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Author Topic: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland  (Read 552774 times)

johnm33

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1050 on: August 23, 2020, 07:58:08 PM »
With a before and after on polarview too.   
   Looking upstream there's an ovaloid area that looked like it collapsed a week or more ago, and the 'banding' which i think suggests the area is grounded in water has been fading plus there've been huge freshwater discharges on hycom it's almost a surprise it took so long given the loss of the melange in front of it. I do wonder if having started to move it may be somewhat lubricated?
 There's a wonderful clear view of Jakobshavn on sentinel from 22:08 which shows calving to both faces.

oren

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1051 on: August 24, 2020, 02:28:51 AM »
A Worldview animation of the whole region from the last really clear day, Aug6-Aug23.
It's interesting that while the bay cleared, some of the largest ice pieces actually moved "backwards" to the north.
The ZI calving can be seen even at this resolution, and perhaps a tiny calving an N79.
Click.

p.s. I think the events confirm again that the sea ice and melange in the bay provides some buttressing, and when cleared calving will tend to be easier.

Espen

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1052 on: August 24, 2020, 09:04:56 AM »
Final result of the calving session at Zachariae Isstrøm between Aug. 21 and Aug. 22 2020:

Please click on image to animate!
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oren

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1053 on: August 24, 2020, 11:33:42 AM »
Thank you Espen.
Could you perhaps update your famous image showing the calving front line for each year?

Espen

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1054 on: August 24, 2020, 04:32:50 PM »
Thank you Espen.
Could you perhaps update your famous image showing the calving front line for each year?

Oren here you go, not much different from 2019, only up against Kap Zachariae and down toward Kap Zach

Please click on image to enlarge!
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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1055 on: August 24, 2020, 10:37:58 PM »
Thanks!

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1056 on: September 01, 2020, 03:36:28 AM »
Wow - open water at the calving face of Zacharie Isstrøm.  Don't recall ever seeing this before.



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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1057 on: September 01, 2020, 06:59:17 PM »
Animation comparing Aug 27 with Aug 31

click to animate


Diaminedave

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1058 on: September 03, 2020, 08:52:26 AM »
Spaltegletscher.
Seems to be on the move and breakink up slightly after being stuck for the last few months

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1059 on: September 06, 2020, 11:45:26 PM »
Very scary picture of the collapsed NE Greenland 2000+ sqkm basin thats up to a km deep behind these Glaciers. On the right the dark area is inland of the coastal ranges. Now islands with the calving front merging all the glaciers from north and ne Greenland into one downsloping, below sealevel front, over 200 km long.

nukefix

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1060 on: September 08, 2020, 01:09:06 PM »
Very scary picture of the collapsed NE Greenland 2000+ sqkm basin thats up to a km deep behind these Glaciers. On the right the dark area is inland of the coastal ranges. Now islands with the calving front merging all the glaciers from north and ne Greenland into one downsloping, below sealevel front, over 200 km long.
I have trouble understanding the point you're making - is the ice stream losing contact with some islands that currently provide back-pressure? I don't think the basin is "collapsing" at this point in time.

vox_mundi

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1061 on: September 14, 2020, 06:40:17 AM »
Warmth Shatters Section of Greenland Ice Shelf
https://www.bbc.com/news/amp/science-environment-54127279



A big chunk of ice has just broken away from the Arctic's largest remaining ice shelf - 79N, or Nioghalvfjerdsfjorden - in north-east Greenland.

The ejected section covers about 110 square km; satellite imagery shows it to have shattered into many small pieces.


The loss is further evidence say scientists of the rapid climate changes taking place in Greenland.

"The atmosphere in this region has warmed by about 3C since 1980," said Dr Jenny Turton.

"And in 2019 and 2020, it saw record summer temperatures," the polar researcher at Friedrich-Alexander University in Germany told BBC News.

Nioghalvfjerdsfjorden is roughly 80km long by 20km wide and is the floating front end of the Northeast Greenland Ice Stream - where it flows off the land into the ocean to become buoyant.

At its leading edge, the 79N glacier splits in two, with a minor offshoot turning directly north. It's this offshoot, or tributary, called Spalte Glacier, that has now disintegrated.


The higher air temperatures recorded in the region are obvious from the large number of melt ponds that sit on top of the shelf ice

Oceanographers have also documented warmer sea temperatures which mean the shelf ice is almost certainly being melted from beneath as well.

