Preliminary Study Hydrothermal Activity Using Microseismic Portable in the Geothermal Potential Area, Case Study: Mt. Lamongan, East Java Indonesia

Abstract

Microseismic a passive seismic method in the geophysics exploration. An application of the method to identify the hydrothermal dynamics in the subsurface. Hydrothermal is a oscillating fluid in the pore spaces of rock caused by volcanic activity. The hydrothermal movement in the subsurface correlated with geothermal potential area. Hydrothermal dynamics have low frequency between 1 to 6 Hz. Preliminary study about intensity of seismicity very important to design of microseismic acquisition with using more sensitive geophone to ground motion detection caused by hydrothermal activity. This preliminary study was conducted using a portable microseismic have range frequency between 4.5 Hz until 120 Hz. This research has been conducted on the geothermal potential area of Mount Lamongan, East Java, Indonesia. Five stations were installed with multiplet acquisition for 5 days in the around of Mt. Lamongan to delineate the active seismic zone. Active seismic zone for acquisition design of microseismic with broadband to record local event from hydrothermal dynamics. Microseismic data processing to determine frequency of local events using EEMD method. Noise comes from nature source such as vibration of the local meteorological conditions, urban, ocean waves, and other events that could lead to oscillation. Recapitulation of the frequency of local events used to delineate seismically active area for microseismic data acquisition design using broadband sensors.