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28-575: The act in its current form has three main provisions: 1) It directs the state's California Geological Survey agency (then known as the California Division of Mines and Geology) to compile detailed maps of the surface traces of known active faults . These maps include both the best known location where faults cut the surface and a buffer zone around the known trace(s); 2) It requires property owners (or their real estate agents) to formally and legally disclose that their property lies within

56-399: A solid or a gas or that generates a non-liquid phase which behaves in accordance with fluid dynamics . It occurs both naturally and artificially . As an example of the latter, a "major commercial application of liquefaction is the liquefaction of air to allow separation of the constituents, such as oxygen, nitrogen, and the noble gases." Another is the conversion of solid coal into

84-410: A dangerous shift in the load. In physics and chemistry , the phase transitions from solid and gas to liquid ( melting and condensation , respectively) may be referred to as liquefaction. The melting point (sometimes called liquefaction point) is the temperature and pressure at which a solid becomes a liquid. In commercial and industrial situations, the process of condensing a gas to liquid

112-487: A development of four units or more are exempt. However, local agencies can be more restrictive than state law requires. While the act mandates that owners disclose the fact that their property lies within the Alquist-Priolo zone when they sell it, there are no legal requirements to disclose the fact to renters living on the property. Renters should investigate the location of active faults on their own before signing

140-557: A lease or rental agreement. Legally, the act only applies to structures for human occupancy (houses, apartments, condominiums, etc.). However, the official geologic maps delineating the fault zones are used to help place a variety of structures on safe ground. For example, the Belmont Learning Center , a large school complex in Downtown Los Angeles was complicated by the discovery of a surface fault on

168-490: A liquid form usable as a substitute for liquid fuels. In geology , soil liquefaction refers to the process by which water-saturated, unconsolidated sediments are transformed into a substance that acts like a liquid, often in an earthquake. Soil liquefaction was blamed for building collapses in the city of Palu, Indonesia in October 2018. In a related phenomenon, liquefaction of bulk materials in cargo ships may cause

196-521: A liquid, for example in food preparation or laboratory use. This may be done with a blender, or liquidiser in British English. Liquefaction of silica and silicate glasses occurs on electron beam irradiation of nanosized samples in the column of transmission electron microscope. In biology , liquefaction often involves organic tissue turning into a more liquid-like state. For example, liquefactive necrosis in pathology , or liquefaction as

224-661: A medical practitioner and active member of the California Academy of Sciences , as Honorary State Geologist. In 1853 the Legislature passed a joint resolution asking him for geological information about the state. He submitted a report On the Geology of the Sierra Nevada , or California Range . About two months later, the Legislature created the first California Geological Survey headed by Trask, who retained

252-409: Is named) to fill the office. A Yale graduate, Whitney had worked on several surveys in the east. The act directed Whitney to make an accurate and complete geological survey of the state. Whitney chose William Henry Brewer as chief botanist to lead the original field party. Brewer then added Clarence King , James Gardiner , topographer Charles F. Hoffmann and packer Dick Cotter . It was one of

280-434: Is sometimes referred to as liquefaction of gases . Coal liquefaction is the production of liquid fuels from coal using a variety of industrial processes. Liquefaction is also used in commercial and industrial settings to refer to mechanical dissolution of a solid by mixing , grinding or blending with a liquid. In kitchen or laboratory settings, solids may be chopped into smaller parts sometimes in combination with

308-620: The 1994 Northridge earthquake occurred on a blind thrust fault not zoned by the act because of a lack of surface evidence. California Geological Survey The California Geological Survey , previously known as the California Division of Mines and Geology , is the California state geologic agency. Although it was not until 1880 that the California State Mining Bureau , predecessor to

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336-648: The Mining Engineering Branch and the Geology Branch. The Division began processing numerous geological quadrangle maps and reports for publication. In 1952 the Division conducted its first public-safety related effort by documenting the impacts of the 1952 Kern County earthquake and its aftershocks. The 1960s were years of development of new programs and modernization of long-standing programs. In 1962, eighty-one years after its creation,

364-526: The Bureau became the Division of Mines within the Department of Natural Resources. In 1928, with the hiring of the first geologist, the focus of the Division began to shift towards the gathering of basic geologic information. In 1938 a new 1:500,000-scale geologic map was published. During the 1940s and 1950s, the Division developed as a state geological survey and two well-defined branches were established:

392-649: The California Geological Survey, was established, the "roots" of California's state geological survey date to an earlier time. As might be expected for a state that owed its existence to the gold rush of 1849, the California State Legislature recognized that geologists could provide valuable information. In 1851, one year after California was admitted to the United States, the Legislature named John B. Trask ,

