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
[1]) 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
[2].
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
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USGS Understanding plate motions
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Mendocino Triple Junction Offshore Northern California
★
Recent North Coast Earthquakes
★
Cascadia tectonic history with map