An iceberg twice the size of New York City is about to break off of Antarctica

An iceberg twice the size of New York City is about to break off of Antarctica

SOURCE: Washington Post DATE: February 25, 2019 SNIP: A chasm and a crack on the Brunt Ice Shelf in Antarctica are creeping closer and closer to one another, and when the two finally meet, a slab of ice twice the size of New York City will break away and float out to sea. The two glacial flaws are about 2.5 miles apart, and it could take days or months for them to finally rendezvous. Even when they do, the iceberg that forms in the Weddell Sea won’t be the largest spawned by Antarctica. In fact, it might not even make the historical top 20. Its size is not what makes it noteworthy — it’s what the break itself says about the natural process of iceberg calving, the way climate change might be destabilizing ice shelves similar to the Brunt, and how the movement could jeopardize the critical scientific research human residents have conducted there for more than 60...
Modest warming risks ‘irreversible’ ice sheet loss, study warns

Modest warming risks ‘irreversible’ ice sheet loss, study warns

SOURCE: NewsAsia DATE: November 13, 2018 SNIP: Even modest temperature rises agreed under an international plan to limit climate disaster could see the ice caps melt enough this century for their loss to be “irreversible”, experts warned on Monday (Nov 12). Scientists have known for decades that the ice sheets of Greenland and Antarctica are shrinking, but it had been assumed that they would survive a 1.5-2°C temperature rise relatively intact. However, according to a new analysis published in the journal Nature Climate Change, even modest global warming could cause irreversible damage to the polar ice, contributing to catastrophic sea level rises. “We say that 1.5-2°C is close to the limit for which more dramatic effects may be expected from the ice sheets,” Frank Pattyn, head of the department of geosciences, Free University of Brussels and lead study author, told AFP. His team crunched data on annual temperature rises, ice sheet coverage and known melt levels and found that both Greenland and Antarctic ice sheets would reach a “tipping point” at around 2°C. “The existence of a tipping point implies that ice-sheet changes are potentially irreversible – returning to a pre-industrial climate may not stabilise the ice sheet once the tipping point has been crossed,” said Pattyn. Many models of the 1.5-2°C scenario allow for the threshold to be breached in the short term, potentially heating the planet several degrees higher, before using carbon capture and other technologies to bring temperatures back into line by 2100. The study warned against this approach, however, saying that a feedback loop set off by higher temperatures would “lead to self-sustained melting of...
What Is Eating Away at the Greenland Ice Sheet?

What Is Eating Away at the Greenland Ice Sheet?

SOURCE: Inside Climate News DATE: April 19, 2018 SNIP: [T]emperatures are rising in the Arctic at about twice the global average. That causes melting around the edges of the ice sheet each year and reaches across more of the surface during summer heat waves. In areas near the edge of the ice sheet, things get even more interesting: a carpet of microbes and algae mixed with dust and soot, a short-lived climate pollutant, is darkening the ice sheet, absorbing the sun’s rays and accelerating the melting of the ice. New research shows this dark zone is growing. The new research, published in the journal Nature Communications, describes a geological feedback loop on the ice that’s expanding the dark zone: Warming melts the western edge of the ice sheet, releasing mineral dust from rock crushed by the ice sheet thousands of years ago. That dust blows to the surface of the ice, nurturing the microbes and algae living there. Those organisms produce colored pigments as sunscreen, which contribute to the darkening of the surface, reducing reflectivity and increasing melting. “Just the little bit of extra heat from a tiny soot particle can start transforming feathery and highly reflective snow crystals into darker, rounded grains that absorb more heat,” said climate researcher Jason...
‘Extreme’ Iceberg Seasons Threaten Oil Rigs and Shipping as the Arctic Warms

‘Extreme’ Iceberg Seasons Threaten Oil Rigs and Shipping as the Arctic Warms

SOURCE: Inside Climate News DATE: March 28, 2018 SNIP: As the planet warms, giant icebergs and sea ice that once would have remained trapped in the frozen Arctic are moving southward faster and more frequently, menacing shipping and oil and gas drilling operations. In the North Atlantic, scientists say the number of icebergs spotted south of 48 degrees latitude—where they start to get into more shipping lanes—is up again this year, following a series of extreme iceberg seasons. That ice can pose serious risks to ships and offshore oil and gas rigs. Last year, strong storms sent a swarm of icebergs surging into the oil and gas drilling field at the Grand Banks off Newfoundland, marking the fourth extreme iceberg season in a row, according to International Ice Patrol Commander Gabrielle McGrath. “There were so many in the area that we couldn’t count them all. Our models couldn’t keep up with how quickly they were moving to the south,” she said. Increased ice mobility is a sign that the Arctic climate system is likely to change in big increments in the next few decades, said University of Manitoba ice researcher Dave Babb, one of scientists who tested the sea ice off Newfoundland last year. The Arctic Ocean along the northern coast of Alaska is remaining unfrozen for more than two months longer than just 30 years ago, and there’s evidence that storms are getting stronger over the open water, and whipping up bigger waves. The extreme conditions would make cleaning up an oil spill nearly...
New Maps Highlight Antarctica’s Flowing Ice

New Maps Highlight Antarctica’s Flowing Ice

SOURCE: EOS DATE: March 12, 2018 SNIP: From bold purple to brilliant yellow-orange bursts, the map above pinpoints regions along coastal Antarctica that have recently experienced moderate to severe ice loss. The map’s surface ice velocities, measured in meters per year, come from Landsat 7 and 8 data averaged over 2013–2015. As this map shows, ice loss in western Antarctica is faster and more extensive than in the east, particularly in the Ronne (upper) and Ross (lower) ice shelves. The data underlying this map that depicts recent Antarctic ice flow are from a 13 February study published in The Cryosphere. Not only is ice loss in western Antarctica already much higher than on eastern shores, but it’s also accelerating, according to the research team behind the map and paper. By comparing the most recently available Landsat data with earlier estimates of ice velocity from 2008, the team could determine where ice loss has sped up or remained steady across nearly the entire Antarctic Ice Sheet. [T]he speed of ice loss [in the Marguerite Bay area] increased from about 2,600 to 3,000 meters per year in some locations. That’s a jump of roughly 400 meters per year...