PEI-sized iceberg just broke away from Antarctica
Wednesday, July 12, 2017, 10:02 AM - A massive iceberg, larger than Prince Edward Island and weighing in at over a trillion metric tonnes, just broke off from Antarctica's Larsen C ice shelf.
As reported towards the end of June, scientists had been monitoring the Larsen C ice shelf - a wide expanse of ice attached to the east coast of the Antarctic Peninsula - for years now, watching a large fissure spread from one end towards the other. Over the past few months, the growth of this fissure had been accelerating, and it was only a matter of time before a new iceberg calved off.
Now, as of July 12, 2017, UK-based Project MIDAS that immense crack has finally closed the distance to the edge of the ice, causing the outer portion of the ice shelf to break off, forming a massive iceberg.
Comparison between Iceberg A68 and Prince Edward Island. Credit: NASA Worldview/Google/Scott Sutherland
According to Project MIDAS:
A one trillion tonne iceberg – one of the biggest ever recorded - has calved away from the Larsen C Ice Shelf in Antarctica. The calving occurred sometime between Monday 10th July and Wednesday 12th July 2017, when a 5,800 square km section of Larsen C finally broke away. The iceberg, which is likely to be named A68, weighs more than a trillion tonnes. Its volume is twice that of Lake Erie, one of the Great Lakes.
While this is sure to speed the demise of the Larsen C ice shelf, as we've already witnessed with the Larsen A and Larsen B shelves, even an iceberg this large will not cause any kind of significant sea level rise. This is due to the fact that the ice shelf was already hanging out over water before the iceberg broke away.
It will still cause some sea level rise, simply because it is composed of fresh water, and fresh water is less dense than salt water, as explained by NASA climate scientist Gavin Schmidt.
The Larsen C ice shelf is a wide expanse of glacial ice that extends out over the waters off the east coast of the Antarctic Peninsula. It is attached to the glaciers on land, which rest directly on the bedrock of the peninsula, but it is far more vulnerable, as warming ocean waters are eroding these ice shelves from the bottom up.
Larsen C one of several ice shelves in the region. The Larsen A and Larsen B ice shelves, which are farther north of Larsen C, closer to the tip of the Antarctic Peninsula, experience similar large calving events in the past, and the rest of those two ice shelves quickly retreated in the aftermath - Larsen A in 1995 and Larsen B in 2002. Larsen D, which is farther south towards the main continent, remains intact and largely stable, however it is very narrow, and is more protected by the rugged shoreline of that part of the peninsula.
The calving of this iceberg is mostly a natural process of these ice shelves, however this event, and the likely decay of the rest of the Larsen C ice shelf, may have been accelerated by warming Antarctic waters.
Stay tuned for further updates on newly calved iceberg A68!
Sources: Project MIDAS | With files from The Weather Network