July 8, 2012
San Francisco Earthquake Proposal
The San Francisco earthquake of April 18, 1906, has gone down in history as one of the most damaging earthquake in United State history. San Francisco and surrounding cities were violently shaken by seismic waves produced by the magnitude 7.8 earthquakes. The proposal is to review the available literature on how geophysical precursors can be used for short-term predictions of earthquakes. The objectives of this review is to explain three commonly monitored geophysical precursors: ground uplift and tilt, increases in radon emissions, and changes in the electrical resistivity of rocks; show what happens to each of these precursors during the five stages of an earthquake; and discuss how each of these precursors is used for short-term earthquake predictions. Scientist depend on geophysical precursors to predict changes in the physical state of the earth that are precursory to earthquakes, with this information scientist can make medium and short term prediction for an earthquake. The stages start with how the rock particles compressed together, then the dilatancy and development of cracks this occurs because the rocks are packed so tightly. Then follows the influx of water and unstable deformation in the fault zone, then the rock can no longer resist the strain which causes the fault suddenly rupture and the final stage where aftershock takes place because of the sudden drop in pressure. The map below shows the San Francisco earthquake in 1906 and the areas that were affected. In the final paper all the objectives will be review in detailed, the three commonly monitored geophysical precursors: ground uplift and tilt, increases in radon emissions, and changes in the electrical resistivity of rocks; and how each of these precursors affect the five stages of an earthquake; and how each of these precursors is used for short-term earthquake predictions.