Cape Mendocino in Humboldt County, California, USA, is the westernmost point on the coast of California. (Mendocino County lies to the south.) It has been a landmark since the 16th century Manila Galleons that would reach the coast here following the trade winds and make their way coastwise southwards. Its first lighthouse was lit December 1, 1868, standing on eight prefabricated panels sent up from San Francisco. Humboldt County is a county located on the northwest coast of California, USA, on the Pacific Ocean. ... Official language(s) English Capital Sacramento Largest city Los Angeles Area  Ranked 3rd  - Total 158,302 sq. ... Mendocino County is a county located on Californias north coast, north of the San Francisco Bay Area and Sonoma County and west of the Central Valley. ... The Manila Galleons were Spanish galleons that sailed once or twice per year across the Pacific Ocean between Manila in the Philippines and Acapulco in New Spain (now Mexico). ... The trade winds are a pattern of wind found in bands around the Earths equatorial region. ... December 1 is the 335th (in leap years the 336th) day of the year in the Gregorian calendar. ... 1868 (MDCCCLXVIII) was a leap year starting on Wednesday (see link for calendar) of the Gregorian calendar or a leap year starting on Friday of the 12-day-slower Julian calendar. ... Flag Seal Nickname: The City by the Bay; The City That Knows How; Golden Mountain (historic Chinese name) Location Location of the City and County of San Francisco, California Government City-County San Francisco Mayor Gavin Newsom Geographical characteristics Area    - City 600. ...

The Cape Mendocino region of California's north coast is one of the most seismically active regions in the "Lower Forty-eight" United States. Three earthquakes with epicenters nearby at Petrolia and offshore west of Cape Mendocino, 25–26 April, 1992, were outstanding, one reaching 7.0 on the Richter scale; they demonstrated that the Cascadia subduction zone is both capable of producing large earthquakes and generating tsunamis. The Richter magnitude test scale (or more correctly local magnitude ML scale) assigns a single number to quantify the size of an earthquake. ...

At Cape Mendocino, there is an unstable triple junction where three tectonic plates come together. The familiar San Andreas Fault, a strike-slip fault, approaches from the south; it separates the Pacific Plate and the North American Plate. To the north lies the Cascadia subduction zone, where the Juan de Fuca Plate and the last bit of its lower section, sometimes called the Gorda Plate, are being subducted under the margin of the North American plate. And west, along the continental shelf, lies the Mendocino fault zone, the strike-slip boundary between the main Juan de Fuca plate and the Pacific plate. Where the three come together, a geologically complex and highly unstable zone results. A triple junction is the point where three tectonic plates diverge. ... The tectonic plates of the world were mapped in the second half of the 20th century. ... View of the San Andreas Fault on the Carrizo Plain in central California San Andreas Fault is a geological fault that runs a length of roughly 800 miles (1287 kilometres) through California, United States. ... The Pacific plate is shown in pale yellow on this map The Pacific Plate is an oceanic tectonic plate beneath the Pacific Ocean. ... The North American plate is shown in brown on this map The North American Plate is a continental tectonic plate covering most of North America, extending eastward to the Mid-Atlantic Ridge and westward to the Cherskiy Range in East Siberia. ... Structure of the Cascadia subduction zone Area of the Cascadia subduction zone The Cascadia subduction zone is a very long sloping fault that stretches from mid-Vancouver Island to northern California. ... hi ... The Gorda Plate is a small oceanic tectonic plate beneath the Pacific Ocean off the coast of northern California. ...  Sediment  Rock  Mantle The continental shelf is the extended perimeter of each continent, which is covered during interglacial periods such as the current epoch by relatively shallow seas (known as shelf seas) andbbccvcnccccccccccccccccccccccccvvvvvvvvvvvvvvcggggggggggggggggyutu7ti8yukiyuiyutuiyuiytui gulfs. ...

Many geologists and seismologists believe that the main shock in the 1992 sequence may be a forerunner of a much more powerful earthquake in the Pacific Northwest.

Off the point, Sugarloaf Mountain is an isolated block of coastline eroded by surf.

External links

• Cape Mendocino Lighthouse
• Cape Menocino Lighthouse
• Cathy Moley, "Why we have earthquakes: a unique geologic setting"
• USGS Mendocino fault zone map