CASCADES VOLCANO OBSERVATORY WEEKLY UPDATE
U.S. Geological Survey
Friday, May 19, 2023, 12:03 PM PDT (Friday, May 19, 2023, 19:03 UTC)
CASCADE RANGE VOLCANOES
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN
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: On the evening of Sunday, May 14, a debris flow in the upper South Coldwater Creek drainage destroyed a bridge over Washington State Route 504, about a mile northeast of Johnston Ridge Observatory (JRO) in the Mount St. Helens National Volcanic Monument (MSHNVM). The debris flow cut off road access and power to JRO, resulting in the loss of signal transmission from several monitoring stations at Mount St. Helens. The number of instruments that remain operational is sufficient to detect increased activity and provide rough earthquake locations. Permanent repairs to the road and power supply could take months or more. In the meantime, the USGS is working with MSHNVM staff on workarounds to restore signal transmission as soon as possible. Seismicity at Mount St. Helens and all other Cascade volcanoes has been at background levels this week.
The U.S. Geological Survey Cascades Volcano Observatory and the University of Washington Pacific Northwest Seismic Network continue to monitor Washington and Oregon volcanoes closely and will issue additional notifications as warranted.
For images, graphics, and general information on Cascade Range volcanoes: https://www.usgs.gov/observatories/cvo
For seismic information on Oregon and Washington volcanoes: http://www.pnsn.org/volcanoes
For information on USGS volcano alert levels and notifications: https://www.usgs.gov/programs/VHP/volcano-notifications-deliver-situational-information