U.S. Geological Survey, Vancouver, Washington
University of Washington, Pacific Northwest Seismic
Network, Seattle, Washington
U.S. Geological Survey, Northern California Seismic Network, Menlo Park, California
CASCADES VOLCANO OBSERVATORY WEEKLY UPDATE
Friday, August 21, 2009 11:26 PDT (Friday, August 21, 2009 18:26 UTC)
Cascade Range Volcanoes Volcano Alert Level: NORMAL
Aviation Color Code: GREEN
Activity Update: All volcanoes in the Cascade Range are at normal levels of background seismicity. These include Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, and Mount Adams in Washington State; Mount Hood, Mount Jefferson, Three Sisters, Newberry Volcano, and Crater Lake, in Oregon; and Medicine Lake volcano, Mount Shasta, and Lassen Peak in northern California.
Mount St. Helens has been at Volcano Alert Level NORMAL (Aviation Color Code GREEN) since July 10, 2008.
Recent Observations: No significant changes in activity occurred during the past week. At Mount St. Helens, field crews: (1) repaired and did standard maintenance on monitoring equipment, (2) measured volcanic gas emissions, (3) collected spring samples for analysis, (4) surveyed channel cross-sections, (5) deployed and surveyed photo targets for aerial photography, (6) conducted a comparison study of oblique photogrammetry and tripod-mounted lidar, which are two techniques for obtaining information about topography and ground deformation, (7) made general observations of the lava domes, Crater Glacier, and other features in the 1980 crater, and (8) continued geologic mapping of the volcanic edifice. At Newberry volcano, CVO staff members collected GPS data as part of a long-term monitoring effort to detect any ground deformation that might occur at Newberry or other Cascade volcanoes. Work will continue at Newberry next week.
The U.S. Geological Survey and University of Washington continue to monitor these volcanoes closely and will issue additional updates and changes in alert level as warranted.
For additional information, background, images, and other graphics: http://vulcan.wr.usgs.gov
For seismic information on Oregon and Washington volcanoes: http://www.pnsn.org/WEBICORDER/PNSN/welcome.html
For seismic information on California volcanoes: http://earthquakes.usgs.gov/eqcenter/recenteqsus/Maps/special/California_Nevada.php
For a definition of alert levels: http://vulcan.wr.usgs.gov/Volcanoes/Cascades/CurrentActivity/volcano_warning_scheme.html
For a webcam view of Mount St. Helens: http://www.fs.fed.us/gpnf/volcanocams/msh/
Past Updates
Mount St. Helens Current Eruption Menu
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