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Author Topic: Pine Island Glacier (PIG) Calving and Discussion  (Read 449431 times)

baking

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2500 on: August 27, 2020, 05:29:29 PM »
I have a little more analysis of the shifting of Point2 and why it is happening now.

First image is a 6-day GIF with all motion relative to Point2.  You can see which pieces of ice are moving attached or along with Point2, and which pieces are moving away.

The second image is my reading of where the middle piece of Cork3 is caught between the prominence on the Southern Ice Shelf and icebergs attached to Point2.  Also shown are they previous contact points from June which demonstrates that shifting ice can result in different binding points that can raise or lower the risk of a major calving.

Third image is from a posting I made on June 16 showing the dynamics at that time.

baking

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2501 on: August 31, 2020, 01:29:22 PM »
Some low-resolution clearing of the melange in the Northern Shear Margin today.  One-day GIF.

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2502 on: September 02, 2020, 08:12:05 PM »
What had to happen, happened  ;)

Almond, goodbye
The outermost piece of Cork3 (relative to the SIS) follows him.

Tomorrow's image will be interesting to see the latecomers who will follow them.

NB: The image is from the 02, but we don't have any images from the 01/09.

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2503 on: September 02, 2020, 08:19:21 PM »
PS: what is interesting is that the base of the Almond has been projected (hence a rotation of 90° degrees clockwise) which shows that a tension existed before calving.

baking

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2504 on: September 03, 2020, 12:23:36 AM »
Yesterday's image came late today so a 1-day comparison is now available.  Don't read too much into what you see in the melange since the middle piece of Cork3 has apparently not moved, I don't think any significant has happened behind it.  It's merely an artifact of the different orbits and resolutions.

Stephan

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2505 on: September 03, 2020, 06:08:15 PM »
Thank you baking and paolo,
almost no week passes by without a mini calving at either NSM or SSM. When will this stop? Until both zones of destruction are emptied??
It is too late just to be concerned about Climate Change

interstitial

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2506 on: September 03, 2020, 11:30:00 PM »
Thank you baking and paolo,
almost no week passes by without a mini calving at either NSM or SSM. When will this stop? Until both zones of destruction are emptied??
When eastern Antarctica returns to a chain of islands? This may temporarily slow but I don't expect it to stop or slow much until that ice river is mostly depleted to the source. Their is some historical evidence of order of magnitude or two faster motion in this glacier.

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2507 on: September 04, 2020, 12:51:45 PM »
For the moment no new developments, but the extension and widening of the "new rift", which seems to connect to the cR1 (central rift 1), as well as an extension of the cR1 towards the front, which seems to be becoming clearer, seem to indicate that the calving of P2, as well as Cork3b, should not be long in coming.
Indeed, the iceberg stacking upstream of Cork3c has recently reactivated and, as a consequence, its action of destabilising the PIG, with extension and widening of the "new rift" and smR2.

Moreover, the two rifts cR1 and smR2 have extended and are to be followed very closely. In the not too distant future, they could lead to a significant calving of the PIG.

Click to zoom in

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2508 on: September 07, 2020, 10:05:48 PM »
P2 and Cork3b detachment underway

Click to zoom in

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2509 on: September 08, 2020, 11:35:49 AM »
Cork3b has detached itself, waiting for P2 ...

Stephan

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2510 on: September 08, 2020, 08:19:45 PM »
so now the last named pieces in the SZD are on their way out.
Wonder how long the NW piece of PIIS with P2 will stay in place.
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Bernard

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2511 on: September 12, 2020, 12:27:27 AM »
Sorry to ask if it's a dumb question.

I've been following this destruction story for months (years?). Correct me if I am wrong, but it is currently just the end of winter in Antarctica. Should not the surroundings of PIG be stuck with sea ice at this time of the year? How comes all those calved icebergs seem able to float off freely and quite quickly?

Stephan

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2512 on: September 12, 2020, 07:27:46 AM »
A very short answer:
It is not about air temperatures and missing insolation during the Austral winter, but about sea water temperatures which are high enough to allow a continuous melting of the ice shelf from below.
Pine Island Bay partly has polynyas, which means that "warmer" (0, 1, 2, 3°C) waters upwell close to the calving front.
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oren

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2513 on: September 12, 2020, 09:48:35 AM »
I think the question was how come there is a polynya in Pine Island Bay. I think it's not just upwelling but also about winds typically blowing offshore? (Maybe this is from the stupid answers department)

charles_oil

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2514 on: September 12, 2020, 11:10:42 AM »
I think also that the bergs are several orders of magnitude more massive (could be 100's of metres) than surrounding new sea ice (few m thick), so I imagine they can move around and displace / crush the sea ice if, as is likely, the winds / currents act differently on them.

