John A. Power (Former Employee)

Between January 1 and December 31, 2011, the Alaska Volcano Observatory (AVO) located 4,364 earthquakes, of which 3,651 occurred within 20 kilometers of the 33 volcanoes with seismograph subnetworks. There was no significant seismic activity above background levels in 2011 at these instrumented volcanic centers. This catalog includes locations, magnitudes, and statistics of the...

Redoubt Volcano, an ice-covered stratovolcano on the west side of Cook Inlet, erupted in March 2009 after several months of escalating unrest. The 2009 eruption of Redoubt Volcano shares many similarities with eruptions documented most recently at Redoubt in 1966–68 and 1989–90. In each case, the eruptive phase lasted several months, consisted of multiple ashproducing explosions...

Between January 1 and December 31, 2010, the Alaska Volcano Observatory (AVO) located 3,405 earthquakes, of which 2,846 occurred within 20 kilometers of the 33 volcanoes with seismograph subnetworks. There was no significant seismic activity in 2010 at these monitored volcanic centers. Seismograph subnetworks with severe outages in 2009 were repaired in 2010 resulting in three volcanic...

We incorporate 14 years of earthquake data from the Alaska Volcano Observatory with data from a 1975 controlled‐source seismic experiment to obtain the three‐dimensional P and S wave velocity structure and the first high‐precision earthquake locations at Augustine Volcano to be calculated in a fully three‐dimensional velocity model. Velocity tomography shows two main features beneath...

A significant number of volcano-tectonic (VT) earthquake swarms, some of which are accompanied by ground deformation and/or volcanic gas emissions, do not culminate in an eruption. These swarms are often thought to represent stalled intrusions of magma into the mid- or shallow-level crust. Real-time assessment of the likelihood that a VT swarm will culminate in an eruption is one of the...

In September of 2004, UNAVCO and the National Science Foundation (NSF) funded EarthScope Plate Boundary Observatory (PBO) installed five permanent Continuous Global Positioning System (CGPS) stations on Augustine Volcano, supplementing one existing CGPS station operated by the Alaska Volcano Observatory. All six CGPS stations proved crucial to scientists for detecting and monitoring the...