|
Induced Seismicity
Induced seismicity is typically minor earthquakes and tremors that are caused by human activity that alters the stresses and strains on Earth's crust. Most induced seismicity is of a low magnitude. A few sites regularly have larger quakes, such as The Geysers geothermal plant in California which averaged two M4 events and 15 M3 events every year from 2004 to 2009. The Human-Induced Earthquake Database (''HiQuake'') documents all reported cases of induced seismicity proposed on scientific grounds and is the most complete compilation of its kind. Results of ongoing multi-year research on induced earthquakes by the United States Geological Survey (USGS) published in 2015 suggested that most of the significant earthquakes in Oklahoma, such as the 1952 magnitude 5.7 El Reno earthquake may have been induced by deep injection of waste water by the oil industry. A huge number of seismic events in fracking states like Oklahoma caused by increasing the volume of injection. "Earthquake rat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthquake
An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from those that are so weak that they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time period. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. The word ''tremor'' is also used for non-earthquake seismic rumbling. At the Earth's surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Katse Dam
The Katse Dam, a concrete arch dam on the Malibamat'so River in Lesotho, is Africa's second largest double-curvature arch dam. (The Tekezé Dam, completed in early 2009, is now Africa's largest double curvature dam). The dam is part of the Lesotho Highlands Water Project, which will eventually include five large dams in remote rural areas. The dam is just below the confluence of the Bokong River, which forms the western arm of the Katse reservoir. The potential of the project was identified by the South African civil engineer Ninham Shand in 1953 as a possible means to supplement the water supply of South Africa's industrial heartland in the Witwatersrand. The World Bank arranged a treaty between the governments of South Africa and Lesotho, allowing the project to proceed. Construction The dam was built by a consortium of Bouygues, Concor, Group 5, Hochtief, Impregilo, Kier Group and Sterling International. The dam was completed in 1996 and the reservoir filled with water b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Oroville
Lake Oroville is a reservoir formed by the Oroville Dam impounding the Feather River, located in Butte County, northern California. The lake is situated northeast of the city of Oroville, within the Lake Oroville State Recreation Area, in the western foothills of the Sierra Nevada. Known as the second-largest reservoir in California, Lake Oroville is treated as a keystone facility within the California State Water Project by storing water, providing flood control, recreation, freshwater releases assist in controlling the salinity intrusion into the Sacramento-San Joaquin Delta and protecting fish and wildlife. The lake is a popular nationally renowned bass fishing location, while coho salmon are stocked from the Feather River Fish Hatchery. This hatchery is a main component of Lake Oroville. History The local indigenous tribe were the Konkow Maidu (translation is 'man') who originally settled the lake region and Feather River for many years. Today many of the small town ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oroville Dam
Oroville Dam is an earthfill embankment dam on the Feather River east of the city of Oroville, California, in the Sierra Nevada foothills east of the Sacramento Valley. At 770 feet (235 m) high, it is the tallest dam in the U.S. and serves mainly for water supply, hydroelectricity generation, and flood control. The dam impounds Lake Oroville, the second-largest reservoir in California, capable of storing more than . Built by the California Department of Water Resources, Oroville Dam is one of the key features of the California State Water Project (SWP), one of two major projects passed that set up California's statewide water system. Construction was initiated in 1961, and despite numerous difficulties encountered during its construction, including multiple floods and a major train wreck on the rail line used to transport materials to the dam site, the embankment was topped out in 1967 and the entire project was ready for use in 1968. The dam began to generate electri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the most populated subnational entity in North America and the 34th most populous in the world. The Greater Los Angeles area and the San Francisco Bay Area are the nation's second and fifth most populous urban regions respectively, with the former having more than 18.7million residents and the latter having over 9.6million. Sacramento is the state's capital, while Los Angeles is the most populous city in the state and the second most populous city in the country. San Francisco is the second most densely populated major city in the country. Los Angeles County is the country's most populous, while San Bernardino County is the largest county by area in the country. California borders Oregon to the north, Nevada and Arizona to the east, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oroville, California
