Seismicity and influence of coulomb stress on the risk of earthquakes in South Sulawesi

Abstract

Abstract This study aims to analyze the distribution of earthquake events, analyze seismicity based on the parameters of b value, analyze changes in Coulomb stress and analyze the risk of earthquake events in South Sulawesi based on seismicity levels and changes in Coulomb stress in the range of 1991-2021. The data used in this study is data on earthquake events in 1991-2021 obtained from the IRIS and ISC catalogues. Data from the IRIS catalogue is mapped using ArcGIS software to see the distribution of the next earthquake spread processed by using MATLAB-based ZMapp 7 software to obtain the value of seismicity parameter (b value). Data from the ISC catalogue is mapped using Google Earth software to see the spread of earthquakes and then processed using MATLAB-based Coulomb 3.1 software to obtain analysis of stress Coulomb changes. Based on the results of the analysis obtained a value of b between 0.9-1.5 shows the value of b obtained is relatively low which correlates with a high level of stress. Based on the results of the analysis of changes in Coulomb stress obtained the movement of increased stress towards the red lobe with a value of 0.1 to 1 bar and decreased stress towards the blue lobe with a value of -0.1 to -1 bar. In general, earthquake-prone areas are located in the northern to central parts of South Sulawesi.