USGS Volcano Notice - DOI-USGS-CVO-2023-11-17T12:05:09-08:00

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 18 located earthquakes in the last week, and 483 since July 15, when the current increase in seismicity began. The largest earthquake over the past week was a magnitude 0.7, while the largest since July 15 was magnitude 2.4. The average depth of earthquakes at Mount St. Helens last week was 5.4 miles below the crater, compared to an average depth of 3.7 miles since July 15.  Although this level of seismicity is elevated compared to the last several years at Mount St. Helens, it is still considered within the background range and does not suggest an imminent eruption.  No changes have been detected in ground deformation, volcanic gas, or thermal emissions at the volcano. Multiple field crews were at Mount St. Helens over the past week to service telemetry and monitoring sites, and to document the effects of small debris flows that occurred on November 4. No changes have been observed at the other Cascade Range volcanoes, with one located earthquake at Mount Hood.