The Gorda Plate, located beneath the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

off the coast of northern

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, is one of the northern remnants of the

Farallon Plate The Farallon Plate was an ancient oceanic plate. It formed one of the three main plates of Panthalassa, alongside the Phoenix Plate and Izanagi Plate, which were connected by a triple junction. The Farallon Plate began subducting under the west ...

. It is sometimes referred to (by, for example, publications from the

USGS The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, a ...

Earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...

Hazards Program) as simply the southernmost portion of the neighboring Juan de Fuca Plate, another Farallon remnant. Unlike most

tectonic plates Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large te ...

, the Gorda Plate experiences significant

intraplate deformation Intraplate deformation is the folding, breaking, or flow of the Earth's crust within plates instead of at their margins. This process usually occurs in areas with especially weak crust and upper mantle, such as the Tibetan Plateau (Figure 1). Int ...

inside its boundaries. Numerous faults have been mapped in both the sediments and basement of the Gorda Basin, which is in the interior of the plate south of 41.6°N. Stresses from the neighboring

North American Plate The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Pacific ...

and

Pacific Plate The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At , it is the largest tectonic plate. The plate first came into existence 190 million years ago, at the triple junction between the Farallon, Phoenix, and Iza ...

cause frequent earthquakes in the interior of the plate, including the 1980 Eureka earthquake (also known as the Gorda Basin event). The easterly side is the

Cascadia subduction zone The Cascadia subduction zone is a convergent plate boundary that stretches from northern Vancouver Island in Canada to Northern California in the United States. It is a very long, sloping subduction zone where the Explorer, Juan de Fuca, a ...

where the plate subducts under the

in northern California. The southerly side is a

transform boundary A transform fault or transform boundary, is a fault along a plate boundary where the motion is predominantly horizontal. It ends abruptly where it connects to another plate boundary, either another transform, a spreading ridge, or a subductio ...

with the

along the

Mendocino Fault The Mendocino Fracture Zone is a fracture zone and transform boundary over 4000 km (2500 miles) long, starting off the coast of Cape Mendocino in far northern California. It runs westward from a triple junction with the San Andreas Fault ...

. The westerly side is a divergent boundary with the Pacific Plate forming the

Gorda Ridge The Gorda Ridge (41°36'19.6"N 127°22'03.1"W), aka ''Gorda Ridges'' tectonic spreading center, is located roughly off the northern coast of California and southern Oregon. Running NE – SW it is roughly in length.Carey, Stein, & Rona. (1990). ...

. This ridge provides morphological evidence of differing spreading rates, with the northern portion of the ridge being narrow, and the southern portion being wide. The northerly side is a

with the Juan de Fuca Plate, the

Blanco Fracture Zone The Blanco Fracture Zone or Blanco Transform Fault Zone (BTFZ) is a right lateral transform fault zone, which runs northwest off the coast of Oregon in the Pacific Northwest of the United States, extending from the Gorda Ridge in the south to the ...

. The subducting Gorda Plate is connected with the

volcanoes A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates a ...

in northern California, namely,

Mount Shasta Mount Shasta ( Shasta: ''Waka-nunee-Tuki-wuki''; Karuk: ''Úytaahkoo'') is a potentially active volcano at the southern end of the Cascade Range in Siskiyou County, California. At an elevation of , it is the second-highest peak in the Cascades ...

and

Lassen Peak Lassen Peak ( ), commonly referred to as Mount Lassen, is a lava dome volcano and the southernmost active volcano in the Cascade Range of the Western United States. Located in the Shasta Cascade region of Northern California, it is part of the ...

. Lassen Peak last erupted in 1914–1917.

References

External links

Understanding plate motions
– USGS

– USGS (David Oppenheimer)
You live in Earthquake Country
– Humboldt State University

–

Burke Museum of Natural History and Culture The Burke Museum of Natural History and Culture (Burke Museum) is a natural history museum in Seattle, Washington, in the United States. Established in 1899 as the Washington State Museum, it traces its origins to a high school naturalist club fo ...

Gorda Plate Structure
–

Oregon State University Oregon State University (OSU) is a public land-grant, research university in Corvallis, Oregon. OSU offers more than 200 undergraduate-degree programs along with a variety of graduate and doctoral degrees. It has the 10th largest engineering co ...

Tectonic plates Geologic provinces of California Geology of the Pacific Ocean {{tectonics-stub

See also

References

External links