The Los Angeles metropolitan area, also known as Metropolitan Los Angeles or the Southland, is the 18th largest metropolitan area in the world and the second-largest metropolitan area in the United States. It is entirely located in the southern portion of the U.S. state of California.
The metropolitan area is defined by the Office of Management and Budget as the Los Angeles-Long Beach-Anaheim, CA Metropolitan Statistical Area (MSA), consisting of Los Angeles and Orange counties, a metropolitan statistical area used for statistical purposes by the United States Census Bureau and other agencies. Its land area is 4,850 sq. mi (12,562 km2) and its estimated 2016 population was 13,310,447 (a 3.75 percent increase over the official 2010 US Census population of 12,828,837).
Los Angeles and Orange counties are the first and third most populous counties in California respectively, and Los Angeles, with 9,819,000 people in 2010, is the most populous county in the United States. The Los Angeles metropolitan area is the most populous metropolitan area in the western United States and the largest in area in the United States. The metro area has at its core the Los Angeles-Long Beach-Anaheim corridor, an urbanized area defined by the Census Bureau with a population 12,150,996 as of the 2010 Census.
The Census Bureau also defines a wider commercial region based on commuting patterns, the Los Angeles-Long Beach, CA Combined Statistical Area (CSA), more commonly known as the Greater Los Angeles Area, with an estimated population of 18,788,800 in 2017. This includes the three additional counties of Ventura, Riverside, and San Bernardino. The total land area of the combined statistical area is 33,955 sq. mi (87,945 km²).
Video Los Angeles metropolitan area
Definitions
The counties and county groupings comprising the Los Angeles Metropolitan Area are listed below with 2017 U.S. Bureau of the Census estimates of their populations.
Los Angeles-Long Beach-Anaheim, CA Metropolitan Statistical Area (13,353,907)
- Los Angeles-Long Beach-Glendale, CA Metropolitan Division (10,163,507)
- Los Angeles County (10,163,507)
- Anaheim-Santa Ana-Irvine, CA Metropolitan Division (3,190,400)
- Orange County (3,190,400)
Division
Major divisions of the Los Angeles-Long Beach-Anaheim, CA Metropolitan Statistical Area
- East: Eastside, San Gabriel Valley, Pomona Valley
- West: Westside, Beach Cities
- South: South Bay, Palos Verdes Peninsula, South Los Angeles, Gateway Cities, North Orange County, South Orange County
- North: San Fernando Valley, portions of the Antelope Valley and Santa Clarita Valley
- Central: Downtown Los Angeles, Mid-Wilshire
Statistical Areas
In addition to the Los Angeles-Long Beach-Anaheim, CA Metropolitan Statistical Area, the following Metropolitan Statistical Areas are also included in the Los Angeles-Long Beach, CA Combined Statistical Area (total pop. 18,788,800):
- Oxnard-Thousand Oaks-Ventura, CA Metropolitan Statistical Area (854,223)
- Ventura County (854,223)
- Riverside-San Bernardino-Ontario, CA Metropolitan Statistical Area (4,580,670)
- Riverside County, California (2,423,266)
- San Bernardino County, California (2,157,404)
Urban areas of the region
The Los Angeles-Long Beach, CA CSA is a multicore metropolitan region containing several urban areas.
Urban areas
The combined statistical area is a multicore metropolitan region containing several urban areas.
Maps Los Angeles metropolitan area
Cities
Principal cities
The following is a list of cities with populations over 50,000 in the Los Angeles metropolitan area with 2011 United States Census Bureau estimates of their population. Cities in bold are considered principal cities of the metropolitan area by the Census Bureau, which represent significant employment centers:
Economy
The economy of the Los Angeles metropolitan area is famously and heavily based on the entertainment industry, with a particular focus on television, motion pictures, interactive games, and recorded music - the Hollywood district of Los Angeles and its surrounding areas are known as the "movie capital of the United States" due to the region's extreme commercial and historical importance to the American motion picture industry. Other significant sectors include shipping/international trade - particularly at the adjacent Port of Los Angeles and Port of Long Beach, together comprising the United States' busiest seaport - as well as aerospace, technology, petroleum, fashion and apparel, and tourism.
