Tsunami risk: do we learn our way forward, or repeat the mistakes of the past?

Abstract

New Zealand has just had its second ‘near miss’ with tsunami risk in three months. An earlier NZIER Insight (no. 63) covered how a tsunami warning was issued 1 hour 20 minutes after the earthquake centred offshore from Te Aroha on Friday 2 September. This warning was issued 1 hour 5 minutes after the arrival of the first wave. The magnitude 7.8 earthquake that struck just after midnight on Monday 14 November again showed the shortcomings of our system for managing tsunami disaster risk. Sirens in places like New Brighton were activated 2 hours after the earthquake, while in Napier they were never used at all as, according to the CEO of Napier City Council, that “would have caused mass panic and evacuation”. To put these times in perspective, the first 2-4 metre tsunami waves generated from Monday’s North Canterbury earthquake arrived in Banks Peninsula after one hour, and for Wellington, following any major earthquake on the subduction zone off the coast, arrival times are likely to be only 20 minutes!