Applicability analysis of HYPOSAT6 location program in Shanghai and adjacent areas

The applicability of a new location program HYPOSAT6 in Shanghai and its adjacent areas is analyzed using 22 catalog earthquakes recorded by Shanghai Seismic Network and some shared seismic stations in adjacent provinces from 2020 to 2022 as test data. The results show that the HYPOSAT6 location program is basically consistent with the catalog results when locating earthquakes in Shanghai and its adjacent areas, but the results are slightly deviated when locating small and micro earthquakes in the marginal sea area. At the same time, when distant locating earthquakes outside the network with unclear P-wave initial phase, the positioning results are poor. In terms of magnitude determination, the HYPOSAT6 location program can improve the problem of small magnitude of near earthquakes in Shanghai seismic network to a certain extent. However, there is also a phenomenon that the magnitude calculated by the location of distant earthquakes outside the network with unclear records is small. In addition, the HYPOSAT6 location program can automatically identify the actual seismic phase type of the first arrival phase position marked by the seismic analyst. This feature is different from the traditional location program, which is helpful to reduce the error caused by the difference of seismic phase identification and improve the positioning accuracy.