Cascade Range Current Update

Volcanoes in the Cascade Range are all at normal levels of background seismicity except for Mount St. Helens. See Mount St. Helens update below.

Other volcanoes include Mount Baker, Glacier Peak, Mount Rainier, and Mount Adams in Washington State; Mount Hood, Mount Jefferson, Three Sisters, Newberry, and Crater Lake, in Oregon; and Medicine Lake, Mount Shasta, and Lassen Peak in northern California.

USGS Cascades Volcano Observatory, the Pacific Northwest Seismograph Network at the University of Washington, and the USGS Northern California Seismic Network and Volcano Hazards Team in Menlo Park, California, monitor the major volcanoes in the Cascade Range of northern California, Oregon, and Washington.

Mount St. Helens Update, October 7, 2004, 6:15 p.m., PDT

Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE

Seismic activity has been at a low to moderate rate today, with earthquakes of magnitude 1 to 2 occurring at a rate of about 1 per minute. Visual observations of the vents and the area of intense uplift on the south side of the 1980-86 lava dome suggest that there has not been noticeable additional uplift in the past 24 hours. However, a new steam vent opened overnight to join the two that have been present for several days. Steaming from the vents generates a cloud that rises above the south side of the lava dome and extends a variable distance toward the crater rim.

Gas-sensing and thermal imaging flights are underway late this afternoon and results will be available later. Crews are also downloading GPS data and completing some work on seismic stations.

As a result of the intense unrest of the past 11 days, we infer that magma is at a very shallow level. During times of unrest, Mount St. Helens and similar volcanoes elsewhere typically go through episodic changes in level of unrest over periods of days to weeks, or even months. Such changes are in part driven by variations in the rate of magma movement. We expect fluctuations in the level of unrest to continue during coming days. Escalation in the degree of unrest and perhaps an eruption could occur suddenly or with very little warning. There may be little time to raise the alert level before a hazardous event occurs. Therefore, we continue to monitor the situation closely and will issue additional updates and changes in alert level as warranted.

Wind forecasts from the National Oceanic and Atmospheric Administration (NOAA), combined with eruption models, show winds this evening will be westerly and any ash clouds will drift east-northeastward. By tomorrow morning the winds will shift more to the south and any ash will drift more northerly.

Press conferences will continue to be held at the Headquarters office of the Gifford Pinchot National Forest. The morning press conference is at 9:30 AM.



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News - Mount St. Helens Current Information