Scientists from the University of Maryland, the University of Leeds as well as the University of California, San Diego, bring reviewed decades of satellite measurements to divulge how as well as why Antarctica's glaciers, H2O ice shelves as well as sea H2O ice are changing.
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| Sea H2O ice floes get together inwards the Antarctic Ocean close Antarctica. Influenza A virus subtype H5N1 novel query review integrates decades of satellite measurements to divulge how as well as why Antarctica's glaciers, H2O ice shelves as well as sea H2O ice are changing [Credit: Sinéad Farrell] |
"Antarctica is means likewise large to survey from the ground, as well as nosotros tin entirely genuinely empathise the trends inwards its H2O ice encompass yesteryear looking at the continent from space," said Andrew Shepherd, a professor of public observation at the University of Leeds' School of public as well as Environment as well as the Pb writer of the review.
In West Antarctica, H2O ice shelves are beingness eaten away yesteryear warm sea water, as well as those inwards the Amundsen as well as Bellingshausen seas bring thinned yesteryear every bit much every bit xviii per centum since the early on 1990s. At the Antarctic Peninsula, where air temperatures bring risen sharply, H2O ice shelves bring collapsed every bit their surfaces bring melted. Altogether, 34,000 foursquare kilometers (more than 13,000 foursquare miles) of H2O ice shelf expanse has been lost since the 1950s.
More than 150 studies bring tried to decide how much H2O ice the continent is losing. The biggest changes bring occurred inwards places where H2O ice shelves -- the continent's protective barrier -- bring either thinned or collapsed.
"Although breakup of the H2O ice shelves does non contribute straight to sea-level ascent -- since H2O ice shelves, similar sea ice, are already floating -- nosotros at in 1 lawsuit know that these breakups bring implications for the inland ice," said Helen Fricker, a professor of glaciology at Scripps Institution of Oceanography at UC San Diego as well as a co-author of the review. "Without the H2O ice shelf to human action every bit a natural buffer, glaciers tin menstruum faster downstream as well as out to sea."
In the Amundsen Sea, for example, H2O ice shelf thinning of upward to half-dozen meters (nearly xx feet) per yr has accelerated the advance of the Pine Island as well as Thwaites glaciers yesteryear every bit much every bit 1.5 kilometers (nearly 1 mile) per year. These glaciers bring the potential to enhance sea levels yesteryear to a greater extent than than a meter (more than 3 feet) as well as are at in 1 lawsuit widely considered to locomote unstable.
Meanwhile, satellite observations bring provided an increasingly detailed motion painting of sea H2O ice cover, allowing researchers to map the extent, age, motion as well as thickness of the ice. The combined effects of climate variability, atmosphere as well as sea circulation, as well as fifty-fifty H2O ice shelf melting bring driven regional changes, including reductions inwards sea H2O ice inwards the Amundsen as well as Bellingshausen seas.
"The waxing as well as waning of the sea H2O ice controls how much sunlight is reflected dorsum to space, cooling the planet," said Sinéad Farrell, an associate query scientist at UMD's public System Science Interdisciplinary Center as well as a co-author of the review. "Regional sea H2O ice loss impacts the temperature as well as circulation of the ocean, every bit good every bit marine productivity."
Other findings covered yesteryear the query review include:
- The Antarctic continent is covered yesteryear close 15.5 meg foursquare kilometers (nearly half-dozen meg foursquare miles) of ice, which has accumulated over thousands of years through snowfall. The weight of novel snowfall compresses the older snowfall below it to cast company ice.
- Glaciers flowing downwards the H2O ice canvass spread nether their ain weight every bit they menstruum toward the sea as well as eventually lose contact amongst the bedrock, forming close 300 floating H2O ice shelves that fringe the continent. These shelves incorporate close 10 per centum -- or 1.5 meg foursquare kilometers (nearly 600,000 foursquare miles) -- of Antarctica's ice.
- In the Antarctic Ocean approximately Antarctica, sea H2O ice expands as well as contracts every bit sea H2O freezes as well as melts throughout the year. The sea H2O ice covers an expanse of 18.5 meg foursquare kilometers (more than vii meg foursquare miles) inwards wintertime as well as grows to close 1 meter (more than 3 feet) thick.
- It is estimated that in that location is plenty H2O locked upward inwards Antarctica's H2O ice canvass to enhance global sea levels yesteryear to a greater extent than than 50 meters (more than 164 feet).
