Earthquakes at Newberry Volcano, April 14-18, 2013

Between April 14–18, five earthquakes were located within or along the margins of the Newberry caldera by the Pacific Northwest Seismic Network (PNSN, http://www.pnsn.org). On April 14 a M 0.3 earthquake occurred at 1506 UTC in the same vicinity as two earthquakes from the previous week (April 12). On April 15, a "low-frequency event", so-called because it lacks higher-frequency waves that are commonly observed in regular earthquakes, occurred at 0115 UTC with a depth of ~15 km. This was similar to, but smaller than, a low-frequency event that occurred last week on April 11. Finally, on April 17 and 18, three small (M < -0.6), shallow earthquakes occurred within the caldera along with 15-20 other very small and unlocatable earthquakes.

Although intriguing from a volcanological perspective, the Newberry earthquakes are collectively small both in size and in number and are nothing to get excited about. Along with the events from April 08-12, these earthquakes are noteworthy because such events have not been commonly seen within or along the margins of the Newberry caldera since the Newberry seismic network was expanded from one to nine seismic stations in the summer of 2011.