Earthquake

Global earthquake epicenters, 1963–1998

An earthquake is a sudden and sometimes catastrophic movement of a part of the Earth's surface. Earthquakes result from the dynamic release of elastic strain energy that radiates seismic waves. Earthquakes typically result from the movement of faults, planar zones of deformation within the Earth's upper crust. The word earthquake is also widely used to indicate the source region itself. The Earth's lithosphere is a patch work of plates in slow but constant motion (see plate tectonics). Earthquakes occur where the stress resulting from the differential motion of these plates exceeds the strength of the crust. The highest stress (and possible weakest zones) are most often found at the boundaries of the tectonic plates and hence these locations are where the majority of earthquakes occur. Events located at plate boundaries are called interplate earthquakes; the less frequent events that occur in the interior of the lithospheric plates are called intraplate earthquakes (see, for example, New Madrid Seismic Zone). Earthquakes related to plate tectonics are called tectonic earthquakes. Most earthquakes are tectonic, but they also occur in volcanic regions and as the result of a number of anthropogenic sources, such as reservoir induced seismicity, mining and the removal or injection of fluids into the crust. Seismic waves including some strong enough to be felt by humans can also be caused by explosions (chemical or nuclear), landslides, and collapse of old mine shafts, though these sources are not strictly earthquakes.

Characteristics

Large numbers of earthquakes occur on a daily basis on Earth, but the majority of them are detected only by seismometers and cause no damage .

Most earthquakes occur in narrow regions around plate boundaries down to depths of a few tens of kilometres where the crust is rigid enough to support the elastic strain. Where the crust is thicker and colder they will occur at greater depths and the opposite in areas that are hot. At subduction zones where plates descend into the mantle, earthquakes have been recorded to a depth of 600 km, although these deep earthquakes are caused by different mechanisms than the more common shallow events. Some deep earthquakes may be due to the transition of olivine to spinel, which is more stable in the deep mantle.

Large earthquakes can cause serious destruction and massive loss of life through a variety of agents of damage, including fault rupture, vibratory ground motion (i.e., shaking), inundation (e.g., tsunami, seiche, dam failure), various kinds of permanent ground failure (e.g. liquefaction, landslide), and fire or a release of hazardous materials. In a particular earthquake, any of these agents of damage can dominate, and historically each has caused major damage and great loss of life, but for most of the earthquakes shaking is the dominant and most widespread cause of damage. There are four types of seismic waves that are all generated simultaneously and can be felt on the ground. S-waves (secondary or shear waves) and the two types of surfaces waves (Love waves and Rayleigh waves) are responsible for the shaking hazard.

Damage from the 1906 San Francisco earthquake. Section of collapsed freeway after the 1989 Loma Prieta earthquake.

Most large earthquakes are accompanied by other, smaller ones, that can occur either before or after the principal quake — these are known as foreshocks or aftershocks, respectively. While almost all earthquakes have aftershocks, foreshocks are far less common occurring in only about 10% of events. The power of an earthquake is distributed over a significant area, but in the case of large earthquakes, it can spread over the entire planet. Ground motions caused by very distant earthquakes are called teleseisms. The Rayleigh waves from the Sumatra-Andaman Earthquake of 2004 caused ground motion of over 1 cm even at the seismometers that were located far from it, although this displacement was abnormally large. Using such ground motion records from around the world it is possible to identify a point from which the earthquake's seismic waves appear to originate. That point is called its "focus" or "hypocenter" and usually proves to be the point at which the fault slip was initiated. The location on the surface directly above the hypocenter is known as the "epicenter". The total size of the fault that slips, the rupture zone, can be as large as 1000 km, for the biggest earthquakes. Just as a large loudspeaker can produce a greater volume of sound than a smaller one, large faults are capable of higher magnitude earthquakes than smaller faults are.

Earthquakes that occur below sea level and have large vertical displacements can give rise to tsunamis, either as a direct result of the deformation of the sea bed due to the earthquake or as a result of submarine landslips or "slides" directly or indirectly triggered by it.

Earthquake Size

The first method of quantifying earthquakes was intensity scales. In the United States the Mercalli (or Modified Mercalli, MM) scale is commonly used, while Japan (shindo) and the EU (European Macroseismic Scale) each have their own scales. These assign a numeric value (different for each scale) to a location based on the size of the shaking experienced there. The value 6 (normally denoted "VI") in the MM scale for example is:

Everyone feels movement. People have trouble walking. Objects fall from shelves. Pictures fall off walls. Furniture moves. Plaster in walls might crack. Trees and bushes shake. Damage is slight in poorly built buildings. No structural damage.

A Shakemap recorded by the Pacific Northwest Seismograph Network that shows the instrument recorded intensity of the shaking of the Nisqually earthquake on February 28, 2001. A Community Internet Intensity Map generated by the USGS that shows the intensity felt by humans by ZIP Code of the shaking of the Nisqually earthquake on February 28, 2001.

The problem with these scales is the measurement is subjective, often based on the worst damage in an area and influenced by local effects like site conditions that make it a poor measure for the relative size of different events in different places. For some tasks related to engineering and local planning it is still useful for the very same reasons and thus still collected. If you feel an earthquake in the US you can report the effects to the USGS.

