Pieces of mantle found rising under north and south ends of Cascadia fault
July 25, 2018, University of Oregon
With four years of data from 268 seismometers on the ocean floor and several hundred on land, researchers have found anomalies in the upper mantle below both ends of the Cascadia Subduction Zone. They may influence the location, frequency and strength of earthquake events along the U.S. Pacific Northwest.
The anomalies, which reflect regions with lower seismic wave velocities than elsewhere beneath the fault line, point to pieces of the Earth's upper mantle that are rising and buoyant because of melting rock and possibly elevated temperatures, said Miles Bodmer, a University of Oregon doctoral student who led a study now online as an accepted paper by the journal Geophysical Research Letters.
Read more at:
https://phys.org/news/2018-07-pieces-mantle-north-south-cascadia.html#jCp
