Quantcast
Climate

Scientists Alarmed as Delaware-Sized Iceberg Breaks Off Antarctic Ice Shelf

By Ilissa Ocko and Mason Fried

Scientists watched with alarm this week as the fourth-largest ice shelf in Antarctica rapidly broke apart, causing an enormous, Delaware-size iceberg to float into the Southern Ocean.


After observing an anomalous rift widening across a section of the so-called Larsen C ice shelf for the past several years, researchers are left with some critical questions: What are this event's broader consequences for the Antarctic ice sheet, what happens next, and—importantly—what role did climate change play here?

For now, this event serves as yet another reminder that Antarctica is changing rapidly—and that action to curb rising global temperatures is critical.

Antarctica: A frontline for climate change

So far, scientists have been hesitant to attribute the Larsen C ice shelf breakup to rising global temperatures.

Indeed, such events—known to scientists as "calving"—occur naturally and are essential for maintaining ice shelf balance. Without them, ice shelves would grow unabated to cover large swaths of the Southern Ocean.

Still, the magnitude and timing of this ice loss warrants attention.

The Antarctic Peninsula, where the Larsen ice shelves reside, has long been viewed as a frontline for climate change. Warming in the peninsula exceeds the global average, glaciers there are retreating, and two other ice shelves on the peninsula already collapsed over the past couple of decades after being stable for thousands of years.

Such changes will help raise global sea levels by three to six feet by 2100, projections show, affecting dense coastal communities along our Eastern Seaboard and across the globe.

Ice breakup starts chain reaction

We do know that this calving event could set in motion a string of chain reactions that further destabilize the ice shelf and surrounding glaciers, and ultimately contribute to global sea level rise.

Ice shelves are floating extensions of grounded glaciers and ice sheets that, importantly, buttress and impede inland ice flow. When an ice shelf collapses or becomes weaker, this defense disappears, allowing inland glaciers to accelerate downslope and transport more ice to the ocean, which can quickly affect sea level.

Scientists worry that the remnant Larsen C ice shelf will now be at considerable risk of further breakup.

The new calving event reduced the ice shelf area by more than 10 percent, leaving behind an ice shelf that is inherently unstable. This can, in turn, trigger new ice cracks and rifting, and cause more icebergs to break off—further increasing the possibility of runaway ice loss amid rising global temperatures.

Whether or not this latest calving event will be attributed to climate change, it's safe to say that it will make the region more vulnerable to the impacts of global warming.

Climate change caused 2002 ice shelf collapse

The Larsen C ice shelf, named for a Norwegian whaling vessel captain who sailed the Southern Sea in the late 1800s, has two smaller northern neighbors known as Larsen A and Larsen B—both of which collapsed in the past 23 years.

Those events taught us that ice sheets, landscapes we used to think of as stable and slow to change, can actually transform rapidly.

The Larsen B collapse was particularly dramatic, with nearly the entire ice shelf disintegrating during a three-week period in 2002 after remaining stable for at least 10,000 years.

The speed of that event was unprecedented and attributed directly to increasing atmospheric warming, although rising ocean temperatures and long-term ice loss from surrounding glaciers may also have played a role.

A hint of what's to come?

After the Larsen B shelf collapse, researchers observed dramatic increases in glacier speed, thinning and ice transfer to the ocean.

Some researchers are already drawing parallels between this week's Larsen C collapse and the series of events that led to the eventual collapse of Larsen B. The latter experienced a similar large calving event in 1995 that foreshadowed further retreat and widespread disintegration in 2002.

While it remains to be seen if and when Larsen C will meet the same fate, warning signs are already in place. What's happening to the Larsen ice shelves could, in fact, be a proxy for what's to come across even larger sections of the Antarctic ice sheet unless we take action to slow warming.

Show Comments ()

EcoWatch Daily Newsletter

Sponsored
Popular
Pxhere

Trump Power Plant Plan Will Significantly Increase CO2 Pollution

The Trump administration is expected on Tuesday to propose a major rollback of the Clean Power Plan, President Obama's signature climate policy.

The replacement will relax rules for coal-fired plants and will very likely increase air pollution and planet-warming carbon dioxide emissions.

Keep reading... Show less
Climate
Global warming in Iceland. Getty Images

Arctic Warming Amplifies Extreme Weather Events Globally: Wildfires, Flooding Likely to Be More Severe

Warming in the Arctic is causing the jet stream, a belt of air held "up" around the Arctic by the temperature difference between the Arctic and warmer climates, to weaken and slow.

Keep reading... Show less
Popular
DWalker44 / Getty Images

Tons of Plastic Trash Enter the Great Lakes Every Year – Where Does It Go?

By Matthew J. Hoffman

Awareness is rising worldwide about the scourge of ocean plastic pollution, from Earth Day 2018 events to the cover of National Geographic magazine. But few people realize that similar concentrations of plastic pollution are accumulating in lakes and rivers. One recent study found microplastic particles—fragments measuring less then five millimeters—in globally sourced tap water and beer brewed with water from the Great Lakes.

Keep reading... Show less
Science
Gorancakmazovic / Getty Images

Blotting Out the Sun to Save the Earth? Seriously?

By Jeff Turrentine

Science fiction doesn't always stay fictional. Space exploration, robots and self-driving cars are just a few of the modern-day wonders that once existed only as plot devices or fantastical theories. Our capacity for turning science-fictional notions into the stuff of everyday life has grown with each new generation of scientists and microchips, such that more and more ideas previously deemed too far "out there" are now actually here, or at least technologically plausible.

Keep reading... Show less
Sponsored
Climate
Flames of the Simi Valley fire ravage a Southern California mountain side on Oct. 29, 2012. U.S. Air Force / Senior Master Sgt. Dennis W. Goff

'Hothouse Earth' Co-Author Says 'People Will Look Back on 2018 as the Year When Climate Reality Hit'

By Jessica Corbett

Amid a flurry of "breathless headlines" about warnings in a new study that outlines a possible "Hothouse Earth" scenario, one co-author optimistically expressed his belief that "people will look back on 2018 as the year when climate reality hit."

Keep reading... Show less
Popular
Kodachrome25 / Getty Images

Roof-to-Garden: How to Irrigate with Rainwater

By Brian Barth

The average American household uses about 320 gallons of water per day, a third for irrigation and other outdoor uses. Collecting the water flowing down your downspouts in rainstorms so you can use it to irrigate in dry periods is often touted as a simple way to cut back. But setting up a functional rainwater irrigation system—beyond the ubiquitous 55-gallon barrels under the downspout, which won't irrigate much more than a flower bed or two—is a fairly complicated DIY project.

Keep reading... Show less
Sponsored
Health
A family wears face masks as they walk through the smoke filled streets after the Thomas wildfire swept through Ventura, California on Dec. 6, 2017. MARK RALSTON / AFP / Getty Images

How to Protect Your Children From Wildfire Smoke

By Cecilia Sierra-Heredia

We're very careful about what our kids eat, but what about the air they breathe?

Keep reading... Show less
Health
Hero Images / Getty Images

Study: Children Have Better Nutrition When They Live Near Forests

Spending time in nature is known to boost mental and emotional health. Now, a new global study has found that children in 27 developing nations tend to have more diverse diets and better nutrition when they live near forests.

The paper, published Wednesday in Science Advances, provides evidence that forest conservation can be an important tool in promoting better nutrition in developing countries, rather than clear-cutting forests for more farmland.

Keep reading... Show less
Sponsored

mail-copy

The best of EcoWatch, right in your inbox. Sign up for our email newsletter!