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Author Topic: Surge of WAIS Ice Mass Loss  (Read 77876 times)

AbruptSLR

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Re: Surge of WAIS Ice Mass Loss
« Reply #200 on: December 13, 2016, 08:40:19 PM »
The linked presentation is entitled: “RAPID RESPONSE OF WEST ANTARCTIC ICE SHELVES TO EL NIÑO AND LA NIÑA”; and it indicates that El Nino events result in accelerated ice mass loss from Amundsen Sea ice shelves:

https://scripps.ucsd.edu/news/scripps-news-2016-agu-fall-meeting

El Niño’s Immediate Effects on Antarctica’s Ice Shelves

C14A-05 • Monday, Dec. 12, 5 p.m. • Moscone West 3007

Description: "Ice shelves experience rapid changes when the global climate phenomenon known as El Niño occurs.  Researchers at Scripps Institution of Oceanography at the University of California San Diego and Earth and Space Research in Corvallis, Ore. found that El Niño thickens the ice shelves by increasing snowfall on top of them, and thins the ice shelves by increasing melt below them as warm ocean water comes into contact with their bases.

The researchers, led by Scripps postdoctoral researcher Fernando Paolo, analyzed surface-height records made between 1994 and 2012 at the Amundsen Sea ice shelves in West Antarctica. They found that El Niño episodes lead to a net loss in ice-shelf mass because the ice lost at the base is denser than the snow gained at the surface.

The study suggests that if El Niños become more frequent in a future climate, the variability of ice shelves will increase. This has a range of implications for the dynamics of grounded ice in Antarctica, which is a source of large uncertainty in global sea-level rise projections. The study also highlights the importance of the contribution of changing snowfall on ice-shelf mass balance at timescales shorter than a decade, which has been underappreciated until now."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
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AbruptSLR

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Re: Surge of WAIS Ice Mass Loss
« Reply #201 on: December 14, 2016, 05:49:27 PM »
The attached Sentinel1 image of the Thwaites Eastern Ice Shelf & residual Ice Tongue is from Dec 14 2016.  It indicates to me that the residual Ice Tongue is continuing to degrade and at some point we can expect another surge of ice flow from this critical area.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

solartim27

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Re: Surge of WAIS Ice Mass Loss
« Reply #202 on: December 17, 2016, 09:00:52 PM »
Here's a gif of a small calving at the southern end of Thwaites, Dec 3 to 17.

http://www.polarview.aq/images/105_S1jpgfull/S1A_EW_GRDM_1SSH_20161217T042738_2F36_S_1.final.jpg

S1A_EW_GRDM_1SSH_20161203T044353_2FFE_S_1.final.jpeg
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AbruptSLR

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Re: Surge of WAIS Ice Mass Loss
« Reply #203 on: January 27, 2017, 11:12:32 PM »
Article on the BBC today:

"The scale and pace of change now taking place in West Antarctica is captured in a new, long-term satellite record.

Scientists have combined nearly a quarter of a century of observations to show how the region's great glaciers are losing height by up to 7m per year.

The satellite data also traces the way this thinning behaviour has spread up the length of the ice streams.

As the glaciers accelerate, they have to take ever more ice from the interior to compensate for the speed-up. This means they thin; they lose height, which we can detect from space," explained Dr Hannes Konrad from the UK's Centre for Polar Observation and Monitoring (CPOM).

"And if there is no increase in snow and ice in the interior then this thinning will just migrate further and further upstream,"

http://www.bbc.com/news/science-environment-38256932

Article here (paywallled):
http://onlinelibrary.wiley.com/doi/10.1002/2016GL070733/full


See also:

Cook, T. (2017), A comparison of surface thinning in West Antarctic glaciers, Eos, 98, doi:10.1029/2017EO066407. Published on 24 January 2017.

https://eos.org/research-spotlights/a-comparison-of-surface-thinning-in-west-antarctic-glaciers?utm_source=eos&utm_medium=email&utm_campaign=EosBuzz012717

“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

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Re: Surge of WAIS Ice Mass Loss
« Reply #204 on: February 18, 2017, 10:11:01 PM »
The attached images come from the following linked website regarding ice mass loss rates for Antarctica from August 16 2002 to July 16 2016.  The first three images respectively show ice mass loss from zones AIS22, AIS21 & AIS 20; which are the three zones in the WAIS with the darkest red shading in the fourth image (with AIS22 for the PIG basin) 

https://data1.geo.tu-dresden.de/ais_gmb/
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson