GEOLOGICAL CHARACTERISTICS IDENTIFICATION OF THE WESTERN TANGKUBAN PARAHU VOLCANIC AREA BASED ON H/V RATIO CURVE ANALYSIS

• Main Author: Denis Radestian, Vigo
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/67339
• Institution: Institut Teknologi Bandung

Tangkuban Parahu is one of the active volcanoes in West Java which is located about 15 km north of Bandung City. Several methods have been used to identify geological characteristics in the Tangkuban Parahu Volcanic Area such as tephrastratigraphic and surface geology studies. The geological characteristics of Tangkuban Parahu Volcano need to be understood further, especially from a geophysical point of view. This final project research applies the H/V ratio method to microtremor data recorded by 17 temporary seismic stations in the west and around the volcanic crater. The H/V curve profile obtained for each station can be used to obtain the VS value. In the data processing, the time span of the data used is 4 hours, also demeaning, detrending and selection of STA/LTA are carried out on the data. The H/V curve obtained at each station allows to estimate the dominant frequency, amplification factor, and VS30 value. This final project research applies the Inverse Distance Weighted (IDW) interpolation method to determine the general profile of the dominant frequency, amplification factor, and VS30 map of the research area. The dominant frequency is obtained in the range of 0.93-9.7 Hz, the amplification factor is in the range of 2.4-11.2, and VS30 is in the range of 196.04- 323.65 m/s. These results can explain that the volcanic tuff and other geological units around the crater of Tangkuban Parahu volcano are relatively more compact. The geological unit in this area is thought to have originated from the debris of older volcanic material in The Western Tangkuban Parahu Volcanic Area