Research On Rapid Location Methods Of Warning Earthquake And Application Using Limited Stations

One of the basic problems of seismology is earthquake location. For theEEWS(Earthquake Early Warning System), especially, to determine the warning timeof a earthquake is very important. As the strongest ground motion usually occurs inthe S-wave arrival or later, using the P-wave to seismic positioning, and effectivelyincreasing the warning time, narrowing the blind region of early warning havebecome the hot issue of scientists’ research. The Earthquake Early Warning in Japan,Mexico, California, USA, Switzerland, Italy, the United States, Turkey, Taiwan andother countries has been put into practical use, but in China it is just beginning,strengthening Earthquake Early Warning based on a limited station to quickly locatemethods and applied research scientific and application value.In this thesis, respectively, using one station P wave waveform, two stations andthree stations P wave arrive time, Research on rapid location methods of single station,two stations and three stations. Achieve the goal of dynamic, near real-timeearthquake rapid positioning, using different positioning methods to reposition72earthquakes. And repositioning results show that the hyperbolic method of threestations to quickly locate has a better positioning accuracy. The rapid positioning ofEarthquake Early Warning has practical value. And repositioning results wereanalyzed, from which we can get the following conclusions:1. Based on the V diagram, utilize one station, two stations and three stations toachieve near real-time dynamic earthquake location, although the early loss accuracy,but increase the timeliness of the earthquake location, warning time ahead of time,produce significant mitigation effectiveness.2. Results of72earthquake events be re-positioned, we see:After the earthquake occurs, only one station records seismic informationavailable about3.27seconds of warning time; over time, we continue the earthquakeepicenter, dynamic positioning and correction, when the two stations recordearthquake information available about9.42seconds of warning time; when there arethree stations recording the earthquake information available about11.28seconds ofwarning time; positioning accuracy is further improved, when the three stations recorded the information, the positioning accuracy of more than50%in Class I.3. The azimuth deviation depends upon the record data SNR(signal to noiseratio). Filtering can significantly improve the calculation accuracy of the azimuth.Azimuth deviation is still one of the factors with the greatest impact on thepositioning accuracy of single and double station positioning.4. Hyperbola is unlimited extension of the opening curve, V Figure hyperbolicdata, not only appropriate restrictions will improve the precision and accuracy of thepositioning, but also data size is greatly reduced. For earthquake early warning, itstimeliness has been greatly improved.