A 300-foot-wide, 70-mile-long rift in Antarctica’s Larsen C ice shelf, as seen in November 2016. John Sonntag/IceBridge/NASA Goddard Space Flight Center
Earlier this week, a crack in Antarctica’s Larsen C ice shelf caused a 1.1-trillion-ton block of ice to calve, forming a colossal iceberg roughly the area of Delaware.
Just days after breaking off the continent, the iceberg, now dubbed A68, has broken into two pieces.
“A68 is starting to lose some chunks already! Still an enormous berg though,” Martin O’Leary a glaciologist at Swansea University, wrote in a tweet early Friday morning for the Antarctic research program Project MIDAS.
After years of lengthening and widening, the rift in the Larsen C ice shelf grew rapidly in the past year, and birthed the iceberg sometime between July 10 and July 12. When it calved, the iceberg was the third largest ever recorded.
The US National Ice Center tracks and unceremoniously assigns icebergs their names based on location and order of discovery. When sizable icebergs break off a main iceberg, they take the same name with added letters.
Adrian Luckman/Twitter; NASA/Suomi
“Just as A68 gets its official name, Suomi … shows that it has broken into two pieces — A68a and A68b I guess?” Adrian Luckman, also a glaciologist at Swansea University and member of Project MIDAS, said in a tweet. Luckman also posted the recent Suomi satellite image of the new fragment shown on the right.
When it calved, iceberg A68 had more than double the volume of Lake Erie in the Great Lakes.
Where A68 goes from here — and when it melts — is anyone’s guess at this point. However, the process could take years, as it has for similarly large icebergs.
rockman on Mon, 17th Jul 2017 12:16 pm
This is certainly not an argument against the global warming that’s happening. But years ago I ready a study (USGS?) that indicated the increase in ice flows of the continent was likely due to a temperature increase (and subsequent melting) “lubricating” the base of the ice. But given the thickness of the ice and its insulation nature it would take about 10,000 years for any surface temperature changes to reach the base of the ice. They could not specifically point to a source that might be warming the ice/earth interface.
Apneaman on Tue, 18th Jul 2017 11:31 am
rockman, the calving itself is somewhat being over-hyped. It’s the thinning of the shelf and what it holds back that is the most cause for concern. Among the brainiacs who study Antarctic ice shelves, some say AGW contributed to it calving when it did, and some say not. I say it’s a moot point.