The elusive AD 1826 tsunami, South Westland, New Zealand

In AD 1826 sealers reported earthquake and tsunami activity in Fiordland, although contemporary or near-contemporary accounts of tsunami inundation at the time are elusive. A detailed analysis of recent sediments from Okarito Lagoon builds on contextual evidence provided by earlier research concerning past tsunami inundation. Sedimentological, geochemical, micropalaeontological and geochronological data are used to determine palaeoenvironments before, during and after what was most probably tsunami inundation in AD 1826. The most compelling chronological control is provided by a young cohort of trees growing on a raised shoreline bench stranded by a drop in the lagoon water level following tsunami inundation.