Antarctica Is Melting, and Giant Ice Cracks Are Just the Start

Antarctica Is Melting, and Giant Ice Cracks Are Just the Start

SOURCE: National Geographic DATE: June 28, 2017 SNIP: Seen from above, the Pine Island Ice Shelf is a slow-motion train wreck. Its buckled surface is scarred by thousands of large crevasses. Its edges are shredded by rifts a quarter mile across. In 2015 and 2016 a 225-square-mile chunk of it broke off the end and drifted away on the Amundsen Sea. The water there has warmed by more than a degree Fahrenheit over the past few decades, and the rate at which ice is melting and calving has quadrupled. On the Antarctic Peninsula, the warming has been far greater—nearly five degrees on average. That’s why a Delaware-size iceberg is poised to break off the Larsen C Ice Shelf and why smaller ice shelves on the peninsula have long since disintegrated entirely into the waters of the Weddell Sea. But around the Amundsen Sea, a thousand miles to the southwest on the Pacific coast of Antarctica, the glaciers are far larger and the stakes far higher. They affect the entire planet. “These are the fastest retreating glaciers on the face of the Earth,” says Eric Rignot, a glaciologist at the NASA Jet Propulsion Laboratory in Pasadena,...
Scientists stunned by Antarctic rainfall and a melt area bigger than Texas

Scientists stunned by Antarctic rainfall and a melt area bigger than Texas

SOURCE: Washington Post DATE: June 15, 2017 SNIP: Scientists have documented a recent, massive melt event on the surface of highly vulnerable West Antarctica that, they fear, could be a harbinger of future events as the planet continues to warm. In the Antarctic summer of 2016, the surface of the Ross Ice Shelf, the largest floating ice platform on Earth, developed a sheet of meltwater that lasted for as long as 15 days in some places. The total area affected by melt was 300,000 square miles, or larger than the state of Texas, the scientists report. That’s bad news because surface melting could work hand in hand with an already documented trend of ocean-driven melting to compromise West Antarctica, which contains over 10 feet of potential sea level rise. Image information: Number of days in January 2016 when surface melt was detected from passive microwave satellite observations. (by Julien...
The Larsen C Iceberg Is on the Brink of Breaking Off

The Larsen C Iceberg Is on the Brink of Breaking Off

SOURCE: Climate Central DATE: May 31, 2017 SNIP: The saga of the Larsen C crack is about reach its stunning conclusion. Scientists have watched a rift grow along one of Antarctica’s ice shelves for years. Now it’s in the final days of cutting off a piece of ice that will be one of the largest icebergs ever recorded. The crack has spread 17 miles over the past six days, marking the biggest leap since January. It’s also turned toward where the ice shelf ends and is within eight miles of making a clean break. There’s not much standing in its way either. “The rift has now fully breached the zone of soft ‘suture’ ice originating at the Cole Peninsula and there appears to be very little to prevent the iceberg from breaking away completely,” scientists monitoring the ice with Project MIDAS wrote on their blog. The breakup is sure to be a spectacle both awe-inducing and horrifying. The iceberg on the verge of splitting off is estimated to be the size of Delaware, covering an area of 1,930 square...
Antarctic sea ice ‘obliterates’ previous minimum record, in remarkable reverse

Antarctic sea ice ‘obliterates’ previous minimum record, in remarkable reverse

SOURCE: The Sydney Morning Herald DATE: March 1, 2017 SNIP: There is about 10 per cent less sea ice in Antarctica this year than the previous record minimum – a stunning reversal after new highs were set in 2014. The area covered by sea ice has been tracking below the previous record low of 2.32 million square kilometres set in February 2011 for most of the past three weeks, and is now about 10 per cent lower. “One would probably say that the old record was obliterated,” Dr Lieser said. Sea ice is now at record lows at both ends of the planet, exposing more of the dark seas to solar radiation, rather it being reflected back to space. The lack of ice will likely add to the build-up in heat in the oceans that could hinder ice recovery in the south and accelerate the melt in the north as seasons shift towards winter and summer,...
Antarctic Bottom Waters Freshening at Unexpected Rate

Antarctic Bottom Waters Freshening at Unexpected Rate

SOURCE: Scripps Institution of Oceanography DATE: February 1, 2017 SNIP: In the cold depths along the seafloor, Antarctic Bottom Waters are part of a global circulatory system, supplying waters rich in oxygen, carbon, and nutrients to the world’s oceans. Over the last decade, scientists have been monitoring changes in these waters. But a new study from the Woods Hole Oceanographic Institution (WHOI) and Scripps Institution of Oceanography at the University of California San Diego suggests these changes are themselves shifting in unexpected ways with potentially significant consequences for the ocean and climate. In a paper published Jan. 25 in the journal Science Advances, a team led by WHOI oceanographers Viviane Menezes and Alison Macdonald and Scripps researcher Courtney Schatzman report that Antarctic Bottom Water (AABW) has freshened (become less saline) at a surprising rate between 2007 and 2016—a shift that could alter ocean circulation and ultimately contribute to rising sea levels. … AABW in the region off East Antarctica’s Adélie Land has grown fresher four times faster in the past decade than it did between 1994 and 2007. … Such a shift, were it global, could significantly disrupt ocean circulation and sea...