Areas where 7 meters (35 ft) of vegetation is stripped off cliff faces. Numerical Simulation of Indonesian Tsunami Dec 26, 2004 Source: Plummer, Mc Geary, Carlson Animations and Movies
Tsunami Warning System Pacific Ocean New Stations Largest Tsunami on Record- Lituya Bay, Alaska
Earthquake triggered landslide produces a local landslide in Lituya Bay, Alaska 524 m (1720 ft) Light green area show shoreline affected by tsunami. Pink is the land slide, and red is the landslide scarp. Lituya Bay, Alaska
Fires- San Francisco “Fire” 1906, 1989 Loma Prieta Disease- Northridge 1994-valley fever Earthquakes Caused by Human Activities: Construction of Reservoirs- loading and increase of water pressure locally- Hoover Dam, many small earthquakes M5- M4 Deep Waste Disposal – injection wells, 1962-1965, Rocky Mountain Arsenal Denver, Colorado M 4.3
Data from Denver 1962-1965 Nuclear Explosions- Nevada Tests produced 5.0 to 6.3 magnitude earthquakes Can Earthquakes be Predicted? Short-range predictions Goal is to provide a warning of the location and magnitude of a large earthquake within a narrow time frame Research has concentrated on monitoring possible precursors – phenomena that precede a forthcoming earthquake such as measuring uplift, subsidence, and strain in the rocks Some Techniques Patterns and frequency of foreshocks Micro-seismic deformation of the ground surface Emission of radon gas
Ground water table Seismic gaps along faults You can see that there is a general trend of older earthquakes to the east and younger to the west. It is highly likely that the next earthquake will occur on one of the fault segments to the west. Radio wave signals Animal behavior Long Range Prediction: Long-range forecasts:
Based on the premise that earthquakes are repetitive or cyclical Using historical records or paleoseismology Are important because they provide information used to: Develop the Uniform Building Code Assist in land-use planning Alquist-Priolo (AP) Act 1970’s USGS Probability Maps for before and after the Loma Preita Earthquake in 1989.
1988-2018 Prediction by the USGS Building Design: The goal is to build structures that can withstand ground motion- -wood frame is better than brick or stucco. -Most dangerous houses are brick and mortar built before 1940. Poorly designed: - multi-story houses with street level garage, stilted houses - High rise -Brick chimneys and fire places, slate or tile roofs, decorative stonework, masonry veneers -Hillside homes with cars parked on the top of the house.
Well designed: -Load bearing walls, good foundations, attach the house to the foundation with anchor bolts
Video link : Hayward Fault Retrofit LA Retrofit- wood framed house being retrofitted with steel beams Seismic Safety Regulation – usually passed as a reaction to a large destructive earthquake 1927- Uniform Building Code- updated every three years 1933 -Long Beach Earthquake- Field Act- state inspection and approval for planned school buildings 1971- San Fernando Valley Earthquake- 1972- Alquist-Priolo Earthquake Fault Zone Act- prohibits the construction of human occupied structure within 50 feet of an active fault trace.
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