Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland

[Andreas T]

This seems to be an old lead, I think it can be recognized in this AVHRR image from January
http://ocean.dmi.dk/arctic/images/MODIS/Joekelbugt/201401030645.NOAA.jpg

[Espen]

Zachariae update:

More movements and action

Please click on image to start animation!

[Andreas T]

Andreas Muenchow has some nice photos of old bits of Zachariae near Isle de France
http://icyseas.org/2014/06/20/icebergs-islands-and-instruments-off-isle-de-france-north-east-greenland/
interesting to see them from a different perspective

[Espen]

Andreas Muenchow has some nice photos of old bits of Zachariae near Isle de France
http://icyseas.org/2014/06/20/icebergs-islands-and-instruments-off-isle-de-france-north-east-greenland/
interesting to see them from a different perspective

Yes those ice cubes really are impressive!

[Wipneus]

Zachariae calving from in 15m res. Lots of melt ponds now, discolorings and all kinds of interesting creases, wrinkles and cracks are appearing

I will make a comparison with a previous date later to check the movement.

You must click the picture if you are ready for a 4M downlod.

[Shared Humanity]

Zachariae calving from in 15m res. Lots of melt ponds now, discolorings and all kinds of interesting creases, wrinkles and cracks are appearing

I will make a comparison with a previous date later to check the movement.

You must click the picture if you are ready for a 4M downlod.

When I look at this image, (beautiful by the way) I can't help but get the sick feeling that  glaciologists are seriously underestimating the potential sea level rise due to glaciers. Not only this one but every single sea terminating glacier that is grounded below sea level. Just as they were surprised by having the Northeast Coast of Greenland getting unlocked, they will be registering surprise by how quickly these glaciers speed up, melt, calve and retreat.

[Laurent]

Seeing how many lakes will drain...yes, there will be lubrification...

[Wipneus]

Here is an detail animation created with images on 2014-04-14 and 2014-07-03. Path/Row are the same:9/3 to minimize distortion.
My favorite hexagonal feature can be recognized (about 40% from the left, a bit above the middle) and helped me to measure the movement there: 31 pix to the right and 1 up. That translates to 5.8 m/day.

I am afraid the crack that will destroy my hexagonal feature, is already forming.

[Shared Humanity]

I am afraid the crack that will destroy my hexagonal feature, is already forming.

Not to worry. Another hexagonal feature will form west of it soon although it will crack later.

[Espen]

Thanks Wipneus!

Yes it is a very dramatic scene, and one of the more serious of the kind, I wonder where this will end in September, we are into the "land of retreat" everyday now!

[Espen]

And now the last reminder animation for now, and my pet project, is it not impressive?

Please click on image to start animation!

[Espen]

Zachariae is still on the move:

Please click on image to start animation!

[Espen]

1 weeks movement at Zachariae Isstrøm:

Please click on image to start animation!

[Espen]

It looks like Zachariae is slowing down a bit, but the calves move on:

Please click on image to start the animation!

[Espen]

Talking about slowing down, Zach woke up to a sudden rush.
In a time span of just 24 hrs a lot of change is seen:

[Andreas T]

the bay in front of Sanddal is quickly loosing its ice and with its entrance stick firmly closed by landfast ice it clearly is melting. Probably has been thin for some time. It always surprises me how this happens from the land side out. Is there enough runoff to warm the sea, is it the air warmed on the ice free surfaces?
http://1.usa.gov/1pd7Hzf

[Espen]

the bay in front of Sanddal is quickly loosing its ice and with its entrance stick firmly closed by landfast ice it clearly is melting. Probably has been thin for some time. It always surprises me how this happens from the land side out. Is there enough runoff to warm the sea, is it the air warmed on the ice free surfaces?
http://1.usa.gov/1pd7Hzf

Andreas,

It is very common the sea ice break from inside out, especially in the fjords where melt water from numerous rivers melts the sea ice. The same is the case around Sanddal (Sand Valley) and Kofoed-Hansen Bræ in the bottom of the fjord.

A good example is this shot from Hagen Bræ, where river water melts the sea ice:

[Espen]

Or this from the extreme north (Flade Isblink / Marsk Stig Bræ), where the glacier actually function as a giant melt water river, note the nice delta to the right of the glacier (Prinsesse Ingeborg Halvø), probably the northern most delta system in the world:

[Andreas T]

I find this more obvious where river waters have some distance to run and time to get warmed. In Sanddal it seems to be coming straight off the ice

[Andreas T]

Ice around Ile de France is breaking uphttp://1.usa.gov/1pkzrz3
It will be interesting to see how the flow up the east coast affects the still landfast ice.
I would expect higher temperatures near the surface, but how do deeper currents respond to that?

[TerryM]

Spring Tide today at NE Greenland so fast ice may be pulling out.
Terry

[Yuha]

Spring Tide today at NE Greenland so fast ice may be pulling out.

