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Apr 28, 2026
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May 11, 2026
Published
May 17, 2026
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Abstract

 In Indonesia, the choice between area source and smoothed seismicity approaches has been driven by data availability rather than scientific evaluation, and no systematic comparison of both methods at the national scale has been conducted. This study compared both approaches across Indonesia to evaluate their differences in PGA estimation and assess the forecasting skill of the smoothed seismicity model. Both models were applied to the same declustered earthquake catalog with a Magnitude of Completeness of 4.7, b-value of 0.89, and a-value of 8.753, using identical Ground Motion Prediction Equations within a probabilistic seismic hazard analysis framework. Both models consistently identified North Sulawesi as the highest hazard region and Kalimantan as the lowest. The smoothed seismicity model produced higher maximum PGA values of 2.13 g compared to 1.1597 g and 1.5901 g from the area source model at 10% and 2% probability of exceedance in 50 years, respectively. Molchan Diagram validation yielded an Area Skill Score of 0.88 and R-score of 0.656, confirming strong forecasting skill. The two methods are complementary, and their integration within a logic tree framework is recommended for future national-scale PSHA in Indonesia.

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Probabilistic Seismic Hazard Analysis Peak Ground Acceleration Indonesia

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1.
Surbakti ENB, Ardian Saputra, Rizki Wulandari, Yudha Styawan. Peak Ground Acceleration Mapping of Indonesia Using Complementary Area Source and Smoothed Seismicity Approaches. EKSAKTA [Internet]. 2026 May 17 [cited 2026 Jun. 29];27(03):241-56. Available from: https://eksakta.ppj.unp.ac.id/index.php/eksakta/article/view/684

