Estimation of Potential Earthquake Epicenter Based on Level of Land Deformation Along Coastal Line of South Java

The south coast of Java is located in an active subduction zone where the Indo-Australian plate is beneath the Eurasian plate with a velocity of 7,0 cm/year. The phenomena lead to the area front of disaster, especially earthquakes and tsunami. Some areas along the coast of JAVA are being pressed (subsidence) or lifted due to the tectonic activity of the plate. Also, the activity can result in the creation of areas that have the potential to experience ground movement. However, information about it with scientific evidence is still inadequate. Therefore it is necessary to observe the effects of tectonic activity in southern Java on land surface changes along the coastline and estimate the potential epicenter of earthquakes due to this activity. In this study, we observed land deformation along the southern coast of Java to determine which areas experienced significant deformation. Based on the result, we can estimate the future earthquake's potential epicenter and the land movement area. Also, we analyzed the duration required since the last observation of earthquake events or land movement in the area. The land deformation observation uses satellite radar SAR data of ALOS-2 PALSAR-2 provided by JAXA. The type of SAR data is a stripmap with a 3 x 8-meter resolution. The time acquisition varied for each area observed from 2017 to 2020. The covered area of studies is spread from West to East (Pandagelang, Lebak, Sukabumi, Cianjur, Garut, Pangandaran, Banjar, Cilacap, Kebumen, Purworejo, and Bantul).