After 1900, California continued to grow rapidly and soon became an agricultural and industrial power. The economy was widely based on specialty agriculture, oil, tourism, shipping, film, and after 1940 advanced technology such as aerospace and electronics industries – along with a significant military presence. The films and stars of Hollywood helped make the state the "center" of worldwide attention. California became an American cultural phenomenon; the idea of the "California Dream" as a portion of the larger American Dream of finding a better life drew 35 million new residents from the start to the end of the 20th century (1900–2010). Silicon Valley became the world's center for computer innovation.
California demographics
California is now the most populous state in the United States. If it were an independent country, California would rank 34th in population in the world. California has had waves of immigration and emigration over the years. The first big wave was the California Gold Rush starting in 1848 of miners, businessmen, farmers, loggers, etc. as well as their many supporters.
There were fewer than 10,000 females in a total California population (not including Native Americans who were not counted) of about 120,000 residents in 1850. About 3.0% of the gold rush Argonauts before 1850 were female or about 3,500 female Gold Rushers, compared to about 115,000 male California Gold Rushers. Massive immigration from mostly other states continued throughout the nineteenth century. California did not reach a "normal" male to female ratio of about one to one until the 1950 census. California for over a century was short on females.
The 1900 census showed emigrations down to "only" a 20% growth rate. The early 1900s showed a massive population increase of over 60% between 1900 and 1910. The population more than doubled again in the next 20 years by 1930. Foreign immigration largely ceased during the Great Depression, as immigration to the United States was held to a low of 23,068 per year by 1933, and many foreign workers were deported. There were not enough jobs to go around. After World War II and the Great Depression, there was a rapidly increasing buildup of United States workers in California as wartime industries boomed. Most of these workers were from other states as they settled in California and increased the California population to 10,586,223 by 1950. Immigration to the United States only started to increase significantly in 1946, when immigration to all of the United States was back up to 108,721 per year The continuing prosperity and emigration from other states and immigration from other countries in the 1950s and 1970s almost doubled the California population again to 19,953,134 by 1970. The 1970–2010 population growth has still been substantial but has slowed to "only" about a 15% growth rate per decade. By 2010 the California population growth rate slowed slightly to 10%.
California earthquakes
Earthquakes in California are common occurrences since the state is traversed by six major strike-slip fault systems with hundreds of related faults, many of which are "brother faults" of the infamous San Andreas Fault that runs nearly the full length of California at the juncture of the Pacific Plate and the North American Plate. The fault systems include the Hayward Fault Zone, Calaveras Fault, Clayton-Marsh Creek-Greenville Fault, and the San Gregorio Fault. Significant blind thrust faults (faults with near vertical motion and no surface ruptures) are associated with portions of the Santa Cruz Mountains and the northern reaches of the Diablo Range and Mount Diablo. The California earthquake forecast gives a rough estimate of where the main earthquake zones in California are. Earthquake damage depends on what area is hit, how close to the surface the center of the earthquake is located, and its magnitude. Earthquake damage, for a given magnitude earthquake, to human structures depends on how well the buildings are built and what the structures are located on. Buildings on soft or filled-in soil suffer the most because they feel shock waves most strongly. Buildings on bedrock suffer less damage because the ground is firmer. Sometimes the ensuing fires, floods or tsunamis caused by the earthquake are often where the greatest damage occurs.
The 1906 San Francisco earthquake struck the city (then the largest in California) and nearby communities at 5:12 a.m. on Wednesday, April 18, 1906. Devastating fires broke out in the city that lasted for several days, destroying about 28,000 buildings. As a result of the quake and fires, over 3,000 people died and over 80% of San Francisco was destroyed. The death toll from the earthquake and resulting fire is the greatest loss of life from a natural disaster in California's history.
The most widely accepted estimate for the magnitude of the earthquake is a moment magnitude (Mw) or Richter magnitude (ML) of 7.8; however, other values have been proposed, from 7.7 to as high as 8.25. Shaking was felt from Oregon to Los Angeles, and inland as far as central Nevada.
The San Francisco 1906 earthquake was caused by a rupture on the San Andreas Fault, a continental transform fault that forms part of the tectonic boundary between the Pacific Plate and the North American Plate. The fault is characterized by mainly lateral motion where the western (Pacific) plate moves northward relative to the eastern (North American) plate. The 1906 rupture propagated both northward and southward from its epicenter for a total of about . The San Andreas Fault runs the length of California from the Salton Sea in the south to Cape Mendocino to the north, a distance of about . The earthquake ruptured the northern third of the fault for a distance of about . The maximum observed surface displacement was about ; however, geodetic measurements show displacements of up to in some places. The most recent analysis by the United States Geological Survey (USGS) shows that the most likely epicenter of the 1906 earthquake was very near Mussel Rock on the coast of Daly City, an adjacent suburb just south of San Francisco.
