Pemetaan Mikrozonasi dan Indeks Kerentanan Seismik Berbasis Data Mikrotremor di Daerah Pondidaha, Kabupaten Konawe, Sulawesi Tenggara

Laode Ihksan Juarzan Ihksan; La Hamimu; Indrawati Indrawati; Sitti Harming

doi:10.56099/ophi.v8i1.p76-85

Authors

Laode Ihksan Juarzan Ihksan Program Studi Teknik Geofisika, Universitas Halu Oleo, Kendari, Indonesia
La Hamimu Program Studi Teknik Geofisika, Universitas Halu Oleo, Kendari, Indonesia https://orcid.org/0000-0003-3276-1923
Indrawati Indrawati Program Studi Teknik Geofisika, Universitas Halu Oleo, Kendari, Indonesia
Sitti Harming Program Studi Teknik Geofisika, Universitas Halu Oleo, Kendari, Indonesia

DOI:

https://doi.org/10.56099/ophi.v8i1.p76-85

Keywords:

mikrotremor, frekuensi dominan, faktor amplifikasi, indeks kerentanan seismik

Abstract

Indonesia is characterized by high seismicity due to active tectonic plate interactions; therefore, local-scale seismic microzonation studies are essential for earthquake risk mitigation. Pondidaha District, Konawe Regency, was selected as the study area following an earthquake that occurred on February 2, 2024, approximately 2.5 km southeast of the district. This study aims to determine the dominant frequency (f₀), amplification factor (A₀), and seismic vulnerability index (Kg) using microtremor data. Measurements were conducted at 24 observation points using an MBB2 (Mini BroadBand) seismometer with a sampling frequency of 50 Hz. The data were analyzed using the Horizontal to Vertical Spectral Ratio (HVSR) method implemented in Geopsy version 3.4.2. The results show that the f₀ values range from 0.890 to 5.382 Hz, A₀ values from 0.994 to 3.634, and Kg values from 0.196 to 6.983 s²/cm. Low-vulnerability zones with Kg values of 0.196–1.778 s²/cm are distributed in Pondidaha, Amesiu, Wawolemo, Wawolahumbuti, Tirawuta, and Lahonggumbi villages, indicating relatively compact and stable subsurface conditions. Moderate vulnerability zones occur in Pondidaha and Amesiu villages with Kg values of 4.706–5.641 s²/cm, while the high-vulnerability zone is identified at point PD13 in Amesiu Village with a Kg value of 6.983 s²/cm, suggesting the presence of soft sediments and stronger seismic wave amplification potential. These findings provide a basis for seismic microzonation, spatial planning, and earthquake-resistant infrastructure development in Pondidaha District.

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