Tuesday, November 29, 2016 3:53:41 PM
Antarctica's Pine Island Glacier breaking up from inside out.
Rift in the Pine Island Glacier
NASA
By Pakalolo
2016/11/28 18:26
The American Geophysical Union (AGU) just issued a press release [ http://news.agu.org/press-release/west-antarctic-ice-shelf-breaking-up-from-the-inside-out/ ] informing the world that a key glacier in West Antarctica is breaking up from the inside out. This suggests, said the AGU statement, that the ocean is weakening the ice on the edges of the Antarctic continent.
The Pine Island Glacier and, “the Thwaites Glacier, sit at the outer edge of one of the most active ice streams on the continent”. They provide a buttressing effect to the ice stream, by creating a backward stress that balances the downward stress of the ice trying to flow out to sea.
In 2015, a massive chunk of ice broke off of the Pine Island Glacier. AGU notes that it wasn't until they started testing for new image processing software recently “that they noticed a crack had formed at the very base of the ice shelf nearly 20 miles inland in 2013. The rift propagated upward over two years, until it broke through the ice surface and set the iceberg adrift over 12 days in late July and early August 2015.
The AGU reports:
“It’s generally accepted that it’s no longer a question of whether the West Antarctic Ice Sheet will melt, it’s a question of when,” said Ian Howat, associate professor of Earth sciences at Ohio State and lead author of the new study. “This kind of rifting behavior provides another mechanism for rapid retreat of these glaciers, adding to the probability that we may see significant collapse of West Antarctica in our lifetimes.”
snip
“Rifts usually form at the margins of an ice shelf, where the ice is thin and subject to shearing that rips it apart,” he explained. “However, this latest event in the Pine Island Glacier was due to a rift that originated from the center of the ice shelf and propagated out to the margins. This implies that something weakened the center of the ice shelf, with the most likely explanation being a crevasse melted out at the bedrock level by a warming ocean.”
Another clue: The rift opened in the bottom of a “valley” in the ice shelf where the ice had thinned compared to the surrounding ice shelf.
The valley is likely a sign of something researchers have long suspected: Because the bottom of the West Antarctic Ice Sheet lies below sea level, ocean water can intrude far inland and remain unseen. New valleys forming on the surface would be one outward sign that ice was melting away far below.
The West Antarctic Ice Sheet is particularly vulnerable to global warming caused by our burning of fossil fuels. It’s collapse will be catastrophic. Pine Island and Thwaites glaciers have 10 feet of sea level rise currently locked up in ice, the rapid flow of that ice into the ocean would submerge most coastal cities throughout the world.
From the study abstract [ http://onlinelibrary.wiley.com/doi/10.1002/2016GL071360/abstract ; full study http://onlinelibrary.wiley.com/doi/10.1002/2016GL071360/full ]:
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.
© Kos Media, LLC
http://www.dailykos.com/stories/2016/11/28/1604949/-Antarctica-s-Pine-Island-Glacier-is-breaking-up-from-the-inside-out [with comments], http://www.youtube.com/watch?v=F9vIj6sH-Vo [as embedded; with comments]
--
Antarctica Ice Shelf is Breaking from the Inside Out
The connected ice sheet could retreat even quicker in the future
November 29, 2016
https://www.scientificamerican.com/article/antarctica-ice-shelf-is-breaking-from-the-inside-out/ [original, sub req'd, at http://www.eenews.net/climatewire/2016/11/29/stories/1060046301 ]
--
The Trump Two-Step
Mike Segar / Reuters
Talk like a maverick. Act like an extremist Republican.
Robinson Meyer
Nov 28, 2016
There’s a pattern shaping up in the Trump administration, at least when it comes to climate change.
It works like this: Donald Trump, the president-elect himself, says something that sounds like he might be moderating on the issue. Then, his staff takes a radical action in the other direction.
Last week, Trump told the staff of The New York Times that he was keeping an open mind [ http://www.nytimes.com/2016/11/23/us/politics/trump-new-york-times-interview-transcript.html ] about the existence of climate change.
“I think there is some connectivity” between human activity and the warming climate, Trump said. “There is some, something. It depends on how much.”
Of course, there is more than “some” connectivity. Scientists overwhelmingly recognize that humans have dramatically warmed the climate [ http://www.bloomberg.com/graphics/2015-whats-warming-the-world/ ] by emitting greenhouse gases like methane and carbon dioxide. The atmosphere now traps heat far more efficiently than it did even 50 years ago, quickly outpacing the “normal” rate of planetary climate change
[ https://xkcd.com/1732/ ].
