The giant iceberg which spawned smaller icebergs seen floating off the Otago coast in 2006 is still drifting southeast of New Zealand.
Nasa's Moderate Resolution Imaging Spectroradiometer terra satellite captured an image of B-15J on December 2, floating in the Southern Ocean 2400km east southeast of New Zealand.
"Sliver-shaped pieces of ice formed an arc around the oblong iceberg, which had disintegrated discernibly since last spotted in late November," Nasa said on its website.
Niwa oceanographer Mike Williams, of Wellington, who has been observing the iceberg drifting since 2006, said B-15J and several smaller icebergs surrounding it would continue heading east towards South America.
"They are trapped in the big current that goes around Antarctica called the Antarctic circumpolar current. It is slowly melting all the time.
Pieces are also breaking off all the time."
In 2000, the Ross Ice Shelf in the Antarctic calved B-15J, one of the world's largest icebergs. It was estimated to measure 295km by 37km wide and had a surface area of 11,000sq km, about one-third the size of Otago.
In November 2006, about 100 small icebergs made their way as far north as New Zealand, with several lying close to the Otago coast for about a month.
Scientists have observed more icebergs breaking off polar ice shelves in the past decade.
However, Mr Williams said it was still too early to say whether this was a result of global warming.
"It's very difficult to tell if the number of icebergs has changed.
"Big icebergs only calve every 50 years or so, hence we don't know if the rate they have been calving has been changing," he said.
- Wing Tan
