Tsunami geochemistry: progress and perspectives

Abstract

This review summarizes geochemical studies in tsunami deposit research. The geochemical characteristics and behavior of tsunami deposits are described, and future research issues are identified and discussed. As geochemical approaches have focused on traces of seawater inflow or environmental changes rather than tsunami deposits themselves, such approaches are expected to contribute to (1) identifying tsunami deposits from geological layers, and (2) reconstructing tsunami inundation areas with high accuracy. After recent giant tsunamis, many geochemical characteristics of tsunami deposits have been reported, and the behaviors of various geochemical proxies have been gradually clarified. However, the usefulness of these proxies and their behaviors in different depositional environments remain poorly understood. In the future, it will be necessary to better understand the geochemical characteristics of both modern and paleo tsunami deposits and to develop and apply new proxies and analytical methods. Collaboration with other research fields will prove indispensable for these purposes; therefore, cross-disciplinary research should be promoted.