Gorda Plate

The Gorda Plate, located beneath the Pacific Ocean off the coast of northern California, is one of the northern remnants of the Farallon Plate. It is sometimes referred to (by, for example, publications from the USGS Earthquake Hazards Program [http://neic.usgs.gov/neis/eq_depot/2005/eq_050617/neic_zkal_ts.html] ) as simply the southernmost portion of the neighboring Juan de Fuca Plate, another Farallon remnant.

Unlike most tectonic plates, the Gorda Plate experiences significant deformation inside its boundaries. Stresses from the neighboring North American Plate and Pacific Plate cause frequent earthquakes in the interior of the plate, including the 1980 M7.2 Trinidad earthquake which caused $1.75 million in damages [http://www.humboldt.edu/~geodept/earthquakes/recent_eqks.html] .

The easterly side is a convergent boundary subducting under the North American Plate in northern California. The southerly side is a transform boundary with the Pacific Plate along an extension of the San Andreas Fault. The westerly side is a divergent boundary with the Pacific Plate forming the Gorda Ridge. The northerly side is a transform boundary with the Juan de Fuca Plate.

The subducting Gorda Plate is connected with the volcanoes in northern California, namely, Mount Shasta and Lassen Peak. Lassen Peak last erupted in 1914-1917.

External links

* [http://pubs.usgs.gov/publications/text/understanding.html USGS Understanding plate motions]
* [http://woodshole.er.usgs.gov/operations/obs/rmobs_pub/html/mendocino.html Mendocino Triple Junction Offshore Northern California]
* [http://www.humboldt.edu/~geodept/earthquakes/recent_eqks.html Recent North Coast Earthquakes]
* [http://www.washington.edu/burkemuseum/geo_history_wa/Cascade%20Episode.htm Cascadia tectonic history with map]