The City of Los Angeles is home to five Fortune 500 companies: energy company Occidental Petroleum, healthcare provider Health Net, metals distributor Reliance Steel & Aluminum, engineering firm AECOM, and real estate group CB Richard Ellis. Other companies headquartered in Los Angeles include American Apparel, City National Bank, 20th Century Fox, Latham & Watkins, Univision, Metro Interactive, LLC, Premier America, Gibson, Dunn & Crutcher, DeviantArt, Guess?, O'Melveny & Myers; Paul, Hastings, Janofsky & Walker, Tokyopop, The Jim Henson Company, Paramount Pictures, Sunkist Growers, Incorporated, Tutor Perini, Fox Sports Net, Capital Group, and The Coffee Bean & Tea Leaf. Korean Air's US passenger and cargo operations headquarters are located in two separate offices in Los Angeles. Entertainment and media giant The Walt Disney Company is headquartered in nearby Burbank.
The Los Angeles-Orange County metro area alone has an economy of roughly $866 billion (estimated for 2014), or the total economic output or income of Indonesia's 250 million people; (coastal California land values) and the rents they command contribute heavily to GDP earnings, at the expense of home affordability and thus future GDP increase. This is evident when comparing the coast with the Inland Empire, a large component of the five-county combined statistical area (CSA) that nevertheless contributes a far smaller portion to regional gross metropolitan product but still dominates in industry. The Southland CSA is the third-largest economic center in the world, after the Greater Tokyo Area and the New York-Newark-Bridgeport CSA.
The Port of Los Angeles and Port of Long Beach together comprise the fifth-busiest port in the world, being the center of imports and exports for trade on the west Pacific Coast as well as being one of the most significant ports of the western hemisphere. The Port of Los Angeles occupies 7,500 acres (3,035 hectares) of land and water along 43 miles (69 kilometres) of waterfront and is the busiest container port in the United States. The Port is the busiest port in the United States by container volume, the 8th busiest container port in the world. The top trading partners in 2004 were: China ($68.8 billion), Japan ($24.1 billion), Taiwan ($10.8 billion), Thailand ($6.7 billion), & South Korea ($5.6 billion)
The Port of Long Beach is the second-busiest container port in the United States. It adjoins the separate Port of Los Angeles. Acting as a major gateway for U.S.-Asian trade, the port occupies 3,200 acres (1,295 hectares) of land with 25 miles (40 kilometres) of waterfront in the city of Long Beach, California. The seaport has approximately $100 billion in trade and provides more than 316,000 jobs in Southern California. The Port of Long Beach imports and exports more than $100 billion worth of goods every year. The seaport provides the country with jobs, generates tax revenue, and supports retail and manufacturing businesses.
Long Beach-Los Angeles-Anaheim
The Long Beach-Los Angeles-Anaheim metropolitan statistical area is located in the southern part of California. In 2014, the metro area's population reached 13,262,220 and ranked second in the United States - a 1 percent increase from 2013.[1] In 2014, Los Angeles-Long Beach-Anaheim had a per capita personal income (PCPI) of $50,751 and ranked 29th in the country. [2]
In 2014, Los Angeles-Long Beach-Anaheim placed third among the largest exporters in the United States (shipment totaling to $75.5 billion). The metro accounted for 40.8 percent of California's merchandise exports, mainly exporting computer and electronic products ($18.6 billion); transportation equipment ($15.3 billion) and chemicals ($5.6 billion)[3]. Nonetheless, the greater Los Angeles metro has immensely benefited from the free trade agreements such that greater Los Angeles exported $25.1 billion to the NAFTA region and $776 million in goods to the CAFTA region.
