Posted by: magmatist | June 8, 2016

More on Boulder Glacier debris flow

2016 scurlock 163414197.NXsFXm1s mark

Overview of the May 25 2016 Boulder Glacier debris flow. Photo courtesy John Scurlock.

John Scurlock flew around Mount Baker today (June 7th, 2016) and got some great photos of the latest Boulder Glacier debris flow. Also, seismologists Steve Malone at Pacific Northwest Seismic Network and Jackie Caplan-Auerbach at WWU went back and examined seismic records and independently discovered the timing: the initial ice avalanche began at 2:00:30 PM May 25th.

2016 scurlock 163414199.4O6c1Kn2 mark

Release scarp on north flank of Sherman Peak. Ice debris blocks east breach of Sherman Crater. rocky debris is picked up as ice avalanche scours volcanic rock below the scarp. Courtesy John Scurlock.

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Overview of the May 25 2016 Boulder Glacier debris flow. Photo courtesy John Scurlock.

Three seismometers picked up good records of the signal: MBW is about 6 km west of the summit, SHUK about 12 km east , and VDB about 25 km north-northeast in Canada.

2016 MBW SHUK VDB

Three seismograms showing onset of avalanche. Top to bottom: MBW, SHUK, and VDB. Vertical scale differs on each. Note long runout as debris flow descends Boulder Glacier for nearly 6 minutes.

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