Submarine landslide inventory for the 2016 Kaikōura earthquake

In a recent study published by Gnesko et al. (2026), researchers have mapped a total of 853 submarine landslides triggered by the 2016 Kaikōura earthquake in New Zealand. The study, which is open access and published under a Creative Commons licence, focuses on the upper Kaikōura Canyon, located just offshore from the region affected by the earthquake.

The upper Kaikōura Canyon is shown in the image below, with the Hundalee Fault outlined in solid orange and projected in dashed orange, running along the upper slopes of the canyon. The study utilized high-resolution bathymetric data collected in 2015, before the earthquake, and again in 2017, after the earthquake, to detect and map the landslides caused by the seismic event.

This approach is notable, as most research on submarine landslides following earthquakes concentrates on large, long-runout events rather than the numerous smaller landslides observed in this study. The researchers found that 853 coseismic submarine landslides were triggered by the Kaikōura earthquake, with the majority being relatively small, averaging a volume of about 9,900 m³, and having a median failure depth of 4 metres.

Less than 4% of the landslides were classified as deep-seated. Additionally, 74% of the landslides were categorized as slides. The study highlights the occurrence of a significant number of submarine landslides following large earthquakes, suggesting that this phenomenon also takes place in submarine environments where topography and sediment availability permit.