Seismologists at the University of California, Riverside studying earthquakes in the seismically and volcanically active Alaska-Aleutian subduction zone have found that “slow earthquakes” are occurring continuously, and could encourage damaging earthquakes.
Seismologists at the University of California, Riverside studying earthquakes in the seismically and volcanically active Alaska-Aleutian subduction zone have found that “slow earthquakes” are occurring continuously, and could encourage damaging earthquakes.
Slow earthquakes are quiet, can be as large as magnitude 7, and last days to years. Taking place mainly at the boundary between tectonic plates, they happen so slowly that people don’t feel them. A large slow earthquake is typically associated with abundant seismic tremor—a continuous weak seismic chatter—and low frequency (small and repeating) earthquakes.
“In the Alaska-Aleutian subduction zone, we found seismic tremor, and visually identified three low frequency earthquakes,” said Abhijit Ghosh, an assistant professor of Earth sciences, who led the research published recently in Geophysical Research Letters. “Using them as templates, we detected nearly 1,300 additional low frequency earthquakes. Slow earthquakes may play an important role in the earthquake cycles in this subduction zone.”
Read more at University of California, Riverside
Image: Image shows tremor sources and low frequency earthquake distribution in the study region and historic large earthquakes in the Alaska-Aleutian subduction zone. Each red star represents the location of 1 min tremor signal determined by the beam back projection method, and the black stars show three visually detected low frequency earthquakes located using arrival times of body waves. (Credit: Ghosh lab, UC Riverside.)