Bernard

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2515 on: September 12, 2020, 01:34:32 PM »
Thanks for the answers, all making sense - for me at least.  :)

baking

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2516 on: September 12, 2020, 02:06:56 PM »
One thing that hasn't been mentioned is that the glacier keeps moving no matter the season.  It pushes "smaller" icebergs and breaks off parts of the neighboring ice shelf as it goes.  When icebergs "float off" they don't usually go gently, but with a massive release of energy.

That said, the recent icebergs have not gone far.  Even in Pine Island Bay which is usually ice free for for large parts of the year, the sea ice is thick enough right now to keep them from floating away.  September is usually considered to be the time of maximum ice extent in Antarctica.

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2517 on: September 12, 2020, 04:29:49 PM »
Some elements to complete and finalize this discussion:

Dimension at stake :
Sea ice: ~1m (the last place in the bay where the sea ice stabilizes and is no longer carried away, neither by the bay's current (turning clockwise) nor by the winds, being precisely the front of the PIG and it has only recently stabilized. The outgoing current, see below, can probably explain this.

Icebergs/Glacier: ~400m

Translated: an elephant and a small beetle

Clearly there is no possible comparison: when an iceberg is " ejected " by calving (expression of the existing tensions before calving which are released almost instantaneously), for it the sea ice does not exist.
Similarly, given its dimensions, if, following calving, it is no longer in static equilibrium and turns over.

On the other hand :
> the presence of sea ice can stop the movement of an iceberg more quickly than sea water alone
> a free iceberg surrounded by sea ice can be retained, even in the presence of currents or winds, if these are not too strong.


Warm current CDW :this enters the bay at depth (< -700m), reaches the grounding line, melts the PIG and comes out, passing under the glacier (and continuing to melt it), with water, whose temperature has dropped, but which is still warmer than sea water, which explains the formation of polynyas especially where it is stronger as in correspondence of the NSM, of the SSM and of the centre of the front (after the last big calving in February a new site appeared in correspondence of the Shear Margin between the SWT and the SIS).
This current is at its peak in autumn, but this is of no importance in relation to calvings. In fact its action, melting of the PIG, clearly has an influence on the dynamics of the glacier, but over the long term and not on a seasonal level.

To conclude, I would like to remind you, as Baking has already done, that the dynamics of the PIG is not currently linked to the seasons!

baking

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2518 on: September 14, 2020, 01:58:22 PM »
Today's high-resolution image of the Southern Shear Margin shows a calving of the Southern Ice Shelf at the prominence where the "almond" was previously attached.  The remains of the "cork" pushing on the ice shelf just upstream probably contributed to the calving.  First image of the GIF is from 18 days ago, second is 6 days ago, and last is today.

baking

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2519 on: September 14, 2020, 02:28:00 PM »
The eye likes to play tricks on you, and sometimes you see things that are not there.  Also, the data compression of JPEGs can take random noise and turn it into a pattern.  But I'm seeing today an extension of rifts on both sides of the PIG and possible cracks joining them, spreading across the entire glacier.  All motion in the GIF (click to view) is relative to the glacier.

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2520 on: September 14, 2020, 02:42:25 PM »
I confirm Baking's impression, it's been several days, that I've been following the development of a fracture pattern over the entire glacier from nmR1 (in the north) to cR1 and smR2 (in the south), but for the moment lacks a clear and indisputable image, that's why I haven't published anything.

In any case we are already in two to have more than one impression!

To be monitored !!

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2521 on: September 14, 2020, 02:57:39 PM »
PS: The only difference is that I have the impression that there is also a system of fractures a little further upstream. We are eagerly awaiting the first Sentinel2 clean image...

grixm

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2522 on: September 14, 2020, 04:36:33 PM »
PS: The only difference is that I have the impression that there is also a system of fractures a little further upstream.

This one?

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2523 on: September 14, 2020, 05:23:07 PM »
Exactly

This was already visible a week ago.

PS: It's a pity, but the season will be interesting.

