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Neven: I added one more image to the aforementioned Jakobshavn post this is a zoomed in look at the April 2011 Landsat image of the fjord. The icebergs can be easily distinguished from the regular sea ice. What is the percentage in your estimate? Then I will share mine.


Thanks for that image, Mauro (where do you get those BTW). If the icebergs are the things with shade I would venture a guess of 5%?

Daniel Bailey

Mauri, is the banding a signal degradation issue, satellite overflight edge, or is it a visual issue inherent in the imagery?

The resolution in what can be seen is pretty decent, so it would seem a processing error/noise issue.

If it could be cleaned up then perhaps some reprocessing software could aid in better determining the ice coverage question.

Since I'm talking imagery again after all these years, any idea of the pixel ground size?

Questions, questions, questions...

The Yooper


The Landsat images are provided free at http://glovis.usgs.gov/. The problem that can exist on many is the gridlines from the distribution of image effects caused by the scan line corrector failure. It is a straight forward but not necessarily a time effective operation for browse images like this.


Here's a funny thought:

Could the flushing out have something to do with the extreme cold we witnessed over Greenland the past few weeks? Allow me to explain. I once translated a documentary about the katabatic winds in Antarctica. When it is extremely cold in the center of an ice sheet, the air gets so cold that it starts rolling down the hill because of gravity.

My guess is that it got so cold over the interior of the Greenland ice sheet that a katabatic wind rolled down and pushed out all the ice from the fjord. It's less cold in the interior now and the fjord seems to be filling up with thin ice again.

Artful Dodger

Neven, to test your theory you need to identify a Met station in the fjord and retrieve it's records. Weather underground may have the archive you need.

Bernard Vatant

I've been lurking at this blog (great stuff) and this thread in particular for quite a while. The view on Jakobshavn Isbrae those days is quite clear on Modis, and the flushing of icebergs into the bay seems interesting to follow. See http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c02.2012177.terra.250m.
Any chance to get an animation of the current period?


Hello and welcome, Bernard. To be frank, I don't think I will make an animation of Jakobshavn Isbrae this time around (too busy), unless something spectacular happens, like a big flush, or better yet: a big section of the glacier breaking up, like two years ago.

I'd appreciate it if you give out a shout here (or mail me) when something like that happens. :-)

Bernard Vatant

Fair enough, Neven. Let's start my small contribution to this blog by monitoring this particular spot. I would also be interested in whatever information/figures about the many melt ponds (well, rather lakes given their size) on the ice sheet in this area, and their contribution to the general flow of water (both liquid and ice) towards the sea, to which extent they are drained inside the ice etc.


Hi Bernard,

The discussion over on ASI 2012 update 5, referencing:


might be of interest to you.


Well, Bernard, according to Werther the calving has already happened.

I'm going to look if this is good animation material.

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