Destruction of the First Nations village of Kwalate by a rock avalanche-generated tsunami

Abstract

The First Nations (Da'naxda'xw) village of Kwalate, Knight Inlet, British Columbia was located along the shore of a funnel-shaped bay. Archaeological investigations show that this was a major village that stretched 90 m along the shoreline and was home to possibly 100 or more inhabitants. Oral stories indicate that the village was completely swept away by a tsunami that formed when an 840-m high rock avalanche descended into the water on the opposite side of the fjord. Shipboard geological mapping, combined with empirical tsunami modelling, indicate that the tsunami was likely 2 to 6 m high prior to run-up into the village. Radiocarbon dates reveal that the village was occupied from the late 1300s CE until the late 1500s CE when it was destroyed by the tsunami.