Small Quake Swarm SW Of Mount Hood

MOUNT HOOD, OREGON, US

A small seismic sequence of quakes is occurring on the SW flank of Mount Hood, Oregon today, with the largest quakes registering at magnitude 2.1. Around 60 quakes (at the time of this writing) have been registered so far. USGS CVO reports that this is likely purely tectonic in nature and is not the result of magma movement.

"On the afternoon of July 8, 2019 a swarm of small earthquakes started near Mount Hood, Oregon. As of 11:00 AM PDT on July 9, the Pacific Northwest Seismic Network has located more than 30 earthquakes, all occurring about 1 mile ENE of Government Camp and about 5 miles south of the Mount Hood summit. The earthquakes are relatively shallow (2-3 miles) and are likely too small (maximum magnitude 2.1) to be felt. Swarms in this area have occurred multiple times over the past two decades, most recently in 2014, with the largest event being a M 2.9 on September 14, 2001.

The largest event ever recorded near Mount Hood was a M 4.5 on June 29, 2002, at a location 3 miles south of the summit. Based on similarity to past seismic sequences near Mount Hood and on past studies of seismicity in the Mount Hood area, we infer that these earthquakes are occurring on tectonic faults and are not directly related to volcanic processes occurring beneath Mount Hood. http://ow.ly/PqBZ50uWRtz Mount Hood earthquake map: http://ow.ly/GY6u50uWRtI PNSN TDH webicorder http://ow.ly/n1xk50uWRtA"

Mount Hood, along the Cascades arc of volcanoes, was last confirmed to have erupted in 1865 with an unconfirmed eruption in 1869, according to the Smithsonian GVP.