第38回統計地震学セミナー / The 38th Statistical Seismology Seminar

場所 (Place): 統計数理研究所 A508号室
/ Room A508 @ Institute of Statistical Mathematics

講演題目 (Title): Seismicity changes revealed by the Region-Time-Length(RTL) algorithm

概要 (Abstract): The Region-Time-Length (RTL) algorithm, which takes into account the epicenter, time, and magnitude of earthquakes, is an effective technique in detecting seismicity changes, especially the seismic quiescence.
Based on the RTL algorithm and the Q-parameter (an average RTL parameter over a certain time window), we can quantify the spatio-temporal characteristics of seismicity changes. In order to reduce the possible ambiguity due to the selection of model parameters in the RTL algorithm, we proposed an improved technique of searching for the optimal model parameters. The applications of the RTL algorithm in various tectonic regions indicated that seismic quiescence anomalies generally started a few years prior to the occurrence of the mainshock. The linear dimension of the seismic quiescence zone could be a few to several times of the rupture dimension of the mainshock. The significance of the seismic quiescence anomalies revealed by the RTL algorithm was supported by the close investigations of model parameter effects and the stochastic test based on randomized earthquake catalogs.