Mar 13, 2017

When will the large crack on this Antarctic ice shelf break away?

by
Catherine Jex
,
Science Nordic

As the crack gets longer, there’s more leverage to pry it open. It’s a mechanical advantage—the longer the crack, the more force there is at the tip of the crack to continue to allow it to march forward,” says Borstad.

...

Scientists from Project MIDAS—a UK based Antarctic research project—have been monitoring the Larsen C ice shelf for the past two years. They predict that more than 5,000 square kilometres of ice will be lost when the rift finally opens up all the way. Borstand puts this closer to 6,000 square kilometres. That is as much as ten per cent of the current ice shelf area.

“This event will fundamentally change the landscape of the Antarctic Peninsula,” writes project leader Adrian Luckman, a professor in glaciology at Swansea University, UK, on the MIDAS project blog.

“We have previously shown that the new configuration will be less stable than it was prior to the rift, and that Larsen C may eventually follow the example of its neighbour Larsen B, which disintegrated in 2002 following a similar rift-induced calving event,” writes Luckman.

Scientists from Project MIDAS—a UK based Antarctic research project—have been monitoring the Larsen C ice shelf for the past two years. They predict that more than 5,000 square kilometres of ice will be lost when the rift finally opens up all the way. Borstand puts this closer to 6,000 square kilometres. That is as much as ten per cent of the current ice shelf area.

“This event will fundamentally change the landscape of the Antarctic Peninsula,” writes project leader Adrian Luckman, a professor in glaciology at Swansea University, UK, on the MIDAS project blog.

“We have previously shown that the new configuration will be less stable than it was prior to the rift, and that Larsen C may eventually follow the example of its neighbour Larsen B, which disintegrated in 2002 following a similar rift-induced calving event,” writes Luckman.

...

“There’s a whole family, you might say, of cracks lining up in the same area of the ice shelf. We still don’t know why this one particular crack grew beyond the point where the others have all stopped,” he says.

The ice could thin because it is being melted from below as the ocean warms. But that’s pure conjecture, says Borstad.

“Otherwise, these things happen periodically on ice shelves anyway, so it could just be sort of a random thing that was going to happen sooner or later,” says Borstad.

...

The question now is whether this event will destabilise other fractures on the ice shelf and whether that will set in motion an irreversible retreat of the ice shelf. If this happens then the Larsen C could become unstable in the not too distant future, says Borstad.