Tuesday, January 04, 2005

Mount St Helens - winding down?

Despite the clear weather at Mount St Helens, the glow from the crater last night was subdued and relatively feeble - apart from one single burst around 20:20. The levels of seismic activity continue at very low levels and it seems the expansion of the lava dome is slowing (see below). Maybe the current eruptive phase is starting to wind down? Time will tell...

Latest Update from the U.S. Geological Survey, Vancouver, Washington and
University of Washington, Pacific Northwest Seismograph Network, Seattle, Washington

Tuesday, January 4, 2005 9:10 a.m. PST (1710 UTC)

Recent observations: The volcano is very clear without a steam plume, but winds are very high. Seismicity continues at a very low level. We had a very successful field day yesterday. Crews placed a GPS unit on the southeast side of the new dome, measured gases, and collected rock samples. Preliminary GPS data show that expansion of the rear part of the dome has slowed to a rate of only a few meters per day. However, observations reveal that the new dome is heavily fractured and faulted; the north end emerging from the vent remains smooth and appears to still be moving relatively rapidly. Measured gases were not significantly different than previous measurements. Rock samples from the new dome are being analyzed. We have no specific field plans for the next several days.


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