A "subduction zone" is a place where one tectonic plate slides under another plate, usually resulting in the formation of mountains and causing earthquakes and volcanic activity. Full definition
State geologists analyze projected impacts of Cascadia Subduction Zone earthquake, magnitude 9.0, and expect tens of thousands of casualties in the... (pamplinmedia.com)
Download Cascadia Subduction Zone Earthquakes: A magnitude 9.0 earthquake scenario (crew.org)
U.S. Geological Survey scientist Jeanne Hardebeck calculated the frictional strength of subduction zone faults worldwide, and the stresses they are under. (sciencedaily.com)