Antarctic glacier in state of 'irreversible retreat' experts say - Tucson News Now

Melting Antarctic glacier in state of 'irreversible retreat' experts say

This 19-mile crack appeared in the massive Pine Island Glacier in October 2011and led to the "calving" of an iceberg the size of Chicago. (Source: NASA/GSFC/METI/ERSDAC/JAROS, and U.S. Japan ASTER Science Team.) This 19-mile crack appeared in the massive Pine Island Glacier in October 2011and led to the "calving" of an iceberg the size of Chicago. (Source: NASA/GSFC/METI/ERSDAC/JAROS, and U.S. Japan ASTER Science Team.)
  • Winter weatherMore>>

  • FIRST ALERT FORECAST: Dry and cool weekend ahead

    FIRST ALERT FORECAST: Dry and cool weekend ahead

    Friday, April 20 2018 4:15 AM EDT2018-04-20 08:15:23 GMT

    Get the latest forecast from the NBC12 First Alert Weather team.

    Get the latest forecast from the NBC12 First Alert Weather team.

  • Minnesota firehouse opens doors during blizzard for prom

    Minnesota firehouse opens doors during blizzard for prom

    Monday, April 16 2018 6:38 AM EDT2018-04-16 10:38:32 GMT
    Thursday, April 19 2018 6:36 AM EDT2018-04-19 10:36:37 GMT
    With as much as 15 inches (38 centimeters) of snow in the forecast, the students couldn't take photos outside for what they called #BlizzardProm.With as much as 15 inches (38 centimeters) of snow in the forecast, the students couldn't take photos outside for what they called #BlizzardProm.

    Firefighters came to the rescue for a group of Minnesota high school students when a blizzard struck during their prom.

    Firefighters came to the rescue for a group of Minnesota high school students when a blizzard struck during their prom.

  • Snowmelt floods roads, fields in much of northern Montana

    Snowmelt floods roads, fields in much of northern Montana

    Wednesday, April 18 2018 6:41 PM EDT2018-04-18 22:41:48 GMT
    Wednesday, April 18 2018 8:17 PM EDT2018-04-19 00:17:11 GMT
    (Ryan Welch/Havre Daily News via AP). Ben Miller looks at the sand bags around the house he owns as water runs over South Main Street in Harlem, Mont., Tuesday, April 17, 2018. The sand bags, all 235 of them, go around the house he rents to Jeff Werk w...(Ryan Welch/Havre Daily News via AP). Ben Miller looks at the sand bags around the house he owns as water runs over South Main Street in Harlem, Mont., Tuesday, April 17, 2018. The sand bags, all 235 of them, go around the house he rents to Jeff Werk w...
    Snowmelt is washing out roads, flooding fields and spilling rivers and streams over their banks in much of northern Montana.
    Snowmelt is washing out roads, flooding fields and spilling rivers and streams over their banks in much of northern Montana.
  • InternationalMore>>

  • Gaza man killed by Israeli fire as 4th border protest begins

    Gaza man killed by Israeli fire as 4th border protest begins

    Friday, April 20 2018 4:22 AM EDT2018-04-20 08:22:55 GMT
    Friday, April 20 2018 8:47 AM EDT2018-04-20 12:47:08 GMT
    (AP Photo/ Khalil Hamra). Palestinian protesters set up tents at the Gaza Strip's border with Israel, Thursday, April 19, 2018. Palestinian activists are moving protest encampments closer to Israel's fence ahead of mass demonstration.(AP Photo/ Khalil Hamra). Palestinian protesters set up tents at the Gaza Strip's border with Israel, Thursday, April 19, 2018. Palestinian activists are moving protest encampments closer to Israel's fence ahead of mass demonstration.
    Israeli military aircraft drop leaflets urging Palestinians to stay away from Gaza border protest.
    Israeli military aircraft drop leaflets urging Palestinians to stay away from Gaza border protest.
  • First clues emerge about Cuba's future under new president

    First clues emerge about Cuba's future under new president

    Friday, April 20 2018 12:13 AM EDT2018-04-20 04:13:03 GMT
    Friday, April 20 2018 8:45 AM EDT2018-04-20 12:45:30 GMT
    (Alexandre Meneghini/Pool via AP). Cuba's new president Miguel Diaz-Canel, left, and former president Raul Castro, salutes, after Diaz-Canel was elected as the island nation's new president, at the National Assembly in Havana, Cuba, Thursday, April 19,...(Alexandre Meneghini/Pool via AP). Cuba's new president Miguel Diaz-Canel, left, and former president Raul Castro, salutes, after Diaz-Canel was elected as the island nation's new president, at the National Assembly in Havana, Cuba, Thursday, April 19,...
    First clues of Cuba's future power structure under new president emerge.
    First clues of Cuba's future power structure under new president emerge.
  • Genesis Prize winner Portman pulls out of Israel ceremony

    Genesis Prize winner Portman pulls out of Israel ceremony

    Friday, April 20 2018 2:53 AM EDT2018-04-20 06:53:12 GMT
    Friday, April 20 2018 8:45 AM EDT2018-04-20 12:45:19 GMT
    Genesis Prize foundation says this year's winner, Natalie Portman, has pulled out of June ceremony in Israel.
    Genesis Prize foundation says this year's winner, Natalie Portman, has pulled out of June ceremony in Israel.