The first attempt to qualitatively define one value to describe the size of earthquakes was the magnitude scale (the name being taking from similar formed scales used on the brightness of stars). In the 1930s, a California seismologist named Charles F. Richter devised a simple numerical scale (which he called the magnitude) to describe the relative sizes of earthquakes in Southern California. This is known as the “Richter scale”, “Richter Magnitude” or “Local Magnitude” (ML). It is obtained by measuring the maximum amplitude of a recording on a Wood-Anderson torsion seismometer (or one calibrated to it) at a distance of 600km from the earthquake. Other more recent Magnitude measurements include: body wave magnitude (mb), surface wave magnitude (Ms) and duration magnitude (MD). Each of these is scaled to gives values similar to the values given by the Richter scale. However as each is also based on the measurement of one part of the seismogram they do not measure the overall power of the source and can suffer from saturation at higher magnitude values (larger events fail to produce higher magnitude values).These scales are also empirical and as such there is no physical meaning to the values. They are still useful however as they can be rapidly calculated, there are catalogues of them dating back many years and are they are familiar to the public. Seismologists now favor a measure called the seismic moment, related to the concept of moment in physics, to measure the size of a seismic source. The seismic moment is calculated from seismograms but can also by obtained from geologic estimates of the size of the fault rupture and the displacement. The values of moments for different earthquakes ranges over several order of magnitude. As a result the moment magnitude (MW) scale was introduced by Hiroo Kanamori, which is comparable to the other magnitude scales but will not saturate at higher values.

Larger earthquakes occur less frequently than smaller earthquakes, the relationship being exponential, ie roughly ten times as many earthquakes larger than 4 occur in a particular time period than earthquakes larger than magnitude 5. For example it has been calculated that the average recurrence for the United Kingdom can be described as follows:

  • an earthquake of 3.7 or larger every 1 year
  • an earthquake of 4.7 or larger every 10 years
  • an earthquake of 5.6 or larger every 100 years.

Causes

Most earthquakes are powered by the release of the elastic strain that accumulate over time, typically, at the boundaries of the plates that make up the Earth's lithosphere via a process called Elastic-rebound theory. The Earth is made up of tectonic plates driven by the heat in the Earth's mantle and core. Where these plates meet stress accumulates. Eventually when enough stress accumulates, the plates move, causing an earthquake. Deep focus earthquakes, at depths of 100's km, are possibly generated as subducted lithospheric material catastrophically undergoes a phase transition since at the pressures and temperatures present at such depth elastic strain cannot be supported. Some earthquakes are also caused by the movement of magma in volcanoes, and such quakes can be an early warning of volcanic eruptions. A rare few earthquakes have been associated with the build-up of large masses of water behind dams, such as the Kariba Dam in Zambia, Africa, and with the injection or extraction of fluids into the Earth's crust (e.g. at certain geothermal power plants and at the Rocky Mountain Arsenal). Such earthquakes occur because the strength of the Earth's crust can be modified by fluid pressure. Earthquakes have also been known to be caused by the removal of natural gas from subsurface deposits, for instance in the northern Netherlands. Finally, ground shaking can also result from the detonation of explosives. Thus scientists have been able to monitor, using the tools of seismology, nuclear weapons tests performed by governments that were not disclosing information about these tests along normal channels. Earthquakes such as these, that are caused by human activity, are referred to by the term induced seismicity.

Another type of movement of the Earth is observed by terrestrial spectroscopy. These oscillations of the earth are either due to the deformation of the Earth by tide caused by the Moon or the Sun, or other phenomena.

A recently proposed theory suggests that some earthquakes may occur in a sort of earthquake storm, where one earthquake will trigger a series of earthquakes each triggered by the previous shifts on the fault lines, similar to aftershocks, but occurring years later.

Preparation for earthquakes

  • Emergency preparedness
  • Household seismic safety
  • Seismic retrofit
  • Earthquake prediction

Specific fault articles

  • Alpine Fault
  • Calaveras Fault
  • Hayward Fault Zone
  • North Anatolian Fault Zone
  • New Madrid Fault Zone
  • San Andreas Fault

