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Author Topic: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada  (Read 11200 times)

Espen

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Just studying the recent Modis 250M from top of Ellesmere Island, I am surprised not to see any shades from Ice Shelf, I assume there is level difference between the Sea Ice and the Ice Shelf.
What are the latest report about the situation, is it still alive?

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r03c03.2013103.terra.250m

http://www.ec.gc.ca/glaces-ice/?lang=En&n=056B4D49-1

Click on image to enlarge:

« Last Edit: July 17, 2013, 07:02:51 PM by Espen »
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Neven

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Re: Ward Hunt Ice Shelf / Ellesmere Island
« Reply #1 on: April 14, 2013, 10:26:35 AM »
For folks who want some quick background info: You do it to your shelf.
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Espen

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Re: Ward Hunt Ice Shelf / Ellesmere Island
« Reply #2 on: April 25, 2013, 05:07:46 PM »
Have a ice day!

Jim Williams

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Re: Ward Hunt Ice Shelf / Ellesmere Island
« Reply #3 on: April 25, 2013, 05:33:16 PM »
A massive crack is developing all along the north of CAA:

http://rapidfire.sci.gsfc.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl2_143.A2013115114500-2013115115000.2km.jpg

Yesterday was impressive and I'm waiting for today.  Wouldn't you know that this is usually one of the last areas to get filled in during the day....

Espen

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Re: Ward Hunt Ice Shelf / Ellesmere Island
« Reply #4 on: April 25, 2013, 05:43:46 PM »
« Last Edit: April 25, 2013, 06:00:20 PM by Espen »
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Jim Williams

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Espen

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Re: Ward Hunt Ice Shelf / Ellesmere Island
« Reply #6 on: April 25, 2013, 06:03:41 PM »
Jim;

The cracks north of Nares are much bigger and more developed today than yesterday.

http://rapidfire.sci.gsfc.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl2_143.A2013115114500-2013115115000.250m.jpg
« Last Edit: April 25, 2013, 06:12:02 PM by Espen »
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Jim Williams

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Re: Ward Hunt Ice Shelf / Ellesmere Island
« Reply #7 on: April 25, 2013, 06:23:44 PM »
So the question is, is it warm enough yet that the cracks don't immediately freeze over?

How I wish we had some decent data from under the ice.....

All the hints are for a fast and wild thaw, but there's nothing that can be called real data saying so.

Espen

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Re: Ward Hunt Ice Shelf / Ellesmere Island
« Reply #8 on: April 25, 2013, 06:27:17 PM »
Jim;

It is still very cold: Alert - 24C
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Peter Ellis

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Re: Ward Hunt Ice Shelf / Ellesmere Island
« Reply #9 on: April 25, 2013, 11:17:18 PM »
Here are the overview pictures back to 2009.  In all honesty, if you gave them to me in a random order, I could not tell which was which, or indicate which was worse than any other.

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?mosaic=Arctic.2009114.terra.4km
http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?mosaic=Arctic.2010114.terra.4km
http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?mosaic=Arctic.2011114.terra.4km
http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?mosaic=Arctic.2012114.terra.4km
http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?mosaic=Arctic.2013114.terra.4km

Yes, this year has a shore lead all the way along the north of Ellesmere island - but by this date 2010 had substantial open water in the Canadian Archipelago, 2011 has more open/shattered ice off the Chukchi coast, and 2012 had more obvious cracks throughout the Beaufort.  The leads from this year's event have had a good couple of months of intense cold to re-freeze and grow more ice.  I think we need to be wary of prophesying doom and gloom - every time we do and it doesn't happen, it makes the real changes that much easier to dismiss.

Neven

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Re: Ward Hunt Ice Shelf / Ellesmere Island
« Reply #10 on: April 25, 2013, 11:53:59 PM »
Wow, will you look at 2010! I started the blog in June that year, but could only vaguely remember how well advanced the break-up was in the CAA, with no ice arches in Nares.

