Probabilities of Earthquake Occurrences along the Sumatra-Andaman Subduction Zone

摘要

Abstract>Earthquake activities along the Sumatra-Andaman Subduction Zone (SASZ) were clarified using the derived frequency-magnitude distribution in terms of the (i) most probable maximum magnitudes, (ii) return periods and (iii) probabilities of earthquake occurrences. The northern segment of SASZ, along the western coast of Myanmar to southern Nicobar, was found to be capable of generating an earthquake of magnitude 6.1–6.4 M_w in the next 30–50 years, whilst the southern segment of offshore of the northwestern and western parts of Sumatra (defined as a high hazard region) had a short recurrence interval of 6-12 and 10-30 years for a 6.0 and 7.0 M_w magnitude earthquake, respectively, compared to the other regions. Throughout the area along the SASZ, there are 70– almost 100% probabilities of the earthquake with M_w up to 6.0 might be generated in the next 50 years whilst the northern segment had less than 50% chance of occurrence of a 7.0 M_w earthquake in the next 50 year. Although Rangoon was defined as the lowest hazard among the major city in the vicinity of SASZ, there is 90% chance of a 6.0 M_w earthquake in the next 50 years. Therefore, the effective mitigation plan of seismic hazard should be contributed.