Reconstruction of Sea Level Change in Indonesia: Preliminary Evidence From Maratua-Kakaban Complex

Abstract

This research was conducted in Maratua-Kakaban Islands, East Kalimantan, Indonesia. This location was chosen because of its stable tectonic activity and its geographical setting as the front most island in Indonesia. This location is also known as its tourism destination and beautiful scenery. A small island like in Indonesia is prone to climate change, especially sea level changes. This research is needed to formulate adaptation and mitigation of sea level change in Indonesia. This research also important to understanding the global sea change. This research also important from national sovereignty and coastal resources management point of view. This research aims to: (1) identify water level changes evidence by marine terraces analysis, cave morphology and speleothem; (2) define the highest and lowest water level in Maratua Island, and (3) reconstruct the sea water level fluctuation during Holocene. Sea level fluctuation data were interpreted using marine terrace data, marine notch, and cave morphology. The data were collected by field survey using profiling method to find surface topography and measuring sea floor profile using echo sounder. Based on the field measurement, there are major and minor marine terraces found in the ocean floor in 82 and 180 m depth (major), 155 and 205 m depth (minor). Marine terrace also found in +6 m above present sea level. Below, marine notch was found covered with sediment.