Seismic vulnerability distribution of the earthquake prone area in Central Aceh

Abstract

Abstract Central Aceh is known as an earthquake-prone area due to the presence of the Sumatra Fault and secondary fault crossing the area resulting the M 6.1 earthquake in 2013. The objective of the research is to investigate seismic vulnerability of Central Aceh. Microtremor observations were conducted at 25 locations in Central Aceh analysed using the Horizontal to Vertical Spectral Ratio (HVSR). Seismic amplification is represented by the maximum values of H/V. The dominant frequency f0 representing the sediment thickness was obtained when the H/V curve is maximum. The frequency values ranged from 14.9 to 25.9 Hz, and the seismic vulnerability values varied from 0.02 to 3.1. The top soil consists of thin layers of sedimentary material dominated by tertiary rocks. The rocks are classified as Type IV and Class I based on the dominant frequency values. This result is consistent with the geology, consisting of sedimentary and volcanic rocks. Areas with a seismic vulnerability value > 1.0 is considered to have a high risk of earthquake damage because they are likely to experience earthquake amplification. Areas with seismic vulnerability value > 1.0 are found in West Aceh and the Geureudong volcano area.