ANALISIS PERUBAHAN NILAI COULOMB STRESS PADA SESAR PALU-KORO AKIBAT GEMPABUMI SULAWESI TENGAH TAHUN 2000-2019

Central Celebes region have a high risk towards earthquake event. This is caused by the source of earthquake can be triggered both on land and at sea. The sea earthquake occurred because the subduction from the Northern Celebes fault that located on Northern part of Sulawesi Island, while the land earthquake source are caused by active faults in Central Sulawesi one of which is Palu – Koro fault, where which is the main fault in Central Sulawesi. Among the many earthquake events recorded during the 2000-2019 period, there are19 major earthquake events with a magnitude ≥ 5.8. The main earthquake events are analyzed using the coulomb stress method to see the distribution of changes in stress values and the interactions between major earthquake events. Research data was obtained from the Global Centroid Moment Tensor (GlobalCMT) and United States Geological Survey (USGS) catalogs. The results showed that the changes in the coulomb stress value were caused by several factors, namely the fault plane parameter, magnitude and hypocenter of the earthquake. The dominant aftershocks events occured in areas where the coulomb stress value has increased and around the fault area. Based on the research result, there was one major earthquake that triggered another major earthquake, namely the 18 August 2012 earthquake which triggered the 29 May 2017 earthquake.