Overall, in 2014 the average wages and salaries reached $57, 519 (in 2010, the average wages and salaries reached $54, 729).[5] Meanwhile, the median household income in 2014 was $56, 935, a 1.4 percent increase from 2013 (average median household income was $56, 164). [6]
Table 2 (refer below) is a chart of the four highest sectors in the metro area, with health care and social assistance reaching 15.54%
Table 3 (refer below) displays the location quotient for employment in the Los Angeles-Long Beach-Anaheim MSA. Top three sectors include information; art, entertainment, and recreation; and real estate and rental and leasing.
Table 3. Data obtained from the Bureau of Labor Statistics. 2014. Data measures Location Quotient for sectors in the MSA area. U.S. Total is the base areas. http://data.bls.gov/location_quotient/ControllerServlet
[1] http://proximityone.com/metros/2013/cbsa31080.htm#6.4
[2] Los Angeles- Long Beach- Anaheim
[3] Los Angeles- Long Beach- Anaheim
[4] Los Angeles- Long Beach- Anaheim
[5] http://proximityone.com/metros/2013/cbsa31080.htm#6 Dollar items are in current dollars (not adjusted for inflation). Per capita items in dollars; other dollar items in thousands of dollars. - See more at: http://proximityone.com/metros/2013/cbsa31080.htm#6
[6] http://www.meyersresearchllc.com/wp-content/uploads/2014/08/Zonda_Market_Report_CA_Los-Angeles-Long-Beach-Anaheim.pdf
Utilities and infrastructure
There are nine electric utility power companies in the Los Angeles metropolitan area. Southern California Edison serves a large majority of the Los Angeles metropolitan area except for Los Angeles city limits, Burbank, Glendale, Pasadena, Azusa, Vernon, Anaheim, and southern Orange County. Southern Orange County is part of the Los Angeles metropolitan area and it is served by San Diego Gas & Electric. There are three natural gas providers in the metropolitan area. Southern California Gas Company serves a large majority of the Los Angeles metropolitan area except for Long Beach and southern Orange County.
The Los Angeles metropolitan area is served by the following utility companies.
Electricity
- Southern California Edison (largest electric utility in the Los Angeles metropolitan area)
- Los Angeles Department of Water and Power (second-largest electric utility in the Los Angeles metropolitan area and the largest within the Los Angeles city limits)
- Burbank Water and Power
- Glendale Water and Power
- Pasadena Water and Power
- Anaheim Water and Power
- Azusa Light & Power
- Vernon Light & Power
- San Diego Gas & Electric (serves southern Orange County, which is part of the Los Angeles metropolitan area)
Natural gas
- Southern California Gas Company
- City of Long Beach Gas Company
- San Diego Gas & Electric (serves southern Orange County, which is part of the Los Angeles metropolitan area)
Cable television
- Charter Communications, known as Charter Spectrum (serves a majority of the Los Angeles metropolitan area)
- Cox Communications (serves parts of Orange County and the Palos Verdes peninsula)
Phone
- AT&T
- Frontier Communications
Demographics
According to the 2009 American Community Survey, the Los Angeles Metropolitan Area had a population of 12,874,797, of which 6,402,498 (49.7% of the population) were male and 6,472,299 (50.3% of the population) were female.
The age composition was the following:
- Under 5 years: 7.3%
- 5 to 9 years: 6.6%
- 10 to 14 years: 7.0%
- 15 to 19 years: 7.2%
- 20 to 24 years: 7.0%
- 25 to 34 years: 15.5%
- 35 to 44 years: 14.8%
- 45 to 54 years: 13.9%
- 55 to 59 years: 5.5%
- 60 to 64 years: 4.4%
- 65 to 74 years: 5.6%
- 75 to 84 years: 3.6%
- 85 years and over: 1.6%
Median age: 34.6 years
According to the survey, the Los Angeles Metropolitan Area was 54.6% White (32.2% non-Hispanic White alone), 7.0% Black or African American, 0.5% American Indian and Alaska Native, 13.9% Asian, 0.3% Native Hawaiian and Other Pacific Islander, 20.6% from Some other race, and 3.2% from Two or more races. Hispanics or Latinos of any race made up 44.8% of the population.
