Identification of Peak Ground Acceleration and hazard potency of earthquake disaster on the mainland surface of Wangi-Wangi Island, Wakatobi Regency, Southeast Sulawesi, Indonesia

Abstract

This study combines microtremor data processed using the Horizontal to Vertical Spectral Ratio (HVSR) method and earthquake data. Microtremor data were obtained by filtering the waveform of ground vibration data obtained through measurements on the mainland surface of Wangi-Wangi Island in the frequency range of 0.5 to 25 Hz using a Band Pass Filter. The ground vibration data were obtained by recording signals at 47 different measurement points in a time range of 29.25 to 48.16 minutes. While the earthquake data used are sourced from 1920 to 2020. The earthquake data processed are those that meet the requirements for moment magnitude (M w) ≥ 5.0 SR and epicenter depth (h) ≤ 45 km. The results of calculations using the Kanai’s formula show that the PGA values are in the range of 0.0463 to 0.3665g. If zoning mapping is carried out, then the hazard potency of disaster due to earthquakes based on the PGA values on the Wangi-Wangi Island area is mostly Low potential (PGA < 0.26g), only a few areas have Medium potential (0.26g ≤ PGA ≤ 0.70g), and there are no areas with High potential for earthquake threat (PGA > 0.70g).