Relokasi Gempabumi Teleseismic Double-Difference di Wilayah Bali – Nusa Tenggara dengan Model Kecepeatan 3D

Abstract

ABSTRAKBali dan Nusa Tenggara memiliki kondisi tektonik yang kompleks. Aktivitas kegempaan di wilayah penelitian bersumber dari Lempeng Indo-Australia yang menunjam ke bawah Lempeng Eurasia dan pensesaran naik busur belakang. Penelitian ini dilakukan untuk mengetahui kondisi tektonik dan kegempaan di wilayah Bali hingga Nusa Tenggara berdasarkan metode relokasi Teleseismic Double-Difference dengan model kecepatan 3D. Data yang digunakan adalah katalog gempa bumi BMKG pada periode pengamatan Januari 2010 -Februari 2017 sebanyak 4.201 kejadian gempa bumi. Hasil relokasi menunjukkan pola sebaran gempa bumi didominasi oleh gempa-gempa dangkal di wilayah barat daerah penelitian. Semakin ke arah timur semakin dalam, yang mengindikasikan bahwa gempa bumi tersebut berasosiasi dengan zona subduksi. ABSTRACT Bali and Nusa Tenggara has a complex tectonic condition. Seismic activity on the regions is generally derived byIndo-Australia Subduction Activity (Sunda Arc) and the back-arc thrust. The objective of this research is to analyze the condition of tectonic setting and the seismicity of these regions using the Teleseismic Double-Difference method with a 3D velocity model. The data are derived from BMKG catalog with the period of observation from Januari 2010 -Februari 2017 with 4201 earthquake events. The result of hypocentre relocation showed the earthquake distribution pattern is dominated by shallow earthquake in the west region of the studied area, and the depths increased to the east of the studied area and mainly indicated by the subduction earthquake activity.

Utilization of Seismic Data as a Tsunami Vulnerability Review

“…The study's results follow the surface structure modeling in Figure 2 [22]. The modeling in Figure 3 corresponds to Setiadi [23]. The relocation results showed a significant decrease in the hypocenter to the north of about 640 km.…”