Stephan

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2524 on: September 14, 2020, 06:25:25 PM »
Maybe we will have the answer in a few days, when (hopefully) clear Sentinel VIS pictures will be available.
It is too late just to be concerned about Climate Change

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2525 on: September 20, 2020, 11:40:26 AM »
Animation with the images of 08/09 and 20/09, no alignment (so the movements are not relative, but absolute).
P2's calving should be soon  ::)
with other debacles from the SSM iceberg melange

oren

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2526 on: September 20, 2020, 01:17:48 PM »
Thank you paolo. I much prefer absolute animations over relative.
I find this worrying. That the SSM melange was expected to calve is clear - the relative speeds of the main shelf and the southern shelf necessitate damage to the shear zone. But P2 could have lasted, there was no intrinsic reason it should calve. So it shows again how the main shelf is fragile.

AbruptSLR

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2527 on: September 20, 2020, 03:22:48 PM »
Thank you paolo. I much prefer absolute animations over relative.
I find this worrying. That the SSM melange was expected to calve is clear - the relative speeds of the main shelf and the southern shelf necessitate damage to the shear zone. But P2 could have lasted, there was no intrinsic reason it should calve. So it shows again how the main shelf is fragile.

As the ice flow velocities of PIIS are currently accelerating the increases in velocities are not uniform across the width of the flow (see the first image from interstitial); which in my opinion results in internal stresses along the boundaries of the main PIIS that result in the pending calving for P2 (as indicated by the second image from paolo).  Thus, in my opinion, there is an intrinsic reason for P2 to calve (otherwise it would not be happening).
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oren

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2528 on: September 20, 2020, 03:33:44 PM »
Thanks for the explanation, ASLR.

baking

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2529 on: September 20, 2020, 03:58:43 PM »
Here is today's 6-day GIF of the Southern Shear Margin.  Today's alignment by Polarview seemed inaccurate so I used Evan's Knoll which gave better results.  Note the separations throughout the downstream melange.  Also a small rift on the Southern Ice Sheet just below the remains of Cork3.

gerontocrat

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2530 on: September 20, 2020, 05:12:35 PM »
 Has this article been picked up already?

https://www.pnas.org/content/pnas/early/2020/09/08/1912890117.full.pdf
https://www.pnas.org/content/pnas/early/2020/09/08/1912890117.full.pdf

Damage accelerates ice shelf instability and mass loss in Amundsen Sea Embayment
Quote
Significance
Pine Island Glacier and Thwaites Glacier in the Amundsen Sea Embayment are among the fastest changing outlet glaciers in Antarctica. Yet, projecting the future of these glaciers remains a major uncertainty for sea level rise. Here we use satellite imagery to show the development of damage areas with crevasses and open fractures on Pine Island and Thwaites ice shelves. These damage areas are first signs of their structural weakening as they precondition these ice shelves for disintegration. Model results that include the damage mechanism highlight the importance of damage for ice shelf stability, grounding line retreat, and future sea level contributions from Antarctica. Moreover, they underline the need for incorporating damage processes in models to improve sea level rise projections.

Abstract
Pine Island Glacier and Thwaites Glacier in the Amundsen Sea Embayment are among the fastest changing outlet glaciers in West Antarctica with large consequences for global sea level. Yet, assessing how much and how fast both glaciers will weaken if these changes continue remains a major uncertainty as many of the processes that control their ice shelf weakening and grounding line retreat are not well understood.

Here, we combine multisource satellite imagery with modeling to uncover the rapid development of damage areas in the shear zones of Pine Island and Thwaites ice shelves. These damage areas consist of highly crevassed areas and open fractures and are first signs that the shear zones of both ice shelves have structurally weakened over the past decade. Idealized model results reveal moreover that the damage initiates a feedback process where initial ice shelf weakening triggers the development of damage in their shear zones, which results in further speedup, shearing, and weakening, hence promoting additional damage development. This damage feedback potentially preconditions these ice shelves for disintegration and enhances grounding line retreat.

