Morphological changes and Tsunami deposits Studies around Northern Part of Sumatra Island, Indonesia

Discourses on the number of tsunamis that had taken place around this area are among the frequent questions raised. This study aimed to collect more evidences of tsunami deposits from undisturbed areas around the northern coast of Sumatra island. The study used sediment deposits around some relatively undisturbed areas around the region to compliment the sediment deposit studies. Numerical simulations were performed using Cornell Multi-grid Coupled Tsunami (COMCOT) to compliment the sediment deposit studies. The simulations focused on several areas around the northern part of Sumatra using COMCOT. Tsunami-induced sediment transport was conducted using Delft3D-Flow applied at the inner grid of the simulation domain. Sediment deposit studies were done at two locations, around Paro Cut and Lhong areas. A number of core-sediment samples were taken from these sites and analyzed to identify microfossils at every layer of the samples. The 2004 Indian Ocean tsunami deposits were convincingly confirmed. Morphological changes due to tsunami waves around these areas were found, with swales and ridges created. The creation of these features is evidence of the large bed shear stress caused by the tsunami waves. The study revealed how much energy was involved in transporting granular sediment and boulders during a tsunami wave. The 2004 Indian Ocean tsunami was simulated using COMCOT to mimic the tsunami waves propagation from the rupture area. Delft3D-Flow was used to simulate the sediment transport process at the inland part of the study area. The two models were used as complementary to each other, as COMCOT does not incorporate sediment transport models, and Delft3D-Flow does not provide multi-fault scenarios for generating tsunami waves. The study area is located at Lhoong Sub-district of Aceh Besar District, facing the Indian Ocean. The area was severely damaged by the 2004 tsunami, but has preserved the tsunami deposit due to minimal human intervention. The study area is situated on the northern coast of Sumatra island, with six villages directly connected to the coastal area. The location is 55 km from Banda Aceh, the biggest city in Aceh Province. The research was conducted in two measures: field measurements and numerical simulation. Field measurements were conducted to measure cross-profiles of the coastal area around Paro village, measure tsunami sediment thickness, and measure size and locations of tsunami boulders. Numerical simulations were done using COMCOT and Delft3D-Flow. The initial tsunami waves were computed using a multi-fault scenario, and the domain of the tsunami simulation was divided into five layers. The numerical simulation results were used as the basis for field investigations to identify tsunami deposits and their thickness. The findings of tsunami boulders were considered to provide a supporting explanation. The study used a spherical coordinate system in the first three layers of the simulations and a Cartesian coordinate system in the fourth layer. The numerical simulation results were used to investigate the tsunami deposit and their thickness. The tsunami waves propagation was simulated based on the 2004 Indian Ocean tsunami scenario proposed by Romano (2009). The time of the simulation was set to start at 00:58 AM on December 26, 2004. Based on the simulation, the sea water was receded, and the first leading wave arrived at the study area about 20 minutes after the simulation started. The simulation results showed that the tsunami waves propagated at a speed of approximately 10 m/s. The simulation results also showed that the tsunami waves caused a significant impact on the coastal area, with a maximum water level of approximately 10 m. The study found that the tsunami waves caused a significant impact on the coastal area, with a maximum water level of approximately 10 m. The study also found that the tsunami waves caused a significant erosion of the coastal area, with a maximum erosion depth of approximately 10 m. The study concluded that the tsunami waves caused a significant impact on the coastal area, with a maximum water level of approximately 10 m. The study also concluded that the tsunami waves caused a significant erosion of the coastal area, with a maximum erosion depth of approximately 10 m.