 | Furnace Creek Fault Earthquake Scenarios Affecting Las Vegas The Collaboratory for Computational Geosciences http://www.seismo.unr.edu/ccog at the College of Science, University of Nevada, is modeling synthetic earthquake motions through complex geological structures. The simulations are teaching us what we need to know in order to accurately anticipate the ground shaking and other effects of likely earthquakes. This narrated video presents two scenarios for the same M7.5 earthquake affecting Las Vegas. In the first, the epicenter of the earthquake is at the southeast end of the fault near the resort of Furnace Creek, Calif., and the fault rupture propagates northwest, away from the city. In the second scenario, the epicenter of the earthquake is at the northwest end of the fault, at Ubehebe Crater, and the rupture is toward Las Vegas to the southeast. The one-minute video presents the the geologic and geotechnical data that went into the model, shows the wave propagation from both rupture scenarios, and compares the peak ground shaking from each scenario in Las Vegas. The direction of the fault rupture and the location of the earthquake's epicenter turn out to be the most important effects on the level of ground-shaking hazard in Las Vegas. To see additional earthquake scenarios affecting Nevada cities, please visit www.seismo.unr.edu/ma . The computations were set up and run by undergraduate Geological Sciences and Engineering students in the fall Geophysics and Geodynamics course at the Univ. of Nevada, Reno. Student Liz Lennox set up the Death Valley scenarios. John Louie, the course instructor, prepared the animations and narrated the video. The narrated video includes the sound of the synthetic seismic waves, sped up by a factor of ten and used to modulate pink noise, for clarity. The noise modulation makes the waves sound a little like ocean waves lapping at a beach. On the left channel is the sound of a station in Amargosa Valley, close to Death Valley. On the right channel is a station in Las Vegas Valley, at the Community College of Southern Nevada, Cheyenne Campus. Being closer to the earthquake, you will hear sounds on the left channel earlier than on the right. Additional sound effects were added for illustration. The wave-propagation animations each last 12 seconds, and they are sped up by a factor of ten over the 120 sec of wave propagation that is simulated. The the initially coherent earthquake energy soon converts to drawn-out horizontal vibrations of energy trapped in the soft sedimentary basins that are sprinkled through this region like the holes in Swiss cheese- each basin rings like a gong. This trapped energy has the highest amplitude and presents the greatest shaking hazard to Las Vegas. Though the trapped energy looks like noise, these synthetics have clean viscoelastic wave propagation with no noise or stochastic effects added. The animations showing the wave propagation illustrate the trapping and amplification well. As in the graphic on the right, each frame of the movies present a map of 3-component ground motions for the region on the map. The movie frames are 281 km wide from NW to SE and 251 km high from SW to NE. The three primary computer display colors of red, green, and blue (RGB) are used to represent the three directional components of ground vibration X, Y, and Z, respectively. Each color is given an intensity related to the intensity of shaking motion in the respective direction. Where there is no color, and you can just see the gray shaded-relief of the basin model, there is very little ground motion; red is motion in the X direction (East, horizontal on the screen); green is motion in Y (North, vertical on the screen); and blue is motion in Z (in and out of the screen). Where shaking directions combine, the colors combine according to the rules of colored light- yellow indicates combined horizontal motion (relative to the ground) of X and Y, adding red and green light, so could be north-south or east-west. White color, adding red, green, and blue all together, indicates high-intensity shaking on all components, including up and down. With these colors, P waves will be mostly blue, S waves red, green, or yellow; and the Rayleigh surface wave is identifiable by having blue up-down motion between the red, green, or yellow radial motions (elliptical particle motions). The wave propagation movies were created with the help of the software listed on the Creating Wave-Propagation Movies page http://www.seismo.unr.edu/ftp/pub/louie/convimage/. |
 | San Andreas Shakes Expected Ground Shaking From Future So. San Andreas Fault Rupture. |
