The rift in the Larsen C Ice Shelf became 11 miles longer between May 25 and May 31, the fastest it has ever occurred since January.
The rift has only 8 miles to go to tear the shelf and create one of the largest icebergs ever recorded. The crack is also starting to drift towards the ice front, which researchers argue is a clear signal of the breakup occurring very soon.
“This event will fundamentally change the landscape of the Antarctic Peninsula,” they assure.
A piece of Antarctica will drift off to the ocean
According to Project MIDAS researchers, the rift has already gone over the soft ice regions, making the full breakup of the iceberg the closest it has ever been. The Larsen C Ice Shelf will lose more than 10 percent of its total area after the massive chunk of ice breaks away from the continent.
In the future, the Larsen B Ice Shelf might be next, as it has already undergone a breakup process in 2002, which was quite similar to the one Larsen C sees today.
Larsen B collapsed in less than two months, leaving behind an iceberg with an area of 1,250 square miles. The breakup was surveyed by NASA with satellite images, as the shelf retreated 6 miles while it splintered in much smaller portions.
“The collapse of the Larsen appears to have been due to a series of warm summers on the Antarctic Peninsula, which culminated with an exceptionally warm summer in 2002. Significant surface melting due to warm air temperatures created melt ponds that acted like wedges; they deepened the crevasses and eventually caused the shelf to splinter,” NASA reported referring to the 2002 breakup of Larsen B.
Project MIDAS has tracked the rift on the Larsen C Ice Shelf for years, and now they are confident that the breakup may occur very soon. Back in February, they had theorized that the breakup could happen in 2017 because the iceberg is causing an extreme leverage upon the remainder of the ice shelf. The breakup would result in an iceberg larger than 1,930 square miles.
Between March and August 2016, the rift grew 13 miles longer, but as time passes the calving becomes more rapid. Researchers usually see the rift through satellite images, but recently they were able to see it from a plane, being able to confirm the new 11 miles that formed in less than two weeks. This year in February, the British Antarctic Survey captured footage of the massive crack that will result in the breakup of the Larsen C Ice Shelf.
Is climate change to blame?
So far, they have not been able to confirm whether the breakup is occurring due to climate change, although they are confident that the process should occur even without human-made climate change. On the other hand, they also know that warming climate has something to do with Antarctic ice shelves decaying over the course of many years.
Following Larsen B’s example, researchers from Project MIDAS believe that the Larsen C breakup should not cause a rise in sea level, mainly because the massive chunk of ice is already floating in the ocean. Some assure that the ice shelf will regrow with time, although others claim that a complete collapse is what’s going to happen in the following years.
If this were the future scenario, sea level would indeed rise, but even so, Project MIDAS researchers say that the increase would be minimal, of just a couple millimeters per year. In fact, not even waves are expected to occur after the shelf breaks up, labeled by researchers as a “slow and graceful” process, what would result in the iceberg simply floating away. One could wonder what will happen if the ice chunk starts floating northbound towards warmer waters.
In this aspect, researchers are not sure of how fast will the iceberg melt after it calves. They consider all possibilities, as the iceberg may remain in colder waters for decades, or perhaps it will drift off due to oceanic currents and winds to the north.
When it comes to local wildlife, researchers assure that no terrestrial creatures, such as penguins, will be harmed in the process. This is because penguins like to live in areas where they can access the sea to feed on fish. The ice chunk is about 200 meters tall on its border, and just like most icebergs, its submerged section is ten times larger than what lies above the ocean.
“There is not enough information to know whether the expected calving event on Larsen C is an effect of climate change or not, although there is good scientific evidence that climate change has caused thinning of the ice shelf. Once the iceberg has calved, the big question is whether Larsen C will start to retreat,” reported Project MIDAS researchers.
Source: Project MIDAS