Earthquakes at Mount Hood, February 2012.

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Typically, several earthquake swarms occur each year at Mount Hood, with some lasting for hours, others lasting for days to weeks.

Beginning at approximately 12:30 pm PST on February 23, 2012, a small swarm of earthquakes occurred at Mount Hood. The earthquakes are approximately 4 miles south southeast of the summit of the volcano, and are occurring at depths of 3-5 miles. Between 12:30 PST Thursday and 8:00 PST Friday, more than 25 small earthquakes were located by the Pacific Northwest Seismic Network (PNSN), with magnitudes ranging from 0.1 to 1.7. Over the last 24 hours (through Saturday late-morning) no additional earthquakes occurred. The February 23-24 swarm locates in roughly the same area as previous swarms.

For more details about this swarm, visit the PNSN web site for an excellent blog posting about the swarm at PNSN blog as well as their Mount Hood seismicity map with locations of the swarm events at PNSN Mount Hood page