High resolution reconstruction of past earthquakes and tsunami during last several hundreds using coral skeletons collected from Sumatra

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Reef corals record various environmental changes and events in their carbonate skeletons with annual bands for a few years. Geochemical analysis along growth axis of coral skeletons has been used as reconstruction of paleo-environments in high resolution weekly to monthly. In order to reconstruct past records of earthquake and tsunami, we collected 15 modern and fossil coral cores using underwater and land-based drilling from southern part of Pagai island, Mentawai islands, Sumatra, Indonesia. We analyzed concentration of trace elements, oxygen and carbon isotopes in coral skeletons. Trace element concentrations varied with sediment disturbance and terrestrial inputs due to tsunami. In addition, carbon isotopes in coral skeletons had a possibility as a quantitative proxy of coral living depth(solar irradiance) changes due to uplift/subsidence with earthquakes because carbon isotopes change with photosynthetic activity of symbiotic algae. These results suggested that coral skeletal structures and geochemical composition can reconstruction of environmental changes with earthquakes.