Electronic Theses and Dissertation

Penelitian ini bertujuan memodelkan dan menganalisis tingkat bahaya gempa bumi di wilayah Aceh Tenggara dan sekitarnya menggunakan pendekatan Probabilistic Seismic Hazard Analysis (PSHA) dengan perangkat lunak OpenQuake Engine. Parameter seismisitas dihitung menggunakan katalog gempa USGS periode 1960–2025 yang telah di-declustering dengan metode Gardner-Knopoff, menghasilkan nilai a-value sebesar 5,98, b-value sebesar 1,14, dan Magnitude of Completeness (Mc) sebesar 4,8. Pada penelitian ini digunakan tiga sumber gempa, yaitu zona subduksi, sesar sumatra dan sumber background berupa area source. Logic tree GMPE disusun dari kombinasi Boore-Atkinson (2008), Campbell-Bozorgnia (2008), dan Chiou-Youngs (2008) untuk sumber kerak dangkal, serta Youngs dkk. (1997) dan Zhao dkk. (2006) untuk sumber subduksi, dengan Vs30 = 760 m/s. Untuk probabilitas terlampaui (PoE) 2% dalam 50 tahun (periode ulang 2475 tahun), nilai PGA berkisar 0,77–1,32 g, sedangkan nilai Spectral Acceleration (SA) berkisar 1,89–2,59 g untuk periode 0,2 s dan 0,68–1,14 g untuk periode 1,0 s. Berdasarkan skala USGS ShakeMap (Worden dkk., 2012), nilai tersebut termasuk kategori guncangan violent (MMI IX) dengan potensi kerusakan berat pada bangunan. Hasil penelitian ini diharapkan dapat menjadi informasi dasar dalam upaya mitigasi bencana, penyusunan tata ruang, serta perencanaan infrastruktur tahan gempa di wilayah Aceh Tenggara dan sekitarnya.

This study aims to model and analyze the level of earthquake hazard in Southeast Aceh and its surrounding areas using the Probabilistic Seismic Hazard Analysis (PSHA) approach with OpenQuake Engine software. Seismicity parameters are calculated using the USGS earthquake catalog for the period 1960–2025 which has been declustered using the Gardner-Knopoff method, resulting in an a-value of 5.98, a b-value of 1.14, and a Magnitude of Completeness (Mc) of 4.8. In this study, three earthquake sources were used, namely the subduction zone, the Sumatran fault, and a background source in the form of an area source. The GMPE logic tree is compiled from a combination of Boore-Atkinson (2008), Campbell-Bozorgnia (2008), and Chiou-Youngs (2008) for shallow crustal sources, and Youngs et al. (1997) and Zhao et al. (2006) for subduction sources, with Vs30 = 760 m/s. For a 2% probability of exceedance (PoE) in 50 years (return period of 2475 years), the PGA value ranges from 0.77–1.32 g, while the Spectral Acceleration (SA) value ranges from 1.89–2.59 g for a period of 0.2 s and 0.68–1.14 g for a period of 1.0 s. Based on the USGS ShakeMap scale (Worden et al., 2012), these values are categorized as violent shocks (MMI IX) with the potential for severe damage to buildings. The results of this study are expected to provide basic information for disaster mitigation efforts, spatial planning, and earthquake-resistant infrastructure planning in Southeast Aceh and its surroundings.