Risk Analysis along Mataram Fault in Yogyakarta, Indonesia
Hasan Tri Atmojo, Eko Wibowo, Naufal Setiawan, Rolan Mart S., Kristanto J. S., Daniel Radityo

UPN Veteran Yogyakarta
Jl. Padjajaran, Sleman, Yogyakarta, Indonesia. 55283

Abstract

The Mataram Fault is a newly identified fault that stretches from west to east of Yogyakarta City. Limited data on the existence of this fault is important to be able to identify mitigation of the dangers that may arise. Therefore, it is necessary to conduct a study regarding the existence of the Mataram Fault to identify the danger zone in order to reduce the impact of risks that might be caused by an earthquake. The method used to identify the existence of the Mataram Fault is geomagnetic and long-term InSAR methods. The geomagnetic method is used to obtain subsurface conditions around Yogyakarta City to be able to see geomagnetic anomalies that can indicate the fault, while long-term InSAR is used to monitor movements that occur in the Mataram Fault area based on satellite imagery. As for risk mitigation from the dangers posed, a study was carried out using soil investigation data in the Mataram Fault area. The hazard risk assessment carried out was by carrying out liquefaction analysis for the area around the fault using drilling data. Based on geomagnetic data, it shows that there is a straightening of the Mataram Fault, however the pattern shown is segmented and not all of it is in an east - west direction. This shows that the Mataram Fault is separated by several segments and is not a unit. Apart from that, this is supported by the results of the InSAR analysis which shows that there are only certain segments that have experienced deformation in the last seven years. In the study of the danger risk in the Mataram Fault area which has been adjusted to geomagnetic and InSAR data, it was found that the potential danger in the Mataram Fault area tends to be small.

Keywords: Mataram fault, liquefaction potential, InSAR

Topic: Engineering