Pacific PlateThe Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At , it is the largest tectonic plate. The plate first came into existence 190 million years ago, at the triple junction between the Farallon, Phoenix, and Izanagi Plates. The Pacific Plate subsequently grew to where it underlies most of the Pacific Ocean basin. This reduced the Farallon Plate to a few remnants along the west coast of North America and the Phoenix Plate to a small remnant near the Drake Passage, and destroyed the Izanagi Plate by subduction under Asia.
Soil liquefactionSoil liquefaction occurs when a cohesionless saturated or partially saturated soil substantially loses strength and stiffness in response to an applied stress such as shaking during an earthquake or other sudden change in stress condition, in which material that is ordinarily a solid behaves like a liquid. In soil mechanics, the term "liquefied" was first used by Allen Hazen in reference to the 1918 failure of the Calaveras Dam in California.
PaleoseismologyPaleoseismology looks at geologic sediments and rocks, for signs of ancient earthquakes. It is used to supplement seismic monitoring, for the calculation of seismic hazard. Paleoseismology is usually restricted to geologic regimes that have undergone continuous sediment creation for the last few thousand years, such as swamps, lakes, river beds and shorelines. In this typical example, a trench is dug in an active sedimentation regime. Evidence of thrust faulting can be seen in the walls of the trench.
Nazca PlateThe Nazca Plate or Nasca Plate, named after the Nazca region of southern Peru, is an oceanic tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru–Chile Trench, of the Nazca Plate under the South American Plate is largely responsible for the Andean orogeny. The Nazca Plate is bounded on the west by the Pacific Plate and to the south by the Antarctic Plate through the East Pacific Rise and the Chile Rise respectively.
Mojave DesertThe Mojave Desert (moʊˈhɑːvi,_mə- ; Hayikwiir Mat'aar; Desierto de Mojave) is a desert in the rain shadow of the southern Sierra Nevada mountains and Transverse Ranges in the Southwestern United States. It is named for the indigenous Mojave people. It is located primarily in southeastern California and southwestern Nevada, with small portions extending into Arizona and Utah. The Mojave Desert, together with the Sonoran, Chihuahuan, and Great Basin deserts, forms a larger North American Desert.
Sierra ClubThe Sierra Club is an American environmental organization with chapters in all 50 U.S. states, Washington D.C., and Puerto Rico. The club was founded on May 28, 1892, in San Francisco, California, by Scottish-American preservationist John Muir, who became the first president as well as the longest-serving president, at approximately 20 years in this leadership position. The Sierra Club operates only in the United States and holds the legal status of 501(c)(4) nonprofit social welfare organization.
Colorado DesertCalifornia's Colorado Desert is a part of the larger Sonoran Desert. It encompasses approximately , including the heavily irrigated Coachella and Imperial valleys. It is home to many unique flora and fauna. The Colorado Desert is a subdivision of the larger Sonoran Desert encompassing approximately . The desert encompasses Imperial County and includes parts of San Diego County, Riverside County, and a small part of San Bernardino County, California, United States.
MexicaliMexicali (pronˌmɛksɪˈkæli; mexiˈkali) is the capital city of the Mexican state of Baja California. The city, seat of the Mexicali Municipality, has a population of 689,775, according to the 2010 census, while the Calexico–Mexicali metropolitan area is home to 1,000,000 inhabitants on both sides of the Mexico–United States border. Mexicali is a regional economic and cultural hub for the border region of The Californias. Mexicali was founded at the turn of the 20th century, when the region's agricultural economy experienced a period of boom.
TijuanaTijuana (tiˈxwana; tiːˈhwɑːnə , USˌtiːəˈwɑːnə , UKtᵻˈhwɑːnə .) is a city and municipal seat of Tijuana Municipality, Baja California, located on the Pacific Coast of Mexico. It is part of the San Diego-Tijuana metro area and the larger Southern California megapolitan area. Tijuana traces its modern history to the arrival of Spanish explorers in the 16th century who were mapping the coast of the Californias. Following the division of the Californias after the American Conquest of California, Tijuana found itself located on an international border, giving rise to a new economic and political structure.
Cocos PlateThe Cocos Plate is a young oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it. The Cocos Plate was created approximately 23 million years ago when the Farallon Plate broke into two pieces, which also created the Nazca Plate. The Cocos Plate also broke into two pieces, creating the small Rivera Plate. The Cocos Plate is bounded by several different plates. To the northeast it is bounded by the North American Plate and the Caribbean Plate.