DETERMINATION OF HYPOCENTERS USING NON-LINEAR METHODS IN CENTRAL SULAWESI BASED ON DATA DATE1 DECEMBER 2019 - 31 JANUARY 2020

• Main Author: Kumara, Ibra
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/81129
• Institution: Institut Teknologi Bandung

The 7.5 Mw earthquake occurred in Donggala Regency, Central Sulawesi, Indonesia, on September 28, 2018, classified as a strong and destructive earthquake. The earthquake was triggered by the activity of the Palu-Koro fault and resulted in a number of aftershocks. Understanding aftershock activity and seismicity patterns is part of earthquake hazard mitigation efforts. In terms of tectonic order, the Sulawesi region, especially Central Sulawesi, has a relatively complicated and active tectonic order. The pattern of tectonic order in a region can be understood from the seismicity pattern obtained from the results of hypocenter determination. In this final project research the author uses recording data of 10 seismograph points with a recording range ranging from 1 December 2019 = 31 januaryy 2020. The seismograph observation network is a collaboration between ITB, BMKG and University of Cambridge. The process of determining the earthquake hypocenter applies a non-linear method and uses the Non-Linear Location (Nonlinloc) program. The authors selected the P and S wave phases manually using Seisgram2K software. Based on the results of determining the location of the earthquake, 44 events were obtained with 492 phases of P and S waves. The results of the hypocenter are displayed in the form of a map of the distribution of the hypocenter in the Central Sulawesi region. In general the seismogenic zone is at a depth of less than 30 km and is spread in the eastern part of the Palu-Koro fault. In addition, there is an earthquake distribution cluster in the eastern part of the Palu-Koro Fault that may be triggered by uncharted active fault.