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Author Topic: Rift in Filchner-Ronne Ice Shelf  (Read 1999 times)

Grygory

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Rift in Filchner-Ronne Ice Shelf
« on: September 12, 2018, 10:13:46 AM »
Further development of the gap in Filchner-Ronne Ice Shelf.With black dots I marked the ends of the crack visible in the pictures. The green dot is likely to increase one of the crack(however, the quality of the images is too low)

oren

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Re: Rift in Filchner-Ronne Ice Shelf
« Reply #1 on: September 12, 2018, 11:13:35 AM »
Beautiful animation. That crack has certainly accelerated in the last few weeks.
How far is it behind the front?

Grygory

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Re: Rift in Filchner-Ronne Ice Shelf
« Reply #2 on: September 15, 2018, 10:20:16 AM »
Dimensions crack (plus minus 10%

oren

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Re: Rift in Filchner-Ronne Ice Shelf
« Reply #3 on: September 15, 2018, 11:18:42 AM »
Thanks Grygory.

Darvince

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Re: Rift in Filchner-Ronne Ice Shelf
« Reply #4 on: September 17, 2018, 05:18:04 AM »
How long ago was the last major iceberg to break off of the FRIS?

Grygory

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Re: Rift in Filchner-Ronne Ice Shelf
« Reply #5 on: September 17, 2018, 04:23:18 PM »
Unfortunately, I do not have photos from an earlier period than half a year. Maybe somebody has an older archive because polarview has no archives over a month.
ps.It seems to me that it is not yet an iceberg and it may take a long time before the second edge separates from the glacier. This rift, which has a size of 40km in the photo, started to be visible in the last half-year.-I wonder if this crack will continue to develop or the stress has been discharged.

FrostKing70

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Re: Rift in Filchner-Ronne Ice Shelf
« Reply #6 on: September 17, 2018, 05:21:49 PM »
Great pictures!  Any idea if the crack will propagate to the top edge (35 KM), or continue running parallel to the right?   If so, is there a natural termination point for the crack if it continues to the right?

Grygory

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Re: Rift in Filchner-Ronne Ice Shelf
« Reply #7 on: September 17, 2018, 08:46:34 PM »
Great pictures!  Any idea if the crack will propagate to the top edge (35 KM), or continue running parallel to the right?   If so, is there a natural termination point for the crack if it continues to the right?
I think that for a while the crack will stop and later it will grow to the right. These three parallel fissures probably stopped on the same obstacle in the form of stronger ice and it will take some time before it can be defeated-It was the same with this new crack(40km) as it probably went through strong ice and began to grow fast
But these are just my thoughts.(I do not know much). When I find time I will find out if someone who knows something more described it. - Pretty much the same looked for Larsen C the slit stopped every now and then on the strong ice. Unfortunately it is a pity that I could not find photos of the entire FRIS.
-Interesting places are where glaciers start developed ice shelf.In places where ice was passing near obstacles it probably becomes stronger and cracks stop at these places later

maga

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Re: Rift in Filchner-Ronne Ice Shelf
« Reply #8 on: September 22, 2018, 01:27:43 PM »
My understanding is also that the rift will propagate parallel to the front but there are also some cracks perpendicular to the front which will split the developing ice berg into parts. As Grygory suggests, and similarly to Larsen C, there are areas in the ice shelf where two ice streams merged (suture zones) which can prevent rift propagation for some time because the ice lost the nicely ordered structure there. Further inhibiting rift propagation at the Ronne ice shelf is bottom accumulation stemming from refreezing supercooled water originating somewhere at greater depth near the grounding line. That can close newly formed rifts again.  However, now we have the left hand side of the ice berg essentially dangling freely and it can move back and forth with the tides etc. It is a huge lever and and should be able to open the rift much faster than before. That was also the case at Larsen C and was the reasoning behind my previous comment about a calving event rather soon. "Soon" in this context may still mean several month to probably a couple of years...

Grygory

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Re: Rift in Filchner-Ronne Ice Shelf
« Reply #9 on: September 26, 2018, 08:07:27 AM »
It seems to me that the right crack is growing - But it's hard to see

Grygory

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Re: Rift in Filchner-Ronne Ice Shelf
« Reply #10 on: September 28, 2018, 07:14:30 PM »
This year Filchner-Ronne ice shelf will be exposed faster to sea waves? - On GIF (if I did not make a mistake, I marked the dominant direction of ice movement in this region) you can see marked sea ice, which protected the shelf from the influence of waves this year is very few and can quickly retreat

source:https://www7320.nrlssc.navy.mil

Grygory

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Re: Rift in Filchner-Ronne Ice Shelf
« Reply #11 on: October 01, 2018, 09:38:43 AM »
It"s still hard to see but in my opinion the crack is heading to the edge. I have marked the outline as if it was a poorly visible outline (which may be a crack) which as if it were continued (stars) goes perfectly into the next crack.-Or maybe it's just an illusion-What do you think ?

source :https://www.polarview.aq/antarctic

ps.the photo has been subjected to several modifications for better contrast in low resolution