'Gigantic' iceberg breaks away from ice shelf in Antarctica
A colossal iceberg roughly the size of Los Angeles or Sydney, Australia, and weighing an estimated 347 billion tons broke off from the Amery Ice Shelf in Antarctica last week.
The 630-square-mile iceberg, named D28, separated from the ice shelf on September 26, next to a location scientists had been watching for nearly 20 years. The area was known as the "Loose Tooth," because it appeared to be barely hanging on to the ice shelf in recent years.
"We first noticed a rift at the front of the ice shelf in the early 2000s and predicted a large iceberg would break off between 2010-2015," said Helen Amanda Fricker, one of the lead researchers on the team studying D28, said in a statement from the Australian government's Antarctic division.
The Antarctic division also released stunning aerial footage showing the "gigantic" hunk of ice that until last week had been hanging on by a thread. Below is a video animation made from satellite imagery showing the moment the break-away iceberg split from the Amery Ice Shelf.
A 1600 km² iceberg broke off Amery Ice Shelf, as seen in @CopernicusEU Sentinel-1 radar images. This part, coined the "Loose Tooth" by @helenafricker and colleagues, has been hanging by a thread since 2002 (https://t.co/IUhXDCWOFF) and finally gave way last week.@sentinel_hub pic.twitter.com/GG60Sk52GB
— Bert Wouters (@bert_polar) September 30, 2019
The GIF shows the iceberg rotating westward, apparently pushed by the prevailing easterly winds, which reached speeds of 40 mph, according to AccuWeather meteorologist Jim Andrews.
"The calving will not directly affect sea level, because the ice shelf was already floating, much like an ice cube in a glass of water," Dr. Galton-Fenzi said in the statement released by the Australian Arctic division.
However, Fenzi said scientists are interested to see if the loss of ice will influence the ocean melting under the remaining ice shelf and the speed at which the ice flows off the continent.
Amery is the third-largest ice shelf in Antarctica, and is a key drainage channel for the east of the continent -- a closely-watched piece of real estate that researchers have been studying since the 1960s.
Currently, there are instruments deployed on the ice measuring the impact of ocean melt and ice flow. "We don't think this event is linked to climate change, it's part of the ice shelf's normal cycle, where we see major calving events every 60 to 70 years," Fricker said.
If the calving isn't linked to climate change, then what should people make of it? "I like to think of it as being akin to our fingernails -- they grow and break off -- at least if we don't keep them clipped," Andrews said.
