Article Details

INVERSION OF GEODETIC DATA FOR SEGMENTATION SLIP RATE ESTIMATION ON THE CIMANDIRI FAULT, WEST JAVA

Oleh   ALWIDYA ANGGA SAFITRI (NIM : 25115016)
Kontributor / Dosen Pembimbing : Pembimbing : Dr. Irwan Meilano, S. T., M .Sc.; Dr. Endra Gunawan, S. T., M. Sc.
Jenis Koleksi : S2 - Tesis
Penerbit : FITB - Teknik Geodesi dan Geomatika
Fakultas : Fakultas Ilmu dan Teknologi Kebumian (FITB)
Subjek :
Kata Kunci : The Cimandiri Fault, Slip Rate, Simple Screw Dislocation, Geodetic Inversion
Sumber :
Staf Input/Edit : Alice Diniarti  
File : 6 file
Tanggal Input : 2018-07-30 10:07:30

The tectonic setting of Indonesia is very complex due to a meeting point of several active tectonic plates, i.e. Eurasian plates, Pacific plates, and Indo-Australian plates. The area of this research, the Cimandiri fault zone, is located in the eastward of the transitional zone between the frontal subduction of Java and the oblique subduction of Sumatra. This fault zone is extended from the Gulf of Pelabuhan Ratu, West Java to the Bandung area, through some populated cities such as Pelabuhan Ratu, Sukabumi, Cianjur, and Padalarang. This research aims to give analysis related to the Cimandiri fault slip rate characteristics. GPS data is used as the representation of the surface deformation. The GPS data use in this research consists of continuous and campaign stations network. The spanning time for continuous GPS data is 6 years extend from 2008 to 2015 while the campaign GPS data is 10 years extend from 2006 to 2016. The average slip rate and locking depth is estimated by Simple Screw Dislocation Method by Savage and Burford (1973). In average slip rate and locking depth estimation process, the fault is divided into three major segments based on its geomorphology (Supartoyo, 2014). The average slip rate and locking depth are used to constrain the slip distribution calculation using Elastic Half-Space Model by Okada (1985) to invert GPS data. The inversion applied continuous fault plane along the strike with discrete model fault in a grid of uniformly sized block in 5 km long by 5 km high. The result can be seen from the pattern of the GPS parallel velocity around the fault. It shows the north side moves faster than the south side of the fault both in the west direction. The pattern shows the type of the Cimandiri fault as strike-slip fault. The average slip rate and locking depth are various between each segment. The first segment which is located in the west part of the fault moves in average rate 4.2 mm/year. The middle segment moves in average rate 5 mm/year and the third segment which is located the east part of the fault moves in average rate 4.3 mm/year. The average locking depths for each segment are 12 km, 17 km, and 8.5 km, respectively. According to the slip distribution from GPS inversion, the Cimandiri fault consists of major creeping part and locking segment. There are locking segment area in the end of the segment 1, segment 2, and segment 3. The locking segment which highly locked is located in the end (east direction) of the segment 1 and decrease to the east.