 | 1989 Loma Prieta Earthquake Shakemap Animation as extracted from http://earthquake.usgs.gov/regional/nca/simulations/1989/ high quality version: http://www.youtube.com/watch?v=3YrAx7ab0aw&fmt=18 Explanation of Colors The movies color the landscape in each frame according to the maximum (peak) intensity of shaking (amplitude of the ground motion) up to that point in time. In order to show the intensity of the current shaking, the colors darken as the shaking intensifies. At some locations, the most intense shaking lasts for several seconds, so the colors will darken as seismic waves continue to cause strong shaking. Comparison with 1906 Earthquake One striking observation for those who experienced the 1989 Loma Prieta earthquake's shaking is the comparison of the extent and intensity of shaking with the 1906 earthquake. The Loma Prieta rupture was about 30 times smaller in energy than the great 1906 earthquake. The rupture in the Loma Prieta earthquake began at a depth of about 19.2km (12 miles) and appears to have ruptured a 40km (25 miles) long portion of the San Andreas fault. Unlike the 1906 earthquake, the rupture in the Loma Prieta earthquake did not reach the surface. As in the 1906 earthquake, the strongest shaking was concentrated along the fault. In 1989 the two areas of most intense shaking were north and south of the epicenter in the Santa Cruz mountains. Shaking in the Marina District and Oakland The simulations do not single out either the Marina District or Oakland as having experienced especially strong shaking. These computer simulations resolve features as small as 195m (650 feet) in scale. However, this means that they do not include the amplification of shaking or liquefaction that occurs as a result of thin sedimentary deposits, such as bay mud. Additionally, the computer simulations do not include the shaking at frequencies higher than 0.5 Hz. Including these additional small-scale effects explains the extensive damage in these areas. Future versions of the computer ground motion simulation models will also include these effects. Role 1989 Loma Prieta Earthquake in 1906 Simulations The 1989 magnitude 6.9 Loma Prieta earthquake was used to validate the computer simulations, because a large number of instrumental observations are available from that event. If the models had not been able to reproduce the shaking in the Loma Prieta event, we would not have confidence in the reconstructions of he 1906 earthquake. In fact, the simulations produce motions that agree quite well with the observations from the Loma Prieta earthquake. |
 | Terashake Volumetric View A volumetric view of the TeraShake simulation showing surface and full subsurface ground motion animations as the fault ruptures from south to north. http://www.scec.org/resources/movies.html |
 | Terashake Velocity 3D A 3D visualization of the TeraShake simulation showing surface instantaneous velocity magnitude plotted as vertical perturbations of togography, as the fault ruptures from south to north. http://www.scec.org/resources/movies.html |
 | 6 quake south o pasedena kills 4 Whittier Narrows earthquake nbc news breaks in to report quake which is the : The Whittier Narrows earthquake struck the southern San Gabriel Valley and surrounding communities of southern California at 7:42 a.m. (Pacific Daylight Time) on October 1, 1987. The magnitude 5.9 earthquake was originally assigned a magnitude of 6.0 but was revised a few days later when additional data became available. Its epicenter actually in the town of Rosemead, California, at a depth of 11 km. The earthquake was caused by slip on a blind thrust fault near the northern end of the Whittier Fault, part of the Elsinore Fault Zone, on a previously unknown fault structure. There was no surface rupture. It has been proposed that the event occurred on an extension of the recently recognized Puente Hills thrust system. A magnitude 5.3 strike-slip aftershock occurred three days later, on October 4, causing additional damage. Three people died as a direct result of the earthquake. One death was of a Southern California Edison worker buried by a landslide in the Muir Peak area of the San Gabriel Mountains while working with a crew installing the footings for a high tension power tower north of Pasadena, California. Five other deaths are attributed indirectly to the event. About $358 million USD in damage resulted. Followe by Gilbert Gottfried selling microwave chicken nuggets |
 | Southern California ShakeMovie - 5.4 Quake 7/29/08 - When an earthquake occurs, seismic waves are generated which propagate away from the fault rupture. Here we see the up-and-down velocity of the Earth's surface. Strong blue waves indicate the surface is moving rapidly downward. Strong red waves indicate rapid upward motion. When the waves pass through soft soils (sediments) they slow down and amplify. Waves speed up when they pass through hard rock. The color of the waves oscillates between red and blue indicating alternating up and down motion. |