"79N became 'the largest remaining Arctic ice shelf' only fairly recently, after the Petermann Glacier in northwest Greenland lost a lot of area in 2010 and 2012," explained Prof Jason Box from the Geological Survey of Denmark and Greenland (GEUS).

"What makes 79N so important is the way it's attached to the interior ice sheet, and that means that one day - if the climate warms as we expect - this region will probably become one of the major centres of action for the deglaciation of Greenland."

The Northeast Greenland Ice Stream drains about 15% of the interior ice sheet. The stream funnels its ice either down N79 or the glacial member just to the south, Zachariae Isstrom. Zachariae has already lost most of its floating ice shelf area.


Prof Box said N79 could resist longer because it was penned in right at its forward end by some islands. This lends a degree of stability. But, he added, the shelf continues to thin, albeit mostly further back along the trunk.

"This will likely lead to N79 disintegrating from the middle, which is kind of unique. I guess, though, that won't happen for another 10 or 20 years. Who knows?" he told BBC News.
« Last Edit: September 14, 2020, 06:46:12 AM by vox_mundi »
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Espen

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1062 on: September 14, 2020, 08:31:11 AM »
« Last Edit: September 14, 2020, 08:59:12 AM by Espen »
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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1063 on: September 15, 2020, 07:49:15 PM »
It always amazed how stuff is pinched in the so called science industry, and in the case about the calving at Spaltegletscher in July this year, is a very good example, the calving happened June 30 2020 and was reported by anaphylaxia and documented by me a few hours later by graphic:

https://forum.arctic-sea-ice.net/index.php/topic,400.msg271321.html#msg271321

https://forum.arctic-sea-ice.net/index.php/topic,400.msg271329.html#msg271329

What really worries me is that happens in the same country Denmark where I am a resident and tax payer, Geus which is 100% subsidized by the Danish State.
And I know for sure I was under "investigation" by GEUS and several of their staff the days before the release of this "report", so they knew what they were doing. I am really dissapointed with the so called professionals in the science industry! Really gefundenes Fressen for people like for instance Trump!
« Last Edit: September 15, 2020, 08:07:12 PM by Espen »
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Stephan

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1064 on: September 15, 2020, 08:18:29 PM »
This calving event made it into the main TV news "Tagesschau" in Germany yesterday. I really wondered why they needed ten weeks to broadcast it...
It is too late just to be concerned about Climate Change

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1065 on: September 15, 2020, 08:27:38 PM »
This calving event made it into the main TV news "Tagesschau" in Germany yesterday. I really wondered why they needed ten weeks to broadcast it...

Because A Science Company in Denmark called GEUS needed a good story, they went on and pinched it from ASIF, wonder why Trump dont believe in science?
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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1066 on: September 24, 2020, 08:12:31 PM »
Before it all gets dark, here is good view of the situation at Zachariae Isstrøm from September 23 2020:

Click on image to enlarge!
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Tor Bejnar

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1067 on: September 24, 2020, 10:16:04 PM »
Sometimes 'Click to Enlarge' doesn't do much for me.  Sometimes it does.  This is one of the "it does" times!
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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1068 on: September 25, 2020, 08:41:05 PM »
Sometimes 'Click to Enlarge' doesn't do much for me.  Sometimes it does.  This is one of the "it does" times!

Seriously! That is an amazing image.

Espen

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1069 on: October 27, 2020, 12:01:48 PM »
A massive calving session happened again at Zachariae Isstrøm between Oct 20 and Oct 26 2020. Nice to have these Sentinel 1 Data now while it is dark up north.

Please click on image to animate!
« Last Edit: October 27, 2020, 06:26:32 PM by Espen »
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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1070 on: December 20, 2020, 08:12:42 PM »
Zachariae Isstrøm:
Is preparing a large beach cleaning south of Lambert Land - December 14 - December 20 - 2020.

Please click on image to enlarge and animate!
« Last Edit: December 21, 2020, 02:40:17 PM by Espen »
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Espen

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1071 on: February 12, 2021, 09:27:02 PM »
Zachariae Isstrøm:
A massive calving session happened between February 6 and February 12 2021, in the middle of the dark North East winter of Greenland.

Please click on the image to enlarge and animate!
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oren

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1072 on: February 12, 2021, 10:11:46 PM »
Impressive.

