Volcanic earthquakes in Alaska's national parks

Alaska’s national parks contain 11 historically active
volcanoes (Figure 2), which produce thousands of small
earthquakes every year. These earthquakes are voices
of the magmatic and geothermal systems within the
volcanoes. The Alaska Volcano Observatory (AVO), a
joint program of the U.S. Geological Survey, the Geophysical
Institute at the University of Alaska Fairbanks,
and the Alaska Division of Geological and Geophysical
Surveys, monitors volcanic earthquakes year round with
networks of seismometers (Figure 4). Data from these
networks allow AVO to evaluate the state of magmatic
systems and provide warning of volcanic unrest, potential
eruptions, and hazards. The key to correctly interpreting
earthquakes lies in understanding the physical
processes that trigger earthquakes at volcanoes.