 | San Francisco Earthquake and Fire April 18, 1906 The California earthquake of April 18, 1906 ranks as one of the most significant earthquakes of all time. Today, its importance comes more from the wealth of scientific knowledge derived from it than from its sheer size. Rupturing the northernmost 296 miles (477 kilometers) of the San Andreas fault from northwest of San Juan Bautista to the triple junction at Cape Mendocino, the earthquake confounded contemporary geologists with its large, horizontal displacements and great rupture length. Indeed, the significance of the fault and recognition of its large cumulative offset would not be fully appreciated until the advent of plate tectonics more than half a century later. Analysis of the 1906 displacements and strain in the surrounding crust led Reid (1910) to formulate his elastic-rebound theory of the earthquake source, which remains today the principal model of the earthquake cycle. This footage is some of the earliest known from a natural disaster. Edison newsreels of San Francisco earthquake / falling buildings / taking away the hurt / troops marching along Van Ness Avenue with relief supplies / pan views of the destruction 1906 Earthquake. |
 | Chile Earthquake 2007 http://www.AirPorn.MOBi Chile Earthquake 2007 - What is an Earthquake 00:00 Strong earthquake shakes northern Chile, kills at least two SANTIAGO (AFP) — A strong earthquake measuring 7.7 rocked arid northe Strong earthquake shakes northern Chile, kills at least two SANTIAGO (AFP) — A strong earthquake measuring 7.7 rocked arid northern Chile Wednesday, killing at least two people, injuring others, sparking panic and causing power outages. Authorities said two women, one aged 88 and the other 54 died when they were crushed under collapsing walls in the city of Tocopilla, 1,600 kilometers (1,000 miles) north of Santiago, doctors said. Local authorities said at least 45 people were injured, but media reports put the figure at about 100. "It is a major quake," Fernandez said of the temblor that struck at 12:43 pm (1543 GMT.) The epicenter was located 1,260 kilometers (783 miles) north of the Chilean capital Santiago. It was felt as far away as Bolivia's capital, La Paz, high in the Andes to the northeast. Images from Chile's TVN television showed cars crushed by debris, and frightened people running onto the streets as the quake struck. Damage was also reported in the northern cities of Calama and Arica which lost electrical power. The government said a plane loaded with humanitarian aid was scheduled to fly to the affected area later in the day. The US Geological Survey said the quake measured 7.7 on the moment magnitude scale, which measures the amount of movement on the underground fault and the area of the fault that ruptured. Many seismologists now use that system rather than the Richter scale that measures an earthquake size based upon the amount of ground shaking. A measurement of seven indicates a major quake and eight a great quake. Authorities initially warned the quake could cause a tsunami but later lifted the warning, saying the epicenter was too far from the Pacific coast. Meanwhile separate earthquakes also hit Argentina and Central America on Wednesday. An earthquake, which US geologists measured at magnitude 5.3, rocked Guatemala and neighboring El Salvador, with no reports of casualties. That quake was not related to the one in Chile, the United States Geological Survey said. "There's no link between the ones in Guatemala and Chile other than they're occurring in the Pacific rim region," John Bellini, a geophysicist at the USGS, told AFP. "They're not related. Nothing triggered the other or anything like that." |
 | October 17 - Eighteen Years Later This morning I went to downtown Santa Cruz to mark the 18th anniversary of the Loma Prieta Earthquake. I lived in Santa Cruz at the time of the quake, and continue to live in the area. Eighteen years later, there's still one hole in the ground of downtown Pacific Avenue, but it will be filled by the time the 20th anniversary of the quake comes along two years from now. Loma Prieta Earthquake - Facts and Statistics: Source: http://www.santacruzpl.org/history/disaster/89quake.shtml The Loma Prieta Earthquake occurred on October 17, 1989 at 5:04 p.m. (Pacific Daylight Time) and lasted for about 15 seconds. The United States Geological Survey gave it a magnitude of 7.1. It was felt over an area of about 400,000 square miles. The rupture occurred on a 30-mile length of the San Andreas fault called the Santa Cruz Mountains segment. The epicenter was eleven and a half miles underground at a spot near China Ridge in Nisene Marks State Park. The land on the seaward side of the fault slipped five and a half feet northwest. Six persons in Santa Cruz County died; it is estimated that 671 persons were injured. Santa Cruz County was the hardest hit county and had the highest number of homes damaged or destroyed. It is estimated that "at least 85,000 persons were adversely affected by earthquake damage to their homes." Many homes were so badly damaged that they were condemned. Many other damaged homes could be saved but were unsafe to live in until they were repaired. Individuals and families found themselves suddenly homeless, living in shelters, with friends or with family. |
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