Espen

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1073 on: February 13, 2021, 05:18:25 PM »
Zachariae Isstrøm:
I will promote the calving mentioned above from a session to an event happening between February 11 and February 12 due to newly released data from ESA (Sentinel 1).
« Last Edit: February 13, 2021, 08:18:36 PM by Espen »
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oren

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1074 on: February 13, 2021, 06:54:29 PM »
Espen - when this calving is finished, could you please make some long term animation of ZI over the last 7-10 years or so, one or two images per year or something like that? I think it could give readers long term perspective of where we are and how fast we are going.
It is my (unsubstantiated) impression that while Jakobshavn's front has been rather stable since 2016, or at least has not receded further, and Petermann is a slow burner calving only once every few years, Zachariae has been steadily calving and receding, even if not very fast.

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1075 on: February 16, 2021, 10:46:48 AM »
A comparison should be possible between Envisat ASAR (from 2003) and S-1 or even ERS-1/2 (from 1991) and S-1. The data is freely available and even though the orbit track is not identical to S-1 there and free tools like SNAP to facilitate co-registration.

oren

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1076 on: February 16, 2021, 11:12:49 AM »
I recall Espen's last update of his famous image showing calving fronts over the last 10 years. Recession of the front has certainly slowed compared to the early part of the 2010s. Not sure where we are now though.


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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1077 on: February 18, 2021, 05:59:39 PM »
A comparison should be possible between Envisat ASAR (from 2003) and S-1 or even ERS-1/2 (from 1991) and S-1. The data is freely available and even though the orbit track is not identical to S-1 there and free tools like SNAP to facilitate co-registration.

Hello Nukefix could you please show an example from early 2000 or earlier to now in a reasonable resolution?
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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1078 on: March 10, 2021, 08:29:49 AM »
Looking forward to another interesting season with my favourite glacier Zachariae Isstrøm, below you find the Grand Opening 2021 image from Sentinel 2:

Please click on image to enlarge!
« Last Edit: March 10, 2021, 11:05:42 AM by Espen »
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kassy

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1079 on: March 10, 2021, 10:24:41 PM »
So the blocky features are above the surrounding terrain?
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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1080 on: March 10, 2021, 11:04:19 PM »
The blocky features in the center-right part of the image are tall icebergs surrounded by sea ice.  The glacier is basically everything on the left side of the image and rock (partly snow/ice covered) shows up at the top.
Arctic ice is healthy for children and other living things because "we cannot negotiate with the melting point of ice"

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1081 on: April 06, 2021, 05:35:21 PM »
Sea Ice is to not my speciality but I would like to mention something that did not happen for almost 20 years, the Sea Ice in front of Jøkelbugt and Zachariae Isstrøm broke up April 1 2021.

What happened in 2003 and thereafter resulted (in my oppinion but I am not an scientist) in the collaps and massive retreat of Zachariae Isstrøm, notice Zachariae Isstrøm is still attached to the now separated tonque in 2003.
More about this can be read in my discussions with Mauri Pelto https://glacierchange.wordpress.com/2012/08/27/zachariae-isstrom-further-retreat-ne-greenland/

Further up North around Flade Isblink at Nordostrundingen the Sea Ice is also being attacked.

This could become a very interesting season if all this continue:

Please click on image to start animation!
« Last Edit: April 06, 2021, 05:44:34 PM by Espen »
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Diaminedave

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1082 on: May 20, 2021, 01:27:08 PM »
I believe that Lake on northern side of 79 fjord glacier is beginning to show signs of melting. from Worldview observation only so I could be wrong!

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1083 on: May 20, 2021, 02:36:43 PM »
It is called Lake Blaso, and it is indeed showing signs of melting, as confirmed by sentinel.
https://apps.sentinel-hub.com/sentinel-playground/?source=S2L2A&lat=79.61997441803977&lng=-22.641448974609375&zoom=10&preset=1_TRUE_COLOR&layers=B01,B02,B03&maxcc=20&gain=1.0&gamma=1.0&time=2020-11-01%7C2021-05-19&atmFilter=&showDates=false

It is of great consequence, as the lake is 300* m over sea level, and has 2 outlets onto 79N, which are blocked by ice dams. Warm meltwater from a large portion upstream on the glacier drains into it. Serious melt potential right at the neck of the glacier tongue.
*corrected from 500
« Last Edit: May 20, 2021, 02:53:14 PM by anaphylaxia »

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1084 on: May 20, 2021, 03:31:28 PM »
Appreciated.
Gerontocrat Mass balance info confirmed my observation to some extent.
The bare dark rock surrounding the lake must act as heat store pumping energy into the water.
Sadly looks like it might be an interesting area this summer

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1085 on: May 20, 2021, 03:35:18 PM »
also hadn't realised that there was such a head difference from lake surface to sea level

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1086 on: May 20, 2021, 05:14:00 PM »
Note that the elevation data is rather scarce, and counterfactual, so the exact height of the water is uncertain. Declassified military maps list the height at 1000 feet, but other internet resources list it at 500 m. And it also shows very big variablity, filling up with meltwater. It can be observed in the summer as the lake rises, and makes a big pond toward the center of Greenland.

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1087 on: May 23, 2021, 10:59:29 PM »
Zachariae Isstrøm : A very large ongoing calving session is taking place at this fascinating Glacier.

Please click on image to enlarge and animate!
« Last Edit: May 23, 2021, 11:09:23 PM by Espen »
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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1088 on: May 23, 2021, 11:15:31 PM »
Zachariae Isstrøm : A very large ongoing calving session is taking place at this fascinating Glacier.


I found it quite interesting how that one rift extended so close to the existing rift in parallel, instead of just joining with it.

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1089 on: May 28, 2021, 12:24:43 AM »
"The most revolutionary thing one can do always is to proclaim loudly what is happening" - Rosa Luxemburg

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1090 on: June 28, 2021, 09:13:16 PM »
Calving today/yesterday

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1091 on: June 28, 2021, 09:52:09 PM »
Very odd that melt ponds either shrunk or disappeared entirely with the calving.

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1092 on: June 28, 2021, 10:06:19 PM »
SH, OK I see them now. The shaking must open cracks that allow the water to drain?
« Last Edit: June 28, 2021, 10:15:53 PM by Bruce Steele »

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1093 on: June 28, 2021, 10:47:35 PM »
Very odd that melt ponds either shrunk or disappeared entirely with the calving.

To be precise: The "before" image is not yesterday because it was somewhat cloudy, it's like 4-5 days ago or something.
It's normal for pools to disappear as the season progresses as they find routes to drain from.

oren

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1094 on: June 28, 2021, 11:16:57 PM »
The glacier front is pushed from behind by gravity into the fast sea ice in the bay. When the front collapses and also shifts the fast ice forward, some of the buttressing is relieved (less front mass to push, less resistant sea ice) and the ice directly behind the front now has more space under less pressure. It makes sense that cracks are generated in this process, and the pools directly behind the front drain into the cracks.

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1095 on: June 29, 2021, 10:05:47 AM »
If you look at Hycom sss you'll see freshwater has broken out before the calving, can't be sure it's from Z. but it's 'normal' to see an outburst before a calving, though one does not predict the other.

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1096 on: July 06, 2021, 04:45:31 PM »
Blaso Lake started draining through the upper inlet of 79N glacier. Lots of meltwter disappearing under the glacier's neck. First gif is animation on 07. -03 -04 -05 of the catchment delta showing a dropping water level. Second gif is the upper inlet of the 79N glacier into the lake. On 07 04 a collapse in the glacier debris can be seen, and on the next day it is again in the original position, suggesting a strong current going under the glacier.

Espen

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1097 on: July 19, 2021, 10:08:31 PM »
Zachariae Isstrøm - A large calving of "Death Ice" in the northern section of the glacier happened between July 16 and July 19 2021, the amount of ice sent away is aprox. 8 km2.

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Have a ice day!

grixm

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1098 on: July 20, 2021, 12:11:09 AM »
Zachariae Isstrøm - A large calving of "Death Ice" in the northern section of the glacier happened between July 16 and July 19 2021, the amount of ice sent away is aprox. 8 km2.


Why is it called "death ice"?

IceConcerned

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Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1099 on: July 20, 2021, 08:50:47 AM »
I guess because it is not any more part of the flow, just a static remain

I am nevertheless concerned that it was kind of a pillar on which the flow's ark was resting, (at least on a 2D project, I guess it gets more complicated once you account for altitude), I would thus expect a further retreat quite soon