Liquefaction Potential Analysis Using The Horizontal to Vertical Spectral Ratio (HVSR) Method in The Arang Beach Area of Labuhan Ijuk Village, Moyo Hilir District, Sumbawa Regency

Abstract

The phenomenon of liquefaction has become a serious threat in earthquake-orone areas, especially in the Arang Beach Area, Moyo Hilir District, which is dominated by alluvial sediments and located near an active subduction zone. This study was conducted to identify the potential for liquefaction through seismic parameter analysis using the Horizontal to Vertical Spectral Ratio (HVSR) method. A total of 70 microtremor measurement points were processed using Geopsy and Dinver software to obtain the natural frequency, amplification factor, shear wave velocity, seismic vulnerability index, Vp⁄Vs ratio, and Poisson's ratio (σ). The study results show f₀ values ranging from 0.274–17.644 Hz, a maximum A₀ of 0.800, low (< 300 m/s) in the northern coastal area, the highest of 227.729 in the northern coast, and a Vp⁄Vs ratio > 2.0 in water-saturated sediment layers indicating high vulnerability to liquefaction. Meanwhile, the northern and western parts of the area. However, what needs to be considered is the need to increase disaster mitigation through structural and non-structural efforts in the Arang Beach area.