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Author Topic: Alert: Heavy Cracking over GIS?  (Read 11094 times)

Espen

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Alert: Heavy Cracking over GIS?
« on: April 21, 2013, 12:03:35 PM »
What on ice is going on here? 2 or more big cracks are seen over the GIS just south west of Dronning Louse Land / North East Greenland::::::
http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c03.2013110.terra.250m
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TerryM

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Re: Alert: Heavy Cracking over GIS?
« Reply #1 on: April 21, 2013, 12:20:21 PM »
Espen


I think they're artifacts of processing. The more northerly one ends exactly at an image border & the other seems to extend across some mountain peaks, then into a Fjord.


Interesting to see if they show tomorrow.


Terry

Espen

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Re: Alert: Heavy Cracking over GIS?
« Reply #2 on: April 21, 2013, 12:25:16 PM »
Terry,

No I don't think so, because of the way they look, and the processing joints are going the other way around, and I am pretty convinced that something is going on in the area.
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TerryM

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Re: Alert: Heavy Cracking over GIS?
« Reply #3 on: April 21, 2013, 12:40:24 PM »
We should know by this time tomorrow.


Terry

Espen

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Re: Alert: Heavy Cracking over GIS?
« Reply #4 on: April 21, 2013, 12:44:31 PM »
Yes expert analyzes?
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Neven

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Re: Alert: Heavy Cracking over GIS?
« Reply #5 on: April 21, 2013, 12:58:16 PM »
I'm not seeing it on Aqua, but could be due to clouds. The second crack looks weird, as Terry says.
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Jim Williams

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Re: Alert: Heavy Cracking over GIS?
« Reply #6 on: April 21, 2013, 01:00:28 PM »
We should know by this time tomorrow.


Terry

Agreed.  I think a piece of sea got overlaid.  Don't they play with transparency to try to mask out clouds?

Espen

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Re: Alert: Heavy Cracking over GIS?
« Reply #7 on: April 21, 2013, 01:06:48 PM »
Neven;

There are sometimes very big differences from Terra to Aqua, and it is vaguely observed on this mornings Terra swath image from the area, today is very cloudy, but I am looking into it, true some contacts in Greenland. We will observe it later this afternoon 3 - 4 pm CEU time, when both todays pairs (Terra / Aqua) from that area is ready.
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Neven

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Re: Alert: Heavy Cracking over GIS?
« Reply #8 on: April 21, 2013, 01:10:08 PM »
OK, keep us up-to-date!
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anonymous

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Re: Alert: Heavy Cracking over GIS?
« Reply #9 on: April 21, 2013, 01:31:55 PM »
condensation trails...?

Peter Ellis

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Re: Alert: Heavy Cracking over GIS?
« Reply #10 on: April 21, 2013, 02:10:15 PM »
It's an aircraft contrail.  You can even see its shadow on the ice below.

Espen

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Re: Alert: Heavy Cracking over GIS?
« Reply #11 on: April 21, 2013, 02:34:32 PM »
Peter;

I noticed what you wrote in your first answer, let it be!

As a ying yang interest, one is aviation, I doubt it is aircraft (3) contrails, no airlines I know of, passes Greenland that far north,  and the IceBridge plane spent all day yesterday around Petermann and Nares.  ;)
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Jim Pettit

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Re: Alert: Heavy Cracking over GIS?
« Reply #12 on: April 21, 2013, 03:48:05 PM »
On the alternate (bands 3-6-7)  image, the larger, more northern "crack" appears to my inexperienced eye to indeed be the shadow from a contrail, as the actual contrail itself can be seen to the south and left of the "crack", especially the northernmost, wind-diffused portions of it. And while Espen is correct that scheduled airlines don't regularly overfly the area, would a pair of military or research aircraft flying in parallel there be unusual?
« Last Edit: April 22, 2013, 02:00:04 PM by Jim Pettit »

ivica

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Re: Alert: Heavy Cracking over GIS?
« Reply #13 on: April 21, 2013, 04:32:55 PM »
Perhaps we shall get air-photo of Vedel Sø ?

