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A 130-metre-wide waterfall drains meltwater from the Nansen Ice Shelf into the ocean. Stuart Rankin via Flickr

Giant Waterfall in Antarctica Worries Scientists

By Tim Radford

Scientists poring over military and satellite imagery have mapped the unimaginable: a network of rivers, streams, ponds, lakes and even a waterfall, flowing over the ice shelf of a continent with an annual mean temperature of more than -50C.

In 1909 Ernest Shackleton and his fellow explorers on their way to the magnetic South Pole found that they had to cross and recross flowing streams and lakes on the Nansen Ice Shelf.

Antarctic Waterways

Now, U.S. scientists report in the journal Nature that they studied photographs taken by military aircraft from 1947 and satellite images from 1973 to identify almost 700 seasonal networks of ponds, channels and braided streams flowing from all sides of the continent, as close as 600km to the South Pole and at altitudes of 1,300 meters.

And they found that such systems carried water for 120km. A second research team reporting a companion study in the same issue of Nature identified one meltwater system with an ocean outflow that ended in a 130-meter wide waterfall, big enough to drain the entire surface melt in a matter of days.

In a world rapidly warming as humans burn ever more fossil fuels, to add ever more greenhouse gases into the atmosphere, researchers expect to observe an increase in the volume of meltwater on the south polar surface. Researchers have predicted the melt rates could double by 2050. What isn't clear is whether this will make the shelf ice around the continent—and shelf ice slows the flow of glaciers from the polar hinterland—any less stable.

"This is not in the future—this is widespread now, and has been for decades," said Jonathan Kingslake, a glaciologist at Columbia University's Lamont-Doherty Earth Observatory, who led the research.

"I think most polar scientists have considered water moving across the surface of Antarctica to be extremely rare. But we found a lot of it, over very large areas."

The big question is: has the level of surface melting increased in the last seven decades? The researchers don't yet have enough information to make a judgment.

"We have no reason to think they have," Dr Kingslake said. "But without further work, we can't tell. Now, looking forward, it will be really important to work out how these systems will change in response to warming, and how this will affect the ice sheets."

Many of the flow systems seem to start in the Antarctic mountains, near outcrops of exposed rock, or in places where fierce winds have scoured snow off the ice beneath. Rocks are dark, the exposed ice is of a blue colour, and during the long days of the Antarctic summer both would absorb more solar energy than white snow or ice. This would be enough to start the melting process.

The Antarctic is already losing ice, as giant floating shelves suddenly fracture and drift north. There is a theory that meltwater could be part of the fissure mechanism, as it seeps deep into the shelves.

Drainage Theory

But the companion study, led by the polar scientist Robin Bell of the Lamont-Doherty Observatory suggests that drainage on the Nansen Ice Shelf might help to keep the ice intact, perhaps by draining away the meltwater in the dramatic waterfall the scientists had identified.

"It could develop this way in other places, or things could just devolve into giant slush puddles," she said. "Ice is dynamic, and complex, and we don't have the data yet."

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Earth's Melting Glaciers Captured in Stunning Before-and-After Images

If you don't agree with 97 percent of climate scientists that climate change is real, you should at least believe your own eyes.

The Earth's rapidly rising temperatures has dramatically transformed our landscapes, as you can see quite clearly in these vivid photos of the world's melting glaciers.

Retreat of the Columbia Glacier, Alaska, USA, by ~6.5 km between 2009 and 2015. Credit: James Balog and the Extreme Ice Survey

The photos appeared in the new paper "Savor the Cryosphere," published in the peer-reviewed GSA Today, a publication of the Geological Society of America. The cryosphere is the Earth's frozen waters.

"We have unretouched photographic evidence of glaciers melting all around the globe," co-author Gregory Baker, adjunct professor of geology at the University of Kansas, said.

"That includes the ice sheets of Greenland and Antarctica—they're reduced in size. These aren't fancy computer models or satellite images where you'd have to make all kinds of corrections for the atmosphere. These are simply photos, some taken up to 100 years ago, and my co-authors went back and reacquired photos at many of these locations. So it's just straightforward proof of large-scale ice loss around the globe."

Baker's research career centers on geophysical imaging of Earth's subsurface and geoscience education.

Stein Glacier, Switzerland, retreat of ~550 m from 2006 to 2015. Credit: James Balog and the Extreme Ice Survey

Photographer James Balog, who was featured in the Emmy Award winning climate change documentary, Chasing Ice, contributed photographs from the Extreme-Ice Survey.

