Pengamatan Deformasi Sesar Kaligarang Dengan GPS Tahun 2015

Abstract

Tectonic activity in Semarang led to the formation of the fault. In the South of Semarang, there is sesar (thrust fault). These faults are cut by flattening the west trending fault sea- southeast or northeast - southwest, including Kaligarang fault . Kaligarang river divides the area of Semarang on North - South direction virtually.To determine the condition of deformation of Fault Kaligarang then conducted observations periodically. The observation is done at existing control point using GPS Dual Frequency. Measurement of control points is done with static methods, and observations made during the 7-8 hours. Observation data processed with scientific software, namely GAMIT 10.5. The results of data processing by Gamit 10.5. is a geocentric coordinates, and the coordinates are transformed into coordinates with the coordinates origin toposentrik coordinate data in 2014 for the old control point and for a new point using the coordinate observations in March 2015 as the origin. The purpose of this research is to know the fault type and Fault rate slide from Kaligarang.The results of this research is the occurrence of a significant displacement from each observation point with the greatest displacement reaches 0,132 m/year, so it can be concluded that at Fault Kaligarang occured deformation. According to the results of this research type of Fault Kaligarang is right-lateral strike slip fault. The value of the slip rate and locking depth of Sesar Kaligarang can not be determined because of a displacement in values large to speed displacement fault between 1,1 mm/year to 26.5 mm/year in the field of fault to the West, while the eastern part of the fault to have a range of speeds displacement between 7.9 mm/year up to 10 mm/year