Whites are the racial majority; whites of both Hispanic and non-Hispanic origin make up 54.6% of the population. Non-Hispanic whites make up under one-third (32.2%) of the population. Approximately 7,028,533 residents are white, of which 4,150,426 are non-Hispanic whites.
The top five European ancestries are the following:
- German: 6.9% (883,124)
- Irish: 5.3% (786,541)
- English: 4.8% (619,364)
- Italian: 3.3% (425,056)
- French: 1.6% (204,635)
Blacks are a sizable minority; blacks of both Hispanic and non-Hispanic origin make up 7.0% of the population. Non-Hispanic blacks make up 6.7% of the population. Approximately 895,931 residents are black, of which 864,737 are non-Hispanic blacks. In the survey, 136,024 people identified their ancestry as "Sub-Saharan African", equal to 1.1% of the population.
American Indians are a small minority; American Indians of both Hispanic and non-Hispanic origin make up 0.5% of the population. American Indians of non-Hispanic origin make up 0.2% of the populace. Approximately 68,822 residents are American Indian, of which 26,134 are American Indians of non-Hispanic origin. Approximately 3,872 Cherokee, 1,679 Navajo, 1,000 Chippewa, and 965 Sioux reside in the area.
Asians are a large minority; Asians of both Hispanic and non-Hispanic origin make up 13.9% of the population. Asians of non-Hispanic origin make up 13.7% of the population. Approximately 1,790,140 residents are Asian, of which 1,770,225 are Asians of non-Hispanic origin.
The six Asian ancestries mentioned are the following:
- Filipino: 3.5% (454,086)
- Chinese: 3.0% (390,192)
- Korean: 2.1% (274,288)
- Vietnamese: 2.0% (254,353)
- Japanese: 1.0% (134,466)
- Indian: 0.9% (116,090)
"Other Asian" is an additional category that includes people who did not identify themselves as any of the groups above. This group includes people of Cambodian, Laotian, Pakistani, Burmese, Taiwanese, and Thai descent, among others. Approximately 166,665 people are in this category, and they make up 1.3% of the population.
Native Hawaiians and other Pacific Islanders are a very small minority; Native Hawaiians and other Pacific Islanders make up 0.3% of the population. Approximately 37,719 residents are Native Hawaiian or of other Pacific Islander ancestries, of which 33,982 are of non-Hispanic origin.
The three Pacific Islander ancestries mentioned are the following:
- Samoan: 0.1% (13,519)
- Native Hawaiian: 0.1% (6,855)
- Guamanian or Chamorro: <0.1% (4,581)
"Other Pacific Islander" is an additional category that includes people who did not identify themselves as any of the groups above. This group includes people of Fijian and Tongan descent, among others. Approximately 12,764 people are in this category, and they make up 0.1% of the population.
Multiracial individuals are a sizable minority; multiracial people of both Hispanic and non-Hispanic origin make up 3.2% of the population, of which 1.8% were of non-Hispanic origin. Approximately 405,568 people are multiracial, of which 228,238 are of non-Hispanic origin.
The four multiracial ancestries mentioned are the following:
- White and Asian: 0.8% (107,585)
- White and American Indian: 0.4% (55,960)
- White and Black or African American: 0.4% (53,476)
- Black or African American and American Indian: 0.1% (12,661)
Hispanic or Latinos, are, by far, the largest minority group; Hispanics or Latinos make up 44.8% of the population. They do not make up a majority, but they make up a plurality, outnumbering every other individual racial group. Approximately 5,763,181 residents are Hispanic or Latino.