That just goes to show that most of the details in the Arctic have happened before, especially around this time.
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Artful Dodger

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Re: Ward Hunt Ice Shelf / Ellesmere Island
« Reply #11 on: April 26, 2013, 06:40:49 AM »
A massive crack is developing all along the north of CAA:
Hi Espen,

Yes, April 25 is the Full Moon. This is to be expected on the Spring Tide. The real issue to watch for is horizontal movement of the pack ice. If it starts heading South toward the Beaufort sea at a steady pace, it will all melt by the end of Summer.

Then it's game over, MYI.
Cheers!
Lodger

Bruce Steele

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Re: Ward Hunt Ice Shelf / Ellesmere Island
« Reply #12 on: April 27, 2013, 07:55:39 AM »
There are two WHOI ice tethered buoys just north of Ellesmere Island # 63 and #48. They show current drift rates that are slow right now. They are in good position to watch the spring proceed.       http://www.whoi.edu/page.do?pid=20781

Espen

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #13 on: July 17, 2013, 12:37:22 PM »
Just did some studies of the remaining ice shelf locations on Ellesmere Island.

The blue areas indicate where I found traces / remains of the Ice Shelves.

Click on image to enlarge:
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TerryM

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #14 on: July 21, 2013, 06:41:36 PM »
I think both halves of Ward-Hunt have been vulnerable since the ice link joining them broke away in 2011. In September & August I check MODIS for clear days in the area just to see if everything is still in place. Back in 2011 I reported the missing link between the two at the ASIB 2 days before it was confirmed by the University of Guelph, so it's still possible to spot features through the clouds before they are announced.


The studies of driftwood dates at Ellesmere are the easiest way to shut deniers up when they insist that this is all part of some regular cycle. England's findings are easy to google and read & offer proof positive that we need to go back to the HTO to find conditions similar to what we're now experiencing.


Terry

Espen

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #15 on: July 21, 2013, 06:50:50 PM »
"Back in 2011 I reported the missing link between the two at the ASIB"


Terry you got it wrong, you announced it and the laurels went elsewhere!
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sidd

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #16 on: December 17, 2013, 12:14:45 AM »
Ward Hunt measurement from 1959

http://www.cbc.ca/news/canada/north/1959-message-in-a-bottle-a-clue-to-glacier-melt-1.2465597

http://thechronicleherald.ca/canada/1173466-54-year-old-message-in-bottle-helps-chronicle-death-of-glacier?from=most_read&most_read=1173466

Looking at their obituaries (both at Journal of Glaciology, other versions elsewhere), I feel certain that Walker knew Mercer and had informed prescience that the glacier would retreat rather than advance.

sidd

TerryM

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #17 on: August 20, 2016, 12:50:24 AM »
This might be a good time to re-visit Ward Hunt.


The wind is crazy, spring tide is in 2 days, and I've been waiting for action since the 'link' broke back in 2011. If GAC2 drifts a little further east Ward Hunt certainly couldn't be faulted for breaking it's last hold on land, or at least shedding a portion of what is left of it's once massive shelf.


Terry




TerryM

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #19 on: August 22, 2016, 01:19:45 AM »
Wow, Terry, I had no idea there was still a piece of it sitting there.  How on earth is it holding on?  It was still there on August 11:

https://worldview.earthdata.nasa.gov/?p=arctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels(hidden),Reference_Features(hidden),Coastlines&t=2016-08-11&v=-611624.4394552563,-782728.5972047597,-218408.43945525633,-593544.5972047597


Still seems to be holding on Aug. 20, but the next few days could be telling. Last time Neven addressed it was back in 2011 after the link between the two sides failed. I don't think things have changed much since then.
http://neven1.typepad.com/blog/2011/09/you-do-it-to-your-shelf-.html


Terry

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #20 on: August 22, 2016, 01:50:02 AM »
Thanks, Terry.  A nice discussion.  Unfortunately, many links now broken.  Is there evidence on how old the Ward Hunt remnant is?

