By Bob Zuur
WWF-New Zealand Marine Advocate
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Bob Zuur is a marine biologist who is spending a month
exploring Antarctica and the sub-Antarctic Islands
to raise awareness of the area and its importance. His current work with WWF
focuses on fisheries, offshore oil exploration and seabed mining, and on
increasing protected areas in our marine environment. He will be
documenting his travels here on
3news.co.nz.
Our
Far South Bob Zuur RSS Feed
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I saw my first iceberg today. Out of the cabin window, glinting in the morning sun. Victor (my cabin mate) woke through my excitement and together we sprinted up to the bridge. We saw that "my" 'berg was but one of many.
The Captain was looking particularly intensely ahead (he's usually pretty intense) as he made his way through the frozen maze. The large, huge and hugest icebergs can be seen easily on the radar. It's the little ones about the size of a car that he needs to look out for. I found out that these are called "growlers" and that those about the size of a house are "bergy bits" and that "bergy bits" is the proper nautical term!
We crossed over the Antarctic Circle this afternoon with a celebration involving a toast of mulled wine, and there are icebergs everywhere. So it feels and looks like were getting close to Antarctica.
Indeed there is so much ice in the northern Ross Sea that we have to sail quite far to the east to avoid much of it. This also means that we will be unable to go to Cape Adare, which marks the northwest corner of the Ross Sea. Perhaps on the way back.
Dan Zwartz from Victoria University is also an expert in icebergs, and is sharing his knowledge with us all. The large, flat icebergs have been calved off the end of the iceshelf. When I see these beautiful ice sculptures I think that "carved" is a better description.
When the sea temperature is -1.8o and the air temperature is about -20o, the sea starts freezing. At first there is "grease ice", because of its oily appearance. Then larger crystals form "frazil ice" and these congeal to form "pancake ice". These pancakes raft together and form solid sea ice. This eventually become strong enough to support the weight of the huge cargo planes the Americans operate into McMurdo Sound.
Ice turns blue when the pressure of tons of ice in glaciers squeezes the air out, that otherwise makes ice white.Yes, the true colour of ice is actually blue. Microscopic plants or algae growing in the ice turn it green and rocks and stones paint brown stripes. This maze was a wonderful melange of colours and shapes.
As global climate change warms the planet, parts of the Antarctic are warming faster than the global average. As I am experiencing firsthand, the south pole and it's northern Arctic counterpart are fragile regions where small temperature increases can have large - and as yet little understood - effects. The Argo floats deployed by Dan throughout this voyage will add to our understanding of ocean warming.
We should expect freezing conditions when we sail back this way in about two weeks. Much as I love this place, I don't really want to be frozen in and have to spend a winter down here like Shackleton did a century ago. I'll keep you posted!