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 8, 2004, 6:30 p.m, PDT

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

Seismic activity has been rising gradually today to a moderate rate of energy release, with earthquakes up to magnitude 2.4 occurring at a rate of about 1 every two minutes. No visual observations of the crater and dome were possible today due to low clouds and rain. AFM data suggest a small lahar flowed out of the crater about midday. Field work was limited to observations of river flows and installation of a satellite dish near Coldwater Visitor Center for telemetry of seismic, GPS, and other data.

Measurements from recent photographs and LIDAR (an acronym for LIght Detection And Ranging) show that the intensely deformed and uplifted area on the south side of the 1980-86 lava dome is about 1300 feet (N-S) by 1600 feet (E-W) with a maximum uplift of about 300-400 feet.

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 remain westerly and any ash clouds will drift northeastward (tonight) and east-northeastward (early tomorrow morning).

Saturday’s press conferences will be held at the Headquarters office of the Gifford Pinchot National Forest at 10:30 a.m.



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News - Mount St. Helens Current Information