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Author Topic: Petermann Gletscher / Petermann Fjord / North West Greenland  (Read 119709 times)

Wipneus

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Re: Petermann Gletscher / North West Greenland
« Reply #100 on: March 26, 2014, 12:20:54 PM »
Clear weather in abundance in North Greenland it seems.

Here is a medium resolution (60m) overview of a Landsat image of Peterman on March 25. High 15m resolution detail shots will follow, requests will be considered.

Note: I am experimenting with color optimization using ImageMagick, instead of doing it with the Gimp.  This avoids some discretization errors due to the 8 bit limitation of the Gimp, but I am not really happy with the result yet. The "adjust white balance" button in the Gimp works better.


Wipneus

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Re: Petermann Gletscher / North West Greenland
« Reply #101 on: March 26, 2014, 12:40:42 PM »
Hi-res (15m) cut-out of the calving front. It is worthwhile to zoom into the image to see the details.
You can see several cracks that can lead to new calving at some time.

Belgrave Glacier in the upper right, Faith Glacier in the dark lower left corner.

BTW, sun elevation is still a low 10.5 degrees.

(picture needs a click for full res image)

Wipneus

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Re: Petermann Gletscher / North West Greenland
« Reply #102 on: March 26, 2014, 01:03:31 PM »
Hi -res (15m) cut -out upstream of the calving front. The big crack is above Cape Bemerton, to the right is (I think) Porsild Glacier.

(no fun if you do not click the picture)

Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #103 on: March 26, 2014, 06:01:00 PM »
Wipneus,

What would we we do without your magic? ;)
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Re: Petermann Gletscher / North West Greenland
« Reply #104 on: March 27, 2014, 05:26:21 PM »
Wipneus


Would it be possible to get one of your great images of the MYI piece that's acting as the northern ice dam in Nares Strait? The stability of this formation may have an effect on Arctic sea ice lost this season.


Terry

Wipneus

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Re: Petermann Gletscher / North West Greenland
« Reply #105 on: March 27, 2014, 06:46:48 PM »

Would it be possible to get one of your great images of the MYI piece that's acting as the northern ice dam in Nares Strait? The stability of this formation may have an effect on Arctic sea ice lost this season.



Terry,

I am afraid we may not have that luck. The dam is at the limit of Landsat 8 high latitude reach.

In the attached image you see images at path,row: 44,1 and 46,1.  That is the nearest images in the whole Landsat 8 archive (2013 and 2014).

As I see it we need path,row=45,1  to see some part of the dam. There is none in the archive.

Landsat images apparently are very spotty, at the northern latitudes there is a lot of overlapping orbits so I get multiple opportunities at Peterman and Zachariae/N79.

At least the weather is favorable, much better than in 2013 until so far.

Screenshot of USGS Earth explorer: http://earthexplorer.usgs.gov/:

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Re: Petermann Gletscher / North West Greenland
« Reply #106 on: March 27, 2014, 07:13:21 PM »
Wipneus and Terry,

The images will come later there is an image (LC80372472013137LGN01) from May 17 2013, but they are rare?
« Last Edit: March 27, 2014, 08:40:07 PM by Espen »
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Wipneus

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Re: Petermann Gletscher / North West Greenland
« Reply #107 on: March 28, 2014, 07:33:26 AM »
Espen I forgot the ascending paths. That is normally the night side, but during the arctic summer we  will have to consider those as well.

Unfortunately current images are not extending that far north yet, attached IR image near Scoresby Sound is has a center latitude of about 71 degrees and is about as far north as we can get them now.

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Re: Petermann Gletscher / North West Greenland
« Reply #108 on: March 28, 2014, 07:38:36 AM »
Espen, if I search the scene LC80372472013137LGN01 that you found, Earth Explorer reports the row as 882. As the maximum row count is 248, I guess the image is rare indeed.

TerryM

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Re: Petermann Gletscher / North West Greenland
« Reply #109 on: March 28, 2014, 08:30:42 AM »
Thanks so much for your efforts. The ice dam will break in it's own time & I was only hoping that an image might indicate how robust it is.
Without the interference of PII-2012 Nares Strait will allow more of the old MYI from Lincoln Sea to drain than was the case in 2013 & I believe that this blockage played some part in the high minimums we experienced last year.
I guiltily confess to hoping that we will have a large enough ice retreat that TPTB will finally take notice, though after the tepid response to 2012 I suppose that's a chimera. Perhaps a vicious el nino and the destruction that will entail will do the trick, but something has to affect the BAU playbook that almost every government now seems intent on following.
Michael Mann's dating of a 2C rise to 2036 should have been a wakeup call for anyone interested in self preservation but the MSM and governments more interested in petro dollars than the next generation seem to have swept it under the rug. I'll feel terrible for all those who are destroyed by whatever cataclysm it is that finally drives the message home but scientific reasoning and logical arguments have fallen on deaf ears.
Sorry for the rant.
Terry

