Investigation of possible Paleo tsunami deposit in Seubadeh Village in the Southern part of Aceh

• Main Authors: Prasetyo, Aditya Vethra, Sukman, Muhammad Mirda, Vahreza, Anshar, Mitaphonna, Rara, Fauzi, Rajibussalim, Ismail, Nazli, Lahna, Kurnia, Idris, Nasrullah
• Format: Conference Proceeding
• Language: English
• Subjects: Coring; Deposition; Geology; Laser induced breakdown spectroscopy; Thickness; Tsunamis; Visual observation
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0162517

A study to locate the paleotsunami deposition was carried out in Seubadeh Village situated in East Bakongan Timur sub-district of South Aceh, which is a part of the province of Aceh, Indonesia. Seubadeh Village is located on the coast and faces directly to Indian Ocean, thus possibly affected by historic tsunamis occured in the past. this area has been identified geologically as one of the areas that has the potential to store paleotsunami deposition. The sample collection was carried out by drilling the ground using coring at several points with depth of up to 3 meters. The collected soil samples have been processed in the laboratory, dried and sifted. Visual observation of the soil and sediment samples taken showed that it mainly consits of sand and ordinary soil. However, it was found that there were parts of the deposited layer that show geological characteristics fit to characteristics of a paleo-tsunami deposition layer. Thus, the excavated deposition layer is a very potential candidate for the paleotsunami layer. The paleotsunami candidate layer was found at at a depth of 2.5 meters below ground level. The deposition layer considered as the candidate paleotsunami deposition consists of 2 separate layers with different thickness. The first deposition layer has a thickness of more than 30 cm, while the second layer has a thickness of more than 9 cm. The paleotsunami deposition layer found will be further characterized by geological methods and optical analytical tools, namely laser induced breakdown spectroscopy (LIBS). This study implies that the south west coast of Aceh holds records of past tsunami events, and Seubadeh Village could be an appropriate area to study paleotsunami further.