CHARACTERIZATION OF TSUNAMI DEPOSITS IN KAYUMALUE, PALU, CENTRAL SULAWESI PROVINCE
Sulawesi is an island in the central part of Indonesia that is located in a complex tectonic environment where the Australian, Sunda and Philippine Plate meet. Therefore, thisisland is very vulnerable to tectonic earthquakes that trigger a tsunami. On September 28th 2018, a tsunami stroke the city o...
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| Format: | Final Project |
| Language: | Indonesia |
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| Online Access: | https://digilib.itb.ac.id/gdl/view/40532 |
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| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | Sulawesi is an island in the central part of Indonesia that is located in a complex tectonic environment where the Australian, Sunda and Philippine Plate meet. Therefore, thisisland is very vulnerable to tectonic earthquakes that trigger a tsunami. On September 28th 2018, a tsunami stroke the city of Palu and the Kayumalue area was also affected by this tsunami. The tsunami was caused by a coastal landslide triggered by the earthquake. The study of modern tsunami deposits caused by tsunamigenic landslides is still limited. Therefore, more researches are needed, on tsunami deposits, to determine the characteristics of tsunami deposits, as references about the tsunami cycle in the Kayumalue area, Palu, Central Sulawesi.
The study was carried out on 44 KML (Kayumalue) samples, from a transect data consist of 9 study points. The characteristics of tsunami deposits are obtained by laboratory analyses grain size analysis, X-ray fluorescence analysis (XRF), Loss on Ignition (LOI) analysis, and microfauna analysis. The results of these analyses show 1-8 cm thick tsunami sediment in the Kayumalue region. Tsunami and pre-tsunami deposits generally have clear erosive contact, except for pre-tsunami deposits KML 01 has relatively the same characteristics as tsunami deposits. Based on the grain size analysis, tsunami deposits consist of 1-6 stratigraphic units. The tsunami deposits are brownish gray in color, showing fining upward sucession, coarse to fine sand indicating finer grain size and increase of clay percentage, medium-bad sorting, fine skewed-very fine skewed, leptokurtic-very leptokurtic, distribution curve unimodal frequency. Based on the XRF analysis, the elements of Ca and Sr in the tsunami deposits are relatively increased compared to the pre-tsunami deposits. Based on LOI analysis tsunami deposits have a higher carbonate content than organic material compared to pre-tsunami deposits. Microfauna analysis shows that in the tsunami layer there were mollusks, and 25 species of bentonic foraminifera as intact or broken, consisting of foraminifera bentonik with lithoral to outter neritic habitat.
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