Assignment 3 in Intro GIS made the subject of earthquakes very popular among the students
On May 12th 2008, a dreadful earthquake cast its shadow on the lands of Sichuan province in China. Nobody had a prior knowledge of how big a catastrophe the earthquake would be and how big a task the Chinese government would have.
At beginning of the earthquake, telephone landlines, signal sending and receiving towers, network centers, roads and highways, all the means of communication were destroyed. Meanwhile, access to clean drinking water, foods, and other life saving supplies was totally interrupted. Residents in those areas that were located around the center of the earthquake were the most severely impacted and seemed to be helpless and isolated from outside world. The injured would have died if help didn’t arrive on time and fatal infectious diseases would have spread with incredible speed if medical prevention were not set up immediately. Fortunately, equipped with GPS, rescuers could have precise information of where they were in the ruined areas and were able to send back geographical information report using their GPS receivers and the satellites. Because of this modern means of positioning and communicating tool, the first fifteen paratroopers successfully arrived in the most damaged and isolated areas. After their arrival, other rescuers knew how to get there and what kind of help was needed. GPS therefore played a very important role in this catastrophe.
Other uses of GPS relating to earthquake can be found in Southern California, USA:
A perfect example of this three-part system in application is the Southern California Integrated GPS Network (SCIGN.) SCIGN is a network of continuously recording GPS receivers throughout Southern California that have been installed in an array to monitor the strain accumulation in Southern California’s crust. This is done with the help of the highly accurate measurements made by the GPS system which allow scientists to record millimetre-scale slip on faults that cannot ordinarily be measured. Understanding of area seismicity could lead to a better understanding of the mechanics behind earthquakes and to better assessment of earthquake hazards and damage estimates. Scientists from NASA/JPL, Scripps Institution of Oceanography, and the U.S. Geological Survey use the data from this array to determine if small-scale motion on faults between earthquakes can indicate precursor signs to an event that may help to predict where and when an earthquake will likely occur.
Apart from its positioning, communicating and measuring function, GPS can also be used in terms of early earthquake warning. As an integrated GPS warning system already been established in California, once earthquake occurs, prepared action like a shutting down of gas lines will be automatically done. It not only enhances the speed of response to earthquake but also reduces avoidable life and property lost.