Other co-authors of the paper include Richard Alley, an American geologist who was invited to testify about climate change by Vice President Al Gore; Patrick Burkhart of Slippery Rock University; Lonnie Thompson of the Byrd Polar Research Center at Ohio State University; and Paul Baldauf of Nova Southeastern University also contributed to the paper.

The team hopes the paper will raise awareness about the world's melting glaciers.

"We have all heard of the impact of melting ice on sea level rise, but the public also need to be aware that places around the world depend on glaciers for their water and are going to come under increasing stress, and we already see how water shortages lead to all kinds of conflict," Baker said.

"The other critical point often overlooked is that when glaciers melt we're losing these scientific archive records of past climate change at specific locations around the Earth, as if someone came in and threw away all your family photos."

Solheimajokull, Iceland, retreat of ~625 m from 2007 to 2015. Credit: James Balog and the Extreme Ice Survey

"Glacier ice contains fingerprint evidence of past climate and past biology, trapped within the ice," Baker continued.

“Analyzing ice cores is one of the best ways to analyze carbon dioxide in the past, and they contain pollen we can look at to see what kind of plant systems may have been around. All of this information has been captured in glaciers over hundreds of thousands of years, and sometimes longer—Greenland and Antarctica cover perhaps up to a million years. The more that glacial ice melts, the more we're erasing these historical archives that we may not have measured yet in some remote glaciers, or deep in ice caps, that can tell us the history of the Earth that will be gone forever."

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Massive Iceberg Hangs by 12-Mile 'Thread'

The growing rift in the Antarctic Peninsula has now lengthened to 110 miles, meaning that the Larsen C ice shelf is now connected to the main ice shelf by only a 12-mile "thread," USA TODAY reports.

The British Antarctic Survey determined that the crack has expanded by 50 miles since 2011.

"It is particularly hard to predict when it will occur," Adrian Luckman of Project MIDAS told USA TODAY about the eventual calving, which would create a Delaware-sized iceberg. "I am quite surprised as to how long it is holding on!"

"The rift (or crack) has continued to open, and the berg continues to drift outward at a very consistent rate," Luckman added.

However, he noted that the crack has not grown longer in recent weeks.

As EcoWatch mentioned previously, the loss of this portion of the ice shelf will not raise sea levels as it is already floating on the water. However, as these ice shelves disintegrate, the land-locked glaciers they hold back may begin sliding into the sea. If all of the ice the Larsen C ice shelf holds back slides into the ocean, it will raise sea levels globally by four inches.

According to Project MIDAS, "there is not enough information to know whether the expected calving event on Larsen C is an effect of climate change or not, although there is good scientific evidence that climate change has caused thinning of the ice shelf."

Temperatures at the Antarctic Peninsula, where the Larsen ice shelf is found, have risen by 2.5 degrees Celsius in the past 50 years.

Antarctica's ice shelves are indeed melting rapidly as ocean waters warm. Climate Nexus reported in October that three glaciers in West Antarctica have undergone "intense unbalanced melting," risking their stability and further acceleration of sea level rise.

Research published in Nature Communications found that the Smith, Pope and Kohler glaciers in the Amundsen Sea embayment collectively lost about 1,000 feet of ice from 2002 to 2009.

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Photo credit: Sea Shepherd Global

333 Minke Whales Killed by Japanese Fleet

Japan's whaling vessels returned to port with 333 minke whales on Friday after its months-long Antarctic hunt.

The Fisheries Ministry said the whales were killed in the name of science.

"The purpose of this research is to carry out a detailed calculation of the catch limit of minke whales and study the structure and dynamics of the ecological system in the Antarctic Ocean," it said.

Japan plans to hunt nearly 4,000 whales over the next 12 years despite the International Whaling Commission's 1986 moratorium on commercial hunting. The country launched its "scientific whaling" program in 1987 as a loophole to the moratorium.

Reuters noted that Japan's ultimate goal is the resumption of commercial whaling. Japan insists that most whale species are not endangered and that eating whale is part of its culture, even though most Japanese people no longer eat it.

Conservation groups have rebuked the most recent hunt.

"Today Sea Shepherd mourns the loss of these whales," the marine wildlife conservation organization said. "We have called an emergency meeting of the Global Board of Directors in Amsterdam this weekend to review our whale defense strategy in the Southern Ocean, and will release a more detailed statement on Monday morning."