TerryM

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #21 on: August 22, 2016, 05:31:10 AM »
Thanks, Terry.  A nice discussion.  Unfortunately, many links now broken.  Is there evidence on how old the Ward Hunt remnant is?
Equally unfortunate that most of my bookmarked links are also no longer viable. IIRC John English has done the heavy lifting re. dating of the old Ellesmere Shelf and ascertained that drift wood behind the current remnants was captured between 9.2 & 5.5 k yr BP. Many of his logs were found upstream in Disraeli Ford, which only opened again in 2002.


The first link is to one of his papers.
http://onlinelibrary.wiley.com/doi/10.1029/2008GL034470/full


The second has great photos (some animated) re. the calving in 2008.
http://www.trentu.ca/iceshelf/wardhunt.html


Somehow I'm drawn to the loss of these ancient shelves that won't be replaced for many generations (if ever).


Terry

TenneyNaumer

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #22 on: August 23, 2016, 06:37:34 AM »
Thanks, Terry!

We know those ice shelves aren't coming back for eons -- it does make one feel a bit sad.

nukefix

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #23 on: August 23, 2016, 11:46:57 AM »
Here's the situation in the west as seen by S-1A 22.8.2016 in dual-pol IW (20m pixel-size UTM zone 16). Red arrows from left indicate:

- Serson ice shelf remnant (still there)
- Petersen ice shelf remnant (practically gone)
- Milne ice shelf remnant (still going strong)

TerryM

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #24 on: August 23, 2016, 07:07:29 PM »
NF


Wonderful graphic, but I think you're a little west? of our subject.


https://worldview.earthdata.nasa.gov/?p=arctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor,MODIS_Aqua_CorrectedReflectance_TrueColor,MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels,Reference_Features(hidden),Coastlines&t=2016-08-16&v=-695356.2946157213,-756959.4090445098,-227388.29461572133,-522975.40904450975


is from the 16th. Ward Hunt extends east across Disraeli Fjord rather than being limited to the larger western portion that is labeled on Worldview.


Terry

nukefix

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #25 on: August 24, 2016, 10:40:06 AM »
Here's a S-1A view of Milne and Ward Hunt ice shelves on 23.3.2016, downsampled to 30m resolution in UTM17:

Shared Humanity

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #26 on: August 24, 2016, 02:28:04 PM »
Here's a S-1A view of Milne and Ward Hunt ice shelves on 23.3.2016, downsampled to 30m resolution in UTM17:

Are the shelves the areas of bright white ice?

nukefix

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #27 on: August 24, 2016, 03:27:47 PM »
Here's a S-1A view of Milne and Ward Hunt ice shelves on 23.3.2016, downsampled to 30m resolution in UTM17:

Are the shelves the areas of bright white ice?
Good question, I added some arrows to make it clearer. The old shelf ice appears striated, while some of the bright smooth ice is small ice caps.

TerryM

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #28 on: August 24, 2016, 08:13:32 PM »
NF


Fabulous Photos !!!


I believe I can make out the ridge patterns that distinguish both portions of the shelf from the very recent fast ice at the end of Disraeli Ford.


At some point huge ice islands will calf, but probably not this year.


Thanks again for the image!
Terry

Shared Humanity

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #29 on: August 25, 2016, 02:40:07 AM »
Here's a S-1A view of Milne and Ward Hunt ice shelves on 23.3.2016, downsampled to 30m resolution in UTM17:

Are the shelves the areas of bright white ice?
Good question, I added some arrows to make it clearer. The old shelf ice appears striated, while some of the bright smooth ice is small ice caps.

Thank you.

sidd

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #30 on: September 23, 2017, 10:54:03 PM »
Charming paper about an arctic epishelf lake on Ellesmere by Hamilton et al.
Open access. Read all about it.

https://doi.org/10.5194/tc-11-2189-2017

sidd

Espen

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #31 on: September 23, 2017, 11:05:46 PM »
Not sure but I could imagine Hunt Fjord, Northern Greenland being an epishelf lake?
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sidd

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Re: Ice Shelves /Ward Hunt Ice Shelf / Ellesmere Island / Canada
« Reply #32 on: September 24, 2017, 12:01:57 AM »
yes, i think more epishelf lakes will be recognized as melt proceeds. I hope more of them get instrumented like this one.