420-548: The California State Geologist to establish regulatory zones (known as Earthquake Fault Zones) around the surface traces of active faults and to issue appropriate maps. ("Earthquake Fault Zones" were called "Special Studies Zones" prior to January 1, 1994.) The maps are distributed to all affected cities, counties, and state agencies for their use in planning and controlling new or renewed construction. Local agencies must regulate most development projects within

448-450: The Division of Mines was renamed the Division of Mines and Geology (DMG). Its focus had shifted from an organization that was primarily mine-oriented to one responsible for a broader range of practical applications of geology, especially geologic hazards and seismic hazards . A highlight of the decade was the completion in 1966 of the geologic mapping program. From the early 1970s to the present, Division programs have expanded often due to

476-516: The Earth's crust move relative to one another. The place where the blocks meet is called a fault , and faults tend to show up as relatively straight lines on maps. Any structure built directly on top of the fault will be torn in two when the blocks move. Constructing a building to withstand this sort of movement (often several feet in a matter of seconds) is not practical, so it is best to avoid building directly on top of an active fault. The law requires

504-528: The act. It went into effect on March 7, 1973. The law was amended a few years later to include a disclosure obligation for real estate licensees. The act was called the Alquist-Priolo State Special Studies Zone Act prior to 1994. The act was amended September 26, 1974; May 4, 1975; September 28, 1975; September 22, 1976; September 27, 1979; September 21, 1990; and July 29, 1991. Earthquakes happen when two blocks of

532-561: The field work was limited and the last field work was done in 1870 by Hoffmann and W. A. Goodyear . In 1874 the Survey was officially ended due to hostility between then Governor of California Newton Booth and Whitney. In 1880 the State Mining Bureau was established by the Legislature. The establishment of the Bureau was a direct action in response to the need for information on the occurrence, mining, and processing of gold in

560-514: The most ambitious geological surveys ever attempted and yielded a vast amount of information about California that was hitherto unknown and unpublished. Among the natural features of California they were the first to describe Kings Canyon, which they discovered in 1864. The original California Geological Survey influenced the future of surveying and spurred the creation of the United States Geological Survey . Funding for

588-550: The new California State Mining Bureau . This was renamed the Division of Mines in 1927. In 1962 the division's name was expanded to be California Division of Mines and Geology , a name that lasted until August 2006, when the state legislature renamed the division the California Geological Survey . Liquefaction In materials science , liquefaction is a process that generates a liquid from

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616-469: The passage of legislation. Following earthquakes and landslide damage during the 1970s and 1980s, legislation passed which clearly focused DMG's authority on several fronts, including: Language was also added which outlined DMG's responsibilities as encompassing: The California Geological Survey has had many names over its history. The original Geological Survey of California was replaced in April 1880 by

644-538: The property in 2002. The Los Angeles Unified School District was required to remove a building that had been built directly atop the fault prior to its discovery. The act only addresses the hazard of surface fault rupture and does not address other earthquake hazards. The Seismic Hazards Mapping Act , passed in 1990, addresses non-surface fault rupture earthquake hazards, including liquefaction and seismically induced landslides . The act only applies to faults which are "sufficiently active" and "well defined"- for example

672-608: The state. Its focus was on California's mining industry and the Governor appointed the State Mineralogist. In 1891, the Bureau published the first geologic map of the state showing eight stratigraphic units in color, along with numerous blank areas where information was lacking. The second colored geologic map of the state, published in 1916, showed 21 stratigraphic units and was accompanied by an explanatory volume (Bulletin 72, Geologic Formations of California). In 1927

700-473: The title of State Geologist. Within a few years the mining of placer gold began to decline and mining of quartz lodes began. These changes, coupled with publication of reports by Trask, created a public clamor for a state geological survey. In 1860 the Legislature passed an act creating the Office of State Geologist and defining the duties thereof. The act named Josiah D. Whitney (for whom Mount Whitney

728-440: The zones defined on those maps before selling the property; and 3) It prohibits new construction of houses within these zones unless a comprehensive geologic investigation shows that the fault does not pose a hazard to the proposed structure. The act was one of several that changed building codes and practices to improve earthquake safety. These changes are intended to reduce the damage from future earthquakes. This state law

756-560: The zones. Buildings built before 1972 may still lie on top of active faults, and those buildings can remain where they were originally built, unless they undergo a major remodel where more than 50% of the building changes. When that happens, they are treated the same as new construction (a geologic investigation must be undertaken and the hazard mitigated before a building permit can be issued). Projects include all land divisions and most structures for human occupancy. Single family wood-frame and steel-frame dwellings up to two stories not part of

784-567: Was a direct result of the 1971 San Fernando earthquake (also called the 'Sylmar earthquake'), which was associated with extensive surface fault ruptures that damaged numerous homes, commercial buildings, and other structures. Surface rupture is the most easily avoided seismic hazard. In January 1972, Governor Ronald Reagan established the Governor’s Earthquake Council as a reaction to the Sylmar quake, whose recommendations led to

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