20 Jan 2022

How the tsunami alert system works in Aotearoa

From Summer Times, 10:25 am on 20 January 2022

When the eruption in Tonga happened on Saturday evening, tsunami alerts rang out across the Pacific Islands - including here, in New Zealand.

5 days on, we're still learning about the extent of the damage, but new estimations from GNS suggest waves of up to 15m were possible.

So how do we know this, and how do our alert systems even work?

GNS Principal Scientist Bill Fry Bill Fry joins Anna to explain.

DART buoy locations

DART buoy locations Photo: GNS