Oroville (''Oro'', Spanish for "Gold" and ''Ville'', French for "town") is the county seat of Butte County, California, United States. The population of the city was 15,506 at the 2010 census, up from 13,004 in the 2000 census. Following the 2018 Camp Fire that destroyed much of the town of Paradise, the population of Oroville increased as many people who lost their homes relocated to nearby Oroville. In 2019, the California Department of Finance estimated the population of Oroville is 20,737. Oroville is considered the gateway to Lake Oroville and Feather River recreational areas. The Berry Creek Rancheria of Maidu Indians of California is headquartered in Oroville. Oroville is located adjacent to State Route 70, and is in close proximity to State Route 99, which connects Butte County with Interstate 5. The city of Chico is located about 23 miles (38 kilometers) northwest of the city, and the state capital of Sacramento lies around 70 miles (112 kilometers) to the south ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vajont Dam
The Vajont Dam (or Vaiont Dam) is a disused dam in northern Italy. It is one of the tallest dams in the world, with a height of . It is in the valley of the Vajont River under Monte Toc, in the municipality of Erto e Casso, north of Venice. The dam was conceived in the 1920s and eventually built between 1957 and 1960 by Società Adriatica di Elettricità (SADE), at the time the electricity supply and distribution monopoly in northeastern Italy. The engineer was Carlo Semenza (1893–1961). In 1962 the dam was nationalized and came under the control of ENEL as part of the Italian Ministry for Public Works. On 9 October 1963, during initial filling, a landslide caused a megatsunami in the lake in which of water overtopped the dam in a wave of , which brought massive flooding and destruction to the Piave Valley below, leading to the destruction of several villages and towns, causing between 1,900 and 2,500 estimated deaths. The dam remained almost intact and two thirds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Koyna Dam Reservoir
The Koyna Dam is one of the largest dams in Maharashtra, India. It is a rubble-concrete dam constructed on Koyna River which rises in Mahabaleshwar, a hillstation in Sahyadri ranges. It is located in Koyna Nagar, Satara district, in the Western Ghats on the state highway between Chiplun and Karad. Details The main purpose of the dam is hydroelectricity with some irrigation in neighboring areas. Today the Koyna Hydroelectric Project is the largest completed hydroelectric power plant in India having a total installed capacity of . Due to its electricity generating potential, Koyna river is considered as the 'life line of Maharashtra'. The spillway of the dam is located at the center. It has 6 radial gates. The dam plays a vital role of flood controlling in monsoon season. The catchment area dams the Koyna river and forms the Shivasagar Lake which is approximately in length. It is one of the largest civil engineering projects commissioned after Indian independence. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aftershock
In seismology, an aftershock is a smaller earthquake that follows a larger earthquake, in the same area of the main shock, caused as the displaced crust adjusts to the effects of the main shock. Large earthquakes can have hundreds to thousands of instrumentally detectable aftershocks, which steadily decrease in magnitude and frequency according to a consistent pattern. In some earthquakes the main rupture happens in two or more steps, resulting in multiple main shocks. These are known as doublet earthquakes, and in general can be distinguished from aftershocks in having similar magnitudes and nearly identical seismic waveforms. Distribution of aftershocks Most aftershocks are located over the full area of fault rupture and either occur along the fault plane itself or along other faults within the volume affected by the strain associated with the main shock. Typically, aftershocks are found up to a distance equal to the rupture length away from the fault plane. The patte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foreshock
A foreshock is an earthquake that occurs before a larger seismic event (the mainshock) and is related to it in both time and space. The designation of an earthquake as ''foreshock'', ''mainshock'' or aftershock is only possible after the full sequence of events has happened. Occurrence Foreshock activity has been detected for about 40% of all moderate to large earthquakes, and about 70% for events of M>7.0. They occur from a matter of minutes to days or even longer before the main shock; for example, the 2002 Sumatra earthquake is regarded as a foreshock of the 2004 Indian Ocean earthquake with a delay of more than two years between the two events. Some great earthquakes (M>8.0) show no foreshock activity at all, such as the M8.6 1950 India–China earthquake. The increase in foreshock activity is difficult to quantify for individual earthquakes but becomes apparent when combining the results of many different events. From such combined observations, the increase before the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epicenter
The epicenter, epicentre () or epicentrum in seismology is the point on the Earth's surface directly above a hypocenter or focus, the point where an earthquake or an underground explosion originates. Surface damage Before the instrumental period of earthquake observation, the epicenter was thought to be the location where the greatest damage occurred, but the subsurface fault rupture may be long and spread surface damage across the entire rupture zone. As an example, in the magnitude 7.9 Denali earthquake of 2002 in Alaska, the epicenter was at the western end of the rupture, but the greatest damage was about away at the eastern end. Focal depths of earthquakes occurring in continental crust mostly range from . Continental earthquakes below are rare whereas in subduction zone earthquakes can originate at depths deeper than . Epicentral distance During an earthquake, seismic waves propagate in all directions from the hypocenter. Seismic shadowing occurs on the opposite s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
