Eg Denver waste water from a military installation was pumped into a deep well

Eg denver waste water from a military installation

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E.g. Denver, waste water from a military installation was pumped into a deep well causing earthquakes. Also happened in Ohio When valleys are flooded to make reservoirs (e.g. Lake Mead, NV&AZ) the additional groundwater pressure can lubricate faults in the region. Also the weight of the lake may bend the land forming normal faults.
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Ground Shaking and Displacement During an Earthquake Displacement a few mm- a few meters Acceleration 0 2 g’s Most Damage Longest Lasting
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Severity of Shaking Depends On: Magnitude of the earthquake Distance from hypocenter The nature of the substrate at your location Unconsolidated rock shakes a lot more, basins can amplify waves E.g. 1985 Mexico city M8.0 300 km away The frequency of the seismic waves High frequency waves do most damage but do not travel very far Car stereo analogy (bass) [TerraShake Animations]
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Buildings - Mexico City, 1985 Before After
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Secondary Effects of Earthquakes Earthquakes can also cause landslides Especially bad in California where faults have uplifted shorelines very quickly before the rock had time to completely lithify California will not sink into the sea, but homes on the coast may.
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More Secondary Effects An earthquake may cause wet sediment to liquefy. This is called liquefaction Similar to quicksand Liquefaction after an earthquake in Taiwan
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Liquefaction Liquefaction can occur on a large scale The ground may separate into several coherent slump blocks if a basal layer liquefies. This happened to a housing development after a large earthquake near anchorage Alaska in 1964.
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Turnagain Heights Disaster, AK 1964
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Sand Volcanoes / Sand Boils Shaking during an earthquake can also mobilize sand layers creating sand boils or sand volcanoes , which may eject sand 10 m into the air during an earthquake.
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Sand Volcano
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Disrupted Bedding
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Fire! Earthquakes can break gas lines and knock down power lines causing numerous fires. Fires were responsible for most of the deaths during the 1906 great San Francisco earthquake
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Fire - San Francisco, 1906
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Tsunamis Tsunami: a large wave that is generated by an earthquake , landslide, or meteor impact Not “Tidal Waves”; They have nothing to do with tides Result when earthquakes cause a large vertical displacement of the seafloor. Water rushes in to fill the lowered points; a wave is formed Associated with normal and reverse faults Subduction zones can produce the largest earthquakes (most slip and rupture length) they can also generate the largest tsunamis
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Tsunami Occurrence Destructive tsunamis occur frequently - about 1/yr. Many tsunami disasters dot recorded history. 94 destructive tsunamis in the last 100 years.
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