The three Hispanic or Latino ancestries mentioned are the following:
- Mexican: 35.5% (4,570,776)
- Puerto Rican: 0.4% (48,780)
- Cuban: 0.4% (47,056)
"Other Hispanic or Latino" is an additional category that includes people who did not identify themselves as any of the groups above. This group include people of Costa Rican, Salvadoran, and Colombian descent, among others. Approximately 1,096,569 people are in this category, and they make up 8.5% of the population.
Source 1:
Source 2:
Medical Services
Los Angeles and Orange counties have separate medical service department but both work jointly. Government and Private hospitals open normally Monday through Friday, excluding City Holidays but some super specialists hospitals open 24X7. [1]
Tourism
Due to L.A.'s position as The Entertainment Capital of the World, there are many tourist attractions in the area. Consequently, the metropolitan L.A. is one of the most visited areas in the world. Here is a breakdown of some of its major attractions:
Amusement parks
Beaches
Shopping malls
Motion picture studios
Water parks
Zoos and aquariums
Night life
Museums
See also, Los Angeles City Museums
Presidential museums
Convention Centers
State parks & beaches
National parks, monuments, & refuges
- Channel Islands National Park
- Hopper Mountain National Wildlife Refuge
- Juan Bautista de Anza National Historic Trail
- Old Spanish National Historic Trail
- Santa Monica Mountains National Recreation Area
- Seal Beach National Wildlife Refuge
Other
Transportation
Commercial airports
The primary airport serving the LA metro area is Los Angeles International Airport (LAX), one of the busiest airports in the United States. LAX is located in southwestern Los Angeles, 16 miles (26 km) from Downtown Los Angeles. LAX is the only airport to serve as a hub for all three U.S. legacy airlines --American, Delta and United.
In addition to LAX, other airports, including Bob Hope Airport, John Wayne Airport, Long Beach Airport, and LA/Ontario International Airport, also serve the region.
Interstates
- Golden State Freeway/Santa Ana Freeway/San Diego Freeway/Montgomery Freeway (Interstate 5)
- Santa Monica Freeway/Rosa Parks Freeway/Golden State Freeway (Interstate 10)
- Veteran's Memorial Highway (Interstate 15)
- Glenn Anderson Freeway/Century Freeway (Interstate 105)
- Harbor Freeway (Interstate 110)
- Foothill Freeway (Interstate 210)
- San Diego Freeway (Interstate 405)
- San Gabriel River Freeway (Interstate 605)
- Long Beach Freeway (Interstate 710)
U.S. highways
- Will Rogers Highway (U.S. Route 66)
- Pacific Highway (U.S. Route 99)
- Santa Ana Freeway/Hollywood Freeway (U.S. Route 101)
California state highways
Los Angeles County Metro
The Metro Rail is the mass transit rail system of Los Angeles County. It is run by the Los Angeles County Metropolitan Transportation Authority and its system runs five rail lines throughout Los Angeles County. Metro Rail currently operates four light rail lines and two rapid transit subway lines, altogether totaling 87.7 miles (141.1 km) of rail, 101 stations, and over 360,000 daily weekday boardings as of December 2012.
- The Blue Line - light rail
- The Red Line - subway
- The Green Line - light rail
- The Gold Line - light rail
- The Purple Line - subway
- The Expo Line - light rail
The systems light rail system is the second busiest LRT system in the United States, after Boston, by number of riders, with 200,300 average weekday boardings during the third quarter of 2012.
Since the region of the city is in close proximity to a major fault area the tunnels were built to resist earthquakes of up to magnitude 7.5. Both subway lines use an electrified third rail to provide power to the trains, rendering these lines unusable on the other three. The Blue and Gold Lines run mostly at grade, with some street-running, elevated, and underground stretches in the more densely populated areas of Los Angeles. The Green Line is entirely grade separated, running in the median of I-105 and then turning southward along an elevated route.
The rail lines run regularly on a 5 am and midnight schedule, seven days a week. Limited service on particular segments is provided after midnight and before 5 am There is no rail service between 2 and 3:30 am Exact times vary from route to route; see individual route articles for more information.