A strong foreshock preceded the mainshock by about 20 to 25 seconds. The strong shaking of the main shock lasted about 42 seconds. The shaking intensity as described on the Modified Mercalli intensity scale reached VIII in San Francisco and up to IX in areas to the north like Santa Rosa, where destruction was devastating. There were decades of minor earthquakes – more than at any other time in the historical record for northern California – before the 1906 quake. They have been widely interpreted subsequently as precursory activity to the 1906 earthquake.
Significant California earthquakesEarthquakeMagnitudeFatalities1906 San Francisco7.83,000+11925 Santa Barbara6.3–6.8131933 Long Beach 6.41151952 Kern County7.3121971 San Fernando6.6651989 Loma Prieta6.9631994 Northridge6.760Notes: 1. The 1906 San Francisco earthquake causedso much damage that the authorities "lied" about the number of casualties. Subsequentresearch has shown that about 3,450 were"known" to have died. Some more were shotfor looting.
Due to a widespread practice by insurers to indemnify San Francisco properties from fire, but not earthquake damage, most of the destruction in the city was blamed on the fires. Some property owners deliberately set fire to damaged properties in order to claim them on their insurance. Capt. Leonard D. Wildman of the U.S. Army Signal Corps reported that he "was stopped by a fireman who told me that people in that neighborhood were firing their houses… they were told that they would not get their insurance on buildings damaged by the earthquake unless they were damaged by fire. The insurance industry eventually paid out over $250,000,000 (the largest amount they paid out for the next 60 years) which significantly helped to rebuild the city." Building standards of the original 1906 buildings had almost no earthquake resistance built in. Since 1906 earthquake standards have been steadily upgraded as damages caused by earthquakes are investigated. Unfortunately, a lot of older buildings do not meet today's standards, and it would typically cost too much to upgrade them. It was discovered in 1906 (again) that all masonry-type structures built of brick and un-reinforced concrete are resistant to fire but not earthquakes. A detailed analysis of the city of San Francisco today estimates that an earthquake over 7.0 magnitude would completely destroy or seriously damage many sections of San Francisco and could possibly result in thousands of deaths. Today in most communities, structures built to later earthquake standards would do well in all but the strongest earthquakes. The water mains and other infrastructure needed for fighting fires have all been upgraded but are yet untested.
California oil industry
California pioneers after 1848 discovered an increasing number of oil seeps—oil seeping to the surface, especially in Humboldt, Colusa, Santa Clara, and San Mateo counties, and in the asphaltum seeps and bituminous residues in Mendocino, Marin, Contra Costa, Santa Clara, and Santa Cruz counties. In southern California, large seeps in Ventura, Santa Barbara, Kern, and Los Angeles counties received the most attention. Interest in oil and gas seeps was stirred in the 1850s and 1860s, becoming widespread after the 1859 commercial uses of oil were demonstrated in Pennsylvania. Kerosene quickly replaced whale oil for lighting, and lubricating oils became an essential product in the Machine Age. Other uses later in the 19th century included providing paving material for many roads and providing power for many steam locomotives and steam-powered shipping—replacing coal.
Oil became a major California industry in the 20th century with the discovery of new fields around Los Angeles and the San Joaquin Valley, and the dramatic explosion in demand for gasoline to fuel the rapidly growing number of automobiles and trucks now being produced. Most of the oil production in California began in the late 19th century. At the turn of the century, oil production in California continued to rise at a booming rate. In 1900, the state of California produced 4 million barrels. In 1903, California became the leading oil-producing state in the US, and traded the number one position back and forth with Oklahoma through 1930. Production at the various oil fields increased to about 34 million barrels per year by 1904. By 1910 production had reached 78 million barrels. California drilling operations and oil production are concentrated primarily in Kern County, the San Joaquin Valley, and the Los Angeles Basin.
As of 2012, California was the nation's third most prolific oil-producing state, behind only Texas and North Dakota. In the past century, California's oil industry grew to become the state's number one GDP export and one of the most profitable industries in California.
There is also some offshore oil and gas production in California, but there is now a moratorium on new offshore oil and gas leasing and drilling in California waters and a deferral of leasing in federal waters. These restrictions were imposed after a series of accidents in the 1969 Santa Barbara oil spill released oil into the Pacific Ocean.
In 1920, oil production in California had expanded to 77 million barrels. Between 1920 and 1930, new oil fields across southern California were being discovered with regularity, including Huntington Beach in 1920, Long Beach and Santa Fe Springs in 1921, and Dominguez in 1923. Southern California had become the hotbed for oil production in the United States.