This worldwide warming trend has made 2016 the hottest year [ http://www.bbc.com/news/science-environment-37949877 ] since modern meteorological records began, in 1880. The six warmest years ever measured [ http://www.ncdc.noaa.gov/sotc/global/201513 ] have all happened in the past decade. The U.S. Department of Defense [ http://www.defense.gov/News/Article/Article/612710 ] and a wide range of American medical associations [ http://www.lung.org/our-initiatives/healthy-air/outdoor/climate-change/declaration-on-climate-change.html ] recognize the reality of human-caused global warming
But Donald Trump once said that global warming was a hoax invented by the Chinese [ http://www.politifact.com/truth-o-meter/statements/2016/jun/03/hillary-clinton/yes-donald-trump-did-call-climate-change-chinese-h/ ], and he’s frequently wondered how global warming can exist when it’s still sometimes “really cold [ https://twitter.com/realDonaldTrump/status/493935815207043072 ]” in New York. (Here’s how [ http://www.usatoday.com/story/opinion/2014/01/30/climate-change-global-warming-polar-vortex-editorials-debates/5066231/ ].) So when he told the Times that he was keeping an open mind about global warming, it was taken by many as good news. I wrote about it [ http://www.theatlantic.com/science/archive/2016/11/what-does-trump-think-about-climate-change-he-doesnt-know-either/508541/ ], as did a slew of other publications. Trump’s new quasi-moderation became a “flip-flop [ http://www.politico.com/magazine/story/2016/11/trump-flip-flops-president-elect-214478 ]” or a “major U-turn [ http://www.independent.co.uk/news/people/donald-trump-says-he-believes-there-is-some-connectivity-between-humans-and-climate-change-in-major-a7432671.html ].” Maybe Trump, ever the maverick, would finally allow the Republican Party to recognize the reality of climate change.
But here’s the second part of the two-step. While Trump was saying something almost moderate, his actual transition team was acting like a more extremist version of George W. Bush-era Republicans. A day after Trump talked to the Times, The Guardian reported that the Trump administration plans could cut all of NASA’s Earth science research [ https://www.theguardian.com/environment/2016/nov/22/nasa-earth-donald-trump-eliminate-climate-change-research ].
NASA’s scientists do some of the finest climate and weather science in the world, and the agency’s fleet of Earth-observing satellites is peerless. Yet Bob Walker, a Trump campaign advisor, told the paper that all this was “politically-correct environmental monitoring.”
“I believe that climate research is necessary, but it has been heavily politicized, which has undermined a lot of the work that researchers have been doing,” Walker told the Guardian. He said that some projects could be moved to other agencies.
These plans are still up in the air. But the Trump team’s staffing choices should also raise concerns. Myron Ebell, who is leading Trump’s EPA transition team, helped lobby the second Bush administration [ https://insideclimatenews.org/news/16112016/myron-ebell-climate-denier-epa-donald-trump ] to barely do anything to stop climate change. He has been involved in professional climate-change denial circles since the 1990s.
Meanwhile, Politico reports [ http://www.politico.com/tipsheets/politico-influence/2016/11/economic-landing-teams-announced-217516 ] that the Heritage Foundation senior research fellow, Steven Groves, has been added to Trump’s State Department transition team. Just last week, Groves called for the United States [ http://dailysignal.com/2016/11/17/the-pathway-out-of-paris/ ] to leave the UN Framework Convention on Climate Change, the overarching treaty that governs how the world organizes itself to address global warming. Groves also said the U.S. should move to “dismantle” domestic climate regulations.
A staffing choice isn’t a firm policy decision, but there isn’t much ambiguity about the Trump administration’s intentions so far. Trump may be sounding a new tune on the existence of climate change. (Though some journalists read the New York Times comments [ https://grist.org/politics/trump-new-york-times-climate/ ] to mean he hasn’t changed his mind about it at all.) But his policy team seems to want to both squash research about global warming while withdrawing the United States from any diplomatic attempt to do anything about it.
That’s the Trump two-step. The president-elect may look like he’s keeping an open mind, but his transition team is acting like a more extreme version of the Bush-era climate deniers.
Copyright © 2016 by The Atlantic Monthly Group
http://www.theatlantic.com/science/archive/2016/11/the-trump-two-step/508643/ [with non-YouTube version of the included YouTube as embedded; with comments], http://www.youtube.com/watch?v=Ai9nxn_Ykck [with comment]
--
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http://investorshub.advfn.com/boards/read_msg.aspx?message_id=124039545 and preceding (and any future following)
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=126843315 and preceding and following,
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=126867422 and preceding and (future) following
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=126853062 and preceding (and any future following)
Rift in the Pine Island Glacier
NASA
By Pakalolo
2016/11/28 18:26
The American Geophysical Union (AGU) just issued a press release [ http://news.agu.org/press-release/west-antarctic-ice-shelf-breaking-up-from-the-inside-out/ ] informing the world that a key glacier in West Antarctica is breaking up from the inside out. This suggests, said the AGU statement, that the ocean is weakening the ice on the edges of the Antarctic continent.