A colossal Antarctic glacier has been rapidly receding and now scientists say it has likely reached a point of uncontrollable retreat. Continued melting of the glacier and the surrounding ice sheet could trigger a dangerous rise in Earth's sea level.

Researchers at the French National Center for Scientific Research in Grenoble have built an ice-flow model indicating that the Pine Island Glacier, which makes up about 10 percent of the total ice on the West Antarctic Ice Sheet, will continue to recede.

"[The Pine Island Glacier] has started a phase of self-sustained retreat and will irreversibly continue its decline," said Gael Durand, a glaciologist from France.

Separate models constructed by the British, Finnish and Chinese produced similar indications.

The melt from the Pine Island Glacier, which is located on the West Antarctic Ice Sheet, contributes about 20 percent of the total ice loss from Antarctica, according to a report by the British Antarctic survey. It is the single largest contributor to sea-level rise in Antarctica.

An international team of scientists in January reported in the journal Nature Climate Change that recent, rapid thinning of the glacier had likely reached a tipping point and will continue unabated.

The French study noted that the grounding line – the place where the part of the glacier that is on land meets its ice shelf, which extends over the water – is on the verge of retreating over an oceanic trench that would allow more water to seep underneath the glacier and accelerate melting, according to an article in livescience.com.

The means the glacier is more prone to collapse, triggering a rapid melting of the Antarctic Ice Sheet.

Scientists' ice-flow models estimate that over the next 20 years the slowly dying glacier will shed as much as 100 billion tons of water, causing global sea levels to rise 3.5 to 10 mm, or 0.14 inches to 0.39 inches.

That doesn't sound like much, but greater rises in sea level are possible because the glacier's instability can have a domino effect on the remainder of the West Antarctic Ice Sheet, said Dr. G. Hilmar Gudmundsson of the British Antarctic Survey, who was involved in the project.

"At the Pine Island Glacier, we have seen that not only is more ice flowing from the glacier into the ocean, but it's also flowing faster... We also can see this boundary is migrating further inland," Gudmundsson said in a statement.

One model suggests that the Pine Island Glacier is set to lose as much as 50 percent of its ice in the next 100 years, and in that time the grounding line will have retreated by more than 200 kilometers (124.3 miles).

The United Nations' climate science body, the Intergovernmental Panel on Climate Change (IPCC) has projected that sea levels are likely to rise between 10.4 and 32.8 inches by 2100.

Some researchers believe the demise of the Pine Island Glacier could have the same effect on surrounding glaciers, leading to a collapse of the entire ice sheet, raising global sea level by 10 to 16 feet.

Copyright 2014 Raycom News Network. All rights reserved.

  • National, world weatherWeather and disaster coverageMore>>

  • Volcano in southern Japan erupts for 1st time in 250 years

    Volcano in southern Japan erupts for 1st time in 250 years

    Friday, April 20 2018 2:24 AM EDT2018-04-20 06:24:25 GMT
    Friday, April 20 2018 7:13 AM EDT2018-04-20 11:13:43 GMT
    (Kyodo News via AP). CORRECTS YEAR - In this April 19, 2018, photo, volcanic smoke billows from Mt. Io, foreground, part of the Kirishima mountain range on Japan’s southern main island of Kyushu, taken over Ebino city, Miyazaki prefecture. The Meteorol...(Kyodo News via AP). CORRECTS YEAR - In this April 19, 2018, photo, volcanic smoke billows from Mt. Io, foreground, part of the Kirishima mountain range on Japan’s southern main island of Kyushu, taken over Ebino city, Miyazaki prefecture. The Meteorol...
    A volcano in southern Japan has erupted for the first time in 250 years, and the authorities have set up a no-go zone around the mountain.
    A volcano in southern Japan has erupted for the first time in 250 years, and the authorities have set up a no-go zone around the mountain.
  • Passing motorist rescues woman trapped in Montana flood

    Passing motorist rescues woman trapped in Montana flood

    Thursday, April 19 2018 8:22 PM EDT2018-04-20 00:22:56 GMT
    Thursday, April 19 2018 8:36 PM EDT2018-04-20 00:36:55 GMT
    A witness is recounting the dramatic rescue of a woman trapped on top her vehicle surrounded by rushing floodwaters in northern Montana.
    A witness is recounting the dramatic rescue of a woman trapped on top her vehicle surrounded by rushing floodwaters in northern Montana.
  • Quake, at least 5.5 in magnitude, strikes southern Iran

    Quake, at least 5.5 in magnitude, strikes southern Iran

    Thursday, April 19 2018 3:21 AM EDT2018-04-19 07:21:55 GMT
    Thursday, April 19 2018 9:44 AM EDT2018-04-19 13:44:51 GMT
    US Geological Survey: Magnitude 5.5 quake hits southern Iran near nuclear plant; felt in Bahrain, Persian Gulf.
    US Geological Survey: Magnitude 5.5 quake hits southern Iran near nuclear plant; felt in Bahrain, Persian Gulf.
Powered by Frankly