The Kaikōura Canyon is a submarine canyon located southwest of the Kaikōura Peninsula off the northeastern coast of the South Island. It is 60 km long, up to 1200 m deep, and is generally U-shaped. It is an active canyon that merges into a deep ocean channel system that meanders for hundreds of kilometres across the deep ocean floor. It is the main sediment source of the 1500 km long Hikurangi Channel, which supplies turbidites to the Hikurangi Trough, as well as to low parts of the oceanic Hikurangi Plateau, and to the edge of the southwest Pacific Basin. It is deeply incised into the narrow, tectonically active, continental margin. It is thought to be the sink for the coastal sediment transport system that carries large amounts of erosional debris northwards up the coast from the rivers draining the tectonically active mountains of the South Island. There is a known risk of an earthquake-triggered tsunami resulting from the displacement of sediment accumulating at the mouth of the canyon. Sediment consisting of fine sand and silt is being deposited at the head of the Kaikōura Canyon with an estimated total volume of 0.24 cubic kilometres accumulated. A near-field tsunami caused by the displacement of this sediment poses a significant threat to the surrounding area, especially coastal infrastructure such as roads and houses. Historical accounts of canyon-related tsunami in this region are uncertain. Geological evidence is also limited, and no palaeotsunami specific studies have been carried out to date. However, in archaeological literature, there are some possible indications of past marine inundation events. Marine sediments can be seen to overlie an historical Maori occupation site on Seddon's Ridge, near South Bay. These deposits indicate that marine inundation occurred sometime within the last 150–200 years. Seddon's Ridge is an uplifted beach ridge and has a long history of Maori settlement. An older village site dating from approximately 650 years before present, situated approximately 350 metres from the shoreline, contains reworked oven stones which are overlain by marine overwash deposits. Without accompanying reliable geological data, this kind of archaeological evidence is only circumstantial. However it does indicate that the ocean has inundated past coastal settlements in the region as a result of a severe storm surge or tsunami. Rapidly accumulating sandy sediment on a steep slope, in an active tectonic region, is likely to be susceptible to failure during moderately large earthquakes.