By Chris Mooney and Brady Dennis
Antarctic glaciers (click here) have been melting at an accelerating pace over the past four decades thanks to an influx of warm ocean water — a startling new finding that researchers say could mean sea levels are poised to rise more quickly than predicted in coming decades.
The Antarctic lost 40 billion tons of melting ice to the ocean each year from 1979 to 1989. That figure rose to 252 billion tons lost per year beginning in 2009, according to a study published Monday in the Proceedings of the National Academy of Sciences. That means the region is losing six times as much ice as it was four decades ago, an unprecedented pace in the era of modern measurements. (It takes about 360 billion tons of ice to produce one millimeter of global sea-level rise.)
“I don’t want to be alarmist,” said Eric Rignot, an Earth-systems scientist for the University of California at Irvine and NASA who led the work. But he said the weaknesses that researchers have detected in East Antarctica — home to the largest ice sheet on the planet — deserve deeper study....
The accelerated melting of the Greenland Icesheet is not surprising to me. During those years NASA would publish images and measurements that proved increased melt water at the top of the glacier, as well as increased melt water discharging into the crevasses which would increase the water volume at the bottom of the glacier and the meander would increase. One the ground scientists were reporting the increased melt water as well.
In one study, there was marked differences in the peripheral extent of the ice. The edges were being lost and were receding. Those preliminary studies and this final assessment validates each other.
January 21, 2019
By Ohio State University
Greenland is melting faster than scientists previously thought (click here) -- and will likely lead to faster sea level rise -- thanks to the continued, accelerating warming of the Earth's atmosphere, a new study has found.
Scientists concerned about sea level rise have long focused on Greenland's southeast and northwest regions, where large glaciers stream iceberg-sized chunks of ice into the Atlantic Ocean. Those chunks float away, eventually melting. But a new study published Jan. 21 in the Proceedings of the National Academy of Sciences found that the largest sustained ice loss from early 2003 to mid-2013 came from
Greenland's southwest region, which is mostly devoid of large glaciers.
"Whatever this was, it couldn't be explained by glaciers, because there aren't many there," said Michael Bevis, lead author of the paper, Ohio Eminent Scholar and a professor of geodynamics at The Ohio State University. "It had to be the surface mass -- the ice was melting inland from the coastline."
That melting, which Bevis and his co-authors believe is largely caused by global warming, means that in the southwestern part of Greenland, growing rivers of water are streaming into the ocean during summer. The key finding from their study: Southwest Greenland, which previously had not been considered a serious threat, will likely become a major future contributor to sea level rise....
By Carol Rasmussen
With a new research plane (click here) and a new base to improve its chances of outsmarting Atlantic hurricanes, NASA's Oceans Melting Greenland campaign takes to the sky this week for its third year of gathering data on how the ocean around Greenland is melting its glaciers.
OMG's first two years of operations already collected the most comprehensive data available on the subject, but OMG Principal Investigator Josh Willis of NASA's Jet Propulsion Laboratory, Pasadena, California, is hungry for more. "We're beginning to see some surprising changes in the ocean, just since the start of OMG in 2016, that are affecting the ice," said Willis, an oceanographer at JPL. "We want to see if those changes are still there after two years, and if they're spreading farther along the Greenland coast."
Willis and Project Manager Steve Dinardo, also of JPL, are leaving for Greenland this week on an airborne campaign to do just that. For the third year in a row, they will drop about 250 probes just offshore all around the island, with some drops close to the fronts of ocean-terminating glaciers. The probes sink 3,000 feet (1,000 meters) into the seawater, recording temperature and salinity as they go. The researchers hope to make their first flight on Aug 22 and complete the work in two to three weeks, depending on weather....
