Below the Antarctic circle

Icebergs in the Antarctic Strait (Margot, Jan 2011)


Antarctica in January 2011 was as breathtaking as I had imagined to be. Surreal landscapes of strangely sculpted icebergs drifting in seas, surrounded by snow covered mountains. Absolutely beautiful. And scary. The Antarctic peninsula is experiencing a frightening level of warming. The average temperature in this Western part of the continent has risen more than four times as fast as the average global temperature. Evidence can readily be found. Spectacular ice shelf break ups, like that of Larsen B, leave massive chunks of ice floating, and melting, in the coastal waters around Antarctica. Where the coastal ice shelf disappears, glacier flows are no longer held back and long tongues of land ice find their way towards the sea.

Iceberg in the South Atlantic, courtesy of my friend Story Musgrave (astronaut)

Why do these ice sheets break up? It is not because of weakening or melting of the ice sheet upper surface. West Antarctica is a collection of islands. They are covered by thick layers of land ice and in many places connected by ice shelves that stretch across the water. In many places, prevailing winds push relatively warm surface water to the ice shelves. Where this water touches the ice, the shelves thin. Eventually they develops cracks, weaken and breaks up.

As temperatures around the Antarctic Peninsula increase further, the combined effect of ice shelf break up and increased glacial flow towards the coastal region may contribute significantly to global sea level rise. How much? This is hard to predict, but the crew and the scientists aboard our ship have over the years seen dramatic changes in ice coverage.

Right now, the one creature that seems most affected by the change in the local temperature is the Adelie penguin, one of my favorite creatures. They don’t do very well in higher temperatures and are gradually being displaced by Gentoo and Chinstrap penguins. It may not seem all that important at the moment. The Adelies can move further South, and they are. But there is much more at stake. Sea level rise is one concern, but so is a change in carbon dioxide absorption by the Southern Sea, thought to be critical in global climate behavior, because of changing ice coverage. We do not know yet how much the ecosystem as a whole will be affected. But I would be surprised if it remained relatively unscathed with this strong and fast West Antarctic warming.

Someone who knows a lot about ice melt and changing glacial ice coverage is photographer James Balog. James started the Extreme Ice Survey. EIS is making the world’s most extensive ground-based photographic glacier study. Time-lapse video and photography reveal the ongoing retreat of glaciers and ice sheets due to temperature changes. EIS has installed 38 time-lapse cameras at 22 glaciers in Greenland, Iceland, Nepal, Alaska, and the Rocky Mountains and conducts annual repeat photography in Iceland, British Columbia, the Alps, and Bolivia. We were very lucky to have James on board with us.

The journey to Antarctica was amazing. So was the wake-up call.

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