The Pine Island Glacier and, “the Thwaites Glacier, sit at the outer edge of one of the most active ice streams on the continent”. They provide a buttressing effect to the ice stream, by creating a backward stress that balances the downward stress of the ice trying to flow out to sea.
In 2015, a massive chunk of ice broke off of the Pine Island Glacier. AGU notes that it wasn't until they started testing for new image processing software recently “that they noticed a crack had formed at the very base of the ice shelf nearly 20 miles inland in 2013. The rift propagated upward over two years, until it broke through the ice surface and set the iceberg adrift over 12 days in late July and early August 2015.
The AGU reports:
“It’s generally accepted that it’s no longer a question of whether the West Antarctic Ice Sheet will melt, it’s a question of when,” said Ian Howat, associate professor of Earth sciences at Ohio State and lead author of the new study. “This kind of rifting behavior provides another mechanism for rapid retreat of these glaciers, adding to the probability that we may see significant collapse of West Antarctica in our lifetimes.”
snip
“Rifts usually form at the margins of an ice shelf, where the ice is thin and subject to shearing that rips it apart,” he explained. “However, this latest event in the Pine Island Glacier was due to a rift that originated from the center of the ice shelf and propagated out to the margins. This implies that something weakened the center of the ice shelf, with the most likely explanation being a crevasse melted out at the bedrock level by a warming ocean.”
Another clue: The rift opened in the bottom of a “valley” in the ice shelf where the ice had thinned compared to the surrounding ice shelf.
The valley is likely a sign of something researchers have long suspected: Because the bottom of the West Antarctic Ice Sheet lies below sea level, ocean water can intrude far inland and remain unseen. New valleys forming on the surface would be one outward sign that ice was melting away far below.
The West Antarctic Ice Sheet is particularly vulnerable to global warming caused by our burning of fossil fuels. It’s collapse will be catastrophic. Pine Island and Thwaites glaciers have 10 feet of sea level rise currently locked up in ice, the rapid flow of that ice into the ocean would submerge most coastal cities throughout the world.
From the study abstract [ http://onlinelibrary.wiley.com/doi/10.1002/2016GL071360/abstract ; full study http://onlinelibrary.wiley.com/doi/10.1002/2016GL071360/full ]:
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.
In 2015, a 225-square-mile iceberg broke off of the Pine Island Glacier in Antarctica, and researchers at The Ohio State University have discovered that the event was no ordinary breakup. The culprit: a deep subsurface rift that cracked through the ice nearly 20 miles inland—a sign that the largest ice reserve in the world may be melting sooner rather than later.
© Kos Media, LLC
http://www.dailykos.com/stories/2016/11/28/1604949/-Antarctica-s-Pine-Island-Glacier-is-breaking-up-from-the-inside-out [with comments], http://www.youtube.com/watch?v=F9vIj6sH-Vo [as embedded; with comments]
--
Antarctica Ice Shelf is Breaking from the Inside Out
The connected ice sheet could retreat even quicker in the future
November 29, 2016
https://www.scientificamerican.com/article/antarctica-ice-shelf-is-breaking-from-the-inside-out/ [original, sub req'd, at http://www.eenews.net/climatewire/2016/11/29/stories/1060046301 ]
--
The Trump Two-Step
Mike Segar / Reuters
Talk like a maverick. Act like an extremist Republican.
Robinson Meyer
Nov 28, 2016
There’s a pattern shaping up in the Trump administration, at least when it comes to climate change.
It works like this: Donald Trump, the president-elect himself, says something that sounds like he might be moderating on the issue. Then, his staff takes a radical action in the other direction.
Last week, Trump told the staff of The New York Times that he was keeping an open mind [ http://www.nytimes.com/2016/11/23/us/politics/trump-new-york-times-interview-transcript.html ] about the existence of climate change.
“I think there is some connectivity” between human activity and the warming climate, Trump said. “There is some, something. It depends on how much.”
Of course, there is more than “some” connectivity. Scientists overwhelmingly recognize that humans have dramatically warmed the climate [ http://www.bloomberg.com/graphics/2015-whats-warming-the-world/ ] by emitting greenhouse gases like methane and carbon dioxide. The atmosphere now traps heat far more efficiently than it did even 50 years ago, quickly outpacing the “normal” rate of planetary climate change
[ https://xkcd.com/1732/ ].
