Tsunami
Posted 2 October 2009 // Caren Wilton
The spread of a tsunami, 2004
The devastating tsunami that hit the coasts of Samoa, American Samoa and Tonga on the morning of 30 September – with waves up to 6 metres high, flooding as far as 1.6 kilometres inland, and killing at least 150 people – was caused by a massive undersea earthquake of magnitude 8.3, some 190 kilometres south of Apia. The Samoa–Tonga region is one of the world’s most seismically active areas, where the Pacific and Australian plates collide – as they do diagonally across New Zealand.
Tsunamis are broad waves in oceans or lakes, caused by large disturbances, locally or far away – movement of the sea floor during earthquakes, landslides under or into the water, or even the impact of a meteor. The New Scientist has a detailed explanation of the causes of the 30 September tsunami.
While tsunamis might seem a remote possibility in New Zealand – perhaps explaining why some people headed for the beach rather than the hills during Wednesday’s tsunami alert – in fact the country has experienced many tsunamis over the centuries. Māori tradition discusses a huge wave that killed many people on the western side of D’Urville Island, and there is archaeological evidence of early Māori moving inland or uphill from coastal settlements, along with evidence of tsunamis near the abandoned villages.
Since Pākehā settlement, there have been no tsunami deaths in mainland New Zealand. But the 1855 Wairarapa earthquake generated a tsunami in Cook Strait which destroyed sheds more than 8 metres above the sea at Te Kopi in Palliser Bay. In March 1947 the coast north of Gisborne was hit by a tsunami after an earthquake. A bridge was swept away, the Tatapōuri Hotel was flooded, and some buildings were sucked out to sea. June Young, whose family owned the hotel, remembers the giant wave, and the seaweed that was left hanging in the power lines. Remarkably, no one died.
But, tragically, this week’s tsunami has wreaked devastation across the south coast of Samoa and American Samoa, and on Niuatoputapu island in Tonga. Those losses are being keenly felt in New Zealand too, as a Pacific nation where many Samoans and Tongans make their home, and the site of the world’s largest Polynesian city. At least three New Zealanders died in the tsunami, with many more still unaccounted for at the time of writing.
New Zealanders have already given over $350,000 to relief agencies’ tsunami appeals; here’s a list of agencies, if you’d like to make a donation.
It’s good to see the mention of the Samoan-Tongan connections with NZ. The mainstream NZ media has highlighted of the few New Zealanders who’ve (v sadly) died. That focus may be understandable when such disasters occur in locations far distant from NZ, but it seems very inappropriate when the disaster takes place in a Pacific neighbour with which there are so many kin connections of kinship and ties of friendship.
I’ve also found the media coverage inappropriate in other ways. People who’ve just found out they’ve lost loved ones should be off limits to TV cameras - they’re in no state to give informed consent. Also the juxtaposition of God-fearing courteous and resilient western Samoans with materialistic (looting) American Samoans. I guess disaster porn boosts the ratings….