Specific earthquake articles

  • Shaanxi Earthquake (1556). Deadliest known earthquake in history, estimated to have killed 830,000 in China.
  • Cascadia Earthquake (1700).
  • Kamchatka earthquakes (1737 and 1952).
  • Lisbon earthquake (1755).
  • New Madrid Earthquake (1811).
  • Fort Tejon Earthquake (1857).
  • Charleston earthquake (1886). Largest earthquake in the Southeast and killed 100.
  • San Francisco Earthquake (1906).
  • Great Kanto earthquake (1923). On the Japanese island of Honshu, killing over 140,000 in Tokyo and environs.
  • Kamchatka earthquakes (1952 and 1737).
  • Great Chilean Earthquake (1960). Biggest earthquake ever recorded, 9.5 on Moment magnitude scale.
  • Good Friday Earthquake (1964) Alaskan earthquake.
  • Ancash earthquake (1970). Caused a landslide that buried the town of Yungay, Peru; killed over 40,000 people.
  • Sylmar earthquake (1971). Caused great and unexpected destruction of freeway bridges and flyways in the San Fernando Valley, leading to the first major seismic retrofits of these types of structures, but not at a sufficient pace to avoid the next California freeway collapse in 1989.
  • Tangshan earthquake (1976). The most destructive earthquake of modern times. The official death toll was 255,000, but many experts believe that two or three times that number died.
  • Great Mexican Earthquake (1985). 8.1 on the Richter Scale, killed over 6,500 people (though it is believed as many as 30,000 may have died, due to missing people never reappearing.)
  • Whittier Narrows earthquake (1987).
  • Armenian earthquake (1988). Killed over 25,000.
  • Loma Prieta earthquake (1989). Severely affecting Santa Cruz, San Francisco and Oakland in California. Revealed necessity of accelerated seismic retrofit of road and bridge structures.
  • Northridge, California earthquake (1994). Damage showed seismic resistance deficiencies in modern low-rise apartment construction.
  • Great Hanshin earthquake (1995). Killed over 6,400 people in and around Kobe, Japan.
  • İzmit earthquake (1999) Killed over 17,000 in northwestern Turkey.
  • Düzce earthquake (1999)
  • Chi-Chi earthquake (1999).
  • Nisqually Earthquake (2001).
  • Gujarat Earthquake (2001).
  • Dudley Earthquake (2002).
  • Bam Earthquake (2003).
  • Parkfield, California earthquake (2004). Not large (6.0), but the most anticipated and intensely instrumented earthquake ever recorded and likely to offer insights into predicting future earthquakes elsewhere on similar slip-strike fault structures.
  • Chuetsu Earthquake (2004).
  • Indian Ocean Earthquake (2004). One of the largest earthquakes ever recorded at 9.0. Epicenter off the coast of the Indonesian island Sumatra. Triggered a tsunami which caused nearly 300,000 deaths spanning several countries.
  • Sumatran Earthquake (2005).
  • Fukuoka earthquake (2005).
  • Kashmir earthquake (2005). Killed over 79,000 people. Many more at risk from the Kashmiri winter.
  • Lake Tanganyika earthquake (2005).

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A recently proposed theory suggests that some earthquakes may occur in a sort of earthquake storm, where one earthquake will trigger a series of earthquakes each triggered by the previous shifts on the fault lines, similar to aftershocks, but occurring years later. (SCI): Angeles City (Pampanga, Philippines), An San (South Korea), Huludao (China), and Phuket (Thailand). These oscillations of the earth are either due to the deformation of the Earth by tide caused by the Moon or the Sun, or other phenomena. Las Vegas has four sister cities, as designated by Sister Cities International, Inc. Another type of movement of the Earth is observed by terrestrial spectroscopy. Las Vegas is frequently depicted in film and television:. Earthquakes such as these, that are caused by human activity, are referred to by the term induced seismicity. However, due to illegal gambling risks, none of the major professional sports leagues have ever had a team in Las Vegas, though the possibility of relocating a team to or adding a team in Las Vegas has came up on more than one occasion.

Thus scientists have been able to monitor, using the tools of seismology, nuclear weapons tests performed by governments that were not disclosing information about these tests along normal channels. There are multiple sports teams: the Las Vegas Gladiators in the Arena Football League, the Las Vegas 51s, a baseball franchise in the Triple A Pacific Coast League, and the Las Vegas Wranglers of the ECHL hockey league. Finally, ground shaking can also result from the detonation of explosives. The Las Vegas Motor Speedway (LVMS), just north of the city hosts NASCAR and other automotive events. Earthquakes have also been known to be caused by the removal of natural gas from subsurface deposits, for instance in the northern Netherlands. The University of Nevada, Las Vegas fields Division I athletic teams and the NCAA football Las Vegas Bowl call the city home. Such earthquakes occur because the strength of the Earth's crust can be modified by fluid pressure. There are also many options for boating, golf, hiking, rock climbing, and parks which offer a wide range of activities.

at certain geothermal power plants and at the Rocky Mountain Arsenal). Not having a major league sports team does not mean there is a lack of sports activities in the area. A rare few earthquakes have been associated with the build-up of large masses of water behind dams, such as the Kariba Dam in Zambia, Africa, and with the injection or extraction of fluids into the Earth's crust (e.g. The city and surrounding areas offer many attractions for both visitors and locals to enjoy. Some earthquakes are also caused by the movement of magma in volcanoes, and such quakes can be an early warning of volcanic eruptions. Union Pacific Railroad (UP) is the only class one railroad to provide rail freight service to the city. Deep focus earthquakes, at depths of 100's km, are possibly generated as subducted lithospheric material catastrophically undergoes a phase transition since at the pressures and temperatures present at such depth elastic strain cannot be supported. As of 2005, however, no such service has been established.

Eventually when enough stress accumulates, the plates move, causing an earthquake. Plans to restore Los Angeles to Las Vegas Amtrak service using a Talgo train have been discussed since the Desert Wind was discontinued. Where these plates meet stress accumulates. Until 1997, the Amtrak Desert Wind train service ran through Las Vegas using the Union Pacific Railroad (UP) rails that run through the city; Amtrak service to Las Vegas has since been replaced by Amtrak's Thruway Motorcoach bus service. The Earth is made up of tectonic plates driven by the heat in the Earth's mantle and core. Primary roadways into and out of Las Vegas include I-15 (north towards Salt Lake City, Utah, and south towards San Diego and Los Angeles, California, and other points in Southern California), US 93 (north towards Ely, Nevada and Jackpot, Nevada, and south towards Kingman, Arizona) and US 95 (north towards Reno and south towards Searchlight, Nevada), providing access to Interstates I-80 and I-40. Most earthquakes are powered by the release of the elastic strain that accumulate over time, typically, at the boundaries of the plates that make up the Earth's lithosphere via a process called Elastic-rebound theory. Intercity bus service to Las Vegas is provided by traditional intercity bus carriers, including Greyhound; many charter services, including Green Tortoise; and several Chinatown bus lines.

For example it has been calculated that the average recurrence for the United Kingdom can be described as follows:. Although general aviation traffic flies into McCarran International, other airstrips are available. Larger earthquakes occur less frequently than smaller earthquakes, the relationship being exponential, ie roughly ten times as many earthquakes larger than 4 occur in a particular time period than earthquakes larger than magnitude 5. The airport also serves private aircraft, domestic and international passenger flights, and freight/cargo flights. As a result the moment magnitude (MW) scale was introduced by Hiroo Kanamori, which is comparable to the other magnitude scales but will not saturate at higher values. McCarran International Airport provides commercial flights into the Las Vegas valley. The values of moments for different earthquakes ranges over several order of magnitude. The street numbering system is divided by the following streets:.

The seismic moment is calculated from seismograms but can also by obtained from geologic estimates of the size of the fault rupture and the displacement. The Las Vegas Monorail runs from the MGM Grand Hotel at the south end of the Strip to the Sahara Hotel at the north end of the Strip. Seismologists now favor a measure called the seismic moment, related to the concept of moment in physics, to measure the size of a seismic source. A need for increased frequency and new routes caused by the tremendous growth in the Valley stretches the system's resources. They are still useful however as they can be rapidly calculated, there are catalogues of them dating back many years and are they are familiar to the public. Ridership on the system has been increasing rapidly since the summer of 2005, when a combination of high gas prices and service improvements began attracting more riders. However as each is also based on the measurement of one part of the seismogram they do not measure the overall power of the source and can suffer from saturation at higher magnitude values (larger events fail to produce higher magnitude values).These scales are also empirical and as such there is no physical meaning to the values. The CAT system carries approximately 175,000 people per weekday, or about 10% of the Valley's population.

Each of these is scaled to gives values similar to the values given by the Richter scale. The CAT Bus is a popular means of public transportation among locals and tourists with various bus routes covering a large portion of the valley. Other more recent Magnitude measurements include: body wave magnitude (mb), surface wave magnitude (Ms) and duration magnitude (MD). The pilot system is installed downtown, around the Fremont Street Experience. It is obtained by measuring the maximum amplitude of a recording on a Wood-Anderson torsion seismometer (or one calibrated to it) at a distance of 600km from the earthquake. In 2004, the city partnered with Cheetah Wireless Technologies and MeshNetwork to pilot a wide area mobile broadband system. This is known as the “Richter scale”, “Richter Magnitude” or “Local Magnitude” (ML). It is intended to be the nation's and possibly the world's preeminent furniture wholesale showroom and marketplace, and is meant to compete with the current furniture market capital of High Point, North Carolina.

Richter devised a simple numerical scale (which he called the magnitude) to describe the relative sizes of earthquakes in Southern California. In 2005, on a lot adjacent to the city's 61 ac (247,000 m²), the World Market Center opened. In the 1930s, a California seismologist named Charles F. It is expected that high rise condominium development will transform the downtown area into a vibrant urban center, and change the demographics of the Las Vegas Strip by adding residential elements to tourist areas. The first attempt to qualitatively define one value to describe the size of earthquakes was the magnitude scale (the name being taking from similar formed scales used on the brightness of stars). Many large projects are planned for downtown Las Vegas as well as the Las Vegas Strip including the largest privately financed development proposed in the United States- Project City Center. If you feel an earthquake in the US you can report the effects to the USGS. New Condominum and hotel high rise projects have caused the entire Las Vegas skyline to change dramatically in recent years.

For some tasks related to engineering and local planning it is still useful for the very same reasons and thus still collected. A substantial increase in the number of high-rises under construction and proposed in Las Vegas began in 2003 and has continued into 2006. The problem with these scales is the measurement is subjective, often based on the worst damage in an area and influenced by local effects like site conditions that make it a poor measure for the relative size of different events in different places. Another promising sign of development has come in the form of high-rise development. No structural damage. The IRS is expected to create a demand for additional businesses in the area, epecially in the daytime hours. Damage is slight in poorly built buildings. The city successfully lured the Internal Revenue Service to move operations from outside the city limits to a new building downtown that opened in April 2005.

Trees and bushes shake. In the early 2000s, some promising signs emerged for downtown Las Vegas. Plaster in walls might crack. It is expected that this change will bring more tourism and business to the downtown area. Furniture moves. The city council of Las Vegas has agreed on zoning changes on Fremont Street, which allows bars to be closer together duplicating efforts of similar cities, like the Gaslamp Quarter of San Diego. Pictures fall off walls. The $50-million Lou Ruvo Alzheimer's Institute designed by architect Frank Gehry is expected to break ground in August of 2006.[5].

