California geography

California is divided into 11 geological provinces: Klamath Mountains , Cascade Mountains , Modoc Plateau , Valley and Ridge Province , Coast Ranges , California Valley , Sierra Nevada , Los Angeles Ranges , Mojave Desert , Baja California , Colorado Desert .

California is a seismic zone, many geological faults pass through the state, the most famous of which is San Andreas . This is a seismically active fault up to 25 km deep with a length of more than 1000 km and a width of up to 20 km ^[1] , which are associated with the largest earthquakes in the history of California. San Andreas connects two segments of the mid-ocean ridge: the continuation of the East Pacific Rise in the Gulf of California and the Juan de Fuca Ridge . The border of the Pacific and North American lithospheric plates runs along it. ^[2]

Also in California there are several volcanoes , including the sleeping volcano Lassen Peak , which erupted in 1914 and 1921 .

Since the 19th century , oil has been mined in the California Valley. Over the past twenty years, the pace of production has been gradually declining. ^[3] In 2008, California produced about 655 thousand barrels of oil per day, which is 1.7% less than the previous year. Currently, the largest oil field is Midway Sunset (36.7 million barrels in 2008). Natural gas production is also declining. In 2008, about 298.3 billion cubic feet (about 8.5 billion m³ ) were produced. Among natural gas fields, Elk Hills leads. ^[3]

California takes third place in the extraction of other minerals (after Arizona and Nevada ). ^[4] According to the US annual geological survey in 2007, the state produced about 30 industrial minerals in 660 mines. In quantitative terms, the state’s main mined minerals are construction sand (about 143 million US tons in 2007) and gravel , as well as cement . Boron minerals are also of great importance to the state’s mining industry. ^[4] Currently, mining of gold and silver continues in California, which began back in the days of the Gold Rush . Gold is one of the symbols of the state , and the official nickname of California is “The Golden State” ( The Golden State ) ^[5] ; however, this metal is currently mined in much smaller quantities and does not play a large role in the state’s economy. ^[four]

Fertile land is concentrated in the middle of the state, in the California Valley . By origin, it is a tectonic deflection filled with sedimentary rocks. Other tectonic depressions are located in the southeast of the state, the largest of them are Death Valley (the lowest point in the United States and all of North America) and Salton Sea .

Sedimentary rocks, deposited over the course of 15 million years by the Los Angeles , San Gabriel, and Santa Ana rivers, formed a flat, flat, even area on the Pacific coast, known as the Los Angeles Basin . The instability of these rocks exposes the Los Angeles city located in the Basin and its agglomeration to significant danger during earthquakes. ^[6]

In the northwest of the state are the Klamath Mountains . This is a mountain range that is partially located in the southwestern part of Oregon . Klamath mountains are geologically diverse ( serpentine and marble are present in significant volumes), and also have a unique flora. The highest point of this mountain range is Thompson Peak (2,744 m).

In northern California is the southern tip of the Cascade Mountains , stretching over a vast distance from British Columbia ( Canada ) through Washington and Oregon. This mountain range includes several volcanoes. All volcanoes erupted in the continental states in historical time belong to the Cascade Mountains system. The last of them erupted Lassen Peak , the southernmost of the active volcanoes of this ridge, in 1921 . Mount Shasta , a sleeping volcano located in California, is the second highest peak of the Cascade Mountains (after Rainier in Washington State). The height of Shasta is 4 322 meters. ^[7]

A significant area in the north-eastern part of the state is the Modoc Plateau , which consists of solidified lava. The height of the plateau ranges between 1,200 and 1,800 meters.

In the center of the state is the vast California Valley, with an area of ​​about 110,000 km² (approximately equal to the state of Tennessee ), the state's agricultural heart. From all sides the valley is bounded by mountains. Coastal ranges are located in the west, Sierra Nevada mountains in the east, Cascade mountains in the north, and Tehachapi mountains in the south. The Sacramento and San Joaquin Delta divides the valley into two parts, which are named after them the Sacramento Valley (northern part) and the San Joaquin Valley (southern part)

To the west of the valley, the Coast Ranges extend along the Pacific Ocean coast, including the Diablo Range to the east of San Francisco and the Santa Cruz Mountains , located south of this city. These mountains are known as the seat of sequoias , the tallest trees on Earth.

In the east of California, the Sierra Nevada Mountains are located , stretching from north to south for a distance of about 750 km. They contain Yosemite Valley and Tahoe , a giant sequoia grows. The height of the mountains gradually increases from north to south. In the interval between the Fredonier Pass and Lake Tahoe, the height of the peaks varies from 1,500 to 2,400 m above sea level. The ridge crest near Lake Tahoe reaches 2,700 m, with several cliffs such as Mount Rose (3,285 m); in the Yosemite National Park, it rises to approximately 4,000 m and reaches its peak on Whitney (4,421 m), the highest mountain of the continental states . Further south, the height gradually decreases.

In the southwest near the ocean are the vast lands of the Los Angeles Basin , while the southeast of California is occupied by deserts.

In California, 16 of the 104 US peaks are located, with an absolute height of more than 4000 meters and a relative height of more than 500 meters .

The two largest rivers in California are the Sacramento and San Joaquin . Both of them flow through the Central Plain and flow into the San Francisco Bay , and their length is 719 and 530 kilometers, respectively. Other major rivers of the state are the Klamath in the north (also flows into the Pacific Ocean ) and Colorado , part of which forms the natural border between California and Arizona .

Most of the state has a Mediterranean climate, with rainy winters and dry summers. The influence of the ocean reduces the temperature spread, leads to cool summers and warm winters. Because of the cold California ocean currents, fog often lays along the coast. When moving deeper into the territory, the climate becomes more continental , with a large variation in temperature in winter and summer. Westerly winds from the ocean bring moisture, and the northern part of the state receives more rain than the southern. The climate is also affected by mountains that do not allow humid air from the ocean to go far inland.

The northwestern part of California has a temperate climate, with a total rainfall of 38-100 cm per year. In the California Valley , a Mediterranean climate prevails, but with a wider variation in temperature. The mountains are characterized by a mountain climate , snowy winters and moderately warm summers. To the east of the mountain ranges are desert areas with cold winters and hot summers.

Most of California is occupied by the California floristic province, which is characterized by high endemicity (species - 48%, generic - 7.5%). Typical plant communities are chaparral and sparse oak plantations, and in the mountains, depending on the height, broad-leaved, mixed and coniferous forests, up to alpine communities. Typical endemic: Sequoia sempervirens , Sequoiadendron giganteum , Umbellularia californica , Lithocarpus densiflora , Fremontodendron californicum , Paeonia californica , Crossosoma californicum , Carpenteria californica , Lyonothamnus floribundus , Cercis caliceles talisis . The flora of California deserts belongs to the sonor province. It is also characterized by species endemism ( Carnegiea , Washingtonia ), and in the south (in the Sonora desert) neotropical elements are noticeable.