Preliminary Results From a Temporary Seismic Network at Mt. Baker, Washington

In August 2007, a temporary network of four broadband seismometers was deployed at Mt. Baker, WA. This marks the first time that a seismic network has been located on Mt. Baker since a period of volcanic unrest in 1975-76. These data can therefore provide a new window into Baker's background seismicity. The network was composed of four Guralp CMG-6TD seismometers, each of which was deployed for 4-8 weeks between August and October 2007. Instruments were located between 0.5 and 10 km from the volcano's summit. Up to 10 earthquakes per day were recorded across the network, although the majority of these events are thought to be associated with ice rather than volcanic processes. Volcanic earthquakes appear to be infrequent, consistent with previous interpretations of Baker seismicity; however, the short duration of the deployment makes it difficult to extrapolate to longer time scales. Other signals recorded during the deployment include rockfalls from the rim of Sherman Crater, regional and teleseismic earthquakes, and a deep long-period earthquake located to the SE of the volcano. Because there is only a single permanent seismometer located within 30 km of Mt. Baker, hypocenters for previous Baker earthquakes have been poorly constrained for all but the largest (>M2) events. This network provides the first opportunity in 30 years to study microseismicity at Mt. Baker and examine its background behavior.