First Results of a Bathymetric Survey of Palu Bay, Central Sulawesi, Indonesia following the Tsunamigenic Earthquake of 28 September 2018
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On 28 September 2018, a 7.7 Mw strike-slip earthquake struck Central Sulawesi at 0.18°S, 119.85°E, ~ 10 km northwest of Palu, the capital of Central Sulawesi Province, affecting more than 230,000 people. The rapid arrival of the wave suggests a tsunami source within Palu Bay. A bathymetric campaign was conducted in Palu Bay and the region south of Cape Manimbaya from 9 to 18 October 2018. One of the goals was to identify a potential source for the tsunami. The bathymetry data show a prominent submarine channel within Palu Bay with sinuosity controlled by the Palu-Koro Fault. The submarine channel continues into deeper water south and west of Cape Manimbaya with a sinuosity index of up to 1.770. Several submarine slumps were identified within the bay, due to the arcuate head scarp, the abrupt change in slope and debris on the seafloor, or the undulating shape of the slope. One possible source location near the mouth of Palu Bay is identified from the estimated volume of displaced sediment. The bathymetry data also show traces of the Palu-Koro Fault and suggestions of uplift of Cape Manimbaya related to activity of the Palu-Koro Fault.
KeywordsBathymetry earthquake tsunami Palu Central Sulawesi
The authors would like to acknowledge the support of the Institut Teknologi Bandung Alumni Association (IAITB), the Coordinating Ministry for Maritime Affairs (CMMA), Agency for the Assessment and Application of Technology (BPPT), and other institutions as well as the generous individuals who made the Operasi Bakti Teknologi (OBT) Sulawesi Tengah campaign possible. The authors express gratitude to two anonymous reviewers and Editor-in-Chief Alexander Rabinovich, D.Sc., for their valuable comments and suggestions that enriched the manuscript. We express thanks to Karla McGrath for proofreading this manuscript.
- Abdulah, (2017). Tsunami di Teluk Palu dan Sesar Palu-Koro. Palu: Tadulako.Google Scholar
- Baeda, A. Y. (2011). Seismic and tsunami hazard potential in Sulawesi Island, Indonesia. Journal of International Development and Cooperation, 17(1), 17–30.Google Scholar
- BMKG. (2018). Katalog gempabumi signifikan dan merusak 1821–2017, Jakarta: Pusat Gempabumi dan Tsunami BMKG. https://cdn.bmkg.go.id/Web/Gempa-Signifikan-dan-Merusak-Per-Tahun-1821-2017.pdf. Accessed 29 Jan 2019.
- BPS Kota Palu. (2019). Palu municipality in figures, BPS Kota Palu, (ISSN 2502-2830) Google Scholar
- Clare, M., Chaytor, J., Dabson, O., Gamboa, D., Georgiopoulou, A., & Jobe, Z. (2018). A consistent global approach for the morphometric characterization of subaqueous landslides. In D. G. Lintern, et al. (Eds.), Subaqueous mass movements (p. 477). London: Geological Society. https://doi.org/10.1144/SP477.15.Google Scholar
- Hennig, J., Hall, R., Forster, M. A., Kohn, B. P., & Lister, G. S. (2017). Rapid cooling and exhumation as a consequence of extension and crustal thinning: Inferences from the Late Miocene to Pliocene Palu metamorphic complex, Sulawesi, Indonesia. Tectonophysics, 712–713, 600–622. https://doi.org/10.1016/j.tecto.2017.06.025.CrossRefGoogle Scholar
- Mishra, R., Sudhakar, M., Pednekar, S. M., & Tyagi, A. (2010). Seabed morphology of the approach channel of Larsemann Hills, Prydz Bay, East Antarctica. Current Science, 99(10), 1405–1412.Google Scholar
- Nugroho, S. (2018). Percepatan pemulihan dampak bencana terus diintensifkan di Sulteng, 2.113 orang meninggal dunia dan 1.309 orang hilang. https://bnpb.go.id/percepatan-pemulihan-dampak-bencana-terus-diintensifikan-di-sulawesi-tengah-2113-orang-meninggal-dunia-dan-1309-orang. Accessed 25 Jan 2019.
- Sadly, M. (2018). Gempabumi tektonik M = 7.7 Kabupaten Donggala, Sulawesi Tengah pada hari Jumat, 28 September 2018, berpotensi tsunami. https://www.bmkg.go.id/press-release/?p=gempabumi-tektonik-m7-7-kabupaten-donggala-sulawesi-tengah-pada-hari-jumat-28-September-2018-berpotensi-tsunami&tag=press-release&lang=ID. Accessed 25 Jan 2019.
- Strass, V. (Ed.) (2018). The Expedition PS113 of the research vessel POLARSTERN to the Atlantic Ocean in 2018. http://hdl.handle.net/10013/epic.c161bfa4-7cfb-4c97-95e5-4ccadb3ce170 and https://doi.org/10.2312/BzPM_0724_2018. Accessed 23 Apr 2019.
- Udrekh, U., Frederik, M. C., Hananto, N., Adhitama, R., Sahabuddin, S., Asrafil, A., & Putra, D. B. (2018). Seafloor deformation analysis of Bay of Palu after the 28 September 2018 Mw 7.4 Palu-Donggala earthquake, AGU Fall meeting 2018 abstract, https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/475886. Accessed 30 Jan 2019.
- USGS. (2018). Earthquake Hazard Program. https://earthquake.usgs.gov/earthquakes/eventpage/373us1000h3p4/executive. Accessed 25 Apr 2019. Accessed 25 Apr 2019.
- Watkinson, I. M., & Hall, R. (2017). Fault system of the eastern Indonesian triple junction: evaluation of quaternary activity and implications for seismic hazards. In P. R. Cummins & I. Meilano (Eds.), Geohazards in Indonesia: Earth Science for Disaster Risk Reduction (Vol. 441, pp. 1–7). London: Geological Society. https://doi.org/10.1144/SP441.8.Google Scholar