Objects fall from shelves. The Newland contract calls for Dan Van Epp, Newland's regional vice president and former president of the Howard Hughes Corp., to oversee his company's work on Union Park. People have trouble walking. on the development of Union Park in October of 2005, San Diego-based Newland Communities was chosen by the city as the new development firm. Everyone feels movement. After failed negotiations with The Related Co. The value 6 (normally denoted "VI") in the MM scale for example is:. Smith Center for the Performing Arts, a new City Hall and a possible baseball stadium.

These assign a numeric value (different for each scale) to a location based on the size of the shaking experienced there. and Mary B. In the United States the Mercalli (or Modified Mercalli, MM) scale is commonly used, while Japan (shindo) and the EU (European Macroseismic Scale) each have their own scales. Las Vegas Mayor Oscar Goodman has announced plans for the Union Park Development which will include residential and office high-rises, The Lou Ruvo Alzheimer's Institute, an academic medical center, The Fred W. The first method of quantifying earthquakes was intensity scales. The city purchased 61 ac (247,000 m²) of property from Union Pacific Railroad during the 1990s with the goal of creating something that would draw tourists and locals to the downtown area. Earthquakes that occur below sea level and have large vertical displacements can give rise to tsunamis, either as a direct result of the deformation of the sea bed due to the earthquake or as a result of submarine landslips or "slides" directly or indirectly triggered by it. As of March 2005, the property is for sale.

Just as a large loudspeaker can produce a greater volume of sound than a smaller one, large faults are capable of higher magnitude earthquakes than smaller faults are. While there have been changes in ownership and management, Neonopolis has not been able to lease all the space available. The total size of the fault that slips, the rupture zone, can be as large as 1000 km, for the biggest earthquakes. The multi-level Neonopolis, complete with food court and theaters, was built to offer more retail and services downtown. The location on the surface directly above the hypocenter is known as the "epicenter". While greatly slowing the decline, it did not stop the decline in tourism and revenue. That point is called its "focus" or "hypocenter" and usually proves to be the point at which the fault slip was initiated. The Fremont Street Experience (FSE) was built in an effort to draw tourists downtown.

Using such ground motion records from around the world it is possible to identify a point from which the earthquake's seismic waves appear to originate. With the Strip expansion in the 1990s, downtown Las Vegas began to suffer. The Rayleigh waves from the Sumatra-Andaman Earthquake of 2004 caused ground motion of over 1 cm even at the seismometers that were located far from it, although this displacement was abnormally large. Chinatown initially consisted of only one large shopping center complex, but the area was recently expanded for new shopping centers that contain various Asian businesses. Ground motions caused by very distant earthquakes are called teleseisms. As a reflection of the city's rapid growing population, the new Chinatown of Las Vegas was constructed in the early 1990s on Spring Mountain Road. The power of an earthquake is distributed over a significant area, but in the case of large earthquakes, it can spread over the entire planet. The urban area has grown outward so quickly that it is beginning to run into the Bureau of Land Management holdings along its edges, increasing land values enough that medium- and high-density development is beginning to occur closer to the core.

While almost all earthquakes have aftershocks, foreshocks are far less common occurring in only about 10% of events. However, as a New York Times series on the city reported in 2004, the median price of housing in the Las Vegas Valley is now at or above the nationwide median. Most large earthquakes are accompanied by other, smaller ones, that can occur either before or after the principal quake — these are known as foreshocks or aftershocks, respectively. Consequently, the city has recently enjoyed an enormous boom both in population and in tourism. S-waves (secondary or shear waves) and the two types of surfaces waves (Love waves and Rayleigh waves) are responsible for the shaking hazard. Having been late to develop an urban core of any substantial size, Las Vegas has retained very affordable real estate prices in comparison to nearby urban centers. There are four types of seismic waves that are all generated simultaneously and can be felt on the ground. The lack of any state individual or corporate income tax and very simple incorporation requirements have fostered the success of this effort.

In a particular earthquake, any of these agents of damage can dominate, and historically each has caused major damage and great loss of life, but for most of the earthquakes shaking is the dominant and most widespread cause of damage. A concerted effort has been made by city officials to diversify the Las Vegas economy from tourism by attracting light manufacturing, banking, and other commercial interests. liquefaction, landslide), and fire or a release of hazardous materials. This resulted in a drop in tourism from which the downtown area is still trying to recover. Large earthquakes can cause serious destruction and massive loss of life through a variety of agents of damage, including fault rupture, vibratory ground motion (i.e., shaking), inundation (e.g., tsunami, seiche, dam failure), various kinds of permanent ground failure (e.g. When The Mirage, the first Megaresort, opened in 1989, it started a movement of people and construction away from downtown Las Vegas to the Las Vegas Strip. Some deep earthquakes may be due to the transition of olivine to spinel, which is more stable in the deep mantle. The World Market Center is an example of this.

