Geochemical Analysis of Near and Far-Field Tsunami Deposits: Little Pigeon Bay, New Zealand, Poster 11

Study of tsunamis and interpretation of the tsunami record is critical in the prediction and mitigation of future events. Tsunamis can be near-field events, originating from seafloor displacement along the nearby plate... [ view full abstract ]

Study of tsunamis and interpretation of the tsunami record is critical in the prediction and mitigation of future events. Tsunamis can be near-field events, originating from seafloor displacement along the nearby plate boundary, or far-field events, originating from displacement along a plate boundary across the ocean, but this can often be indistinguishable within the sedimentary record. In late 2016, Little Pigeon Bay, New Zealand, was exposed to and recorded inundation from the near-field Kaikoura tsunami. This study examines the geochemical characteristics of two cores from Little Pigeon Bay, surficial samples of the Kaikoura tsunami, and source sediments of the valley and offshore system, to determine relationships and characteristics of near and far-field inundation events. The results show that geochemical signatures vary between near and far-field inundation events, due to the incorporation of different materials into the tsunami deposit, likely as a function of wave strength. In addition, our study provides insights into the identification of tsunami-source based strictly on a sediment’s geochemical signature.