Regional and commuter rail
There are two providers of heavy rail transportation in the region, Amtrak and Metrolink. Amtrak provides service to San Diego, Santa Barbara, San Luis Obispo, and points in between on the Pacific Surfliner. It also provides long-distance routes, including the Coast Starlight which goes to the San Francisco Bay Area, Portland, Oregon, and Seattle, Washington; the Southwest Chief which goes to Flagstaff, Arizona, Albuquerque, New Mexico, Kansas City, Missouri and Chicago; and the Sunset Limited which provides limited service (three days a week) to Tucson, El Paso, Houston, and New Orleans.
Metrolink provides service to numerous places within Southern California, including all counties in the region. Metrolink operates to 55 stations on seven lines within Southern California which mostly (except for the Inland Empire-Orange County Line) radiate from Los Angeles Union Station.
Codes of metropolitan Los Angeles
Area codes
- 213 - Downtown Los Angeles, surrounded by 323 (October 1947)
- 310/424 - Santa Monica, Malibu, Pacific Palisades, Compton, Lynwood, Torrance, Beverly Hills, Catalina Island; the southwestern portion of Los Angeles County. (Split from 213 on November 2, 1991; overlaid by 424 on August 26, 2006)
- 323 - a ring around downtown Los Angeles, including the Hollywood and Eagle Rock neighborhoods of Los Angeles; South Los Angeles; the cities of South Gate, Huntington Park, Vernon, Walnut Park, Florence, Bell, Bell Gardens, Cudahy, Montebello, and East Los Angeles. (Split from 213 on June 13, 1998)
- 562 - Long Beach, Downey, Whittier; Norwalk, Lakewood, Bellflower, Paramount, Cerritos, southeast Los Angeles County, and a small portion of coastal Orange County. (Split from 310 on January 25, 1997)
- 626 - Pasadena, Monterey Park, Rowland Heights, Alhambra, and West Covina; the San Gabriel Valley, and eastern suburbs of Los Angeles. (Split from 818 on June 14, 1997)
- 657/714 - Anaheim, Huntington Beach, Santa Ana, Orange, Garden Grove; northern and western Orange County (Overlaid by 657 on September 23, 2008)
- 661 - Bakersfield, Santa Clarita, Palmdale; northern Los Angeles County including the Antelope Valley, and most of Kern County, including the southern San Joaquin Valley. (Split from 805 on February 13, 1999)
- 747/818 - the cities of Burbank, Glendale, San Fernando; the North Hollywood, Van Nuys, Panorama City, Sherman Oaks, and Northridge neighborhoods of Los Angeles; the San Fernando Valley. (Split from 213 on January 7, 1984)
- 909 - Pomona, Walnut, Diamond Bar, San Dimas, La Verne, Claremont, and Eastern Glendora. (The Eastern San Gabriel Valley)
- 949 - Irvine, Laguna Beach, Newport Beach, San Juan Capistrano; southern and eastern Orange County. (Split from 714 on April 18, 1998)
ZIP codes
The following is the list of ZIP codes for select areas within the metropolitan area.
Sports
Sports teams
As a whole, the Los Angeles area has more national championships, all sports combined (college and professional), than any other city in the United States, with over four times as many championships as the entire state of Texas, and just over twice that of New York City. It is the only American city to host the Olympic games twice: once in 1932, and more recently in 1984. Los Angeles will also be the host of the 2028 Summer Olympics, becoming the third city to host three Olympic Games, after London and Paris.