At subduction zones where plates descend into the mantle, earthquakes have been recorded to a depth of 600 km, although these deep earthquakes are caused by different mechanisms than the more common shallow events. The redevelopment listed below shows how the city is trying to diversify the local economy and revitalize the downtown area. Where the crust is thicker and colder they will occur at greater depths and the opposite in areas that are hot. George Federal District Courthouse, draws numerous legal service industries providing bail, marriage, divorce, tax, incorporation and other legal services. Most earthquakes occur in narrow regions around plate boundaries down to depths of a few tens of kilometres where the crust is rigid enough to support the elastic strain. Las Vegas as the county seat and home to the Lloyd D. Large numbers of earthquakes occur on a daily basis on Earth, but the majority of them are detected only by seismometers and cause no damage . In the 2000s retail and dining have become attractions of their own.

. Several companies involved in the manufacture of electronic gaming machines, such as slot machines, are located in the Las Vegas area. Seismic waves including some strong enough to be felt by humans can also be caused by explosions (chemical or nuclear), landslides, and collapse of old mine shafts, though these sources are not strictly earthquakes. The primary drivers of the Las Vegas economy have been the confluence of tourism, gaming, and conventions which in turn feed the retail and dining industries. Most earthquakes are tectonic, but they also occur in volcanic regions and as the result of a number of anthropogenic sources, such as reservoir induced seismicity, mining and the removal or injection of fluids into the crust. As of the 2004 census estimate, the Las Vegas metropolitan area contained over 1.6 million residents, and contains the largest Hawaiian community, outside of Hawaii. Earthquakes related to plate tectonics are called tectonic earthquakes. Out of the total population, 15.4% of those under the age of 18 and 8.3% of those 65 and older are living below the poverty line.

Events located at plate boundaries are called interplate earthquakes; the less frequent events that occur in the interior of the lithospheric plates are called intraplate earthquakes (see, for example, New Madrid Seismic Zone). 11.9% of the population and 8.6% of families are below the poverty line. The highest stress (and possible weakest zones) are most often found at the boundaries of the tectonic plates and hence these locations are where the majority of earthquakes occur. The per capita income for the city is $22,060. Earthquakes occur where the stress resulting from the differential motion of these plates exceeds the strength of the crust. Males have a median income of $35,511 versus $27,554 for females. The Earth's lithosphere is a patch work of plates in slow but constant motion (see plate tectonics). The median income for a household in the city is $44,069, and the median income for a family is $50,465.

The word earthquake is also widely used to indicate the source region itself. For every 100 females age 18 and over, there are 102.5 males. Earthquakes typically result from the movement of faults, planar zones of deformation within the Earth's upper crust. For every 100 females there are 103.3 males. Earthquakes result from the dynamic release of elastic strain energy that radiates seismic waves. The median age is 34 years. An earthquake is a sudden and sometimes catastrophic movement of a part of the Earth's surface. In the city the population is spread out with 25.9% under the age of 18, 8.8% from 18 to 24, 32.0% from 25 to 44, 21.7% from 45 to 64, and 11.6% who are 65 years of age or older.

Lake Tanganyika earthquake (2005). The average household size is 2.66 and the average family size is 3.20. Many more at risk from the Kashmiri winter. 25.0% of all households are made up of individuals and 7.5% have someone living alone who is 65 years of age or older. Killed over 79,000 people. There are 176,750 households out of which 31.9% have children under the age of 18 living with them, 48.3% are married couples living together, 12.2% have a female householder with no husband present, and 33.5% are non-families. Kashmir earthquake (2005). 23.61% of the population are Hispanic or Latino of any race.

Fukuoka earthquake (2005). The racial makeup of the city is 69.86% White, 10.36% African American, 0.75% Native American, 4.78% Asian, 0.45% Pacific Islander, 9.75% from other races, and 4.05% from two or more races. Sumatran Earthquake (2005). There are 190,724 housing units at an average density of 649.9/km² (1,683.3/mi²). Triggered a tsunami which caused nearly 300,000 deaths spanning several countries. The population density is 1,630.3/km² (4,222.5/mi²). Epicenter off the coast of the Indonesian island Sumatra. As of the censusGR2 of 2000, there are 478,434 people, 176,750 households, and 117,538 families residing in the city.

One of the largest earthquakes ever recorded at 9.0. Although winter snow is usually visible from December to May on the mountains surrounding Las Vegas, it rarely snows in the city itself. Indian Ocean Earthquake (2004). July through September, the Mexican Monsoon often brings enough moisture from the Gulf of California across Mexico and into the southwest to cause afternoon and evening thunderstorms. Chuetsu Earthquake (2004). Showers occur less frequently in the Spring or Autumn. Not large (6.0), but the most anticipated and intensely instrumented earthquake ever recorded and likely to offer insights into predicting future earthquakes elsewhere on similar slip-strike fault structures. The coldest temperature ever recorded is 8 °F set on January 25, 1937 at present-day Nellis Air Force Base.

Parkfield, California earthquake (2004). Winter daytime highs are normally around 60 °F and winter nighttime lows are usually around 40 °F. Bam Earthquake (2003). Winters are cool and windy, with the majority of Las Vegas' annual 4.49 in (114 mm) of rainfall coming from January to March. Dudley Earthquake (2002). The hottest temperature ever recorded is 117 °F set twice, on July 19, 2005 at McCarran International Airport and July 24, 1942 at present-day Nellis Air Force Base. Gujarat Earthquake (2001). Highs in the 90's are common in the months of May, June, and September and temperatures normally exceed 100 °F for several days in the months of July and August, but there is very low humidity.

