Pacific tsunami four storeys high

Graphic showing how tsunamis are formed deep under the ocean. Source: National Oceanic and Atmospheric Administration (NOAA)

New Zealand scientists have worked out that the Pacific's killer tsunami was nearly four storeys high when it slammed into Samoa's coast.

Conflicting eyewitness accounts have never made it clear how many waves there were and what their heights were.

The National Institute of Water and Atmospheric Research (NIWA) and GNS Science have carried out field work the tsunami, releasing their data today.

"The Samoa tsunami consisted of two to three significant waves; the second wave was said by witnesses to be larger," the statement said.

"The delay between the earthquake and the arrival of the first wave was about 10 minutes in Samoa and 20 minutes in American Samoa.

"The maximum height reached by the tsunami on the land was 14 metres above mean sea level in Samoa and 10 metres in American Samoa. 

"The furthest inland the waves reached was over 700 metres from the shore."

At one of the worst hit areas, Lepa in the Aleipata district, eyewitness Karen Niumata gave Stuff.co.nz a dramatic account of the wave.

"We saw the reef suddenly, and we saw all the rocks were shiny, and then the wave filled the sky...

"The wave, it reached the sky, oh my god, we ran.

"We thought we would die."

On September 29 a magnitude 8.3 earthquake occurred in the Tonga Trench, 190 kilometres from Apia. It generated the tsunami which resulted in the deaths of 180 people in American Samoa, Samoa and Tonga.

- © Fairfax NZ News