Jim Hunt

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Re: Petermann Gletscher / North West Greenland
« Reply #110 on: March 30, 2014, 07:21:58 PM »
Terry - Have you seen the latest DMI RadarSat images?  Go to http://ocean.dmi.dk/arctic/kennedy.uk.php and search through the ASAR archive. By way of example:

Reality is merely an illusion, albeit a very persistent one - Albert Einstein

mspelto

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Re: Petermann Gletscher / North West Greenland
« Reply #111 on: April 19, 2014, 12:44:22 PM »
It is evident in spring 2014 that there is no rift that is substantial enough to predict an imminent large calving event. 

Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #112 on: April 19, 2014, 01:01:56 PM »
It is evident in spring 2014 that there is no rift that is substantial enough to predict an imminent large calving event.

I agree, there may be some minor calvings due to 2 fissures at the southern edge. The Kap Bemerton fissure is to far away, though.: Image courtesy of Wipneus / Landsat
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Shared Humanity

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Re: Petermann Gletscher / North West Greenland
« Reply #113 on: April 19, 2014, 03:19:22 PM »
If you follow those two crevasse that you've pointed out in a gentle curve to the most active calving portion of the glacier face, it looks as if there are cracks/crevasses that align fairly well with these two. Could this entire portion of the calving front be at risk of calving and, if so, is this still a minor calving event?

Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #114 on: April 19, 2014, 03:27:11 PM »
If you follow those two crevasse that you've pointed out in a gentle curve to the most active calving portion of the glacier face, it looks as if there are cracks/crevasses that align fairly well with these two. Could this entire portion of the calving front be at risk of calving and, if so, is this still a minor calving event?

Minor? At least compared to the more recent calvings.
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Shared Humanity

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Re: Petermann Gletscher / North West Greenland
« Reply #115 on: April 19, 2014, 03:31:26 PM »
If you follow those two crevasse that you've pointed out in a gentle curve to the most active calving portion of the glacier face, it looks as if there are cracks/crevasses that align fairly well with these two. Could this entire portion of the calving front be at risk of calving and, if so, is this still a minor calving event?

Minor? At least compared to the more recent calvings.

Thanks Espen, so, one more question. Given the landfast portion of the glacier front seems more resistant to calving, if this landfast portion were to calve, would this expose the more active portion of the calving front to more rapid retreat?

Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #116 on: April 19, 2014, 03:39:05 PM »
If you follow those two crevasse that you've pointed out in a gentle curve to the most active calving portion of the glacier face, it looks as if there are cracks/crevasses that align fairly well with these two. Could this entire portion of the calving front be at risk of calving and, if so, is this still a minor calving event?

Minor? At least compared to the more recent calvings.



Thanks Espen, so, one more question. Given the landfast portion of the glacier front seems more resistant to calving, if this landfast portion were to calve, would this expose the more active portion of the calving front to more rapid retreat?

If these fissures will result in a calving, it will probably "only" be involving a third of the present calving front (+/- 6 km).
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sidd

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Re: Petermann Gletscher / North West Greenland
« Reply #117 on: April 20, 2014, 11:45:11 PM »
Comparison of surface and bedrock. Note the kinks where surface contour crosses bedrock canyons. Csatho saw this also, in 2006. For more such comparison and some of Csatho's work, please see

http://membrane.com/sidd/greenland-2013/walkback.html

sidd

Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #118 on: April 26, 2014, 12:12:10 PM »
There is 1 year between these 2 frames (April 25 2013 and April 25 2014), the scene is the fissure at Kap Bemerton (Petermann Gletscher):

Notice in the second animation from Petermann Front, the 2nd fissure at the left is developing, could be the next calving reason?

Please click on image to start animation!
« Last Edit: April 26, 2014, 01:19:23 PM by Espen »
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Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #119 on: April 26, 2014, 02:26:07 PM »
New fissures, this image is from April 25 and is also seen in the animation above, I have encircled the newly developed fissures, they follow a same pattern as pre-calvings.

Please click on image to enlarge!
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Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #120 on: May 16, 2014, 09:35:02 AM »
Fissure update.

