Life under the ice
Dr Ian Allison — research scientist
I’m Ian Allison. I’m a research scientist studying mostly ice and I head up the Antarctic Division’s Ice, Ocean, Atmosphere and Climate Program.
The ice shelves are the area of Antarctica that is changing the most. We now know that the Antarctic ice sheet is losing mass to the oceans and that’s occurring because ice shelves are thinning or collapsing. So, we really need to know what’s going to happen in the future. It’s the largest uncertainty in what global sea level will do in the next hundred years, is understanding how the ice sheets and the ice shelves will behave.
The ice shelves fringe about 44–45% of the Antarctic coast. Most of the ice that drains out from the interior goes through floating ice tongues or ice shelves. Now, if those ice shelves melt, and there’s been a number of them have along the Antarctic Peninsula, they don’t themselves raise sea level but they act as a bit of a cork to the ice behind so, if the ice shelf disappears you get more rapid drainage of the ice behind them and that does lead to sea level rise.
We’ve got a finalisation of the large program looking at the Amery Ice Shelf. The main thing we’re doing is putting holes through the ice shelf. We use a hot water drill, basically melt a hole through the ice shelf, 600, 700 metres, and then deploy instruments into the ocean to look at the ocean’s circulation, the structure of the ocean, how it changes seasonally, how much of the ice shelf is melting from underneath.
The surprising thing was that, even under the ice shelf 200 kilometres back from the very front, there’s living organisms. There’s things swimming in the water column, there’s things living on the sea bed in pitch darkness, obviously fed by nutrients that are swept in in the ocean, but we didn’t really expect to find life there.
As well as this work we do in the field, we do satellite remote sensing to study the larger picture and we also develop models, computer models, the interaction of the ice and the ocean, so we can use those to predict the future.