Tsunami

New Zealand’s entire coast is at risk of tsunami. A tsunami can violently flood coastlines, causing devastating property damage, injuries and loss of life.

A tsunami is a natural phenomenon consisting of a series of waves generated when a large volume of water in the sea, or in a lake, is rapidly displaced. Tsunami are known for their capacity to violently flood coastlines, causing devastating property damage, injuries, and loss of life.

A tsunami can occur during any season of the year and at any time, day or night. On the open ocean tsunami waves are barely noticeable, but when the waves enter shallow water they will rise in height. Some tsunami can be very large and can rapidly and violently inundate coastlines, causing loss of life and property damage.

Other waves can be small but still dangerous to those near or in the coastal water. It is important to remember that not all earthquakes will generate a tsunami, and that earthquakes are not the only sign of an impending tsunami so it is critical to know what to do as a precaution if you are in a vulnerable area.

In the media, tsunami are often described as being either local, regional or distant. The following definitions for these terms will help you understand their meaning.

Local tsunami

These are tsunami with less than 1 hour travel time to the nearest New Zealand coastline, noting that many travel times are less than 30 minutes and some travel times are as short as a few minutes.

Regional tsunami

These are tsunami with 1-3 hours travel time to the nearest New Zealand coastline.

Distant tsunami

These are tsunami with more than 3 hours of travel time to the nearest New Zealand coastline e.g. Chile tsunami 2010.

Click here for tsunami flooding projections - find out the Waikato region's coastal areas that may be vulnerable in the event of a tsunami

 

Click on the animation to see how a tsunami works (supplied by TVNZ):

Read more about tsunami

Be prepared

What to do if you feel a strong coastal earthquake

Tsunami warnings

What to do after a tsunami

What are our tsunami risks?

Tsunami travel time maps

Tsunami Community Action Plans

Tsunami news and information

Tsunami brochure   (406kb PDF)