AUTOMATIC DETECTION AND LOCALIZATION OF SEISMIC EVENTS IN X GEOTHERMAL FIELDS

• Main Author: Kevin Chrysant J, Fredericus
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/68872
• Institution: Institut Teknologi Bandung

One of the jobs in microseismic is to determine the location, which previously requires the arrival time of P and S waves at each earthquake event at each station. A large amount of data in exploration and microseismic monitoring activities have the potential to cause long processing times, due to long duration of the acquisition of microseismic data. Usually, seismometers are installed according to the acquisition design surrounding the prospect area in a geothermal field. In this study, the Template Matched Filter (TMF) method was used to look for events. Then the arrival times of P waves was estimated by the Akaike Information Criteria (AIC). Finally, Differential Evolution (DE) was employed to estimate the location of microseismic events. Based on the steps of the TMF method, 270 pieces of seismogram were found which were suspected to have microseismic events. Furthermore, from these pieces, the P wave onset pick was carried out using the AIC method. The estimation of the location using the DE method and plot using GMT to produce 106 local microseismic events. At the estimation stage, a homogeneous P wave velocity of 5 km/s was used. Comparison with manual data processing shows that the automatic data processing revealed more microseismic events indicating the effectiveness of the automatic method. The resulting event location proved to be more accurate and described the most active fault in this geothermal field, namely the Rancabali Fault