Analysis Of Seismic Quiescence Precursors Before The M7.4 Earthquake Of 28 September 2018 In Central Sulawesi Based On Seismotectonic Spatial Distribution And Earthquake Fracture Lengths
Penulis
Zurahma zu , Syafriani , Letmi Dwiridal , Zulhendra ZulhendraDiterbitkan:
2024-11-06Versi:
- 2024-11-06 (2)
- 2024-11-06 (1)
Terbitan:
Vol 6 No 1 (2025): In PressArticles
Abstrak
The Central Sulawesi earthquake with coordinates 2°30‘S -1°50’ N and 119°0'-124°20 E magnitude 7.4 in Palu, Donggala Regency on 28 September 2018. This earthquake was a significant and destructive earthquake in Central Sulawesi. A significant earthquake is preceded by a seismic quiescence. The aim of the study was to determine when the seismic quiescence occurred and seismic activity after the earthquake alongside fracture length. The method of analysis of seismic quiescence and fracture length is z-value and Wells and Coppersmith equation. Data processed with MATLAB and Zmap were 1478 events from 1983-2023. The study area is divided into several grids with sizes of 0.1°* 0.1°. The number of earthquakes included (N = 800, 700, 600, 500, 400, 300, and 200). The z-value was calculated for each grid based on the earthquake data organized in one grid and seismic activity after earthquake. The results of the analysis of the z-value calculation in each grid show of seismic quiescence before a significant earthquake. Based on the results of the spatial distribution of z-value in Central Sulawesi, the seismic quiescence preceded the 28 September 2018 earthquake event (M 7.4) by about 21 years beginning in 1990. When cut at 2019.6, there was a decrease in seismic activity again, which indicated that an earthquake would occur, so it was thought to be a trigger factor for future earthquake precursors. While the fracture length of the 7.4 Mw earthquake of 104,232 meters shows a positive correlation between magnitude and fracture length.Referensi
Gumawan. I and Subarjo, "Pengantar Seismologi," 2005.
Cipta. A and Robiana, "A Probalistic Seismic Hazard Assesment for Sulawesi,Indonesa," Earth Science for Disaster Risk Reduction Geological Society, 2016.
PuSGeN, "Peta Sumber dan Bahaya Gempa Indonesia Tahun 2017," 2017.
Bellier. O, Sebrier. M and Beaudouinet, "High Slip Rate for A Low Seismicity Along the Palu-Koro Active Fault in Central Sulawesi (Indonesia)," Blackwell Science, vol. 13, no. 6, pp. 463-470, 2001.
Simangunsong. A, Priadi. R, Dwilyantari. A and Marsono. A, "Determination of Temporal Value of a-value and b-value to Identify the Level Brittle of Rock and Seismic Activity in the Palu Region," Journal of Physics : Theories and Applications, vol. 3, no. 1, pp. 1-8, 2019.
Papadimitriou. P, "Identification of Seismic Precursors Before Large Earthquakes: Decelerating and Accelerating Seismic Patterns," Journal of Geophysical Research, vol. 113, 2008.
Syafriani and Yulkifli, "Correlation of Seismotectonic Parameter and Seismic Quiescence Z-value in West Sumatra Idonesia," Journal of Physics, pp. 1-7, 2018.
Huang. Q, Oncel. A and Sobolev. G, "Precursory Seismicity Changes Associated with the Mw=7.4 1999 August Izmit (Turkey) Earthquake," Geophysics Journal International, vol. 151, pp. 235-242, 2002.
Katsumata. K, "Precursory Seismic Quiescence Before The Mw=8.3 Tokachi-Oki,Japan,Earthquake on 26 September 2003 Revealed by A Re-Examined Earthquake Catalog," Journal of Geophysical Research, vol. 116, 2011.
Main. I, Meredith. P and Jones. P, "A Reinterpretation of The Precursory Seismic b-value Anomaly From Fracture Mechanics," Geophysical Journal, pp. 131-138, 1989.
Richter, "Bulletin of te Seismological Society," vol. 32, no. 3, pp. 163-191, 1942.
Wyss. M and Sobolev. C, "Seismic Quiescence Precursors to two M7 Earthquakes on Sakhalin Island,Measured by two Methods," Earth Planet Space, vol. 56, pp. 725-740, 2004.
Puangjaktha and Pailoplee. P, "Evolution of Precursory Seismic Quiescence of the Mw 6.8 Nam Ma Earthquake,Thailand-Myanmar Borders," Bulletin of Earth Sciences of Thailand, vol. 7, no. 1, pp. 1-15.
Diansari and Subakti, "Analysis of Rupture Area of Aftershocks Caused by Twin Earthquake (Case Study:11 April 2012 Earthquakes of Aceh-North Sumatra)," AIP Confrence Proceedings, pp. 1-8, 2015.
Wells and Coppersmith, "New Empirical Relatinships Among Magnitudo,Rupture Length,Riupture Width,Rupture Area,and Surface Displacement," Bulletin of the Seismological Society of Amerika, vol. 84, pp. 974-1002.
Wiener, "A Software Package to Analyze Seismicity : ZMAP," Seismological Research Letters, vol. 72, no. 2, pp. 373-382, 2001.
Wiemer and Wyss, "ZMAP A Tools For Analyses of Seismicity Patterns," Typical Application and Uses : A Cookbook, 2001.
Ozturk. S and Bayrak, "Spatial variations of precursory seismic quiescence observed in recent years in the eastern part of Turkey," Acta Geophys, vol. 60, pp. 92-118, 2012.
Sirait. R, "Estimasi Waktu Ulang dan Dimensi Patahan Penyebab Gempabumi Padang,Sumatera Barat 6 April 2010," Jurnal Hasil Penelitian Bidang Fisika, pp. 53-37, 2020.
Woessner. J, Werner. M, Meier. M and Wiemer. S, "The Importance of Small Aftershocks for Earthquake Trigerring," Researchgate Net Publication, 2011.
Syaputri. R, "Analisis Prekursor Seismic Quiescence Sebelum Gempabumi M = 7.6 SR 30 September 2009 Padang Berdasarkan Distribusi Spasial Seismotektonik," Skripsi, 2021.
Polcari. M., et al, "SAR and Optical Data Comparison for Detecting Co-Seismic and Induced Phenomena during the 2018 Mw 7.5 Sulawesi Earthquake," Sensors, pp. 1-16, 2019.
