GRANULOMETRIC ANALYSIS OF PALEOTSUNAMI DEPOSITS CANDIDATE IN TERNATE ISLAND, NORTH MALUKU
Abstract
Ternate Island is a volcanic island located in the Maluku Sea. Tsunami ever hit Ternate before 1900 or occurred before the age of the people living in this island. The paleotsunami suspect have been found in the western coast of Ternate Island. The outcrop has 50 m length and 1 m width, was discovered beneath the Gamalama eruption product which occurred in 1907. The paleotsunami candidate consists of at least five layers originating from different tsunami events. The granulometric analysis was carried out for each layer. The results obtained were that paleotsunami sediments had poorly sorted which indicated that the grain sizes were mixed, this was due to the energy of tsunami wave varied in time when transporting and depositing the sediments. Skewness varies from very fine to very coarse, indicating a change in the energy of the tsunami wave that occurs from very high when rising inland to decreasing as it returns to sea. Kurtosis varies from leptokurtic, platykurtic, and mesokurtic. Variations in mean, sorting, skewness and kurtosis values indicate a change in tsunami wave energy which causes a change in grain size. The granulometric analysis shows that the deposition of the youngest paleotsunami deposits candidate was initiated by a very strong current with the greatest energy, thus depositing very coarse sand to gravel, followed by a gradual decrease in energy and the tsunami wave process began to reverse towards the sea, then receded with the lowest energy and deposited finer grains. The sediment sources come from two different places, this shows that the sources come from the sea and the coast around the deposited paleotsunami candidates.
Keywords
Full Text:
PDFReferences
Akif., M., 2021. Online Lecture of Sedimen Lecture, Texture: Grain Sorting. Sedimentology Lecture 2, Texture: Grain Sorting - YouTube
Balsillie, J.H., 1995. William F. Tanner on Evironmental Clastic Granulometry: Florida Geological Survey, Special Publication No. 40, 144 p.
Balsillie, J.H., Donoghue, J.F., Butler, K.M., and Koch, J.L., 2002. Plotting equation for Gaussian, percentiles and a spreadsheet program for generating probability plots. Journal of Sedimentary Research, 72 (6), p. 929-933.
Blott, S.J. and Pye, K., 2001. GRADISTAT: a Grain Size Distribution and Statistics Package for the Analysis of Unconsolidated Sediments. Earth Surface Processes and Landforms 26, 1237-1248.
Bronto, S., Hadisantono, R.D., Lockwood, J.P., 1982. Peta Geologi Gunung Api Gamalama, Ternate, Maluku Utara. Direktorat Vulkanologi, Departemen Energi dan Sumber Daya Mineral.
Folk, R.L., and Ward, W.C., 1957. A Study in the Significance of Grain-Size Parameters. Journal of Sedimentary Petrology, 27, 3-26. https://doi.org/10.1306/74D70646-2B21-11D7-8648000102C1865D
Fujiwara, O., 2008. Tsunami Depositional Processes Reflecting the Waveform in a Small Bay Interpretation from the Grain-Size Distribution and Sedimentary Structures. In Book: Tsunamiites pp. 133-152
Geocache, 2023. Urban earth - Sediment Sculptor. https://www.geocaching.com/geocache/GC7Z2X2
Google Earth, 2022. Ternate Island. Online Application.
Haris, Ron., dan Major, J., 2016. Waves of destruction in the East Indies: the Wichmann catalogue of earthquakes and tsunami in the Indonesian region from 1538 to 1877. Geological Society Publication. https://www.lyellcollection.org/journal/sp
Heinzel, C.E., 2016. Particle-Size Analysis. Online Presentation. Dept. of Earth and Environmental Science, University of Iowa.
Jerram, D.A., 2001. Visual Comparator for Degree of Grain-Size Sorting in Two and Three Dimensions. Computers and Geosciences 27 (4): 485-492. http://doi.org/10.1016/S0098-3004(00)00077-7
McLaren, P., 1980. An Interpretation of Trends in Grain Size Measures. Geological Survey of Canada.
Rachman, G., Santosa, B.J., Nugraha, A.D., Rohadi, S., Rosalia, S., Zulfakriza, Sungkono, Sahara, D.P., Muttaqy, F., Supendi, P., Ramdhan, M., Ardianto, Afif, H., 2002. Seismic Structure Beneath the Molucca Sea Collision Zone from Travel Time Tomography based on Local and Regional BMKG Networks. Appl. Sci. 2022, 12(20), 10520; https://doi.org/10.3390/app122010520
Satake, K., and Imamura, F., 1995. Tsunami in Ternate Island. In Latief et al., 2000, Tsunami Catalog.
Soloviev, S.L., dan Go., Ch. N., 1974. Tsunamis on the Western Shore of the Pasific Ocean. Moscow, “Nauca” Publishing House, 308 Halaman.
Tanner, W.F., 1986. Inherited and Mixed Traits in The Grain Size Distribution: In W.F. Tanner (ed.), Modern Coastal Sediments and Processes, Proceedings of the 9th Symposium on Coastal Sedimentology Tallahassee, FL: Department of Geology, Florida State University, p. 41-50.
Tanner, W.F., 1991. Suite Statistics: the Hydrodynamic Evolution of the Sediment Pool: In J.P.M. Syvitski (ed.) Principals and Application of Particle Size Analysis, Cambridge: Cambridge University Press, p 225-236.
Trenhaile, A.S., 2005. Beach Sediment Characteristics. In Schwartz, M.L., (eds) Encyclopedia of coastal science. Encyclopedia of Earth Science Series. Springer, Dordrecht. pp 177-179. https://doi.org/10.10071/1-4020-3880-1_41
DOI: http://dx.doi.org/10.32693/bomg.38.2.2023.807