USGS Volcano Notice - DOI-USGS-CVO-2023-11-10T12:03:56-08:00

Activity Update: All volcanoes in the Cascade Range of Oregon and Washington are at normal background activity levels. These include Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, and Mount Adams in Washington State and Mount Hood, Mount Jefferson, Three Sisters, Newberry, and Crater Lake in Oregon.

Past Week Observations: Mount St. Helens continues to have higher seismicity than typical of recent years, with 19 located earthquakes during the last week, and 465 since July 15, when the current increase in seismicity began. The largest earthquake last week was a magnitude 1.35, while the largest since July 15 was magnitude 2.35. Average depth of earthquakes at Mount St. Helens last week was 4.4 miles below the crater, compared to an average depth since July 15 of 3.7 miles.  This level of seismicity is still within the background range and does not appear to suggest an imminent eruption.  No changes have been detected in ground deformation, volcanic gas or thermal emissions at Mount St. Helens. Unrelated to the seismic activity, heavy rains on Nov. 4 triggered several small debris flows at Mount St. Helens. No changes have been observed at other Cascade Range volcanoes.