Nisqually Earthquake (2001). Las Vegas' climate is typical of the Mojave Desert, in which it is located, marked with hot summers, mild winters, abundant sunshine year-round, and very little rainfall. Chi-Chi earthquake (1999). Another part of the water conservation efforts include scheduled watering groups for watering residential landscaping. Düzce earthquake (1999). Due to water resource issues, there is now a movement to encourage xeriscaping instead of lawns. İzmit earthquake (1999) Killed over 17,000 in northwestern Turkey. Within the city, however, there are a great deal of lawns, trees, and other greenery.

Killed over 6,400 people in and around Kobe, Japan. As befits a desert, much of the landscape is rocky and dusty. Great Hanshin earthquake (1995). The city is located in an arid basin surrounded by mountains varying in color from pink to rust to gray. Damage showed seismic resistance deficiencies in modern low-rise apartment construction. The total area is 0.04% water. Northridge, California earthquake (1994). 293.5 km² (113.3 mi²) of it is land and 0.1 km² (0.1 mi²) of it is water.

Revealed necessity of accelerated seismic retrofit of road and bridge structures. According to the United States Census Bureau, the city has a total area of 293.6 km² (113.4 mi²). Severely affecting Santa Cruz, San Francisco and Oakland in California. Las Vegas is located at 36°11′39″N, 115°13′19″W (36.194168, 115.222060)GR1. Loma Prieta earthquake (1989). Marriage licenses are filed at the Clark County Courthouse.. Killed over 25,000. (Councilmembers' official city websites are also available).

Armenian earthquake (1988). A Paiute Indian reservation occupies about 1 acre (4,000 m²) in the downtown area of Las Vegas. Whittier Narrows earthquake (1987). The City Manager also maintains an intergovernmental relationships with federal, state, county and other local governments. 8.1 on the Richter Scale, killed over 6,500 people (though it is believed as many as 30,000 may have died, due to missing people never reappearing.). The City Manager is responsible for the administration and the day to day operation of all of the municipal services and city departments. Great Mexican Earthquake (1985). In the event that the Mayor cannot preside over a City Council meeting the Mayor Pro-Tem is the presiding body of the meeting until such time as the Mayor returns to his seat.

The official death toll was 255,000, but many experts believe that two or three times that number died. The Mayor sits as a Councilmember-At-Large and presides over all of the City Council meetings. The most destructive earthquake of modern times. The City of Las Vegas government operates as a council-manager government. Tangshan earthquake (1976). They are also represented by advisory boards, which are appointed by and give nonbinding suggestions to the Clark County Commission. Caused great and unexpected destruction of freeway bridges and flyways in the San Fernando Valley, leading to the first major seismic retrofits of these types of structures, but not at a sufficient pace to avoid the next California freeway collapse in 1989. Residents of these towns cannot vote for the Mayor and City Council of Las Vegas, but they can vote for members of the Clark County Commission, which governs their areas.

Sylmar earthquake (1971). These towns formed during a 1940s water dispute between the City of Las Vegas and early homeowners south of San Francisco Street, now Sahara Avenue. Caused a landslide that buried the town of Yungay, Peru; killed over 40,000 people. The largest of these towns are Paradise (188,768) between Las Vegas and Henderson(224,829), Sunrise Manor (184,801) east of Las Vegas and North Las Vegas, and Spring Valley (161,286) southwest of Las Vegas. Ancash earthquake (1970). In fact, of the nearly 1.6 million people who live in the Las Vegas valley, only 575,973 live inside Las Vegas city limits. Good Friday Earthquake (1964) Alaskan earthquake. Most of the people and businesses who call Las Vegas home actually live in neighboring unincorporated communities that have no city government or in other nearby cities, some of which are listed below.

Biggest earthquake ever recorded, 9.5 on Moment magnitude scale. Exceptions include cities with their own law enforcement agency; including North Las Vegas, Henderson and Boulder City. Great Chilean Earthquake (1960). The Las Vegas Metropolitan Police Department provides most law enforcement services in the city and surrounding county. Kamchatka earthquakes (1952 and 1737). Las Vegas has also benefitted from the economic woes of California, whose high-tax, high-regulation business climate has caused companies desiring or needing a West Coast presence to relocate to more business-friendly Nevada. On the Japanese island of Honshu, killing over 140,000 in Tokyo and environs. The influx of military personnel and casino job-hunters helped start a land building boom which still goes on today.

Great Kanto earthquake (1923). This money came from the establishment of what is now Nellis Air Force Base. San Francisco Earthquake (1906). The constant stream of tourist dollars from the hotels and casinos was augmented by a new source of federal money. Largest earthquake in the Southeast and killed 100. The increase in tourism and the legalization of gambling led to the advent of the casino-hotels for which Las Vegas is famous. Charleston earthquake (1886). Federal dollars from Hoover Dam soon converted to tourist dollars after the dam was built.

Fort Tejon Earthquake (1857). With the growth of the railroads, Las Vegas became less important, but the building of the Hoover Dam injected new blood into Las Vegas and the city has never looked back. New Madrid Earthquake (1811). It was a staging point for all the mines in the surrounding area, especially from the town of Bullfrog, that shipped their goods out to the country. Lisbon earthquake (1755). Las Vegas started as a stopover on the pioneer trails to the west, and became a popular railroad town in the early 1900s. Kamchatka earthquakes (1737 and 1952). Major events in Las Vegas' history include:.

