SEISMICITY ANALYSIS IN UNDERGROUND MINES USING DOUBLE DIFFERENCE METHOD FOR HYPOSENTER RELOCATION

• Main Author: Gustama Pasya, Ariq
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/57937
• Institution: Institut Teknologi Bandung

Earthquakes can be categorized based on their cause. One of the causes of earthquakes is the presence of induced seismicity due to human activities. An example of an earthquake due to induced seismicity is an earthquake in mining. The study of seismicity in mining can be used to determine the characteristics of earthquakes in underground mines. In analyzing seismicity in underground mines, manual picking, analysis of the dominant frequency of earthquake events in underground mines were carried out. It was found that the magnitude affects the dominant frequency of the waveform. The larger the magnitude, the smaller the dominant frequency contained in the waveform. The dominant frequency obtained also varies from 30-150 Hz. The results of the picking test also show that picking and the velocity model used are factors that influence the results of determining the location. In determining the location, the hypocenter coordinate data processing was carried out using a non-linear location. After that, the velocity model was also updated using the Joint Hypocenter Determination method to get better results for the hypocenter location. The velocity model resulting from the Joint Hypocenter Determination is used as input for relocation using the Double Difference method. The results of the relocation of the hypocenter using the Double Difference method with a 1D velocity model provide the best alternative in determining the earthquake hypocenter in underground mines. This is proofed by the difference between the XYZ distance and the location in the 2000 event earthquake catalog at the “UC” mining field on October 30????? 2019 - November 2???????? 2019 with 49.56 meter and the smallest Root Mean Squared (RMS) compared to the Nonlinloc and Joint Hypocenter Determination methods with value of 0.001699.