The nearest one, measuring about 30 yards tall, was 160 miles southeast of New Zealand's Stewart Island and was part of a 'flotilla' of icebergs that can be seen on satellite images, Australian glaciologist Neal Young said.
The alert comes three years after cold weather and favorable ocean currents saw dozens of icebergs float close to
'It's an alert to shipping to be aware these potential hazards are around and to be on the lookout for them,' Maritime New Zealand spokeswoman Sophie Hazelhurst said.
No major shipping lanes or substantial fishing grounds are in the area, but most ships there have little hull protection if they collide with an iceberg — which typically has 90 per cent of its mass under water.
On Monday, Rodney Russ, expedition leader on the tourist ship Spirit of Enderby, spotted a 500-foot-long iceberg about 60 miles northeast of Macquarie Island and heading north — about 500 miles south of New Zealand. Australian scientists reported another mass of 20 icebergs drifting north past
Young said satellite images showed the group of icebergs, spread over a sea area of 600 miles by 440 miles, moving on ocean currents away from
Large numbers of icebergs last floated close to
It is rare for whole icebergs to drift so far north before melting, but a cold snap around southern
Icebergs are formed as the ice shelf develops. Snow falls on the ice sheet and forms more ice, which flows to the edges of the floating ice shelves. Eventually, pieces around the edge break off.
Young said that having the icebergs end up near New Zealand is not necessarily linked to global warming, but said that the rate of icebergs breaking off the Antarctic ice shelf in recent years may have increased due to dramatically rising temperatures on the continent over the past 60 years.— AP