PENGGUNAAN DATA GEMPA TEKTONIK UNTUK PENCITRAAN TOMOGRAFI SEISMIK BAWAH PERMUKAAN JAWA TENGAH DAN DIY; THE USE OF TECTONIC EARTHQUAKE DATA FOR SEISMIC TOMOGRAPHY IMAGING OF CENTRAL JAVA AND DIY SUBSURFACE

Adi, Efita Pratiwi, Gede Bayu Suparta

2015 | Disertasi | FMIPA

A Research on the use of tectonic earthquake data for Central Java and DIY subsurface seismic tomography imaging has been conducted. This research aims to make the image of the subsurface internal structure of Central Java and Yogyakarta in 1D and 3D by using the Lotos-12 and to determine the subsurface structure of Central Java and Yogyakarta. This study used BMKG Yogyakarta earthquake data from 2009 to 2014 recorded by stations located in Central Java and Yogyakarta. Data processing used LOTOS-12 (Local Tomography Software) to produce images of the P wave velocity anomaly and the S wave and Vp/Vs ratio. Results of tomographic images in Central Java and Yogyakarta are fairly large negative anomaly (-5%), which is under Mount Merapi and Mount Merbabu which estimated a thick sedimentation and the hot fluid path and there are positive anomalies (+ 4.5%) in the west and south. The subsurface structure of Central Java and Yogyakarta consists of thick sedimentation and predicted there are types of basalt and granite rocks at depths of 5-15 km and there peridotite, pyroxenite dunit and at depths of more than 20 km.

Kata Kunci : tectonic earthquake; seismic tomography; Central Java; imaging.