People are being urged to find out more about tsunamis as the first World Tsunami Awareness Day is held.
The UN General Assembly decided to mark the day on Saturday to highlight the risks and New Zealand officials are getting behind it because all of New Zealand's coastline is at risk of tsunami.
In the last 200 years, there have been at least three tsunami that were more than 10 metres high at the New Zealand coast.
Maori mythology also speaks of large tsunami. Some were caused by distant earthquakes, some by underwater quakes not far off the coast.
A tsunami is a series of waves caused by large earthquakes.
Their destructive power has been shown in the Indian Ocean tsunamis in 2004 and 2005, Samoa in 2009, Chile in 2010 and Japan in 2011.
Acting Director of Civil Defence and Emergency Management, David Coetzee, says all of New Zealand's coast is at risk of tsunami.
For a local source tsunami, which could arrive in minutes, officials will unlikely to be able to issue official warnings in time before the first waves arrive.
"It is therefore important not to wait for official warnings, but instead recognise the natural warning signs and act quickly."
This means moving immediately to the nearest high ground, or as far inland as you can.
Warning signs include feeling a strong earthquake that makes it hard to stand up, or a weak rolling earthquake that lasts a minute or more, seeing a sudden rise or fall in sea level and hearing loud and unusual noises from the sea.