Tsunami science

Summary

This research analyses a sedimentary deposit left by the 2016 Kaikōura tsunami in Little Pigeon Bay, Banks Peninsula. Sedimentary and geochemical analysis was undertaken on samples collected within and around a damaged cottage.

Sediment distribution and flow direction indicators suggest that the sediment and debris found within the cottage were predominantly the result of a single wave that had been channelled up the stream bed rather than from offshore. Salinity data indicated that the maximum tsunami-wetted and/or seawater-sprayed area extended 12.5 m farther inland than the maximum inundation distance. Mean grain size demonstrated a decrease in tsunami energy upon moving inland. Analysis of three cores along an inland transect indicated a distinct elevated elemental signature. Comparable signatures were also identified within subsurface stratigraphic sequences, and likely represent older tsunamis known to have inundated this bay as well as adjacent bays in Banks Peninsula.

Emergency management relevance

This research contributes to our understanding of how tsunamis behave around Banks Peninsula, and their impacts.

Additional information

Authors: Shaun Williams, Tianran Zhang, Catherine Chagué, James Williams, James Goff, Emily M.Lane, Jochen Bind, Ilyas Qasim, Kristie-Lee Thomas, Christof Mueller, Sam Hampton, Josh Borella

Date: 2018

Funders: NIWA Taihoro Nukurangi through New Zealand government strategic science investment funding

Format: Published - Sedimentary Geology

Reference: Williams, S., Zhang, T., Chague, C., Williams, J., Goff, J., Lane, E. M., Bind, J., Qasim, I., Thomas, K., Mueller, C., Hampton, S., & Borella, J. (2018). Sedimentary and geochemical signature of the 2016 Kaikōura tsunami at Little Pigeon Bay; a depositional benchmark for the Banks Peninsula region, New Zealand. Sedimentary Geology, 369, 60-70. https://doi.org/10.1016/j.sedgeo.2018.03.013