Sea Shepherd's long-running Operation Nemesis campaign has a mission of ending Japan's whaling program. The group is urging governments to "stop making hollow statements of disapproval and start taking action to hold Japan accountable" or the "needless slaughter of marine life will continue."

Kitty Block, the executive vice president of Humane Society International, had similar sentiments.

"There is no robust scientific case for slaughtering whales," Block said. "Commercial whaling in this, or any other disguise, does not meet any pressing human needs and should be relegated to the annals of history."

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The women of Homeward Bound. Photo credit: Anne Christianson

These 76 Women Scientists Are Changing the World

By Molly Taft

Heidi Steltzer's job, as she put it, is "hiking where no one else will go." As a mountain and polar ecologist studying rare plants, she's accustomed to traveling to breathtaking Arctic vistas to chase flora along mountain ridges.

But watching glaciers calve on her first trip to Antarctica last December was a one-of-a-kind experience for the scientist. "You kind of want to see it," she said. "Even though you know it's not a good thing, you kind of want to be there."

As she watched the great icebergs float by the boat in Neko Harbor, another member of Seltzer's trip waved her arm at the scene, as if summoning a force to shave the glaciers surrounding them.

"Can you imagine if any one of us had that kind of power to see ice calve when you wanted to see it?" laughed Seltzer. "But at the same time, we knew, collectively—we do have that power. You can't say these specific glaciers are definitively calving because of human action. But these events continuing to happen is consistent in that system and consistent with what we know about human activity and climate change."

Heidi Steltzer.Anne Christianson

Seltzer's colleagues were more knowledgeable than your average gaggle of tourists. The travelers on her trip were all scientists and several of them focus specifically on climate change. What's more, her 75 companions on the three-week trip were all women, bound together on the largest-ever, all-female expedition to Antarctica. The trip was the focal point of a year-long leadership development program called Homeward Bound, which aims to groom 1,000 women with science backgrounds over the next 10 years to influence public policy and dialogue.

While women made up more than 50 percent of the U.S. workforce in 2016, they represented only 24 percent of workers in STEM—science, technology, engineering and math. Representation in public policy is even worse: Women hold less than 23 percent of parliamentary positions worldwide and less than 20 percent of Congress is female. The founder of Homeward Bound told Reuters that inspiration came from the trip from hearing two scientists joke that a beard was a requirement to land an Antarctic research leadership role.

The women of Homeward Bound. Anne Christianson

The problem of female leadership in STEM isn't a new one. When Katharine Hayhoe, director of the Climate Science Center at Texas Tech University and a leading U.S. climate voice, was a second-year undergraduate physics student, the head of the department called her into his office to ask how the program could help encourage her career as a female physicist.

"My mentors in science from day one have all been male," she recalled. "I've learned a lot from them and I've been incredibly encouraged and supported by them. But at the same time, there have been differences between us."

Katharine Hayhoe.Katharine Hayhoe

Lifestyle and family changes, Hayhoe emphasized, provide a particular sticking point between the genders in STEM. "As I got older, I started to realize how big the gap was between colleagues who basically had a spouse who managed everything full time," she said. "They could just, at the drop of the hat, leap on an airplane and be off to a meeting, versus a mother who, before you do anything, you've got to do all the laundry, freeze the meals, figure out who is picking the kids up from schools. At this point, if someone asks me to do something at the drop of the hat, the answer is no—and this still happens to me today."

Steltzer echoed similar experiences. "At one point in time, women were present in equal measures to myself at a peer level," she said. "But now that I'm in my early 40s, an associate professor, in many environments I'm in there are fewer women. There are ways we can do better."

The polar plunge at Neko Bay.Sarah Brough

She pointed out that the perception of "good old boys' clubs" in male-dominated fields may just be men connecting with each other over shared experiences. Getting a group of female scientists together can create a collaborative, experience-based atmosphere that can be difficult for women to find at home. "Homeward Bound created for us women a space and a place where we feel connected to one another."

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63.5º F: Antarctica's New Record High Temp

The World Meteorological Organization announced Wednesday that Antarctica hit a new record high recorded temperature of 63.5 degrees F.

The record, set at an Argentine research base in 2015 and just confirmed by the World Meteorological Organization, breezes past the previous record of 59 degrees.

Meanwhile, real time data released from the National Snow and Ice Data Center showed only 2.131 million square kilometers of sea ice surrounding the continent on Feb. 28—about 159,000 square kilometers less than the record low set in 1997. The Antarctic ice sheet contains 90 percent of the world's freshwater, which would raise sea levels by 200 feet if it were to melt.