This worldwide warming trend has made 2016 the hottest year [ http://www.bbc.com/news/science-environment-37949877 ] since modern meteorological records began, in 1880. The six warmest years ever measured [ http://www.ncdc.noaa.gov/sotc/global/201513 ] have all happened in the past decade. The U.S. Department of Defense [ http://www.defense.gov/News/Article/Article/612710 ] and a wide range of American medical associations [ http://www.lung.org/our-initiatives/healthy-air/outdoor/climate-change/declaration-on-climate-change.html ] recognize the reality of human-caused global warming
But Donald Trump once said that global warming was a hoax invented by the Chinese [ http://www.politifact.com/truth-o-meter/statements/2016/jun/03/hillary-clinton/yes-donald-trump-did-call-climate-change-chinese-h/ ], and he’s frequently wondered how global warming can exist when it’s still sometimes “really cold [ https://twitter.com/realDonaldTrump/status/493935815207043072 ]” in New York. (Here’s how [ http://www.usatoday.com/story/opinion/2014/01/30/climate-change-global-warming-polar-vortex-editorials-debates/5066231/ ].) So when he told the Times that he was keeping an open mind about global warming, it was taken by many as good news. I wrote about it [ http://www.theatlantic.com/science/archive/2016/11/what-does-trump-think-about-climate-change-he-doesnt-know-either/508541/ ], as did a slew of other publications. Trump’s new quasi-moderation became a “flip-flop [ http://www.politico.com/magazine/story/2016/11/trump-flip-flops-president-elect-214478 ]” or a “major U-turn [ http://www.independent.co.uk/news/people/donald-trump-says-he-believes-there-is-some-connectivity-between-humans-and-climate-change-in-major-a7432671.html ].” Maybe Trump, ever the maverick, would finally allow the Republican Party to recognize the reality of climate change.
But here’s the second part of the two-step. While Trump was saying something almost moderate, his actual transition team was acting like a more extremist version of George W. Bush-era Republicans. A day after Trump talked to the Times, The Guardian reported that the Trump administration plans could cut all of NASA’s Earth science research [ https://www.theguardian.com/environment/2016/nov/22/nasa-earth-donald-trump-eliminate-climate-change-research ].
NASA’s scientists do some of the finest climate and weather science in the world, and the agency’s fleet of Earth-observing satellites is peerless. Yet Bob Walker, a Trump campaign advisor, told the paper that all this was “politically-correct environmental monitoring.”
“I believe that climate research is necessary, but it has been heavily politicized, which has undermined a lot of the work that researchers have been doing,” Walker told the Guardian. He said that some projects could be moved to other agencies.
These plans are still up in the air. But the Trump team’s staffing choices should also raise concerns. Myron Ebell, who is leading Trump’s EPA transition team, helped lobby the second Bush administration [ https://insideclimatenews.org/news/16112016/myron-ebell-climate-denier-epa-donald-trump ] to barely do anything to stop climate change. He has been involved in professional climate-change denial circles since the 1990s.
Meanwhile, Politico reports [ http://www.politico.com/tipsheets/politico-influence/2016/11/economic-landing-teams-announced-217516 ] that the Heritage Foundation senior research fellow, Steven Groves, has been added to Trump’s State Department transition team. Just last week, Groves called for the United States [ http://dailysignal.com/2016/11/17/the-pathway-out-of-paris/ ] to leave the UN Framework Convention on Climate Change, the overarching treaty that governs how the world organizes itself to address global warming. Groves also said the U.S. should move to “dismantle” domestic climate regulations.
A staffing choice isn’t a firm policy decision, but there isn’t much ambiguity about the Trump administration’s intentions so far. Trump may be sounding a new tune on the existence of climate change. (Though some journalists read the New York Times comments [ https://grist.org/politics/trump-new-york-times-climate/ ] to mean he hasn’t changed his mind about it at all.) But his policy team seems to want to both squash research about global warming while withdrawing the United States from any diplomatic attempt to do anything about it.
That’s the Trump two-step. The president-elect may look like he’s keeping an open mind, but his transition team is acting like a more extreme version of the Bush-era climate deniers.
Copyright © 2016 by The Atlantic Monthly Group
http://www.theatlantic.com/science/archive/2016/11/the-trump-two-step/508643/ [with non-YouTube version of the included YouTube as embedded; with comments], http://www.youtube.com/watch?v=Ai9nxn_Ykck [with comment]
--
in addition to (linked in) the post to which this is a reply and preceding and (other) following, see also (linked in):
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=124039545 and preceding (and any future following)
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=126843315 and preceding and following,
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=126867422 and preceding and (future) following
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=126853062 and preceding (and any future following)
Greensburg, KS - 5/4/07
"Eternal vigilance is the price of Liberty."
from John Philpot Curran, Speech
upon the Right of Election, 1790
F6
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