Realtime Earthquake Mechanism Monitoring System based on Long-period Seismic Wavefield

在本研究计画中，我们打算监测长周期地震波场，以推断与长周期波场一致的地震活动场。在之前的研究项目中，我们已经注意到每秒都可以实时进行。如何实现系统的连续运行是我们面临的挑战，我们已经开发并实现了这样一个基于长周期地震波场连续监测的实时矩张量反演系统。该系统每隔一秒确定一个矩张量解，该矩张量解最好地解释了观测到的长周期地震波场。通过目前的实施，可以用一台PC监控250 kmx 250 km（100 km深）的区域。东京大学地震研究所现在使用该系统监测本州岛东海岸沿着的5个地区的地震活动。结果公布在GRiD MT主页（http：//wwweic.eri.u-tokyo.ac.jp/GRiD_MT/）。

In this research project, we intended to monitor the long-period seismic wavefield to infer the earthquake activity field which is consistent with the long-period wavefield. In the previous research project, we had noticed that it may be possible to do that every second in realtime. The challenge was how to implement the system which operates continuously.We have developed and implemented such a realtime moment tensor inversion system based on continuous monitoring of the long-period seismic wavefiled. The system determines a moment tensor solution which explains the observed long-period seismic wavefield best every one second. With the current implementation, a 250kmx250km (100km in depth) area can be monitored with a single PC. The earthquake Research Institute of the University of Tokyo now monitors the seismicity of 5 regions along the east coast of Honshu island using this system. Results are posted at GRiD MT home page (http://wwweic.eri.u-tokyo.ac.jp/GRiD_MT/).