Microzonation of Probolinggo Fault Using Microtremor as an Effort for Earthquake Disaster Mitigation

Earthquake can be caused by several things, one of which is due to an active fault. To mitigate earthquake disasters that can be caused by the Probolinggo Fault, measurement of the microtremor geophysical method is carried out to analyze seismic vulnerability. In this study, the microtremor measurements were carried out on 30 measurement points. The data obtained from measurements are then processed using EasyHVSR software to obtain natural frequency (f0) and natural amplification (A0) values. This value is then used to create a microtremor microzonation map, which is seismic vulnerability index, based on natural frequency and amplification . it founded that low natural frequency mostly founded on eastern of measurement area, caused by thick sedimentary from Lamongan volcanic. High amplification mostly founded from middle to western area, and high seismic vulnerability index founded on western of measurement area, include Maron and Krucil Sub-district. It means seismic wave can very destructive on those area.