Abstract:We investigate the regional characteristics of the slope of the initial part of the P-wave envelope, which is used to determine epicentral distances in the Japan Meteorological Agency and Japan Railway Company earthquake early warning (EEW) systems. The Tohoku region is chosen as the study region. 265 events are collected. By fitting the function Bt·exp(-At) to the initial part of P-wave envelopes, we obtain sets of the parameters of A and B. Then, the intercepts of the above formula for each event are determined, keeping the slope to -2.27 to investigate the regional characteristics. Two tendencies emerge: shallow events have lower values of c, and deeper events have higher values of c.
LIAN Chao,KONG Yuyang,CHEN Xinqiang. A Preliminary Study on Regional Characteristics of the Slope of the Initial Part of P-Wave Envelope[J]. jgg, 2018, 38(2): 157-160.