The fissures observed at the Northern shore of Petermann between Kap Eisendecher (Hubert Glacier) and Kap Fulford (Sigurd Berg Glacier) seems to develop into something that may lay the foundation for another major calving in the future (encircled #1).
The fissure seen at Kap Bemerton on the opposite shore is all ready known (encircled # 2). 

Please click on image to enlarge!
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Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #121 on: May 22, 2014, 06:01:11 PM »
Petermann update. Fissures in progress. See the red encircled areas:

Please click on image to start animation!
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Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #122 on: June 01, 2014, 10:20:53 AM »
Fissure development, one of the fissures reported above is getting more pronounced now, the fissure is encircled in red in the animation below:

2nd image is May 31 2014 and not May 31 2013.

Please click on the image to start animation! 
« Last Edit: June 01, 2014, 11:25:10 AM by Espen »
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icefest

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Re: Petermann Gletscher / North West Greenland
« Reply #123 on: June 01, 2014, 10:51:02 AM »
I'm assuming that's meant to say 2014.

Do you have any images from the same time last year so we can compare how much of the increased fissure visibility is due to melting snow and how much due to an increase of the fissure size?
i.e. compare 29-apr-13/31-may-13 to 29-apr-14/31-may-14
Open other end.

Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #124 on: June 01, 2014, 11:27:09 AM »
I'm assuming that's meant to say 2014.

Do you have any images from the same time last year so we can compare how much of the increased fissure visibility is due to melting snow and how much due to an increase of the fissure size?
i.e. compare 29-apr-13/31-may-13 to 29-apr-14/31-may-14

The aniamtion is based on April 29 2013 and May 31 2014.
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Shared Humanity

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Re: Petermann Gletscher / North West Greenland
« Reply #125 on: June 01, 2014, 03:17:21 PM »
Espen......

I love your animations  of the various  glaciers. I look at them every time you post one. Heck, I look at every non-animated image as well.

As I've scanned these images, it's becoming very clear that you can find repeating patterns of fractures as you move away from the calving face. These fractures often (not always) mimic the shape of the calving face. The images follow this pattern on both of the grounded sides of the glacier. I will often follow the pattern further away from the calving face to see where the next fracture will appear. I may be kidding myself but I can frequently see where these will occur.

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Re: Petermann Gletscher / North West Greenland
« Reply #126 on: June 01, 2014, 05:17:51 PM »
Shared Humanity,

Yes Landsat 8 is a goldmine when it comes to evidence, just wished I had the same capacity as Wipneus to further dig into it :-[
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Re: Petermann Gletscher / North West Greenland
« Reply #127 on: June 01, 2014, 06:19:17 PM »
I always check out, and appreciate these animations too, this one however looks more to do with the sun being first aligned with then at 90deg. ish to the fissures.

Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #128 on: June 01, 2014, 06:56:05 PM »
I always check out, and appreciate these animations too, this one however looks more to do with the sun being first aligned with then at 90deg. ish to the fissures.

Hello Johnm33,

That may be so, but then we need an explanation why the 2 fissures in front, not do the same?
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Yuha

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Re: Petermann Gletscher / North West Greenland
« Reply #129 on: June 01, 2014, 07:09:42 PM »
Thanks for the images and animations, Espen.
A couple of observations about the latest:

There seems to be a very minor calving happening on the right-hand side.

Those brown stains on the right margin in the May image are probably melt water off the banks.

Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #130 on: June 10, 2014, 08:51:02 PM »
The fissures mentioned above are definitely expanding.

Please click on image to start animation!
« Last Edit: June 10, 2014, 09:02:01 PM by Espen »
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Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #131 on: June 28, 2014, 02:04:32 PM »
Petermann update:

In the animation below you will find 4 spots of interest.

1. A fissure to crack development, although this crack is a part of the melt water channel system, it is also a crack on its own, and a possible mother crack for a future major calving.

2. This crack, just outside Belgrave and Hubert Glaciers, will probably already this season result in a minor calving.

3. The 2 cracks seen left of Faith Gletscher, will probably soon result in a worth to mention calving.

4. Between May 25 2014 and June 27 2014, Petermann Gletscher moved ~ 120 meters, measured at the major melt water river outlet.

