HYPOCENTER RELOCATION AND 1-D P AND S WAVE VELOCITY STRUCTURES ESTIMATION BELOW THE SURFACE OF GEDE VOLCANO, DECEMBER 2017

• Main Author: Reny
• Format: Theses
• Language: Indonesia
• Subjects: Fisika
• Online Access: https://digilib.itb.ac.id/gdl/view/38211
• Institution: Institut Teknologi Bandung

Most regions of Indonesia have active volcanoes. The condition of Indonesia which is surrounded by active volcanoes brings two impacts, namely positive impacts and negative impacts. The positive impact is providing fertile land around the volcanic area so that many residents live around the volcanic area. The negative impact of Indonesia is a country prone to natural disasters, especially natural volcanic eruptions. One of the active volcanoes in Indonesia is Mt. Gede and includes active type A volcanoes. An increase in the implementation of natural disaster mitigation is needed to avoid all forms of harm and unwanted losses. Information on the accuracy of earthquake parameters is one of the important things in natural disaster mitigation efforts. One way to improve the accuracy and accuracy of earthquake parameter information is by relocating hypocenter earthquakes. The method that can be used to relocate hypocenter earthquakes is more accurate, using the Coupled Velocity-Hypocenter method. Based on the results of data processed using GAD and VELEST 3.3 software, an epicenter was seen spreading around Mt. Gede and Mt. Pangrango. The hypocenter depth of a volcanic earthquake at Mt. Gede uses GAD, which is -2.5 – 4.0 km. Then hypocenter relocation was carried out using VELEST 3.3 software, the hypocenter depth of the earthquake ranged from 1.5-9.7 km. The seismic movement looks to the surface and is held by an impermeable layer which is predicted to be the hydrothermal clay produced from alteration rocks and this movement is centered northeast. The volcanic earthquake magnitude that occurred in December 2017 is worth the range from -2.9 to -0.6.