(SACBEE) – A 45-minute “earthquake swarm” reported this week near Oregon’s Mount Hood has the U.S. Geological Survey offering explanations — and reassurance the volcano is not becoming more active.
Dozens of earthquakes, most not felt on the surface, came in succession around 12:13 p.m. Monday, centered about a half-mile southwest of the volcano, geologists say. Data show the quakes came from 3 to 4 miles beneath the summit, officials said Tuesday. The volcano is about 50 miles east of Portland.
“The Pacific Northwest Seismic Network located eight events so far with a maximum magnitude of M 1.3; dozens of other events were too small to locate,” the USGS posted. “Although not a common occurrence, short-lived swarms have occurred near the summit in the past, including November 2013, September and October of 2014, and May 2016.”
It was likely “pressurized” super-heated water — not bubbling hot magma, experts say. “The recent earthquakes at Mount Hood are interpreted to be the movement of hydrothermal fluids along preexisting faults,” the USGS said. READ MORE
