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Domain: the-cryosphere.net
Stories and comments across the archive that link to the-cryosphere.net.
Stories · 3
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Massive Undersea Walls Could Stop Glaciers From Melting, Scientists Say (cnn.com)
An anonymous reader quotes a report from CNN: Building walls on the seafloor could prevent glaciers from melting and sea levels rising due to global warming, scientists say. Barriers of sand and rock positioned at the base of glaciers would stop ice sheets sliding and collapsing, and prevent warm water from eroding the ice from beneath, according to research published this week in the Cryosphere journal, from the European Geosciences Union. The audacious idea centers on the construction of "extremely simple structures, merely piles of aggregate on the ocean floor, although more advanced structures could certainly be explored in the future," said the report's authors, Michael Wolovick, a researcher at the department of geosciences at Princeton University, and John Moore, professor of climate change at the University of Lapland in Finland.
Using computer models to gauge the probable impact of walls on erosion of the Thwaites glacier in Antarctica, one of the world's largest, Wolovick and Moore hoped to test the efficiency of "a locally targeted intervention." They claimed the simplest designs would allow direct comparison with existing engineering projects. "The easiest design that we considered would be comparable to the largest civil engineering projects that humanity has ever attempted," they said. "An ice sheet intervention today would be at the edge of human capabilities." For example, building four isolated walls would require between 0.1 and 1.5 cubic km of material. "That is comparable to the 0.1 km3 that was used to create Palm Jumeirah in Dubai ($12 billion)...(and) the 0.3 km3 that was used to create Hong Kong International Airport ($20 billion)," the report said. The authors say there's only a 30% probability of success due to the harsh environment, but did mention that the scientific community could work on a plan that was both achievable and had a high probability of success. -
Antarctica Is Losing Ice Faster Every Year (qz.com)
A survey of satellite data published in the journal Cryosphere confirms what scientists have suspected for a while now: ice loss from the critical region of Antarctica is happening at an increasingly fast pace. Quartz reports: In total, researchers found that Antarctica lost roughly 1,929 gigatons of ice in 2015, which amounts to an increase of roughly 36 gigatons per year every year since 2008. (A gigaton is one billion tons.) Nearly 90% of that increase in loss occurred in West Antarctica, "probably in response to ocean warming," according to NASA. The new data analysis mostly confirms other recent research, but does so with a higher degree of precision by using a new technique that can process a larger amount of satellite data than was possible before.
West Antarctica has been losing a lot of ice in recent years, and at an ever-growing pace, while East Antarctica is losing ice more steadily. The West Antarctic ice sheet is of particular concern because, like a building that stands on an uneven foundation, it is inherently unstable, making it especially vulnerable to the warming climate. If the entire ice sheet were destabilized and melted into the sea, researchers estimate it would lead to 3 meters (9 feet) of sea level rise globally. Models suggest that under a low-emissions scenario, where the world commits to "peaking" and then steadily reducing emissions in the near future, complete destabilization of the West Antarctic ice sheet is possible to avoid. But under medium- or high-emissions scenarios, the loss of the ice sheet becomes inevitable. -
Greenland's Fastest Glacier Sets New Speed Record
vinces99 writes "The latest observations of Jakobshavn Glacier show that Greenland's largest glacier is moving ice from land into the ocean at a speed that appears to be the fastest ever recorded. Researchers from the University of Washington and the German Space Agency measured the speed of the glacier in 2012 and 2013. The results were published Feb. 3 in The Cryosphere, an open access journal of the European Geosciences Union. Jakobshavn Glacier, which is widely believed to be the glacier that produced the large iceberg that sank the Titanic in 1912, drains the Greenland ice sheet into a deep-ocean fjord on the west coast of the island. This speedup of Jakobshavn means that the glacier is adding more and more ice to the ocean, contributing to sea-level rise. 'We are now seeing summer speeds more than four times what they were in the 1990s, on a glacier which at that time was believed to be one of the fastest, if not the fastest, glacier in Greenland,' said lead author Ian Joughin, a glaciologist at the UW's Polar Science Center. The new observations show that in summer of 2012 the glacier reached a record speed of more than 10 miles (17 km) per year, or more than 150 feet (46 m) per day. These appear to be the fastest flow rates recorded for any glacier or ice stream in Greenland or Antarctica, researchers said."