KORELASI PERUBAHAN KECEPATAN TITIK PENGAMATAN GPS TERHADAP AKTIVITAS TEKTONIK DI PROVINSI JAWA BARAT

• Main Author: Dwi Nugroho, Aji
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/50386
• Institution: Institut Teknologi Bandung

West Java is one of the provinces in Java Island which has a high level of vulnerability to earthquake tectonic activity. Based on the earthquake hazard map of Indonesia published by the Geological Research and Development Center in 2004, West Java Province is included in the earthquake hazard area number VI. Several earthquakes with a large enough magnitude have been recorded in this region. This condition is caused by the high tectonic activity of Java Island because it is located in the converging zone of tectonic plates converging between Indo-Australia and Eurasia. In this study, an analysis of changes in the speed of movement of GPS observation points was carried out and their correlation or relationship with tectonic activity in West Java Province. The tectonic activity in question is an earthquake phenomenon that is common in the case study area. The initial data used is time series data from 17 CORS observation stations belonging to BIG in West Java for the period 2008-2018. This time series data is the result of processing the GAMIT / GLOBK software and it is necessary to carry out a further correction process so that the data quality can be better. The correction process includes correction for Sundaland Block movement, coseismic correction, and outlier correction. After the correction process is complete, the next step is calculating the velocity value and the direction of the movement speed vector from the GPS-CORS observation station per two years. From this process, it shows the results that changes in speed occur at each CORS station. CORS stations move with various speed and direction or always change with time. From the calculation of the change in velocity of the CORS station caused by seismic activity and the calculation of the station's distance from the epicenter, it can be seen a correlation or relationship that the value of the change in the speed of the movement of the GPS observation point is directly proportional to the magnitude of the earthquake that occurred but is inversely proportional to the distance of the GPS observation point to the epicenter.