A closer look to submarine landslide deposits beneath the Makassar Strait and its ability to generate tsunami Rizqi Valentra (a*), Rima Rachmayani (b), Benyamin Sapiie (c)
a) Earth Science Study Program, Faculty of Earth Science, Bandung Institute of Technology, Bandung, Indonesia
*rizqi.valentra[at]gmail.com
b) Oceanographic Research Group, Faculty of Earth Science, Bandung Institute of Technology, Bandung, Indonesia
c) Geodynamics and Sedimentology Research Group, Faculty of Earth Science, Bandung Institute of Technology, Bandung, Indonesia
Abstract
In 2020, several Mass Transport Deposits (MTD) were identified beneath the Makassar Strait. These deposits which formed since 2.6 Mya were considered as the product of submarine landslide that was not caused by a seismic activity but by rapid sedimentation from Mahakam Delta and slope erosion and deposition by Indonesian Throughflow. With volume range that could reach more than 600 km3, these deposits were spread along the west side of the Makassar Strait. Although these deposits had been mapped, the volume of each deposit and the formation process are still questionable. It is also unknown whether these gigantic MTDs were tsunamigenic or not. In this research, more data was used to examine the MTDs through different point of view and tsunami model was run using NHWAVE and FUNWAVE-TVD. Looking at both interior and exterior features of the largest MTD, it was found that this MTD was deposited in a slumping process which moved very slow rather than in a gravity fall so that it may not be able to generate tsunami even though the volume of the mass could reach hundreds of kilometers. It was also proven through the tsunami model that the impact of a tsunami that caused by a 280 km3 and a 180 km3 of landslides would be decreased significantly when the velocities were reduced up to ten times from the original.
Keywords: Makassar Strait- Submarine Landslide- Mass Transport Deposit- Tsunami Model
