METHOD AND SYSTEM FOR DETERMINING ARRIVAL OF PRINCIPAL SHOCK OF EARTHQUAKE

摘要

PROBLEM TO BE SOLVED: To provide a simple method and a simple system for determining arrival of a principal shock of an earthquake, which are capable of further determining, after detecting arrival of a P-wave of the earthquake at a time of occurrence of the earthquake, arrival of an S-wave with high accuracy.;SOLUTION: A method for determining arrival of a principal shock of an earthquake is used to determine arrival of an S-wave at a site from a vibration waveform of a P-wave of the earthquake detected by a seismometer installed at the site that is an object of the determination, the method including: chronologically calculating short-term average (STA)/long-term average (LTA) from the vibration waveform measured by the seismometer at the site; detecting arrival of the P-wave when an obtained value exceeds a threshold preset for P-wave detection; then continuing measurement of the vibration waveform of the P-wave to calculate the STA/LTA; and determining that the S-wave has arrived when an obtained value exceeds a threshold preset for S-wave detection.;COPYRIGHT: (C)2016,JPO&INPIT