ANALYSIS OF ONE-DIMENSIONAL SHEAR WAVE VELOCITY (Vs) MODEL FROM RAYLEIGH WAVE USING AMBIENT SEISMIC NOISE METHOD AROUND PIDIE JAYA.

• Main Author: IRFAN SHIDQAN ( NIM: 12313029), AHMADA
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/20835
• Institution: Institut Teknologi Bandung

Ambient noise as a method of imaging the crust beneath Earth’s surface is relatively new with many advantages compared to conventional passive seismic. Ambient noise data does not need to rely on explosive source, with the signal-to-noise ratio could be enhanced with the use of stacking. These reasons made the method efficient enough in data acquisition and computation. The data used in this research are seismic records from 9 active seismometers that recorded ± 1 month (December 2016 until January 2017) around Pidie Jaya, Aceh. Rayleigh wave were extracted through ambient noise seismic interferometry, and their dispersion curves were measured using Multiple Filtering Technique. These dispersion curves then inverted from group velocity as a function of period into shear velocity as a funnction of depth, using linearized least square technique. Local and regional shear wave velocity models were made in three cases. The result around local area velocity model revealed low shear velocity values down to 6 km depth that indicates thicker sediment layers than global reference model CRUST1.0. If the sediment layers were thicker then seismic amplifications could be stronger. This could explain the huge damage around Pidie Jaya regency caused by recent earthquake (December 2016). The regional area velocity models was also made with the values relatively following the global reference model by a slight margin.