Tsunami science

Summary

This research models inundation depths and water velocities in Christchurch for 500-year and 2500-year return period South American tsunami scenarios, under different sea level rise scenarios (2019 sea level, and 0.19m, 0.41m and 1.06m sea level rises).

Both tsunami scenarios result in major inundation across Christchurch, which worsens with higher sea level scenarios. Notably, 79% more area would be inundated by the highest sea level rise scenario (1.06m above the 2019 sea level) than for the same tsunami occurring at the 2019 sea level. These events would cause severe erosion at the mouth of the Waimakariri River and the Avon-Heathcote Estuary, and at the Bridge Street bridge over the Avon River and the Ferry Road bridge over the Heathcote River, which could cause increased inundation.

Emergency management relevance

This research provides modelled inundation depths and water velocities for two distant-source tsunami scenarios for Christchurch, and can be used for tsunami evacuation zones, evacuation and response planning, infrastructure planning, public education and some types of land use planning.

Additional information

Authors: Cyprien Bosserelle, Jade Arnold, Emily Lan

Date: 2019

Funders: Christchurch City Council

Format: NIWA report

Reference: Bosserelle, C., Arnold, J., Lane, E. (2019). Lane Drainage Recovery Report: Tsunami Study. NIWA. Retrieved from: https://www.ccc.govt.nz/assets/Documents/Environment/Water/Flooding-Land-Drainage/Tsunami-Study-Final-report-June-19.pdf