FrankD

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Re: Alert: Heavy Cracking over GIS?
« Reply #14 on: April 21, 2013, 06:07:06 PM »
At the eastern end the "crack" runs straight through the expose rock between the edge of the ice sheet and the coast. No crack in the ice sheet could do that, which leaves aircraft trails as the most likely.

But contrails? No! Clearly chemtrails - not content with steering hurricanes around the Atlantic, now the gummint is trying to mess with the GIS for their own nefarious purposes.  :o

ChrisReynolds

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Re: Alert: Heavy Cracking over GIS?
« Reply #15 on: April 21, 2013, 06:54:43 PM »
Note; that's day 111, the first link this thread was day 110.

Set up both in two windows.
http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c03.2013111.terra.250m
and
http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c03.2013110.terra.250m

Scroll down until the land is visible in the bottom part of screen and switch between them - what ever it is it moves. This alone seems to rule out cracking.

Arctic Mosaic:
http://rapidfire.sci.gsfc.nasa.gov/subsets/?mosaic=Arctic
This confirms r02 c03 is over Greenland ice sheet, not sea ice.

Where are IceBridge Flying? Their flightpaths need to be low altitude, contrail is possible aloft on the ice sheet, shadows cast would be feasible due to low altitude. FrankD has also noticed the continuation of one track onto rocky coast range.

Most likely explanation - I agree with others, contrail is the most likely explanation, specifically from IceBridge missions.

Espen

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Re: Alert: Heavy Cracking over GIS?
« Reply #16 on: April 21, 2013, 07:55:06 PM »
There is "one crack" on the image today, so what this is all about it still unclear.

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c03.2013111.terra.250m
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Peter Ellis

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Re: Alert: Heavy Cracking over GIS?
« Reply #17 on: April 21, 2013, 10:50:48 PM »
Look at it in the infra-red band 3-6-7

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c03.2013111.terra.367.250m

You can clearly see the white line of each contrail, and then a dark line parallel to it, which is the shadow on the ice.

Hunter

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Re: Alert: Heavy Cracking over GIS?
« Reply #18 on: April 21, 2013, 11:47:37 PM »
FYI they have been resupplying Alert and Nord and maybe other stations for the last 2 weeks or so.

Don't know if it has anything to do with these contrails

I would expect its normal commercial traffic.  believe it or not there is a lot.
« Last Edit: April 21, 2013, 11:59:34 PM by Hunter »

Gray-Wolf

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Re: Alert: Heavy Cracking over GIS?
« Reply #19 on: April 22, 2013, 12:03:06 PM »
I've been 'watching' a crack down on the ross Ice shelf (from Roosevelt island to mid shelf) and these appear very similar to those features. When we get good images with low level sun we should be able to gauge them better from the shadow cast from the edge of the crevasse.

The other point I'd like to raise is the 'bulge' in the snow cover over the snow free topography below. It's almost like a giant landslip has flowed over that section of landscape?

The images show the snow line following quite a straight path until the base of the 'cracks' where it bulges out? I cannot see any obvious topographical reason for this extension in the snow cover and it appears to cross valleys as though a 'flow' of some kind?

Could we be lookingmonumentalmental avalanche tied in with the lines of weakness that show up as crevasses? Was there movement in the rocks which 'shook off' the snow cover?
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Peter Ellis

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Re: Alert: Heavy Cracking over GIS?
« Reply #20 on: April 22, 2013, 12:45:39 PM »
I've been 'watching' a crack down on the ross Ice shelf (from Roosevelt island to mid shelf) and these appear very similar to those features. When we get good images with low level sun we should be able to gauge them better from the shadow cast from the edge of the crevasse.
No you won't, because they won't be in the next image. Each feature has only shown up once and never again, as Chris pointed out only four posts above yours.

