Analysis of peak ground acceleration based on microtremor data in Rejang Lebong, Bengkulu

Abstract

Rejang Lebong is a regency in the province of Bengkulu, located in the Bukit Barisan mountainous region. The area is dominated by fault earthquakes due to its proximity to the Musi and Ketaun faults. This article presents the results of a study on earthquake hazard analysis through microtremor measurement using the HVSR method to determine the value of Peak Ground Acceleration (PGA). Measurements were taken at 10 points for 60 minutes with a 2 km interval. The HVSR method was used to obtain the dominant period value. The determination of PGA value was based on historical fault earthquakes in RejangLebong in 1943 with a magnitude of Mw 7.4. The largest PGA value obtained was 627.34 gal, which was in the western part of the study area. This is significantly correlated with the earthquake hazard in 1943, which caused the highest damage in the Tes village located in the western part of the study area. This research is useful for pre-disaster earthquake mitigation plans through risk management to reduce the impact of earthquake hazards.