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New Zealand authorities braced for disaster yesterday after the powerful Solomon Islands earthquake triggered a tsunami warning.
But by last night, the possibility of destructive waves hitting the coast was considered slim, although the Ministry of Civil Defence and Emergency Management remained on alert after the magnitude 8.1 quake.
The Pacific Tsunami Warning Centre in Hawaii placed New Zealand on its tsunami "watch" list after the 8.40am quake, and waves about half a metre high were expected to hit the west coast between 3.30pm and 8.30pm yesterday.
Scientists planned to examine sea-level data today to gauge the exact time and height of the waves, but expected minimal impact in both main islands.
New Zealand was one of several countries around the Pacific placed on the warning centre's tsunami watch list, prompting the ministry to alert regional authorities as part of a standard emergency management plan.
A media release was issued at 11.15am saying there was no immediate threat but regional councils had already sprung into action, mobilising staff to prepare for a possible tsunami and Civil Defence emergency.
In Auckland, rangers were called to alert people at Muriwai Beach of the threat of destructive waves.
"They just said to people, 'Look, it's probably a good idea to keep an eye out'," said Auckland Regional Council spokesman Mark McLauchlan.
Although considered at lesser risk than areas on the west coast, the Bay of Plenty also took measures to prepare.
After the alert, the Tauranga-Western Bay Emergency Management office informed the chief executives of the Tauranga and Western Bay of Plenty District Councils and called the local emergency management controller to the office.
Across the Tasman, surfers and swimmers ignored "closed" signs put up at beaches along Australia's eastern coastline.
New Zealand scientists had not detected the tsunami hitting the coastline by yesterday evening and the ministry said the waves could go unnoticed because fluctuations in sea-level up to 1m were common.
GNS Science duty seismologist Bryan Field said it was hard to tell when the biggest waves would hit.
"The energy's got to travel for a very long time," he said. "There are a lot of variables."
GNS Science hoped to gather data from a pilot testing site in Wellington Harbour.
The National Institute of Water and Atmospheric Research would examine data from a sea-level monitoring network around the coast.