Listing of the professional sports teams in the Los Angeles metropolitan area
- National Football League (NFL)
- Los Angeles Rams
- Los Angeles Chargers
- National Basketball Association (NBA)
- Los Angeles Clippers
- Los Angeles Lakers
- Women's National Basketball Association (WNBA)
- Los Angeles Sparks
- Major League Baseball (MLB)
- Los Angeles Angels of Anaheim
- Los Angeles Dodgers
- National Hockey League (NHL)
- Los Angeles Kings
- Anaheim Ducks
- Major League Soccer (MLS)
- Los Angeles Galaxy
- Los Angeles Football Club (announced for 2018)
Professional venues
Note # symbol means venue has held an Olympic event.
- Angel Stadium
- Auto Club Raceway
- Auto Club Speedway
- Dodger Stadium #
- Hollywood Park Racetrack (Defunct)
- Honda Center
- John C. Argue Swim Stadium #
- Long Beach Marine Stadium#
- Los Angeles Memorial Coliseum# (Temporary)
- Los Angeles Memorial Sports Arena (Defunct)#
- Rose Bowl #
- Santa Anita Park #
- Staples Center
- StubHub Center #
- The Forum #
- VELO Sports Center
Media
The Los Angeles metropolitan area is home to the headquarters of several well-known media companies including: the Los Angeles Times, Fox Broadcasting Company, Universal Studios, and The Walt Disney Company. Local television channels broadcasting to the Los Angeles market include KCBS-TV 2 (CBS), KNBC 4 (NBC), KTLA 5 (CW), KABC 7 (ABC), KCAL-TV 9 (Independent/CBS), KTTV 11 (FOX), KCOP 13 (myNetworkTV), KPXN-TV 38/30 (Ion), and KLCS 41/58 (PBS). Radio stations serving the area include: KKJZ, KIIS, KNX (AM), and KSUR.
Geology
Much of the west coast of North America used to be part of a large convergent plate boundary between the Farallon Plate and North American Plate from 165 to 55 million years ago. Here, the Farallon Plate subducted under the North American Plate creating volcanoes about 100 miles east of this boundary which can still be seen today as the Sierra Nevada which it has its southern border about 30 miles east of Grapevine, California in the Tejon Pass. The Farallon Plate was subjected to high temperatures and pressures as it subducted under the North American Plate. This led to the formation of molten plutons which rose because they were less dense than the surrounding magma. When they rose, they cooled and some formed enormous granite monoliths. Only less than 1% of these plutons ever made it to the surface out of a volcano or fissure vent. The 1% that did make it all the way to the surface erupted in andesitic lava which would pile on top of each previous flow. This would create steep volcanoes with extremely high elevations. Most of the ejecta that came out of a volcano is gas. About 60% is just carbon (C) and water vapor (H2O). About 30% is sulfur (S). The sulfur mixes with the water vapor to form sulfuric acid which is notorious for eating away at almost anything from plants to rocks.
For the 99% percent of plutons that didn't make it to the surface they cooled to form granite monoliths under these volcanoes. When subduction activities ceased about 55 million years ago, these volcanoes were subject to erosion due to their steep slopes. Because granite is classified as a hard igneous rock, it is the only remnant of the volcanic chain from this subduction zone. These enormous granite monoliths can still be seen in Yosemite National Park as Half Dome and El Capitan about 300 miles from Los Angeles. Please refer to the Geologic History of Yosemite page to learn more specifically of the local geology of that area.
When the subduction zone ceased about 55 million years ago, the Farallon Plate was split into two distinctive plates which can still be observed today as the Juan de Fuca Plate and the Cocos Plate. Both were part of the same plate, but were discovered independently before this connection was made. At the time of this break off, the Pacific Plate had a general north west movement while the North American Plate had a general south east movement. This created a new fault zone when a weak point gave way between these two plates. This is the beginnings of the infamous San Andreas Fault. The San Andreas Fault is a right-lateral strike strip transverse fault. When this fault was just created, a volcano from the ancient subduction zone was situated about 3/4th on the Pacific Plate and 1/4th on the North American plate somewhere in what is today Central California. Nearly 55 million years later, this volcano was offset by about 250 miles. It is the largest known offset of the San Andreas Fault and it help geologist determine important information such as average slip movement and the age of the fault. The northern part of this offset is now called Pinnacles National Park near Soledad, California. The other half of Pinnacles is located in Three Points, California which is in Los Angeles County.
