Warm waters melting Antarctic ice shelves may have appeared for the first time in over 7,000 years

Warm waters melting Antarctic ice shelves may have appeared for the first time in over 7,000 years

SOURCE: The Conversation DATE: October 19, 2017 SNIP: The vast expanse of the Antarctic is a region of the world particularly vulnerable to climate change, where ice loss has the potential to significantly increase sea levels. Now, for possibly the first time in 7,000 years, a phenomenon known as “upwelling” (the upward flow of warmer ocean water to the surface), is thought to have caused recent ice shelf collapse around the continent – and the glacial thinning associated with it. The ocean surrounding Antarctica is extremely cold, but water over 300m deep, Circumpolar Deep Water (CDW), is about 3⁰C above the melting point of ice. Normally, the very cold water above keeps this away from ice shelves. But in some areas, CDW is spilling onto the shallow Antarctic continental shelf, causing the ice to thin. Ice shelf thinning has accelerated in recent decades, but the picture is not the same everywhere. While the east of the Antarctic has shown modest gains in ice thickness, the west has outstripped this with significant ice loss – up to 18% in vulnerable areas like the Amundsen and Bellingshausen...
Sinking into the sea: The coastline of the Northwest Territories is  eroding faster than scientists can measure it

Sinking into the sea: The coastline of the Northwest Territories is eroding faster than scientists can measure it

SOURCE: CBC News DATE: October 13, 2017 SNIP: In late August, the temperature of the Beaufort Sea hovers just above 10 degrees Celsius. For some people, the first steps into the water might be invigorating, but if you linger, it becomes stingingly painful — which is why Dustin Whalen came prepared with large rubber chest waders. This was not a personal mission to dip a toe in chilly Arctic waters and come away with photographic proof. On the contrary, the federal government scientist was looking for a time-lapse camera, one of three that met a watery end by the very forces they were meant to capture: rapid erosion on what may be the world’s fastest-disappearing island. “This is our third year trying, and as of today, this is our third year failing,” said Whalen, who works for Natural Resources Canada. “We really can’t predict just how the island will change.” Pelly, the island in question, lies about 100 kilometres northwest of Tuktoyaktuk, N.W.T., a hamlet largely known for its remoteness. The average rate of erosion for an island in this area is about 1.5 metres a year. What they have found on Pelly is that it’s washing away by as much as 40 metres each...
Worrying new research finds that the ocean is cutting through a key Antarctic ice shelf

Worrying new research finds that the ocean is cutting through a key Antarctic ice shelf

SOURCE: Washington Post DATE: October 11, 2017 SNIP: A new scientific study published Tuesday has found that warm ocean water is carving an enormous channel into the underside of one of the key floating ice shelves of West Antarctica, the most vulnerable sector of the enormous ice continent. The Dotson ice shelf, which holds back two separate large glaciers, is about 1,350 square miles in area and between 1,000 and 1,600 feet thick. But on its western side, it is now only about half that thickness, said Noel Gourmelen, a researcher at the University of Edinburgh in Scotland and the lead author of the research, which was just published in Geophysical Research Letters. The reason is the same one that is believed to be shrinking glaciers and pouring ice into the ocean across West Antarctica — warm ocean water located offshore is now reaching the ice from below. “We think that this channel is actually being carved for the last 25 years,” said Gourmelen, whose research team detected the channel using satellite observations. “It’s been thinning and melting at the base for at least 25 years, and that’s where we are now.” Dotson ice shelf as a whole has been thinning at an average rate of more than eight feet per year since 1994, even as the speed of ice flowing outward through the shelf has increased by 180 percent. But the thinning in the channel has been far greater. The research calculates that 45 feet of ice thickness is being subtracted annually from the channel. The new study calculates that as a result of this highly uneven melting,...
Narwhals Are Helping NASA Understand Melting Ice and Rising Seas

Narwhals Are Helping NASA Understand Melting Ice and Rising Seas

SOURCE: Bloomberg DATE: August 24, 2017 SNIP: Greenland’s ice cap holds beneath it 10 percent of the earth’s freshwater, enough to raise global sea levels by 20 feet. While there’s no doubt it is melting, scientists have little certainty about exactly what’s happening inside this 10,000-year-old ice roughly three times the size of Texas. Last winter was the warmest on record in the Arctic, and as Greenland heats up, understanding this glaciate has become essential to navigating our future. That’s why scientists need narwhals, whales with 9 foot long unicorn-like tusks, which are some of the only mammals benefiting from all that melting ice. “The narwhals like it,” said Josh Willis, the project lead for NASA’s Oceans Melting Greenland. When melting ice falls into the sea, it churns up the water, bringing such food as plankton and krill to the surface. The whales tend to feed at the bottom of melting glaciers and can dive to depths of 1,800 meters, precisely the areas that OMG needs to survey. It’s a perfect match. So far, OMG has measured Greenland’s seafloor and mapped the continental shelf, a crucial piece in the melt puzzle. “Ancient glaciers carved these troughs through the continental shelf,” Willis said. The channels allow warm water to flow between the glaciers, eating away at the ice. Unfortunately, “a lot more of these glaciers sit in deeper water than we expected,” he...
Scientists discover 91 volcanoes below Antarctic ice sheet

Scientists discover 91 volcanoes below Antarctic ice sheet

SOURCE: The Guardian DATE: Aug 12, 2017 SNIP: Scientists have uncovered the largest volcanic region on Earth – two kilometres below the surface of the vast ice sheet that covers west Antarctica. The project, by Edinburgh University researchers, has revealed almost 100 volcanoes – with the highest as tall as the Eiger, which stands at almost 4,000 metres in Switzerland. “If one of these volcanoes were to erupt it could further destabilise west Antarctica’s ice sheets,” said glacier expert Robert Bingham, one of the paper’s authors. “Anything that causes the melting of ice – which an eruption certainly would – is likely to speed up the flow of ice into the sea.” The discovery is particularly important because the activity of these volcanoes could have crucial implications for the rest of the planet. If one erupts, it could further destabilise some of the region’s ice sheets, which have already been affected by global warming. Meltwater outflows into the Antarctic ocean could trigger sea level rises. “We just don’t know about how active these volcanoes have been in the past,” Bingham said. However, he pointed to one alarming trend: “The most volcanism that is going in the world at present is in regions that have only recently lost their glacier covering – after the end of the last ice age. These places include Iceland and Alaska.” “Theory suggests that this is occurring because, without ice sheets on top of them, there is a release of pressure on the regions’ volcanoes and they become more...