MORPHOTECTONIC ANALYSIS AND EARTHQUAKE HAZARDS AGAINST BARIBIS FAULT SEGMENTS IN REGIONS SINDANGLAUT, KECAMATAN LEMAHABANG, CIREBON DISTRICT, WEST JAVA

• Main Author: Maria Neysa Prayacita, Naomi
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69608
• Institution: Institut Teknologi Bandung

Java Island complex geological structure cannot be separated with subduction activity between Indo-Australian plate and Eurasian plate. Baribis Fault, which extends from Subang to Kuningan, is one of that tectonic subduction activity results. Besides the fault segment allegedly crosses the capital city of DKI Jakarta, Baribis Fault is also interesting to be studied because there were six earthquakes since 2009. Therefore, a segment of Baribis Fault that spread along northwest to southeast of Sindanglaut, Lemahabang District, Cirebon Regency, West Java become the research object. Research purposes are identifying the fault movement type and its activeness and mapping the earthquake hazard area that can be generated. There are two main methods in this research, remote sensing methods that implemented in geomorphological analysis, morphometric analysis, tectonic geomorphology mapping, and DSHA (Deterministic Seismic Hazard Analysis) methods that analyzed the earthquake hazard area. Data used are Digital Elevation Model (DEM) with ± 8 m resolution from Badan Informasi Geospasial (DEMNAS), satellite from Sentinel-02 and satellite Global Forest Cover Change (GFCC). The research starts with identifying the fault movement type based on its vertical and horizontal displacement and geomorphic marker of its active fault. Next, the activeness analysis of fault segment is performed using several morphometric methods, curves and hypsometry integrals (HI), knickpoints (ksn), river flow length gradient index (SL) and ratio of valley floor width and valley height (Vf). The last stage is earthquake hazard analysis with the acceleration of ground movement (PGA) calculation using two different magnitude values based on earthquake catalog from 2003-2018 and the maximum moment magnitude that can be produced. The calculation result will be converted into Modified Mercalli Intensity (MMI) scale to show level of damage around the earthquake source. Research object along 7.56 km length indentified as dextral strike-slip fault with horizontal displacement dominancy around 231 m. The fault section found on two geomorphological units, the fault scarp and the steep slope. The morphometric analysis, the fault segment located in an area that had a relatively high level of uplift and tectonic activity. The maximum magnitude moment that can be produced by the fault section studied is M 6,14. Based on maximum magnitude calculation, resulting PGA value range from 0.23-1.70 g. The result shows high earthquake risk. In another with calculation using earthquake catalog data states PGA value around 0.02-0.04 g and indicates low earthquake risk.