The Pacific Plate is the largest known plate on Earth. It is considered an oceanic plate because it is much more dense than a continental plate. That is the reason why oceanic plates always subduct under another plate. There are only a few places where the Pacific Plate is actually above the ocean. Most of the coastline of the state, below Eureka, California is part of the Pacific plate. The thickest part on land in California can be observed as far inland as the Salton Sea. To the south of the Salon Sea, there is a gap between plate boundaries. This gap acts like a divergent plate boundary where the land is being pulled apart. Mud volcanoes can be observed just at the southern edge of the sea as well as hot springs. Geothermal energy plants are abundant in the area, which power much of the local rural communities.
When the San Andreas Fault originally formed, tension on the North American Plate grew. The plate buckled and began uplifting similar to swelling in nearly all portions of the west. Numerous faults were created as a result; geologic blocks that rose and fell over and over again in patterns and in sequences. The extension of surface led to cracks which formed many independent faults. This is the creation of the Basin and Range Province. Sometimes these faults created a pathway, which molten rock could flow up to the surface creating cinder cone volcanoes. The Los Angeles Area has a few volcanoes that formed. Along Route 66 in Amboy, California, is the extinct volcano Amboy Crater which is estimated to be aged at 80,000 years. It is relatively new in geologic terms, but heavily eroded by wind. While driving along Interstate 40, lava fields are seen that can stretch for miles. Within Death Valley National Park is another, much larger cinder cone volcano called Ubehebe Crater. It is extremely young, although many geologists dispute the numbers with some estimates as old as 10,000 years with recent ages such as 800 years. One thing is for sure: this volcano is still very active and can erupt. Because of its location, it will likely not affect many people. Within Orange County, lava flows and dikes can be seen in El Modena although no actual crater can be seen, likely because either it has been totally eroded or it was formed in a small fissure, which would explain why it's so localized.
The land on which the Los Angeles metropolitan area sits is among the newest rocks in the continental United States. It is estimated to be about 20 million years old. Most of the rocks in this area are part of the larger Monterey Formation which covers most of the California coastal ranges. The Monterey Formation consists of shale rocks, which were created from the accumulation calcium-rich shells of dead marine life of millions of years. Before then, it was submerged and was part a shallow ocean floor. It has since been uplifted due to pressures between the many different fault zones at an average rate of 2 millimeters per year.
The Los Angeles area is known to be geologically active. The San Andreas Fault is located about 40 miles north east of Downtown Los Angeles. The closest towns and cities to Los Angeles which contain the San Andreas Fault are Gorman and Palmdale, California. Historically, major earthquakes have occurred along the fault, large enough to cause fatalities and millions of dollars in damages. A major earthquake hasn't happened in the southern section of the San Andreas Fault in over 150 years and geologist have determined a 50% probability of a 7.0 earthquake, registered on the moment magnitude scale within the years 2010 to 2040. Some geologists say that this probably is over speculated. There is currently no way to accurately predict an earthquake anywhere on any specific fault. On the contrary, major efforts have been made to fund a practical earthquake warning system, similar to what Japan used in Tokyo during the 2011 Japan earthquake, in Southern California. Today, the area gets hits with many earthquakes per day, most reregistering below a 2.5 on the moment magnitude scale, too insignificant to feel any shaking on the surface.
List of major fault zones
Note: Plate boundary faults are indicated with a (#) symbol.
Significant earthquakes
Note: Earthquakes with epicenters in the Los Angeles Metro Area are marked with the (#) symbol. Other earthquakes mentioned means shaking was felt.
See also
- Chicago metropolitan area
- Greater Los Angeles Area
- List of Metropolitan Statistical Areas
- New York metropolitan area
References
External links
Source of article : Wikipedia
0 Comments