Cascadia Earthquake (1700). Las Vegas became an incorporated city on March 16, 1911 when it adopted its first charter. Deadliest known earthquake in history, estimated to have killed 830,000 in China. Las Vegas was part of Lincoln County until 1909 when it became part of the newly established Clark County. Shaanxi Earthquake (1556). Clark's San Pedro, Los Angeles and Salt Lake City Railroad, was auctioned off in what is now downtown Las Vegas. San Andreas Fault. Las Vegas was established as a railroad town on May 15, 1905, when 110 acres owned by Montana Senator William A.

New Madrid Fault Zone. A Fort was built near the current downtown area, serving as a stopover for travelers along the "Mormon Corridor" between Salt Lake and the briefly thriving Mormon colony at San Bernardino, California. North Anatolian Fault Zone. On May 10, 1855, following annexation by the United States, Brigham Young assigned 30 Mormon missionaries led by William Bringhurst to the area to convert the Paiute Indian population. Hayward Fault Zone. He was a leader of a group of scientists, scouts and observers for the United States Army Corps of Engineers. Calaveras Fault. Frémont traveled into the Las Vegas Valley on May 3, 1844, while it was still part of Mexico.

Alpine Fault. John C. Earthquake prediction. In the 1800s, areas of the Las Vegas Valley contained artesian wells that supported extensive green areas or Meadows (Vega in Spanish), hence the name Las Vegas. Seismic retrofit. Las Vegas was given its name by Spaniards in the Antonio Armijo party, who used the water in the area while heading north and west along the Old Spanish Trail from Texas. Household seismic safety. .

Emergency preparedness. The nickname favored by local government and promoters of tourism is The Entertainment Capital of the World. The city's glamorous image has made it a popular setting for films and television programs. an earthquake of 5.6 or larger every 100 years. The center of gambling in the US, Las Vegas is sometimes called Sin City due to the popularity of legalized gambling, availability of alcoholic beverages any time (like all of Nevada), various forms and degrees of adult entertainment, and legalized prostitution in nearby counties (it is illegal, though, in Las Vegas and Clark County; Nevada law prohibits prostitution in counties which have populations greater than 400,000). an earthquake of 4.7 or larger every 10 years. This 4½ mi (7¼ km) stretch of Las Vegas Boulevard is mostly outside the Las Vegas city limits, in the unincorporated town of Paradise. an earthquake of 3.7 or larger every 1 year. The name Las Vegas is often applied to the unincorporated areas of Clark County that surround the city, especially the resort areas on and near the Las Vegas Strip.

Recent figures place the population for the Las Vegas metropolitan area, which includes all of Clark County, at over 1.6 Million people (2004 [3]), and the region is the fastest growing in the United States. [2]. The city’s Planning and Development Department reported an increase of 41,126 in 2005, for a total population of 575,973. The Census Bureau's official population estimate as of 2004 was 534,847.

The 2000 census reported that the city had a population of 478,434 [1]. Las Vegas has been the county seat of Clark County since the formation of the county in 1909. Las Vegas was established in 1905, and officially became a city in 1911. The city is the largest to be founded in the 20th century, and is a major vacation, shopping, and gambling destination.

Las Vegas is the most populous city in the state of Nevada, United States.
Location of Las Vegas in Nevada. List of television shows set in Las Vegas. List of movies shot in Las Vegas.

List of movies set in Las Vegas. Las Vegas Boulevard divides the east-west streets from the Las Vegas Strip to near the Stratosphere, then Main Street becomes the dividing line from the Stratosphere to the North Las Vegas border, after which the Goldfield Street alignment officially divides east and west. Westcliff Drive, US-95 Expressway, Fremont Street and Charleston Boulevard divides the north-south block numbers from west to east. Barbara Jo (Roni) Ronemus – City Clerk.

Douglas Selby – City Manager. Steve Ross – 6th Ward Councilmember (Term Expires in 2009). Lawrence Weekly – 5th Ward Councilmember (Term Expires in 2007). Larry Brown – 4th Ward Councilmember (Term Expires in 2009).

Steve Wolfson, Esq – 2nd Ward Councilmember (Term Expires in 2009). Lois Tarkanian – 1st Ward Councilmember (Term Expires in 2007)¹. Gary Reese – Mayor Pro-Tem and 3rd Ward Councilmember (Term Expires in 2007). Goodman – Mayor and Councilmember at Large (Term Expires in 2007).

Oscar B. 100th birthday, or Centennial, of Las Vegas (May 15, 2005). Opening of the Mirage (November 22, 1989), which began the era of megaresort casinos. MGM Grand Hotel fire (November 21, 1980), the worst disaster in Nevada history.

The floods of 1955, 1984, 1999, and 2003. Atmospheric nuclear testing (1951 to 1962). Opening of Bugsy Siegel's Flamingo Hotel on what would become the Las Vegas Strip (December 26, 1946). Completion of Hoover Dam (October 9, 1936).

Legalization of gambling (March 19, 1931). Establishment of Las Vegas as a railroad town (May 15, 1905).

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