The beautiful landscapes of western Oregon and Washington—and the geological hazards we live with—are products of the Cascadia Subduction Zone. Sedimentary layers and basalt from the ocean floor are scraped off and uplifted as the Juan de Fuca Plate dives beneath the edge of the continent, forming the Coast Range. Farther inland the top of the descending plate becomes so hot that it dehydrates; the rising water melts rock that rises as magma to form the Cascade volcanoes. Puget Sound in…
Area of the Cascadia subduction zone, including the Cascade Volcanic Arc (red triangles), site of recurring megathrust earthquakes at average intervals of about 500 years, including the Cascadia Earthquake of USGS
314 years ago Sunday, a megathrust earthquake devastated the region … ready for another?
THE CASCADIA SUBDUCTION ZONE: The geography of northern California, Oregon, Washington, and southern British Columbia is shaped by the Cascadia subduction zone, where the North American Plate collides with a number of smaller plates. The smaller plates “subduct” (descend) beneath the North American Plate as they converge along a 700-mile long (1,130 km) boundary. Above: Schematic view of the source area for the largest Cascadia earthquakes.
An ocean data buoy is alerting to an “event” in the Cascadia Subduction Zone off the west coast of Oregon. This is where a magnitude 9 earthquake hit in According to the data buoy, the water column height (depth) fell sharply within minutes.
The Cascadia Subduction Zone (CSZ) 'megathrust' fault is a Km long dipping fault that stretches from Northern Vancouver Island to Cape Mendocino California.It separates the Juan de Fuca and North America plates.
The Cascadia Subduction Zone off the coast of North America spans from northern California to southern British Columbia. This subduction zone can produce earthquakes as large as magnitude 9 and corresponding tsunamis.