Tests of a tsunami warning system are being held in Wellington on Wednesday.
In the case of a tsunami alert, the Wellington Emergency Management Office says 12 vehicles would drive around low-lying areas, telling people to move to higher ground.
At 110 decibels - about the volume of a power saw - WEMO says the messages can be heard up to 500 metres away.
A speaker system for two helicopters will undertake similar tests over the city from 6pm to 7pm on Wednesday.
