(CN) — An enormous city-sized ice shelf broke off in East Antarctica, alarming scientists who believed the region was one unlikely to be immediately affected by a changing climate.
The Conger Ice Shelf, a chunk of ice the size of Rome, collapsed into the ocean this month — marking the first time in human history that an ice structure of that size has broken off in the frigid corner of the planet that is widely regarded as Earth’s coldest.
The ice collapse came amid soaring temperatures in the region, with daily temperatures in East Antarctica 70 degrees Fahrenheit above normal and alarming scientists who study the region.
“Antarctic climatology has been rewritten,” tweeted Stefano Di Battista, a researcher who studies temperatures in the Antarctic region.
The Conger Ice Shelf spans about 460 square miles and is a parcel of the larger Antarctic Sheet, which scientists fear is rapidly collapsing and melting due to higher global surface temperatures. Its failure could cause problems for coastal communities by raising the level of the oceans.
“The complete collapse of the Conger Ice Shelf in recent days is the end of a long-term multidecadal demise of the ice shelf,” said Bertie Mills, a research fellow at the University of Edinburgh.
While some scientists are ringing alarm bells, saying the ice shelf collapse is a preview of accelerated melting in the polar regions, others are taking a more measured approach to the event.
“Iceberg calving events are a natural part of the “checks and balances” of the Antarctic Ice Sheet, it has to shed the mass it gains through snowfall,” said Helen Amanda Fricker, a scientist with the Scripps Polar Institute. “But since there was also an extreme warming event around this time, obviously we do need to examine if there is a link.”
The Antarctic Ice Sheet is losing about 200 billion metric tons of ice every year due to warming, scientists say, creating about a half millimeter of sea-level rise annually.
But unlike the Arctic polar region, which is much more predictable for scientists, Antarctica remains mysterious, with some regions of the southern continent seeming more prone to melting and ice shelf collapse than others.
One reason the Conger Ice Shelf collapse is so concerning for some scientists is because East Antarctica, where the shelf is located, has long been one of the more stable regions in terms of temperature and melting.
In 2002, the Larsen B Ice Shelf collapsed into the sea over a months-long period, which first caught the attention of polar researchers who believed the event was closely connected to human-caused climate change.
“One hundred years ago, and even 50 years ago, and actually even 20 years ago, we thought that ice shelves in Antarctica changed on really really long time scales,” Fricker told Scientific American this year. “And then 2002, boom! Larsen Ice Shelf collapses, and we’re all like, ‘What just happened?’”
The Conger collapse created a major iceberg, called C-38.
While some scientists believe the record temperatures impacted the collapse, others believe ocean currents, with warmer waters being driven toward Antarctica, represent the true culprit.
“A brief heat wave won’t affect things too much in that regard,” said Walter Meier with the National Snow and Ice Data Center.
But the largest ice shelf collapse on record has created a consensus among scientists that the Antarctic region is changing dynamically and at a pace not seen in human history.