Earthquake vulnerability mapping based on probabilistic seismic hazard analysis (PSHA) in the Nias Islands, Indonesia

Astri Angraeni, Lailatul Husna Lubis, Ratni Sirait, Reinhard Sipayung

Abstract


The Nias Islands are categorised as seismically active, making them susceptible to earthquakes. The Nias Islands region is situated on the ring of fire and a subduction line that experiences annual movement, which is the primary factor contributing to its susceptibility to earthquakes. The occurrence of earthquakes in the Nias Islands is supported by a documented record of 7,152 incidents with a magnitude strength more than 4 Mw from 1910 to 2022, indicating a 500-year return period. In order to assess the susceptibility of the Nias Islands region to earthquakes, a process called earthquake vulnerability mapping is conducted. This involves utilising the probabilistic seismic hazard analysis (PSHA) approach to calculate the peak ground acceleration value.  The investigation commences with gathering seismic events within the study region from the IRIS and BMKG catalogues. The earthquake data was subsequently transformed from magnitude to Mw (magnitude moment), and then de-clustered to isolate the primary event from the entire dataset of earthquakes. First, the a-value and b-value are calculated in order to identify the background earthquake source. Then, PSHA processing is conducted to calculate the spectral acceleration value for each predefined grid. The processing findings indicate that the peak ground acceleration (PGA) value at time 0 s ranges from 0.05 – 1.2 g, the PGA value at time 0.2 s ranges from 1 – 1.2 g, and the PGA value at time 1 s ranges from 0.4 – 0.5 g.

Keywords


Earthquake; Nias Islands; PGA; PSHA

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References


1. Khoiridah, S., Ibad, M. I. & Setyonegoro, W. (2017). Validasi Potensi Tsunami Berdasarkan Estimasi Durasi Patahan dan Pemodelan Tsunami di Wilayah Barat Sumatra (Studi Kasus: Gempa Bumi Nias 2005 dan Mentawai 2010). OLDI (Oseanologi dan Limnologi di Indonesia), 2(1), 39–54.

2. Irsyam, M., Wayan, S., Fahmi, A., Sri, W., Wahyu, T., Danny, H. N. et al. (2010). Ringkasan hasil studi tim revisi peta gempa Indonesia 2010. Bandung.

3. Zebua, A. W. (2018). Analisis gaya gempa bangunan rumah tinggal di wilayah gempa tinggi. Siklus: Jurnal Teknik Sipil, 4(1), 23–35.

4. Badan Geologi. (2023). Diakses pada tanggal 17 Maret 2023, https://geologi.esdm.go.id/id/.

5. Natawidjaja, D. H. (2007). Gempabumi dan tsunami di Sumatra dan upaya untuk mengembangkan lingkungan hidup yang aman dari bencana alam. Laporan KHL, LIPI, Jakarta.

6. Kurniawan, R. (2017). Pemetaan ground acceleration menggunakan metode probabilistic seismic hazard analysis di propinsi Nusa Tenggara Barat pada zona megathrust. Proceeding Seminar Nasional Teknologi Informasi dan Kedirgantaraan (SENATIK), 3, 132–137.

7. Irwansyah, E. & Winarko, E. (2015). Zonasi daerah bahaya kegempaan dengan pendekatan peak ground acceleration (PGA). Seminar Nasional Informatika (SEMNASIF), 1(5).

8. Baker, J. W. (2013). An introduction to probabilistic seismic hazard analysis. White Paper Version, 2(1), 79.

9. Pasau, G. & Tanauma, A. (2011). Pemodelan sumber gempa di wilayah Sulawesi Utara sebagai upaya mitigasi bencana gempa bumi. Jurnal Ilmiah Sains, 202–209.

10. Wiemer, S. (2001). A software package to analyze seismicity: ZMAP. Seismological Research Letters, 72(3), 373–382.

11. Aki, K. (1965). Maximum likelihood estimate of b in the formula log N= a-bM and its confidence limits. Bulletin of the Earthquake Research Institute, Tokyo University, 43, 237–239.

12. IRIS Earthquake Browser. (2023). Diakses pada tanggal 17 Maret 2023, http://ds.iris.edu/ieb/.

13. Irsyam, M., Sri, W., Danny, H. N., Irwan, M., Ariska, R. et al. (2017). Peta sumber dan bahaya gempa Indonesia tahun 2017. Bandung: Kementerian Pekerjaan Umum dan Perumahan Rakyat.




DOI: http://dx.doi.org/10.31258/jkfi.21.2.%25p

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