Locally generated tsunami along the Kaikoura coastal margin: Part 2. Submarine landslides

Abstract

An examination of the underwater landscape along the northeast coast of the South Island, New Zealand, identified a substantial potential for a submarine landslide in Kaikoura Canyon. A numerical model was applied to calculate runup and inundation arising from a local tsunami generated by such a landslide. The model is based on the Reynolds‐averaged Navier‐Stokes (RANS) equation and used a finite element spatial approximation, implicit time integration, and a semi‐Lagrangian advection approximation. The results indicate that a landslide‐generated tsunami represents a large potential hazard to the area from South Bay to Oaro, South Island, New Zealand, and has the potential to generate large tsunami runup heights along this section of coast. In addition, the tsunami events are characterised by a short time interval between generation and runup.

Key words:

• tsunami
• submarine landslide
• Kaikoura Canyon
• New Zealand