10 Jan 2014

Tsunami risk in mega-quake zone

7:39 am on 10 January 2014

New research into giant earthquakes shows a tsunami from a quake east of New Zealand could take less than 15 minutes to reach the coast.

A team of scientists has published research they say show where giant earthquakes are most likely to strike - including off the east coast of New Zealand.

The team's leader, Wouter Schellart from Monash University in Melbourne, said quakes of magnitude 9 and over happen only in subduction zones, where one plate sinks below another into the earth's interior.

The team has mapped the zones, showing which areas produce those massive quakes.

Professor Schellart said a tsunami generated by a giant earthquake on the Tonga-Kermadec-Hikurangi fault, about 200km east of the North Island, would have the same impact as the Japan earthquake and tsunami of 2011.

He said the waves would travel from the fault to New Zealand in 10 to 15 minutes, and would go further inshore than previously thought.

"There's not a lot of time between the earthquake and the actual tsunami reaching the coastline, so that's a challenge for people (working on) natural hazards and risk mitigation."

The other zones are in Indonesia, the Caribbean, Mexico, Central America and Greece.

Professor Schellart and Professor Nick Rawlinson, from the University of Aberdeen, have been working on the research since 2009.