Hypocenter Relocation Using Fast Marching Method (FMM) in Tarutung

Abstract:

Tarutung is a geothermal potential region and has relatively high seismicity due to the Sumatra fault system and young arc volcanism. There were many recorded significant earthquakes occurred in Tarutung. The seismic activity proves that a good understanding of the Tarutung tectonics is necessary. This research aims to study the tectonic setting and seismic activity of Tarutung area. In this study, we used Fast Marching Method (FMM) to relocate hypocenters using the arrival time of P-wave data. This data from temporary seismic station network deployed around Tarutung and Sarulla. The seismic station network consists of 42 short-period stations that deployed in May 2011 and continued to record 10 months of seismic activity. The relocation process used global velocity model of AK135, modified AK135, and local velocity model. The results show differences in terms of hypocenter relocated using each model. By analyzing the relocated hypocenters, each result can be used to represent the crustal seismic activity and tectonic settings of this region. The Sarulla region is on the Toru fault with a vertical linear distribution of earthquakes with a dip of 90⁰. The distribution of earthquakes is more spread out in the Tarutung area, which is a graben area. This is the result of the third velocity model with a residual travel time is 934.07 milliseconds.

• Periodical: Construction Technologies and Architecture (Volume 11)
• Pages: 47-53
• DOI: https://doi.org/10.4028/p-58rWfh
• Online since: February 2024
• Authors: Zaenal Abidin Al Atas*, Umar Muksin, Muzli Muzli, Vrieslend Haris Banyunegoro
• Keywords: Fast Marching Method, Hypocenter Relocation, Tarutung, Velocity Model

References

[1] O. Bellier and M. Sebrier, "Relationship between tectonism and volcanism along the Great Sumatran Fault Zone deduced by SPOT image analyses," Tectonophysics, vol. 233, no. 1994, p.215–231, 1994.

DOI: 10.1016/0040-1951(94)90242-9

[2] D. H. Natawidjaja, "Major Bifurcations, Slip Rates, and A Creeping Segment of Sumatran Fault Zone in Tarutung-Sarulla-Sipirok-Padangsidempuan, Central Sumatra, Indonesia," Indonesian Journal on Geoscience, vol. 5, no. 2, p.137–160, 2018.

DOI: 10.17014/IJOG.5.2.137-160

[3] M. Nukman and M. P. Hochstein, "The Sipoholon Geothermal Field and adjacent geothermal systems along the North-Central Sumatra Fault Belt, Indonesia: Reviews on geochemistry, tectonics, and natural heat loss," J Asian Earth Sci, vol. 170. Elsevier Ltd, p.316–328, Feb. 01, 2019.

DOI: 10.1016/j.jseaes.2018.11.007

[4] PGT BMKG, Katalog Gempabumi Signifikan dan Merusak Tahun 1821-2018., BMKG, Jakarta 2019.

[5] U. Muksin, C. Haberland, M. Nukman, K. Bauer, and M. Weber, "Detailed fault structure of the Tarutung Pull-Apart Basin in Sumatra, Indonesia, derived from local earthquake data," J Asian Earth Sci, vol. 96, p.123–131, Sep. 2014.

DOI: 10.1016/j.jseaes.2014.09.009

[6] E. P. Sari, R. Idha, H. Nugroho, S. Humaidi, A. V. H. Simanjuntak, and U. Muksin, "Model Mekanisme Patahan Gempa Bumi Tarutung 2022 Mw 5.8," Jurnal Penerapan Sistem Informasi (Komputer & Manajemen), vol. 4, no. 2, p.478–486, 2023.

DOI: 10.30871/jagi.v7i1.5662

[7] R. Idha, E. P. Sari, S. Humaidi, A. V H Simanjuntak, and U. Muksin, "Model Kecepatan Seismik 1-Dimensi Pada Wilayah Gempa Bumi Tarutung 2022 Mw 5.8," Jurnal Penerapan Sistem Informasi (Komputer & Manajemen), vol. 4, no. 2, p.469–477, 2023.

DOI: 10.30871/jagi.v7i1.5662

[8] U. Muksin, K. Bauer, and C. Haberland, "Seismic Vp and Vp_Vs structure of the geothermal area around Tarutung (North Sumatra, Indonesia) derived from local earthquake tomography," Journal of Volcanology and Geothermal Research, vol. 260, p.27–42, 2013.

DOI: 10.1016/j.jvolgeores.2013.04.012

[9] T. Ryberg, U. Muksin, and K. Bauer, "Ambient seismic noise tomography reveals a hidden caldera and its relation to the Tarutung pull-apart basin at the Sumatran Fault Zone, Indonesia," Journal of Volcanology and Geothermal Research, vol. 321, p.73–84, Jul. 2016.

DOI: 10.1016/j.jvolgeores.2016.04.035

[10] N. Rawlinson and M. Sambridge, "The fast marching method: an effective tool for tomographic imaging and tracking multiple phases in complex layered media," Exploration Geophysics, vol. 36, p.341–350, 2005.

DOI: 10.1071/eg05341

[11] U. Muksin et al., "AcehSeis project provides insights into the detailed seismicity distribution and relation to fault structures in Central Aceh, Northern Sumatra," J Asian Earth Sci, vol. 171, no. June 2018, p.20–27, 2019.

DOI: 10.1016/j.jseaes.2018.11.002

[12] Pusgen PUPR, Peta Sumber dan Bahaya Gempa Indonesia Tahun 2017., PUPR, Jakarta 2017.