Perhaps caused by the tide, there was a big calving:

[Espen]

Spring Tide today at NE Greenland so fast ice may be pulling out.

Perhaps caused by the tide, there was a big calving:

No it was more a movement of already calved calves.

[Espen]

Zachariae update, just a bit relocation of calves:

Will be interesting to see how the calves and the glacier will react when the sea ice is gone in a few weeks?

[Shared Humanity]

Espen...

What does the northeastern face of the separated tongue look like?

[Espen]

Espen...

What does the northeastern face of the separated tongue look like?

SharedHumanity,

This is an image from august 2013

[Shared Humanity]

Thanks Espen....looks like a  lot of  melt ponds on the ice last fall.

[Espen]

Thanks Espen....looks like a  lot of  melt ponds on the ice last fall.

The remains will be depending on the sea, meaning in-situ disintegration and melt since it is now a "dead body".

[Wipneus]

Fast ice is now cracking over big way (Aqua-MODIS Aug 2):

[Espen]

Wipneus it is actually not fast ice since it was almost all gone last year, but it is interesting to see that the Belgica Bank is holding on. There is no fast ice left in East Greenland, the only fast ice left around Greenland I can think of is a few spots between Hellefiskfjord and Sands Fjord

[Espen]

Zachariae update, still moving on:

[Espen]

Nioghalvfjerdsfjorden / 79 N Glacier update, I wonder if this glacier is still alive, hardly no movements in over 2 months, maybe due to its next door neighbor Zachariae taking over calving business?: 

Please click on the image to start the animation!

[Wipneus]

Sequence of Zachariae Jul 3 - Aug 4.
Obviously calving has been faster than the glacier itself. My favorite "hexgonal" feature is still visible.
During the 32 days between the images, the feature moved 7.5 m/day, faster than any measurement before. That could be because it is nearing the calving front, more inwards I measure a speed of about 6.7 m/day, that is still among the highest measurements.

(click to view 2.5M animation)

[Espen]

Sequence of Zachariae Jul 3 - Aug 4.
Obviously calving has been faster than the glacier itself. My favorite "hexgonal" feature is still visible.
During the 32 days between the images, the feature moved 7.5 m/day, faster than any measurement before. That could be because it is nearing the calving front, more inwards I measure a speed of about 6.7 m/day, that is still among the highest measurements.

(click to view 2.5M animation)

Wipneus,

It looks like the southern part of calving front / area is moving more than the northern, the southern part is even expanding southward towards the hidden Kap. 

[Wipneus]

It looks like the southern part of calving front / area is moving more than the northern, the southern part is even expanding southward towards the hidden Kap.

Yes, in comparison the glacier is moving rather uniformly.

[sidd]

there is a trough under the southern edge, i suspect warm water is coming in there. i believe i have posted some topo earlier, but i am very pressed for time and cannot verify.

sidd

[Espen]

there is a trough under the southern edge, i suspect warm water is coming in there. i believe i have posted some topo earlier, but i am very pressed for time and cannot verify.

sidd

Yes Sidd, I know you are busy, yes I suspect a change is happening in the "southern front".

[Wipneus]

Same Landsat image as in post #232, but compared with one taken April 14, 112 days difference.

Here is a detail of the 79N calving front, as Espen noted very little movement about 4 pixels which calculates to 4*15/112=0.54 m/day. Less then a tenth of the speed of Zachariae! Even the calving in progress is not making much progress at all.

(click to animate)

[Wipneus]

Now this is 60km upstream. Here the movement is much faster, about 3.5 m/day.

(must click this one as well)

[Espen]

Now this is 60km upstream. Here the movement is much faster, about 3.5 m/day.

(must click this one as well)

So the question is, what is happening in between?

[Hans]

Now this is 60km upstream. Here the movement is much faster, about 3.5 m/day.

(must click this one as well)

A remarkable feature in the 2014-08-04 image of the animation above. The meltwater lake in the bottom-right corner has some faint echo imprints down stream. We have seen in other occasions that melt lakes year-on-year form on the same geographic location and don't move with the ice. Are these white spots the remains of the "same" melt lake in previous years?

[Espen]

Hans,

It is called a watermark, you see them often in banknotes etc. 

Nice catch by the way!

[Shared Humanity]

Now this is 60km upstream. Here the movement is much faster, about 3.5 m/day.

(must click this one as well)

A remarkable feature in the 2014-08-04 image of the animation above. The meltwater lake in the bottom-right corner has some faint echo imprints down stream. We have seen in other occasions that melt lakes year-on-year form on the same geographic location and don't move with the ice. Are these white spots the remains of the "same" melt lake in previous years?

The only possible explanation for the melt lakes not moving is that they are related to the underlying topography.