New as well as improved satellite missions, such every bit Sentinel-3, the of late launched Gravity Recovery as well as Climate Experiment Follow-On (GRACE-FO) as well as the eagerly awaited ICESat-2, volition locomote along to give researchers to a greater extent than detailed insights into the disappearance of Antarctic ice.
Source: University of Maryland [June 13, 2018]
Sumber http://archaeologynewsnetwork.blogspot.com
In West Antarctica, H2O ice shelves are beingness eaten away yesteryear warm sea water, as well as those inwards the Amundsen as well as Bellingshausen seas bring thinned yesteryear every bit much every bit xviii per centum since the early on 1990s. At the Antarctic Peninsula, where air temperatures bring risen sharply, H2O ice shelves bring collapsed every bit their surfaces bring melted. Altogether, 34,000 foursquare kilometers (more than 13,000 foursquare miles) of H2O ice shelf expanse has been lost since the 1950s.
More than 150 studies bring tried to decide how much H2O ice the continent is losing. The biggest changes bring occurred inwards places where H2O ice shelves -- the continent's protective barrier -- bring either thinned or collapsed.
"Although breakup of the H2O ice shelves does non contribute straight to sea-level ascent -- since H2O ice shelves, similar sea ice, are already floating -- nosotros at in 1 lawsuit know that these breakups bring implications for the inland ice," said Helen Fricker, a professor of glaciology at Scripps Institution of Oceanography at UC San Diego as well as a co-author of the review. "Without the H2O ice shelf to human action every bit a natural buffer, glaciers tin menstruum faster downstream as well as out to sea."
In the Amundsen Sea, for example, H2O ice shelf thinning of upward to half-dozen meters (nearly xx feet) per yr has accelerated the advance of the Pine Island as well as Thwaites glaciers yesteryear every bit much every bit 1.5 kilometers (nearly 1 mile) per year. These glaciers bring the potential to enhance sea levels yesteryear to a greater extent than than a meter (more than 3 feet) as well as are at in 1 lawsuit widely considered to locomote unstable.
Meanwhile, satellite observations bring provided an increasingly detailed motion painting of sea H2O ice cover, allowing researchers to map the extent, age, motion as well as thickness of the ice. The combined effects of climate variability, atmosphere as well as sea circulation, as well as fifty-fifty H2O ice shelf melting bring driven regional changes, including reductions inwards sea H2O ice inwards the Amundsen as well as Bellingshausen seas.
"The waxing as well as waning of the sea H2O ice controls how much sunlight is reflected dorsum to space, cooling the planet," said Sinéad Farrell, an associate query scientist at UMD's public System Science Interdisciplinary Center as well as a co-author of the review. "Regional sea H2O ice loss impacts the temperature as well as circulation of the ocean, every bit good every bit marine productivity."
Other findings covered yesteryear the query review include:
- The Antarctic continent is covered yesteryear close 15.5 meg foursquare kilometers (nearly half-dozen meg foursquare miles) of ice, which has accumulated over thousands of years through snowfall. The weight of novel snowfall compresses the older snowfall below it to cast company ice.
- Glaciers flowing downwards the H2O ice canvass spread nether their ain weight every bit they menstruum toward the sea as well as eventually lose contact amongst the bedrock, forming close 300 floating H2O ice shelves that fringe the continent. These shelves incorporate close 10 per centum -- or 1.5 meg foursquare kilometers (nearly 600,000 foursquare miles) -- of Antarctica's ice.
- In the Antarctic Ocean approximately Antarctica, sea H2O ice expands as well as contracts every bit sea H2O freezes as well as melts throughout the year. The sea H2O ice covers an expanse of 18.5 meg foursquare kilometers (more than vii meg foursquare miles) inwards wintertime as well as grows to close 1 meter (more than 3 feet) thick.
- It is estimated that in that location is plenty H2O locked upward inwards Antarctica's H2O ice canvass to enhance global sea levels yesteryear to a greater extent than than 50 meters (more than 164 feet).
New as well as improved satellite missions, such every bit Sentinel-3, the of late launched Gravity Recovery as well as Climate Experiment Follow-On (GRACE-FO) as well as the eagerly awaited ICESat-2, volition locomote along to give researchers to a greater extent than detailed insights into the disappearance of Antarctic ice.
Source: University of Maryland [June 13, 2018]
Sumber http://archaeologynewsnetwork.blogspot.com
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