Study of Identification of the Sunda Plate Boundary in Java Island Based on Continuous GPS Observation Data for 2016-2019

Abstract

ABSTRACT.
The Sunda Plate is a minor tectonic plate that stretches on the equator in the eastern hemisphere where the majority of Southeast Asia is located. This particular region of Southeast Asia is considered to be one of the most seismically and tectonically active regions on earth, particularly on the Java Island. Java Island has a very complex deformation and almost all of its areas are not stable areas. The deformation complex of Java Island with many active faults in the region has raised questions about the true southern boundary of the Sunda Plate on Java Island. The geodynamic model used in this research is to identify the boundary, namely the block model. This model is represented by Euler's rotation parameters consisting of Euler's poles (latitude and longitude of Euler's poles) and angular rotational speed from continuous GPS observation data. To identify the boundaries of the Sunda plate on the Java Island, this study used residue vector analysis with a residue value of less than 3 mm / year. In addition, seismity data and geological structure of Java Island are used to identify the boundaries of the Sunda Plate. The results obtained in this study include the Cimandiri Fault, the Baribis-Kendeng Fault (Subang, Demak, Purwodadi, Cepu, and Waru Segments), Ciremai Faults and Ungaran Faults. Thus, the block rotation model from the plate boundary identification results can be used to properly eliminate the effect of block / plate rotation on the island of Java in order to obtain good elastic deformation information.