Please click on image to start animation!
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Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #132 on: July 05, 2014, 07:59:18 PM »
Reminder of the good old days:

Please click on the image to start animation!
« Last Edit: July 05, 2014, 08:11:30 PM by Espen »
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crandles

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Re: Petermann Gletscher / North West Greenland
« Reply #133 on: July 05, 2014, 08:07:11 PM »
Looks like second image is 2014 not 2006  ;)

Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #134 on: July 05, 2014, 08:12:13 PM »
Looks like second image is 2014 not 2006  ;)

Corrected thanks! ;)
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Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #135 on: July 07, 2014, 06:43:55 PM »
Further crack expansion near the calving front just outside Hubert Gletscher and Belgrave Gletscher:

Please click on image to start the animation!
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Re: Petermann Gletscher / North West Greenland
« Reply #136 on: July 13, 2014, 09:41:40 PM »
Washington Land situated between Petermann Gletscher to the north, Humboldt Gletscher to the south and Nares Strait to the west, and a future large island when the ice is gone.
Over the last 38 years we can watch how the ice fields (iskapper) are getting smaller and smaller:

Please click on the image to start the animation!
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Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #137 on: July 16, 2014, 07:48:51 AM »
The chances of having Petermann calving this season is increasing by the days:

 
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Sonia

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Re: Petermann Gletscher / North West Greenland
« Reply #138 on: July 16, 2014, 12:49:34 PM »
Those cracks on the southern side look more prominent as well.  Also very interesting in that image is how the melt ponds on the sea ice all all disappeared.  I imagine this is from the ice decompressing following the Nares breakup.

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Re: Petermann Gletscher / North West Greenland
« Reply #139 on: July 16, 2014, 02:29:18 PM »
Those cracks on the southern side look more prominent as well.  Also very interesting in that image is how the melt ponds on the sea ice all all disappeared.  I imagine this is from the ice decompressing following the Nares breakup.

Wouldn't that be pond drainage?

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Re: Petermann Gletscher / North West Greenland
« Reply #140 on: July 16, 2014, 02:56:41 PM »
Those cracks on the southern side look more prominent as well.  Also very interesting in that image is how the melt ponds on the sea ice all all disappeared.  I imagine this is from the ice decompressing following the Nares breakup.

Wouldn't that be pond drainage?

Right.  I'm thinking that as the ice is allowed to expand down the fjord, the "seals" break on the ponds and they drain.

Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #141 on: July 21, 2014, 07:03:40 AM »
Further crack development:

Please click on image to start animation!

« Last Edit: July 21, 2014, 07:12:12 AM by Espen »
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Re: Petermann Gletscher / North West Greenland
« Reply #142 on: July 21, 2014, 12:23:20 PM »
Espen..

What is that  trail of visible brown surface that extends along  the eastern length of the glacier? Is it soil debris that  has been picked up, transported and exposed by melt?

Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #143 on: July 21, 2014, 05:33:30 PM »
Espen..

What is that  trail of visible brown surface that extends along  the eastern length of the glacier? Is it soil debris that  has been picked up, transported and exposed by melt?
Yes it is sand/rock debris which originates from a desert like place in Hellerup Land (just behind Kap Agnes) between Sigurd Berg Gletscher and the very large Porsild Gletscher.
« Last Edit: July 21, 2014, 05:47:08 PM by Espen »
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Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #144 on: August 01, 2014, 09:32:51 PM »
On the day of the calving at Ryder Gletscher, a very similar glacier to Petermann Gletscher in most ways, only the size is the difference, as only women know the importance of!
It is time for a fissure / crack update. As you can see from the animation below there is plenty of room for many headlines in the near future (within a few years), so don't worry if the sea ice don't go your way, there is always the glaciers. The potential future calving events are encircled in red:

Please click on image to start the animation!
« Last Edit: August 01, 2014, 11:20:02 PM by Espen »
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Espen

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Re: Petermann Gletscher / North West Greenland
« Reply #145 on: August 05, 2014, 03:49:54 PM »
Petermann Calving?

This is only a modis image from today, that little piece mentioned above may have calved already?

Will be updated as soon better images are available!
« Last Edit: August 05, 2014, 07:15:24 PM by Espen »
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Re: Petermann Gletscher / Petermann Fjord / North West Greenland
« Reply #146 on: August 21, 2014, 05:07:16 PM »
The ice peninsula in front of Belgrave Glacier took off:
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Re: Petermann Gletscher / Petermann Fjord / North West Greenland
« Reply #148 on: September 08, 2014, 11:16:45 PM »
Looking at reply #110 above, it looks like some ice rubble might just have floated away, as opposed to a calving event.
FNORD

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Re: Petermann Gletscher / Petermann Fjord / North West Greenland
« Reply #149 on: February 12, 2015, 01:53:04 PM »
The first high resolution (10m/pix)  Ground Range Detected ( GRD) data covering the Petermann calving front entered the ESA Sentinel public archive ( aka datahub).

I think it is fantastic (click on the picture for the full image) Sorry that I had to reduce the resolution to 20m/pix for a reasonable image size.