Comparison of two earthquake early warning location methods

According to earthquake catalog records of Fujian Seismic Network, the <i<T</i<<sub<now</sub< method and the four-station continuous location method put forward by Jin Xing are inspected by using P-wave arrival information of the first four stations in each earthquake. It shows that the four-station continuous location method can locate more seismic events than the <i<T</i<<sub<now</sub< method. By analyzing the results, it is concluded that the reason for this is that the <i<T</i<<sub<now</sub< method makes use of information from stations without being triggered, while some stations failed to be reflected in earthquake catalog because of discontinuous records or unclear records of seismic phases. For seismic events whose location results can be given, there is no obvious difference in location results of the two methods and positioning deviation of most seismic events is also not significant. For earthquakes outside the network, the positioning deviation may amplify as the epicentral distance enlarges, which may relate to the situation that the seismic stations are centered on one side of epicenter and the opening angle between seismic stations used for location and epicenter is small.