28 November 2016, Geophysical Research Letters (REPORT) Pine Island Glacier has undergone several major iceberg calving events over the past decades. These typically occurred when a rift at the heavily fractured shear margin propagated across the width of the ice shelf. This type of calving is common on polar ice shelves, with no clear connection to ocean-ice dynamic forcing. In contrast, we report on the recent development of multiple rifts initiating from basal crevasses in the center of the ice shelf, resulted in calving further upglacier than previously observed. Coincident with rift formation was the sudden disintegration of the ice mélange that filled the northern shear margin, resulting in ice sheet detachment from this margin. Examination of ice velocity suggests that this internal rifting resulted from the combination of a change in ice shelf stress regime caused by disintegration of the mélange and intensified melting within basal crevasses, both of which may be linked to ocean forcing. Read More here
Tag Archives: oceans
22 November 2016, The Guardian, ‘Extraordinarily hot’ Arctic temperatures alarm scientists. The Arctic is experiencing extraordinarily hot sea surface and air temperatures, which are stopping ice forming and could lead to record lows of sea ice at the north pole next year, according to scientists. Danish and US researchers monitoring satellites and Arctic weather stations are surprised and alarmed by air temperatures peaking at what they say is an unheard-of 20C higher than normal for the time of year. In addition, sea temperatures averaging nearly 4C higher than usual in October and November. “It’s been about 20C warmer than normal over most of the Arctic Ocean, along with cold anomalies of about the same magnitude over north-central Asia. This is unprecedented for November,” said research professor Jennifer Francis of Rutgers university. Temperatures have been only a few degrees above freezing when -25C should be expected, according to Francis. “These temperatures are literally off the charts for where they should be at this time of year. It is pretty shocking. The Arctic has been breaking records all year. It is exciting but also scary,” she said. Read More here
20 November 2016, New York Times, A Wrenching Choice for Alaska Towns in the Path of Climate Change. SHAKTOOLIK, Alaska — In the dream, a storm came and Betsy Bekoalok watched the river rise on one side of the village and the ocean on the other, the water swallowing up the brightly colored houses, the fishing boats and the four-wheelers, the school and the clinic. She dived into the floodwaters, frantically searching for her son. Bodies drifted past her in the half-darkness. When she finally found the boy, he, too, was lifeless. “I picked him up and brought him back from the ocean’s bottom,” Ms. Bekoalok remembered. The Inupiat people who for centuries have hunted and fished on Alaska’s western coast believe that some dreams are portents of things to come. But here in Shaktoolik, one need not be a prophet to predict flooding, especially during the fall storms. Laid out on a narrow spit of sand between the Tagoomenik River and the Bering Sea, the village of 250 or so people is facing an imminent threat from increased flooding and erosion, signs of a changing climate. With its proximity to the Arctic, Alaska is warming about twice as fast as the rest of the United States and the state is heading for the warmest year on record. The government has identified at least 31 Alaskan towns and cities at imminent risk of destruction, with Shaktoolik ranking among the top four. Some villages, climate change experts predict, will be uninhabitable by 2050, their residents joining a flow of climate refugees around the globe, in Bolivia, China, Niger and other countries. Read More here
1 November 2016, The Guardian, Great Barrier Reef: why are government and business perpetuating the big lie? At the core of the Australian government’s failure to protect our Great Barrier Reef is the big lie. Through its actions and inaction, rhetoric, funding priorities and policy decisions, the Australian government has implicitly pursued the line that it is possible to turn things around for the reef without tackling global warming. This is the big lie. Last year, when the federal and Queensland governments released the Reef 2050 long-term sustainability plan, experts were emphatic about the deceit. Eminent coral reef scientist Prof Terry Hughes commented that the “biggest omission in the plan is that it virtually ignores climate change, which is clearly the major ongoing threat to the reef”. Great Barrier Reef historian Iain McCalman wrote that the new measures “deliberately ignore the dire long-term threats to the reef that are contained in the now unutterable words ‘climate change’”. “They are akin to investing in cures for a patient’s skin diseases while ignoring their cancer symptoms,” he wrote. As the experts make plain, any attempt to decouple the future of the Great Barrier Reef from the quest to contain global warming is simply dishonest. As another expert, Prof Ove Hoegh-Guldberg of the University of Queensland, has said, we either “re-examine the current plans for unrestricted coal exports, taking proper account and responsibility for the resulting greenhouse emissions, or watch the reef die”. Read More here