CASCADES VOLCANO OBSERVATORY WEEKLY UPDATE

Friday, October 19, 2012 8:06 AM PDT

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 levels of background seismicity. 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 Volcano, and Crater Lake, in Oregon.

Recent Observations: The Cascade Range of Washington and Oregon remained volcanically quiet again this week. Aside from the usual small seismic chatter that is typical of the volcanoes, the only earthquake of note was a M2.1 at 7.7 km depth at Mount Hood on Saturday, October 13. This is not atypical for Mount Hood. We note that the onset of regional rains, lack of significant snow cover, and loose sediment on the flanks of the regions volcanoes could induce small, local lahars in some channels. Furthermore, rivers in the area are on the rise at this time of year. People working and recreating in the mountains at this time should be alert for mass flow and high-water hazards.

The U.S. Geological Survey Cascades Volcano Observatory and the University of Washington continue to monitor the Washington and Oregon volcanoes closely and will issue additional updates and changes in alert level as warranted.