If a massive earthquake rattles the Kermadec trench, a tsunami could hit New Zealand in less than three hours.
So, Civil Defence is testing the nation's tsunami readiness starting today.
More than 100 organisations and several hundred staff right across the country are involved in the exercise that will test our preparations before a tsunami, in the immediate aftermath, and long term.
Civil Defence director Sarah Stuart-Black joined Mark Sainsbury, filling in for Paul Henry, to explain.
