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Published byGrant Webster Modified over 8 years ago
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Dealing With Earthquakes
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Options To do nothing and to accept the hazard. To adjust to living in a hazardous environment and strengthen their home. To leave the area.
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Dealing With Earthquakes Better forecasting and warning. Building design. Building location. Emergency procedures.
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Predicting And Monitoring Crustal movement: Small-scale movement of plates. Changes in electrical conductivity. Strange and unusual animal behaviour, especially carp fish. Historic evidence: Whether there are trends in the timing of earthquakes in a region.
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Predicting Volcanoes And Earthquakes
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Volcanoes (Mount Pinatubo) It is virtually impossible to monitor all active volcanoes. Satellites offer the prospect of global coverage from space and being developed for remote warning systems. In the 1992, Mount Pinatubo eruption, over 320 people died, mostly due to collapse of ash- covered roofs. Many more lives were saved because early warnings were issued and at least 58,000 people were evacuated from the high-risk areas.
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Management (Mount Pinatubo) State-of-the-art volcano monitoring techniques and instruments were applied. The eruption was accurately predicted. Hazard-zonation maps were prepared and circulated a month before the violent explosions. An alert and warning system was designed and implemented. The disaster response machinery was mobilised on time.
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Earthquakes (San Andreas Fault) The most reliable predictions focus on… Measurement of small-scale ground surface chances. Small-scale uplift or subsidence. Ground tilt. Changes in rock stress. Anomalies in the Earth’s magnetic field. Changes in radon gas concentration. Changes in electrical resistivity of rocks.
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Management (San Andreas Fault) One intensively studied site is Parkfield, California, on the San Andreas Fault. Parkfield is heavily instrumented: strain meters measure deformation at a single point; two-colour laser geodimeters measure the slightest movement between tectonic plates; and magnetometers detect alterations in the Earth’s magnetic field, caused by stress changes in the crust. Nevertheless, the 1994 Northridge earthquake was not predicted and it occurred on a fault that scientists did not know existed. Technology helps, but not all the time.
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Activity Read the “San Francisco Faces Big Shaker” article and highlight the following in different colours: Locations Dates Numbers/Values Any prediction Any basis upon which a prediction is made Any issues with earthquake prediction
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