Satellite images show iceberg bigger than Seattle break away from Antarctic glacier
Satellite images from the European Space Agency show when a massive iceberg split from a glacier in Antarctica on Tuesday. Combined, the images demonstrate how icebergs — the size of major cities and small countries — are breaking off into the ocean at a faster rate due to the earth's changing climate.
Captured over three years, the images were combined into a time-lapse animation by Adrian Luckman, a satellite imaging glaciologist and professor of geology at Swansea University in Wales. Together, they show three major calving events — the term for when intact chunks of ice split off into the ocean — over the past three years.
The animation begins in June 2017, and ends earlier this week on February 11, 2020, when the most recent calving took place.
Without a reference point, satellite images can make it difficult to conceptualize the size of these gigantic ice masses. For scale, Tuesday's calving produced an iceberg bigger than the city of Seattle, twice the size of Washington D.C., about the same size as Las Vegas, nearly the size of Atlanta, and roughly the same size as the nation of Malta.
Photos taken just a couple miles from the glacier by polar marine scientist Richard Larter show how up close the iceberg appears as an imposing wall of ice. The glacier's "floating ice front" has an average thickness of approximately 500 meters, according to the European Space Agency.
The chunk broke off from the Pine Island Glacier in Antarctica, which helps connect the West Antarctic Ice Sheet with the ocean, the agency says.
It is usually difficult to capture calvings, according to the United Kingdom's Centre for Polar Observation and Modelling. That's because most of the processes that drive the natural event are hidden below the water, and satellites typically pass overhead only once a day, oftentimes missing the moment of action.
Pine Island, however, is shrinking fast. Its rapid disintegration has made it one of the most "intensively and extensively investigated glaciers" in the Antarctic, according to the agency.
The heightened attention on Pine Island led scientists to spot "growing cracks" in satellite images of the glacier last year. "Since then, scientists have been keeping a close eye on how quick the cracks were growing," the agency wrote.
Along with its neighbor the Thwaites Glacier, Pine Island has continuously lost ice over the last 25 years.
"Satellites have established a porthole through which the public can watch events like this unfold in remote regions around the world," said Mark Drinkwater, a senior scientist and cryosphere specialist.
After Tuesday's historic calving, the iceberg quickly shattered into many smaller pieces. What these pieces will do to overall sea level rise remains unknown. However, Larter warned on Twitter that the iceberg is "part of an ice shelf at the terminus of a glacier containing enough ice" to raise the sea level by more than 0.5 meters (over 1.5 feet). And, according to the European Space Agency's website, ice loss from Pine Island has already "contributed more to sea-level rise over the past four decades than any other glacier in Antarctica."
The Antarctic Peninsula is one of the fastest-warming places on Earth. During the first week of February, the weather on the Peninsula was sunny and a preliminary record-breaking 64.9 degrees Fahrenheit — warmer than most of Texas.
New research published in December indicated that "Antarctica is highly vulnerable to projected increases in ocean temperatures and may drive ice–climate feedbacks that further amplify warming."
According to Drinkwater, "what is unsettling is that the daily data stream reveals the dramatic pace at which climate is redefining the face of Antarctica."
