Paleo-tsunami research along the west coast of Sumatra, Indonesia: Science in the Covid-19 Pandemic

Abstract:

The repeat times of giant tsunamis can occur centuries to millennia apart and are not fully captured in historical and instrumental records. A more refined understanding of the long-term variations in timing and recurrence of giant 2004 Indian Ocean tsunami is essential for producing realistic vulnerability assessments for coastal communities of Sumatra. In previous years we have built up this evidence of paleotsunami history in Aceh, Sumatra by stratigraphical surveys of coastal wetlands and caves supported by ground penetrating radar, and archaeological investigations of imported Chinese, Thai and Burmese trade ceramics along the northern coast of Banda Aceh. Applying these approaches required multiple experts with differing research interests, traveling on numerous expeditions to the field sites in Sumatra.

Our project has presented an extraordinary 7,400 year stratigraphic sequence of prehistoric tsunami deposits from a coastal cave in Aceh, Indonesia (Rubin et al., Nature Communications, 2016). This record demonstrates that at least 11 prehistoric tsunamis struck the Aceh coast between 7,400 and 2,900 years. Furthermore, the incorporation of archaeological methods has allowed an improved understanding of resettlement, and economic and political responses to previous tsunami events (Daly et al., PNAS, 2019). Our future work is now challenged by the current travel restrictions due to the Covid-19 pandemic. However, through a combination of training using online multimedia of local collaborators from Syiah Kuala University, we aim to expand our research from the previous study area of Aceh province to all of the western coast of Sumatra. The local field team is composed entirely of young graduates with geoscience degrees and they will receive additional training in coring and sediment analysis based on the Handbook of Sea-Level Research by Shennan et al., (2015) and other materials noted therein, specifically tailored to the environments and conditions of fieldwork in Sumatra. These training efforts will also be informed by lessons from our previous successful training of 60 Acehnese staff to recognize, document, and collect imported trade ceramics.