SEISMICITY RATE CHANGE AND REGION-TIME-LENGTH ALGORITHM INVESTIGATIONS ALONG SUMATRA-ANDAMAN SUBDUCTION ZONE

Abstract

In this study, prospective areas of the forthcoming major earthquakes were investigated along the Sumatra-Andaman Subduction Zone (SASZ) using simultaneously 2 seismological techniques called 1) seismicity rate change (Z value) and 2) region-time-length (RTL). After statistical investigation, the earthquake dataset with Mw 4.4 recorded during 1980-2014 were defined as the completeness data representing directly the seismotectonic activities along the SASZ. Using suitable characteristic parameters, both Z value and RTL reveal temporally the anomalous seismic quiescence, i.e., Z 6.7 and RTL -0.3, within 1-7 year before the major earthquakes. In addition, regarding spatial investigation, the quiescence illustrates in the vicinity of the epicenters of major earthquakes generated previously along the SASZ. Due to there is no evidence of man-made seismicity, both temporal and spatial Z-value and RTL anomalies obtained in this study, therefore, imply empirically the precursor of the earthquake. Base on the suitable conditions of both Z and RTL, the present-day Z and RTL maps were also contributed. The results reveal that there is only one location of Z and RTL anomalies which still quiescence from the major earthquakes, i.e., the segment in the vicinity of the Nicobar Islands. Therefore, the effective mitigation plan should be contributed urgently.