For a deeper dive:

Temps: Reuters, USA Today, Gizmodo

Sea ice: Washington Post

Commentary: Forbes, Marshall Shepherd column

For more climate change and clean energy news, you can follow Climate Nexus on Twitter and Facebook, and sign up for daily Hot News.

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Photo credit: NASA Earth Observatory

Manhattan-Sized Iceberg Breaks off Antarctica

Antarctica's Pine Island Glacier lost another large chunk of ice at the end of January. The section of ice that broke off the glacier on the western coast of Antarctica was roughly the size of Manhattan. It was 10 times smaller than the piece the same glacier sloughed in July 2015.

After the enormous piece of ice broke off The Pine Island Glacier in 2015, cracks were spotted during a late 2016 flyover, Climate Central reported. The recent smaller, though still substantial, ice breakage is considered an "after-shock" event, Ohio State glaciologist Ian Howat told NASA. NASA's Operational Land Imager captured a series of images documenting the ice loss.

The Pine Island Glacier is known as a fast stream glacier because it moves quickly and commonly sheds ice. It is already responsible for 25 percent of Antarctica's ice loss, according to Digital Journal.

The phenomenon of rapid glacial calving or ice loss "fits into the larger picture of basal crevasses in the center of the ice shelf being eroded by warm ocean water, causing the ice shelf to break from the inside out," Howatt said. Basal crevasses are cracks that extend upward from the base of the body of ice.

Sometimes, basal ice cracks are not visible. Small rifts of this nature exist about six miles into the Pine Island Glacier and are expected to result in further calving.

Also in Antarctica, a crack longer than 80 miles in the Larsen C ice shelf is currently being monitored. As the rift grows, the shelf gets closer to shedding a more than 3,000 square mile iceberg.

In March 2016, a study, Contribution of Antarctica to past and future sea-level rise, in the journal Nature explained how ocean warming was driving rising sea levels and the collapse of the Western Antarctic ice sheet.

"Antarctica has the potential to contribute more than a meter of sea-level rise by 2100 and more than 15 meters by 2500, if emissions continue unabated. In this case atmospheric warming will soon become the dominant driver of ice loss, but prolonged ocean warming will delay its recovery for thousands of years," the study states.

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Shocking Crack in Ice Shelf Grows Another 11 Miles

A 70-mile long crack in the Larsen C ice shelf grew another shocking 11 miles in December alone. That leaves just 12 miles before an iceberg the size of Delaware snaps off into the Southern Ocean.

"The Larsen C Ice shelf in Antarctica is primed to shed an area of more than 5000 square kilometers [approx. 3,100 square miles] following further substantial rift growth," wrote the Project MIDAS team, which has been studying the ice shelf.

"After a few months of steady, incremental advance since the last event, the rift grew suddenly by a further 18 kilometers [about 11 miles] during the second half of December 2016."

During the last Antarctic winter, the rift averaged about three miles per month of growth. In December, NASA released a set of images that found the crack measured 70 miles in length, 300 feet wide and one-third of a mile deep.

The sudden acceleration of the split in the ice has scientists convinced that a massive calving event is imminent.

"If it doesn't go in the next few months, I'll be amazed," Professor Adrian Luckman, project leader from Swansea University, told BBC News.

By itself, the iceberg that is set to break off won't lead to a rise in sea levels, as the ice shelf already floats on the ocean. However, the Larsen ice shelf acts as a buttress against continental glaciers that could then be free to slide into the sea. BBC reports that if all the ice that Larsen C holds back were released into the ocean, global waters would rise by 10 cm, or four inches.

Globally, sea levels have risen about eight inches since 1901. Its effects can be seen in increased flooding in South Florida, coastal erosion in Louisiana, intrusion of seawater into ground aquifers and stronger storm surges such as those seen in Superstorm Sandy.

Antarctica—which holds 90 percent of the Earth's fresh water—is losing about 92 billion tons of ice per year. The rate of loss has doubled from 2003 to 2014.

Long-term satellite observations show that Antarctic glaciers are rapidly retreating. A separate rift in the East Antarctic is forcing a British research station to relocate.

The Larsen C is the latest section of the huge ice shelf to break off. Larsen A collapsed in 1995. In 2002, Larsen B began to break apart. Within six weeks, a 1,235 square mile chunk of ice slipped away.

When the Larsen C ice shelf breaks off, it "will fundamentally change the landscape of the Antarctic Peninsula," said the U.K.-based Project MIDAS team.

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