The water marks suggest that Alan Greenspan is somehow involved.   

[Wipneus]

An evening (ascending part of the orbit) image of Zachariae shows more of the relief on the surface due to the longer shadows.

Enjoy (must click for a download of 3.5 MB image).

[Espen]

Zachariae update, notice not a scratch on the former tongue?

[A-Team]

Here is the new piece from BBC on this region: http://www.bbc.com/news/science-environment-28852980

"A new assessment from Europe's CryoSat spacecraft shows Greenland to be losing about 375 cu km of ice each year. Added to the discharges coming from Antarctica, it means Earth's two big ice sheets are now dumping roughly 500 cu km of ice in the oceans annually. "The contribution of both ice sheets together to sea level rise has doubled since 2009," said Angelika Humbert from Germany's Alfred Wegener Institute. "To us, that's an incredible number," she told BBC News.

Significant thinning is seen also in the North East Greenland Ice Stream (NEGIS). "This has three outlet glaciers and one of these, the Zachariae Isstrom, has retreated quite a bit and some volume loss has already been reported. But we see now that this volume loss is really propagating to upper areas, much further into the interior of the ice sheet than has been recorded before," explained Prof Humbert."

I chased down the article and the original graphic (which is much higher resolution but still badly anti-aliased, use http://pdfaid.com/ExtractImages.aspx for that (page 13, image 18). A lot of the color key was not used at all but for those that were, I worked out their percentages. (Seems like I discussed this article 2-3 week ago on the Jakobshavn forum when it was still being finalized.)

The real research action is not at the calving front but about halfway up to the ridgeline. A large consortium drilled the NEGIS core back in 2012 and those papers have now come out -- really first rate. The rate-of-loss image shows however that the Zachariae Isstrøm, while no longer slumbering, is not yet a major player in sea level rise.

Elevation and elevation change of Greenland and Antarctica derived from CryoSat-2
V. Helm et al
http://static2.egu.eu/media/filer_public/ac/f2/acf2d697-4a67-433b-bfd4-2a1f569cdb86/tc-2014-18.pdf

Initial results from geophysical surveys and shallow coring of the Northeast Greenland Ice Stream (NEGIS)
P Vallelonga et al
http://www.the-cryosphere.net/8/1275/2014/

Sustained mass loss of the northeast Greenland ice sheet triggered by regional warming
SA Khan et al
Nature Climate Change 4, 292–299 (2014) doi:10.1038/nclimate2161
http://www.indiaenvironmentportal.org.in/files/file/greenland.pdf
http://www.nature.com/nclimate/journal/v4/n4/extref/nclimate2161-s1.pdf

Inferred basal friction and surface mass balance of North-East Greenland Ice Stream using data assimilation of ICESat-1 surface altimetry and ISSM
E Larour et al
http://www.the-cryosphere-discuss.net/8/2331/2014/tcd-8-2331-2014.pdf

Basal conditions and ice dynamics inferred from radar-derived internal stratigraphy of the northeast Greenland ice stream
BA Keisling et al
Annals of Glaciology 55(67) 2014
doi: 10.3189/2014AoG67A090 (paywalled but obtained)

Dilatant till facilitates ice-stream flow in northeast Greenland
K Christianson et al
Earth and Planetary Science Letters 401 (2014) 57–69
doi.org/10.1016/j.epsl.2014.05.060 (paywalled but obtained; also at DeepDyve)

[Shared Humanity]

Because it doesn't have remarkable calvings or spectacular retreat, we tend not to pay attention to Humboldt Glacier but this area of the ice sheet appears to be losing elevation faster than Peterson or Zacharie.

[Espen]

Zachariae update:

[Espen]

Zachariae Isstrøm current retreat up date:

As you can see from the image below, Zachariae already retreated ( ~13,5 km²) considerably during the 2014 season, and the season is not over yet:

No changes on the former tongue.

[A-Team]

Here are the historic elevation changes and calving front positions along with transects up the main channels. It represents a prodigous amount of imagery acquisition and processing as can be seen from the Supplemental Material. Sidd posted parts of this before.

This is a very different system from the other glaciers, originating as it does on the distant central ridgeline above an area of abnormal but steady geothermal heat flux, with sharp shear margins and not much by way of tributaries. I've attached a radar transect that, while not quite the one we want, still shows that summit radar horizons -- and their ice dating -- get all the way to the coast with deformations mostly along shear margins and not so evident bottom freezeups like at Petermann.

Sustained mass loss of the northeast Greenland ice sheet triggered by regional warming
SA Khan et al NATURE CLIMATE CHANGE | VOL 4 | APRIL 2014
http://www.indiaenvironmentportal.org.in/files/file/greenland.pdf
http://www.nature.com/nclimate/journal/v4/n4/extref/nclimate2161-s1.pdf