The buttressing occurs in regions, called “shear margins,” where faster flowing ice meets ice that is more static and stable, often because it is moored to some part of the landscape. “[A] warming ocean thinned the ice shelves, this reduced buttressing, this let the non-floating ice move faster, contributing some to sea-level rise and also starting to break the sides of the ice shelves, but additional acceleration could occur if the rest of the steps (further fracture and ice-shelf loss) should occur.”. Ice-flow modelling studies have shown that it can undergo periods of rapid mass loss, but no study has shown that these future changes could cross a tipping point and therefore be effectively irreversible. Sound familiar? Last month, Canada lost its last major Arctic ice shelf. In recent years, the Pine Island Glacier and the Thwaites Glacier in west Antarctica has been undergoing rapid changes, with potentially major consequences for rising sea levels. When the antics of a bear disarm a hunter, Gross campaign releases record of his killing of a bear in self-defense, a major campaign talking point, Tracking COVID-19 in Alaska: 117 new cases, no new deaths.
. (CNN)A story about a glacier shedding mass at the edge of the world, threatening to raise ocean levels and potentially contribute to untold environmental change. But it has been losing ice over the past 25 years. The changes to the glacier have been mapped by ESA-built satellites since the 1990s, with calving events occurring multiple times since 1992. Pine Island Glacier, in the West Antarctic Ice Sheet, has an area of 175,000 square kilometres and loses about 45 billion tons of ice each year. An edge of the Thwaites Ice Shelf. And in Greenland, the largest remaining ice shelf in the northern hemisphere, sometimes known as 79 North due to its latitude (its full name is Nioghalvfjerdsfjorden), just lost a large chunk of ice equivalent in size to roughly two Manhattan islands, according to the Geological Survey of Denmark and Greenland. “So it has nothing to buttress up against at this point,” she says. The largest of them was so big, it was even given a name: B-49. As anticipated, Pine Island Glacier, known as PIG for short, in Antarctica has just spawned a huge iceberg. "What you are looking at is both terrifying and beautiful," Mark Drinkwater, head of the Earth and Mission Sciences Division at the ESA, told CNN. pic.twitter.com/iubE8JffVR, The Argentine research base Esperanza, on the northern tip of #Antarctic Peninsula, saw a new record temperature of 18.3°C today (old one 17.5°C on 24 March 2015), per @SMN_Argentina. Small pieces have now broken off from the original iceberg. All rights reserved. For Pine Island glacier, the new study finds that while the cracking and fraying at the shear margin dates back to 1999, it accelerated in 2016. Located along the coast of the Amundsen Sea in West Antarctica, the enormous Pine Island and Thwaites glaciers already contribute around 5% of global sea level rise. The region holds enough ice to raise global sea levels by 1.2 meters, or 4 feet, according to NASA. Trump tweets intent to issue permit for rail line connecting Alaska to Canada and Lower 48. "These satellites are showing how much mass has been lost.". But now, calving events occur “almost annually” on Pine Island, she says. He has reported from the 2015 Paris climate negotiations, the Northwest Passage, and the Greenland ice sheet, among other locations, and has written four books about science, politics and climate change. Pine Island Glacier in Antarctica spawns new iceberg on February 11, 2020. The areas of Paris and Manhattan are used to show the scale of the glacier's cracks. Pine Island Glacier, along with its neighbor Thwaites Glacier, effectively act as arteries connecting the West Antarctic ice sheet to the ocean. “The new paper shows that the Amundsen Sea Embayment ice shelves have gone through most, but not all, of the Jakobshavn steps,” Alley said in an email. My employer turned us all into contractors. Drinkwater suggested this was due to the continuing instability of the ice shelf, with greater levels of warm water under the glacier causing even greater disruption at the base of it. The glaciers' so-called “shear margins,” where their floating ice shelves encounter high levels of friction or “buttressing,” are progressively weakening and in some cases breaking into pieces.