Earthquake Hazard and Engineering Determinations for Indonesian Region Using IMS Network Data

Earthquake hazard and related earthquake engineering determinations usually need estimate of return periods, probabilities of exceedance of specific levels of design load criteria or extremal safety conditions. For these insistences Indonesian region bounded by -14°S–10°N and 93–141°E have been considered for potential earthquake hazard analyses. This region is one of the most seismically Trans-Asian and Circum-Pacific belts type active plate regions of the world where large to great earthquakes have occurred during the past hundred years. Nineteen years recent earthquake data from June 13, 1999 to July 10, 2017 have been taken from International Monitoring System (IMS) Network setup by Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), Vienna Austria. The earthquake occurrences agree with the Gumbel’s Type I extreme distribution function and has been applied to analyses those maximum magnitude data with a satisfactory degree of correlation (0.96). The result of analysis has enabled earthquake hazard that exist in Indonesian region to be quantified in terms of recurrence periods and probabilities of occurrence of earthquake of any given magnitude. The line of expected extremes (LEE) which is based on 19 years (1999-2017) of seismicity data of yearly extreme values of earthquakes for the region has been plotted. The medium to large size earthquakes which, expected to occur in this region have been predicted. Study indicates that the most probable largest annual earthquakes are close to 6.0. The most probable earthquake that may occur in an interval of 50 years is estimated as 6.8.