reinforcing the assessment that no eruptions are imminent. In the broader context, the last eruptive period for Mount Rainier took place around 1,000 years ago, without any lava flows. Comparatively, the volcano's history of eruptions is relatively mild, and the last destructive eruption in the region was at Mount St. Helens in 1980. Visitors and residents near Mount Rainier National Park can now feel assured that despite the increased seismic activity, the volcano remains in a state of normalcy, warranting continued monitoring but no immediate alarm.