TEMPLATE MATCHING COMBINATION, AKAIKE INFOSYS CRITERION (AIC), AND GLOBAL OPTIMIZATION FOR DETERMINING THE DISTRIBUTION OF MICRO SEISMICITY GEOTHERMAL FIELD D

• Main Author: Safa'atul Nur Muhammad, Maulana
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/77620
• Institution: Institut Teknologi Bandung

Geothermal fields naturally occur as a result of a magma chamber that heats fluids that lie below the earth's surface and are related to the surrounding geological and tectonic structures. When there is a production activity, there are microearthquakes caused by changes in the balance of rocks below the surface. This research was conducted to determine the location of the earthquake source. The earthquake that occurred over a span of seven months, from 1 June 2021 – 31 December 2021, had a high intensity and this earthquake had a duration of less than three seconds. For large volumes of data, alternative data processing modes are needed that are more efficient compared to classical methods. Detection and localization of microearthquakes will be easier and more efficient if done automatically. Automatic detection can be done using Template Matching. Meanwhile, determining the onset of microearthquakes can be done using the Akaike Information Criterion (AIC). After that, the location of the microearthquake source is determined through a global optimization approach using Non-Linear Location (Nonlinloc). It is evident from the results of the Wadati Diagram for wave pick onset quality control (Vp/Vs = 1.7463) showing that the implementation of using Template Matching and Akaike Information Criterion (AIC) provides fairly accurate results in carrying out onset picking. Obtained 148 microearthquakes using Template Matching and AIC provided fairly accurate onset picking results. The seismicity distribution map shows that the presence of a hypocenter is correlated with the presence of a fault and is at a depth of 1000 – 3500 meters.