Environment

Giant iceberg enters "final phase" of breaking away from Antarctica

The Halloween Crack, discovered in October 2016, is threatening the Brunt Ice Shelf
The Halloween Crack, discovered in October 2016, is threatening the Brunt Ice Shelf
View 1 Image
The Halloween Crack, discovered in October 2016, is threatening the Brunt Ice Shelf
1/1
The Halloween Crack, discovered in October 2016, is threatening the Brunt Ice Shelf

A huge iceberg, roughly twice the size of New York City, is set to soon break off from the Brunt Ice Shelf in Antarctica. With two large cracks due to meet within the next few months, a research station has already been relocated as scientists watch the rifting event enter its "final phase."

The soon-to-be-born iceberg would measure more than 1,500 sq km (580 sq mi), and is between 150 and 250 m (492 and 820 ft) thick. Researchers have been watching the Brunt Ice Shelf carefully since 2012, when a crack that had sat dormant for 35 years suddenly showed signs of movement again. Chasm 1, as it's known, has grown steadily over the last seven years.

Then in October 2016, a second crack appeared. The "Halloween Crack," as it came to be known, was spotted to the north, running perpendicular to Chasm 1. A meeting of the two seemed likely, which would separate a large chunk of the Brunt Ice Shelf from the Antarctic mainland. In response, the Halley VI Research Station was towed about 14 miles (23 km) inland, to the other side of the cracks.

That fateful meeting finally looks set to happen within as little as two months. Interestingly enough, while it sounds like the kind of event we'd expect in a world with a changing climate, scientists aren't chalking this one up to that usual suspect.

"What many people do not realize is that this is a natural process and something which has happened time and again," says Hilmar Gudmundsson, an author of a study examining the calving event. "We recognize that climate change is a serious problem which is having an impact around the world, and particularly in the Antarctic. However, there is no indication from our research that this particular event is related to climate change."

The loss of the Brunt Ice Shelf isn't expected to contribute to sea level rise, either. Since the ice is floating on the ocean, it's already displacing the same amount of water as it will add after it melts. To back up the claim that this event is a part of the natural life cycle of the ice shelf, the team also points to historical evidence.

"Maps drawn by Shackleton and Wordie during their expedition to the Brunt Ice Shelf in 1915 show that, at that time, the ice shelf was quite extended," says Gudmundsson. "However, by the time the Halley Research Station was established in the 1950s the reach of the ice shelf was much shorter, indicating that a large iceberg must have broken away at some point after 1915."

The research is being considered for publication in the journal The Cryosphere, and the team describes the work in the video below.

Source: Northumbria University

Large Antarctic Ice Shelf, home to a UK research station, is about to break apart

6 comments
watersworm
Like (almost) every end of south hemisphere summer... Not the biggest Anatarctiqua iceberg anyway.
emccaff
Sadly, the amount of shelf ice that is leaving the glacier, while certainly not the first event of it's type, will certainly not be replaced by newly formed ice shelf. So, yes, the information given is correct. The information not spoken is what will bring us down.
mc08990
It rained in Georgia a few days ago as well. We are in the middle of a brief inter-glacial warming period. The period is called the Holocene. Also, icebergs struggle to survive in the Antarctic. It's hard for ice to build up on water. Glaciers are constantly breaking off in the Antarctic, even in the coldest of times.
ljaques
Thank you, Hilmar, for acknowledging that this is a repeat, natural function that is not associated with anyone's hysterical global warming fits.
aksdad
emccaff says "the amount of shelf ice that is leaving the glacier...will certainly not be replaced by newly formed ice shelf." Really? As the article pointed out, ice shelves break off regularly. They are replaced by new ice flowing out from the continent. That "new ice" is formed from continuing snowfall over the continent. Antarctica's ice isn't going away anytime soon, measured in geologic terms, let alone dozens of human lifetimes.
Robert in Vancouver
The same people at NASA who were saying there was global warming are now saying the last 2 years have been the most global cooling in 100 years, and are concerned this could be an ongoing trend. In other words, the science isn't settled. (Real science is never settled)