Espen

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Re: Alert: Heavy Cracking over GIS?
« Reply #21 on: April 22, 2013, 02:56:58 PM »
No wonder facts are hidden away, when having guys like Peter around?
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Peter Ellis

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Re: Alert: Heavy Cracking over GIS?
« Reply #22 on: April 22, 2013, 07:04:42 PM »
Eh? As I think many others on the board will attest, I'm no denier.  I'm one of the ones providing facts here.  Hunter, being one of the actual scientists in the actual planes, is the one you should pay most attention to though.

gfwellman

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Re: Alert: Heavy Cracking over GIS?
« Reply #23 on: April 22, 2013, 07:14:36 PM »
Commercial aviation has routes over Greenland.  See http://en.wikipedia.org/wiki/Polar_route for *some* examples, but the map there is missing direct flights from Europe to Seattle/Vancouver, so there are plenty more.

Espen

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Re: Alert: Heavy Cracking over GIS?
« Reply #24 on: April 22, 2013, 07:24:57 PM »
Gfwellman;

I know a lot of airlines crosses Greenland, most east-west bound (transatlantic),  much more south though, those passes further north are not normal for Civil Aviation( the once commented), since routes entering north of Greenland (Asia/NorthAmerica) are having a more north-south direction.

And since I know the IceBridge team wasn't there, they spend the day around Petermann, couldn't be them.   
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Espen

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Re: Alert: Heavy Cracking over GIS?
« Reply #25 on: April 22, 2013, 07:26:46 PM »
Peter;

I was more about your attitude, I read your first comment, before it was deleted, I don't doubt your facts?
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Gray-Wolf

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Re: Alert: Heavy Cracking over GIS?
« Reply #26 on: April 22, 2013, 10:57:09 PM »
http://lance-modis.eosdis.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl2_143.A2013112125000-2013112125500.250m.jpg

Though the section of the ice field is heavily clouded the northern most 'crevasse' does indeed appear on the next image Peter?

From my years of the Ross Crevasse i know that ,should these prove to be what they appear to be, melt season will enable a better view as surface snow melt reveals the fracture below.

This is a 250m image so whatever has appeared on the 3 days of images is quite large?

Again I'd ask folk to ponder why the snow fan at the bottom of the ice sheet in this region? I cannot see any topographical feature demanding such an extension of snow cover?

The other point has to be how do folk expect the ice sheet to decay? We know a lot of melt water has seeped into lowoflayers ovf the snow pack so do we expect catastrophic failure of some of the steep sections once weight of melt water becomes an issue?
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Peter Ellis

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Re: Alert: Heavy Cracking over GIS?
« Reply #27 on: April 23, 2013, 01:54:58 AM »
Espen:  Apologies if offense was given.  I originally posted in a mildly sarcastic fashion, thought better of it, and edited it myself after about 1 minute.  I guess you caught it in that window.  I also suspect you've taken it as much ruder than I intended - which was precisely why I edited it!

Grey-Wolf:  I'm not sure what you're linking to there: it looks to be some sort of part-processed picture with massive distortion and artifacts.  If you look at the properly registered/stitched images, the contrail does indeed disappear on the next  picture.

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c03.2013110.terra.367.1km 
4/20 has a single contrail.

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c03.2013111.terra.367.1km
4/21 has three contrails in different locations from 4/20

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c03.2013112.terra.367.1km
4/22 has wispy cloud but no linear contrails

It's clear enough on the 1km imagery (just set up those three and click between them), but you can go to 250m if you like.  At the higher resolution it's easier to make out the contrail and the shadow separately.

Vergent

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Re: Alert: Heavy Cracking over GIS?
« Reply #28 on: April 23, 2013, 04:52:58 AM »
http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c03.2012110.terra.250m.jpg

This was a year ago. The contrail crosses a stitch line, but has moved between orbits. I think that we have discovered that there is an airline that can keep to schedule. Now, which one?

Vergent
« Last Edit: April 23, 2013, 05:04:12 AM by Vergent »

Laurent

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Re: Alert: Heavy Cracking over GIS?
« Reply #29 on: June 12, 2013, 10:24:29 AM »
There is some n(ice) cracking on the east coast ! I can't find something similar last year !
Last year the fjords started to open around the 20th of June !