KARAKTERISASI SUMBER GEMPA DAN ANALISIS BAHAYA GEMPABUMI SESAR AKTIF BARIBIS-KENDENG SEGMEN PEKALONGAN

• Main Author: Nizar Maulana, Muhammad
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/77995
• Institution: Institut Teknologi Bandung

There were 40,000 earthquake data ranging from magnitudes M 1.4–8.5 recorded between April 2009 and July 2016 in the nearby area of Indonesia, documented in the earthquake catalog of the National Earthquake Center. The National Earthquake Center identified 31 active fault segments on the island of Java and its surroundings. The high population density on Java renders the island highly susceptible to earthquake hazards. Thus, accurate identification of earthquake source geometry and hazard analysis is imperative to mitigate the high vulnerability to earthquake hazards. This research was conducted in the administrative region of Pekalongan Regency, situated 12.5 km southwest of Pekalongan City. The objective of this study was to identify the geometry of the Baribis-Kendeng Fault Pekalongan Segment which serves as a seismic source and to analyze the potential earthquake hazard it may produce. The data employed consisted of digital elevation model (DEM) data, field observations, seismic reflection profile data, and earthquake catalogs. The methodology used to identify fault geometry included literature review, remote sensing, field observations, and interpretation of seismic reflection profiles. The identified fault geometry was then utilized in the earthquake hazard analysis. The potential earthquake hazard analysis generated by the fault is calculated using the deterministic seismic hazard analysis (DSHA) method. The research results indicate the presence of the Baribis-Kendeng Fault Pekalongan Segment, extending approximately ±16 km on the surface with a strike fault direction of northeast-southwest and a fault dip towards the south. The fault is classified as a thrust fault and correlates with the earthquake occurrence on April 18, 2018, at 13:28:35 WIB in Banjarnegara Regency. According to empirical equations, the fault is capable of generating earthquakes with a maximum magnitude of up to 6.4 Mw. Using two attenuation equations, the fault can produce peak ground acceleration (PGA) values of 0.87–0.92 g at the engineering bedrock level.