Sunday, February 08, 2009

Alaska's Mount Redoubt Update

RSAM stands for Real-time Seismic Amplitude Measurement. It summarizes seismic activity during heightened volcanic activity. RSAM calculates and stores the average amplitude of ground shaking caused by earthquakes and volcanic tremor over 10-minute intervals. RSAM values increase as tremor amplitude or the rate of occurrences and the size of earthquakes increase. Because it tallies all the signals from all the events during the 10-minute interval, it provides a simplified measure of the overall level of seismic activity. (From the Alaska Volcano Observatory's site AVO)

This is today's posted chart of RSAM from AVO. While I'm no volcanologist, it is easy to see that there is some sustained vibrations that are well above the activity from earlier in the week. I wish that I had saved some of these charts from the last week or so, because I think it would be interesting to compare the changes.

Other reports from the AVO twitter, there has been a steam plume, but no actual eruption.

I suspect for the scientists who are studying this volcano, it is a little like waiting for the arrival of a baby. You know it's coming, you just don't know when. And for a volcano, you may know that something is getting ready to happen, but right now I don't think we have any way to know in advance what level the eruption is going to be or how long it will last. But it must be very interesting to be a volcanologist in Alaska right now.

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