References

  1. [1] S. Dey Rahmawati. (2025). Spatial Modeling of Earthquake Risk in Sulawesi and Maluku Based on Geological Factors, ESTIMASI: Journal of Statistics and Its Application, vol. 6, no. 2, pp. 2721–379.
  2. [2] N. R. Ananda and D. Pujiastuti. (2024). Studi Bahaya Seismik dengan Metode PSHA (Probabilistic Seismic Hazard Analysis) di Nusa Tenggara Barat Menggunakan Data Gempa Tahun 1900 - 2023, Jurnal Fisika Unand, vol. 13, no. 5, pp. 665–670.
  3. [3] M. M. Gallahue et al. (2022). A study on the effect of site response on California seismic hazard map assessment, Front. Earth Sci. (Lausanne), vol. 10.
  4. [4] R. I. Hielmy and M. L. Rajagukguk. (2026). Analisis Probabilistik Bahaya Seismik Di Denpasar Dan Sekitarnya Berdasarkan Pendekatan Psha, KURVATEK, vol. 11, no. 1, pp. 21–28.
  5. [5] R. Wulandari, C.-H. Chan, J.-C. Gao, and D. H. Natawidjaja. (2024). Probabilistic Seismic Hazard Assessment of Sumatra, Indonesia, Research Square.
  6. [6] A. Daswita, D. Pujiastuti, T. Anggono, F. Bumi, J. Fisika, and F. Matematika dan Ilmu Pengetahuan Alam. (2023). Studi Bahaya Seismik dengan Metode Probabilistic Seismic Hazard Analysis di Sumatera Barat, Jurnal Fisika Unand, vol. 12, no. 3, pp. 445–451.
  7. [7] A. Frankel. (1995). Mapping Seismic Hazard in the Central and Eastern United States, Seismological Research Letters, vol. 66, no. 4, pp. 8–21.
  8. [8] A. Saputra. (2024). Implementasi Metode Smoothing Seismicity Dalam Analisis Distribusi Gempa Bumi Pada Data Seismisitas (1900-2024) Di Wilayah Indonesia, Repository ITERA.
  9. [9] R. Mountainshia, P. Pramono Rahardjo, and D. Damara Aditramulyadi. (2022). Analisis Probabilitas Bahaya Gempa di Ibu Kota Baru Indonesia, USGS Report / Online Open Source.
  10. [10] M. M. Rahman, L. Bai, H. Li, and C. Liu. (2025). Probabilistic Seismic Hazard Map for Bangladesh Including the Smoothed Background Seismicity and Local Site Effects, Pure and Applied Geophysics.
  11. [11] R. Wulandari and Y. Styawan. (2026). Enhancing Seismic Hazard Preparation in Lampung, Sumatra: Improved Magnitude Conversion, Seismicity Smoothing, and Area-Source Modeling, Indonesian Journal on Geoscience, vol. 13, no. 2, pp. 189–209.
  12. [12] C. H. Chan et al. (2020). Probabilistic seismic hazard assessment for Taiwan: TEM PSHA2020, Earthquake Spectra, vol. 36, no. 1_suppl, pp. 137–159.
  13. [13] T. C. Hanks and H. Kanamori. (1979). A moment magnitude scale, Journal of Geophysical Research: Solid Earth, vol. 84, no. B5, pp. 2348–2350.
  14. [14] P. Reasenberg. (1985). Second‐order moment of central California seismicity, 1969–1982, Journal of Geophysical Research: Solid Earth, vol. 90, no. B7, pp. 5479–5495.
  15. [15] R. Hanafi, I. Kusuma Dewi, and N. Ngatijo. (2024). Pemetaan Magnitude Of Completeness (Mc) Untuk Gempa Di Wilayah Bengkulu, JGE (Jurnal Geofisika Eksplorasi), vol. 10, no. 2, pp. 121–138.
  16. [16] M. Irsyam et al. (2020). Development of the 2017 national seismic hazard maps of Indonesia, Earthquake Spectra, vol. 36, no. 1_suppl, pp. 112–136.
  17. [17] R. Lewerissa, R. Rumakey, Y. A. Syakur, and L. Lapono. (2021). Completeness magnitude (Mc) and b-value characteristics as important parameters for future seismic hazard assessment in the West Papua province Indonesia, Arabian Journal of Geosciences, vol. 14, no. 23, p. 2588.
  18. [18] V. A. Ritz, A. P. Rinaldi, and S. Wiemer. (2022). Transient evolution of the relative size distribution of earthquakes as a risk indicator for induced seismicity, Communications Earth & Environment, vol. 3, no. 1, p. 249.
  19. [19] G. M. Geffers, I. G. Main, and M. Naylor. (2023). Accuracy and precision of frequency-size distribution scaling parameters as a function of dynamic range of observations: example of the Gutenberg-Richter law b-value for earthquakes, Geophysical Journal International, vol. 232, no. 3, pp. 2080–2086.
  20. [20] A. Kijko and A. Smit. (2017). Estimation of the frequency-magnitude Gutenberg-Richter B-value without making assumptions on levels of completeness, Seismological Research Letters, vol. 88, no. 2A, pp. 311–318.
  21. [21] M. Taroni and A. Akinci. (2021). A new smoothed seismicity approach to include aftershocks and foreshocks in spatial earthquake forecasting: Application to the global mw ≥ 5.5 seismicity, Applied Sciences, vol. 11, no. 22, p. 10899.
  22. [22] J. K. Lapajne, B. Šket Motnikar, B. Zabukovec, and P. Zupančič. (1997). Spatially smoothed seismicity modelling of seismic hazard in Slovenia, Journal of Seismology, vol. 1, no. 1, pp. 73–85.
  23. [23] G. Molchan and V. Keilis-Borok. (2008). Earthquake Prediction: Probabilistic Aspect, Geophysical Journal International, vol. 173, no. 3, pp. 1012–1017.
  24. [24] J. D. Zechar and T. H. Jordan. (2008). Testing alarm-based earthquake predictions, Geophysical Journal International, vol. 172, no. 2, pp. 715–724.
  25. [25] E. Biondini, F. D’Orazio, B. Lolli, and P. Gasperini. (2025). Pseudo-prospective earthquake forecasting experiment in Italy based on temporal variation of the b-value of the Gutenberg–Richter law, Geophysical Journal International, vol. 240, no. 3, pp. 1755–1772.
  26. [26] C. A. Cornell. (1968). Engineering Seismic Risk Analysis, Bulletin of the Seismological Society of America, vol. 58, no. 5, pp. 1583–1606.
  27. [27] M. P. Moschetti et al. (2024). The 2023 US National Seismic Hazard Model: Ground-motion characterization for the conterminous United States, Earthquake Spectra, vol. 40, no. 2, pp. 1158–1190.
  28. [28] G. Kaviris et al. (2023). A Logic-Tree Approach for Probabilistic Seismic Hazard Assessment in the Administrative Region of Attica (Greece), Applied Sciences, vol. 13, no. 13, p. 7553.
  29. [29] D. M. Boore, J. P. Stewart, E. Seyhan, and G. M. Atkinson. (2014). NGA-West2 equations for predicting PGA, PGV, and 5% damped PSA for shallow crustal earthquakes, Earthquake Spectra, vol. 30, no. 3, pp. 1057–1085.
  30. [30] K. W. Campbell and Y. Bozorgnia. (2014). NGA-West2 ground motion model for the average horizontal components of PGA, PGV, and 5% damped linear acceleration response spectra, Earthquake Spectra, vol. 30, no. 3, pp. 1087–1115.
  31. [31] B. S. J. Chiou and R. R. Youngs. (2014). Update of the Chiou and Youngs NGA model for the average horizontal component of peak ground motion and response spectra, Earthquake Spectra, vol. 30, no. 3, pp. 1117–1153.
  32. [32] Pusat Studi Gempa Nasional (Indonesia). (2017). Peta sumber dan bahaya gempa Indonesia tahun 2017, Pusat Penelitian dan Pengembangan Perumahan dan Permukiman, Kementerian Pekerjaan Umum.
  33. [33] F. Scherbaum and N. M. Kuehn. (2011). Logic tree branch weights and probabilities: Summing up to one is not enough, Earthquake Engineering Research Institute.
  34. [34] GEM Foundation. (2019). The OpenQuake-engine User Manual, Global Earthquake Model (GEM) OpenQuake Manual for Engine version 3.5.0.
  35. [35] A. Khalqillah, M. Umar, A. V. H. Simanjuntak, A. Jihad, and V. H. Banyunegoro. (2025). Seismic Hazard Estimation for Sumatra and Kalimantan Region Using Event-Based Probabilistic Seismic Hazard Analysis (EB-PSHA), Journal of Geoscience, Engineering, Environment, and Technology, vol. 10, no. 3, pp. 329–337.
  36. [36] A. ur Rahman, F. A. Najam, S. Zaman, A. Rasheed, and I. A. Rana. (2021). An updated probabilistic seismic hazard assessment (PSHA) for Pakistan, Bulletin of Earthquake Engineering, vol. 19, no. 4, pp. 1625–1662.
  37. [37] L. Danciu et al. (2024). The 2020 European Seismic Hazard Model: overview and results, Natural Hazards and Earth System Sciences, vol. 24, no. 9, pp. 3049–3073.
  38. [38] G. Woo. (1996). Kernel Estimation Methods for Seismic Hazard Area Source Modeling, Bulletin of the Seismological Society of America, vol. 86, no. 2, pp. 353–362.
  39. [39] M. D. Petersen et al. (2024). The 2023 US 50-State National Seismic Hazard Model: Overview and implications, Earthquake Spectra, vol. 40, no. 1, pp. 5–88.