Cape Mendocino

Cape Mendocino, located on the Lost Coast entirely within Humboldt County, California, USA, is the westernmost point on the coast of California. The South Cape Mendocino State Marine Reserve and Sugarloaf Island are immediately offshore, although closed to public access due to their protected status. Sugarloaf Island is cited as California's westernmost island.

History

Named by Spanish explorer Andrés de Urdaneta in 1565 in honor of Antonio de Mendoza, Viceroy of New Spain, Cape Mendocino has been a landmark since the 16th century, when Manila Galleons followed the prevailing westerlies across the Pacific to the Cape, then followed the coast south to Acapulco, Mexico. The Cape Mendocino Light was lit December 1, 1868, standing on eight prefabricated panels sent up from San Francisco; an automated light stood near the original location but was removed in 2013.

Geology

The Cape Mendocino region of California's north coast is one of the most seismically active regions in the contiguous United States. Three earthquakes with epicenters nearby at Petrolia and offshore west of Cape Mendocino, 25–26 April 1992, were outstanding, one reaching 7.2 M_w; they demonstrated that the Cascadia subduction zone is both capable of producing large earthquakes and generating tsunamis. 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.