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Author Topic: Halley base shut down and new crack in Brunt shelf  (Read 37163 times)

Stephan

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #100 on: June 15, 2019, 11:35:42 AM »
OK. I could not detect this tiny crack in the animation above.
Nevertheless I wonder about the stability of all the ice with a lot of thick cracks W and N of that ice rumple. In my lay man opinion it should have calved already...
It is too late just to be concerned about Climate Change

b_lumenkraft

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #101 on: June 15, 2019, 12:15:42 PM »
For how i understand it, to become loose, it also needs to melt from the bottom.

interstitial

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #102 on: June 15, 2019, 11:57:39 PM »
That makes more sense. I saw several cracks that I thought should let it break free but the just seemed to get snowed over and disappear. Thanks BL

b_lumenkraft

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #103 on: June 16, 2019, 05:35:16 AM »
Welcome, Interstitial. :)

solartim27

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #104 on: January 24, 2020, 04:35:44 PM »
Well, this has taken longer than I expected.  I'm going to go on a ledge and say this summer for sure.
Here's a link to Bert Wouters latest tweet
https://twitter.com/bert_polar/status/1216852873788653568?s=19
35 Mb image https://www.polarview.aq/images/105_S1jpgfull/S1A_EW_GRDM_1SSH_20200123T233940_DC58_S_1.final.jpg
« Last Edit: January 24, 2020, 04:50:27 PM by solartim27 »
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FredBear

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #105 on: February 14, 2020, 05:15:17 PM »
Cloudy image on    arctic.io   today (2020-02-14) - but has the end of Brunt ice shelf fallen off & drifted south?

blumenkraft

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #106 on: February 14, 2020, 05:50:39 PM »
Yes, i think so.

Hard to see but in the image of the 14th there is ice melange indicating a calving.
« Last Edit: February 14, 2020, 07:19:24 PM by blumenkraft »

FredBear

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #107 on: February 15, 2020, 11:12:04 AM »
Brunt - False alarm - sorry!

blumenkraft

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #108 on: February 16, 2020, 01:12:39 PM »
Well, a little bit came off after all.  ;D ;D ;D

Andreas T

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #109 on: February 16, 2020, 07:08:57 PM »
nor has Chasm 1 connected to one of the cracks west of that ice rumple.

Sorry, Stephan, i have to correct you.

Chasm1 has cracked all the way to the rumple now.

I'm expecting calving any time now.
any time = any number of months I guess.
I cobbled this gif together from blumenk's image and the S1A from today. It required scaling which I did by trying to match distances in the vertical (Y) direction, so the more distant movement may be to large or too small.
But what shows, I think is that the movement is driven from a push of the shelf past the ice rumple rather than a pull of the nearly detached piece. There is widening of the crack further south west (beyond the frame)
I find it entirely possible that this won't detach fully for another season at least. But that is as much of a guess as anybody elses

blumenkraft

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #110 on: February 16, 2020, 07:19:45 PM »
any time = any number of months I guess.

Exactly! Just like PIG! ;)

So sorry for the BS i said there, Andreas. I was too young back then.

But since you said it can hold another season, i expect it to calve any moment now. ;)

Stephan

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #111 on: February 16, 2020, 08:35:51 PM »
It might be necessary that the Haloween Crack expands further west and pass the ice rumples to destabilize the SW part of the Brunt Ice Shelf so that a calving can take place??
It is too late just to be concerned about Climate Change

baking

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #112 on: February 17, 2020, 09:06:32 PM »
There is a particular Sentinel-1B orbit that runs parallel to the crack that is particularly good at picking at details, probably because the side aperture radar is close to perpendicular to the crack.  I started watching this crack back in April and I compare my oldest image to the newest one in this GIF.

Zoom in on the center of the image.  Even though things are obviously moving, cracks are widening, new cracks are forming, it doesn't really seem that much closer to calving if you look at how far away the cracks on either side are.  The newest image is due tonight at midnight UTC so maybe we will see some change, but this one is a slow mover so don't get too excited.

IceConcerned

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #113 on: February 28, 2020, 10:41:22 PM »
When looking at the last Sentinel SAR image I tend to concur : the iceberg is detaching
Besides, a "parllel" to halloeen crack is developing
Both are underlined in the attached image

solartim27

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #114 on: September 29, 2020, 08:53:43 PM »
New Sentinel 1 image posted from
https://twitter.com/JanWuite/status/1311007660930719745?s=19  Some nice videos by Stef Lhermitte upthread.
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paolo

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #115 on: September 29, 2020, 10:05:34 PM »
But we can do better, using Sentinel1 images directly without waiting for their publication on Twitter. Even better, given the season, we can use Sentinel2 images. ;)

Attached a zoom on the still intact part between the two rifts (today's image)

nukefix

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #116 on: October 21, 2020, 04:48:50 PM »
For best sensitivity one should do S-1 interferograms to detect propagation of hairline cracks that are much smaller than the resolution of S-1 or S-2. There are free tools for doing this from ESA but the process is complex with a steep learning curve.

FredBear

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Re: Halley base shut down and new crack in Brunt shelf
« Reply #117 on: November 23, 2020, 01:53:57 PM »
Planned Halley team visit leaving from Harwich 05/11/2020:-
"From Rothera, a team of 10 staff will fly to Halley Research Station to spend four to six weeks collecting data, servicing the scientific instruments and maintaining the station infrastructure before flying back to Rothera. At Halley, core scientific data can be collected year-round through the Halley Automation Project. Autonomous scientific equipment around the station and on the Brunt Ice Shelf collects information on weather, climate and the ozone."

https://www.bas.ac.uk/media-post/rrs-james-clark-ross-departs-for-antarctica