Bodega Head
Encyclopedia
Promontory
Promontory may refer to:*Promontory, a prominent mass of land which overlooks lower lying land or a body of water*Promontory, Utah, the location where the United States first Transcontinental Railroad was completed...
on the Pacific
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
coast of northern California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. It is located in Sonoma County
Sonoma County, California
Sonoma County, located on the northern coast of the U.S. state of California, is the largest and northernmost of the nine San Francisco Bay Area counties. Its population at the 2010 census was 483,878. Its largest city and county seat is Santa Rosa....
at 38.311°N 123.066°W, approximately 40 mi (64 km) northwest of San Francisco and approximately 20 mi (32 km) west of Santa Rosa
Santa Rosa, California
Santa Rosa is the county seat of Sonoma County, California, United States. The 2010 census reported a population of 167,815. Santa Rosa is the largest city in California's Wine Country and fifth largest city in the San Francisco Bay Area, after San Jose, San Francisco, Oakland, and Fremont and 26th...
.
The peninsula, which is approximately 4 mi (6.4 km) long and 1 mi (1.6 km) wide, emerges from the coast to the south. It shelters the shallow sandy Bodega Bay
Bodega Bay
Bodega Bay is a shallow, rocky inlet of the Pacific Ocean on the coast of northern California in the United States. It is approximately across and is located approximately northwest of San Francisco and west of Santa Rosa...
the inner portion known as Bodega Harbor
Bodega Harbor
Bodega Harbor is a small shallow natural harbor on the Pacific coast of northern California in the United States, approximately 40 mi northwest of San Francisco...
. Sonoma Coast State Beach
Sonoma Coast State Beach
Sonoma Coast State Beach is a State of California property in Sonoma County consisting of public access use on lands adjoining the Pacific Ocean. This extent of beach runs from a coastal point about north of Jenner and continues for approximately to the south to terminate at Bodega Head...
comprises beaches and dunes along the south side of the promontory. The University of California
University of California
The University of California is a public university system in the U.S. state of California. Under the California Master Plan for Higher Education, the University of California is a part of the state's three-tier public higher education system, which also includes the California State University...
runs an ongoing marine biology
Marine biology
Marine biology is the scientific study of organisms in the ocean or other marine or brackish bodies of water. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather...
program at the Bodega Marine Laboratory. The laboratory is located on the grounds of Bodega Marine Reserve, which is part of the UC Natural Reserve System. The peninsula is considered a prime spot to observe the migration of whale
Whale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...
s. A series of trails are a popular destination for recreational hiking
Hiking
Hiking is an outdoor activity which consists of walking in natural environments, often in mountainous or other scenic terrain. People often hike on hiking trails. It is such a popular activity that there are numerous hiking organizations worldwide. The health benefits of different types of hiking...
.
The peninsula was probably inhabited by the Coast Miwok
Coast Miwok
The Coast Miwok were the second largest group of Miwok Native American people. The Coast Miwok inhabited the general area of modern Marin County and southern Sonoma County in Northern California, from the Golden Gate north to Duncans Point and eastward to Sonoma Creek...
people before the arrival of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
ans. Campbell Cove, on the east side of the promontory, is a candidate for Sir Francis Drake's
Francis Drake
Sir Francis Drake, Vice Admiral was an English sea captain, privateer, navigator, slaver, and politician of the Elizabethan era. Elizabeth I of England awarded Drake a knighthood in 1581. He was second-in-command of the English fleet against the Spanish Armada in 1588. He also carried out the...
1579 landing site.
Geology
Bodega Head lies just on the west side of the San Andreas FaultSan Andreas Fault
The San Andreas Fault is a continental strike-slip fault that runs a length of roughly through California in the United States. The fault's motion is right-lateral strike-slip...
, which runs between the base of the promontory and the mainland. During the 1906 San Francisco earthquake
1906 San Francisco earthquake
The San Francisco earthquake of 1906 was a major earthquake that struck San Francisco, California, and the coast of Northern California at 5:12 a.m. on Wednesday, April 18, 1906. The most widely accepted estimate for the magnitude of the earthquake is a moment magnitude of 7.9; however, other...
, the promontory shifted approximately 15 ft (5 m), displacing the harbor to the north relative to the mainland.
Geologically
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
, the rocks of Bodega Head differ greatly from those on the mainland just to the east. Whereas the rocks of Bodega Head are exposed continental granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
, the mainland rocks are of oceanic origin from the Franciscan Complex. Bodega Head is the northern tip of a vast geologic province known as the Salinian Block
Salinian Block
The Salinian Block or Salinian terrane is a geologic terrane which lies west of the main trace of the San Andreas Fault system in California. It is bounded on the south by the Big Pine Fault in Ventura County, and on the west by the Nacimiento Fault...
whose core is of the same origins as the core of the Sierra Nevada Mountains. The block was torn off the continent as the San Andreas Fault came into existence about 20 million years ago, and was transported northward hundreds of miles. Other nearby examples of the Salinian Block are the Point Reyes Peninsula and the Farallon Islands
Farallon Islands
The Farallon Islands, or Farallones , are a group of islands and sea stacks in the Gulf of the Farallones, off the coast of San Francisco, California, USA. They lie outside the Golden Gate and south of Point Reyes, and are visible from the mainland on clear days...
.
A controversial attempt by Pacific Gas & Electric Company to construct a nuclear power plant
Nuclear power plant
A nuclear power plant is a thermal power station in which the heat source is one or more nuclear reactors. As in a conventional thermal power station the heat is used to generate steam which drives a steam turbine connected to a generator which produces electricity.Nuclear power plants are usually...
on the peninsula in the late 1950s was thwarted because of environmental concerns and the possibility of danger from earthquake
Earthquake
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...
s.