The largest wave ever measured in the southern hemisphere has been recorded by a solitary buoy in the remote Southern Ocean.
A wave rider buoy moored at Campbell Island off New Zealand’s South Island registered the wave of 23.8 metres on Tuesday, Meteorological Metservice of New Zealand has said.
Tom Durrant, a senior oceanographer at Metocean, part of Metservice, said: “This is a very exciting event and to our knowledge it is largest wave ever recorded in the Southern Hemisphere.
“However, it is likely that the peak heights during this storm were actually much higher, with individual waves greater than 25 m being possible as the wave forecast for the storm show larger wave conditions just north of the buoy location.”
Durrant explained that the buoy only sampled the waves for just 20 minutes every three hours, recording the height, period and direction of every wave during that time.
“It's very probable that larger waves occurred while the buoy was not recording,” he said.
The new record beat the previous maximum individual 22.03 metres recorded at an Australian buoy south of Tasmania in 2012.
““Our own previous record was one year ago when we measured a 19.4 m wave, and before that in 2012 an Australian buoy recorded a maximum individual wave (Hmax) of 22.03 m. So, this is a very important storm to capture, and it will add greatly to our understanding of the wave physics under extreme conditions in the Southern Ocean,” said Durrant.
The huge waves were due to a fast-developing low-pressure cell that travelled at the same speed as the waves it was forcing.
"Essentially the peak of the waves could stay under the storms for quite a long period of time, and that's what allowed them to grow so rapidly," Dr Durrant told Fairfax Media.
Whipped up for a rapidly developing storm cell in the Southern Ocean, the waves were hitting New Zealand’s west coast on Thursday and are due to hit North America in about a week.