The results of this study suggest that damage feedback processes are key to future ice shelf stability, grounding line retreat, and sea level contributions from Antarctica. Moreover, they underline the need for incorporating these feedback processes, which are currently not accounted for in most ice sheet models, to improve sea level rise projections.
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paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2531 on: September 20, 2020, 06:07:21 PM »
Oren,
At the beginning of my active follow-up I was fine with using absolute alignment and I had had a discussion with Baking about it. But afterwards I had often given in to using relative alignment, partly for the "aesthetic" effect and partly, I must admit, because sometimes it was faster to implement.
After a little experience I actually come back to my initial position: always use absolute alignment, if it is not problematic (images incoherent with each other), and if there is not a specific effect to highlight, which would otherwise be hidden by all the relative movements.  But in the latter case it would probably be more judicious to create two animations: relative and absolute.Indeed relative alignments can lead to misinterpretations of reality (and sometimes help us to see what we want to see ...).


Baking,
> more than on Even's Knill (which gives an absolute alignment, being motionless) your animation, seems to be aligned with the SIS which, I remind you, has a speed of about one km per year!
> For Cork3c I think we have the same impression: even if it is the piece that was linked to the SIS, the crumbling of its base (SIS) could (should) lead to a calving of this last piece too.
> This clear enough division between the northern and southern part of the melange and the relative movements seems to indicate that the friction between the PIG and the SIS is weakening and once calved the icebergs downstream should almost stop, which will certainly have an effect on the PIG upstream (at the last effective point of friction).

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2532 on: September 20, 2020, 06:19:28 PM »
Gerontocrat.
I'm reading it, it gives reason to what, all together, we highlighted this year (this forum is good !!).
On the other hand, there is at least one point that leaves me perplexed and on which I will intervene in the next few days (but the article, I believe, was written in 2018).

gerontocrat

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2533 on: September 20, 2020, 08:21:13 PM »
Gerontocrat.
I'm reading it, it gives reason to what, all together, we highlighted this year (this forum is good !!).
On the other hand, there is at least one point that leaves me perplexed and on which I will intervene in the next few days (but the article, I believe, was written in 2018).
Picked up the article from a link from one of the standard emails from Skeptical Science.

& yes, the number of times I read a paper / article and say to myself, but it was on the ASIF yonks ago
"Para a Causa do Povo a Luta Continua!"
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paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2534 on: September 21, 2020, 01:54:04 PM »
Micro calving at the NSM, a small iceberg has been detached and the separation between the PIG and the NE-IS is getting deeper and deeper, inexorably...

Animation based on yesterday's image (high resolution) and today's image (low resolution)

Click to animate

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2535 on: September 22, 2020, 10:41:48 PM »
New Sentinel2 image, but of terrible quality!
However the NSM and SSM are partially clear

A bad discovery at the NSM: the opening of rifts across the groundind line!

On the SSM side we can see very well, in the upstream and central parts, the separation between the two iceberg populations: PIG side and SIS side.

Click to zoom in

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2536 on: September 23, 2020, 11:18:37 PM »
You will find in this post :
> a history of the front for the northern half: an image containing the positions of the front between 17/02 and 20/09 by 12 days interval, but the positions of the front of 29/02 and 03/08 are missing (no PolarView image). The image is very busy, hence the use of a white background.
> an image containing only the front positions on 17/02 and 12/03 to highlight the important calving that occurred shortly after the big calving in February.
> an image containing only the positions of the front on 17/02 and 20/09 to highlight the totality of the losses
> an image containing only the positions of the forehead on 08/09 and 20/09 to highlight the calvings that occurred during this last period. I have added the calving information for 21/09

More posts will follow

Click to zoom in

oren

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2537 on: September 23, 2020, 11:35:46 PM »
Thank you paolo.

baking

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2538 on: September 25, 2020, 09:37:54 PM »
It might just be the acquisition angle, but today's high-resolution radar image shows a very well defined rift across the connection between Point2 and the portion of PIG above the largest transverse rift.

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2539 on: September 25, 2020, 10:30:50 PM »
Baking,
I had had the same reaction, but I discovered afterwards that this transverse rift (towards the front) was already there on 20/09.
It seems to me, on the other hand, that on the 20/09 the rift of P2 stopped at this transversal rift and that it was not extended in the direction of the cR1 (central rift N°1), as it is currently the case.
It could well be that P2 will come off with a piece of the front ...

The almond is broken into two pieces.

There was a lot of movement to the south, even the ice mélange was moved, but I can't see what happened. I only found a very micro calving that can't be the cause, little mystery!

Because of the missing images in PolarView I made an animation based on the images of 20/09 and 25/09. So there are a lot of effects due to the different orbits.

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2540 on: September 26, 2020, 01:29:54 AM »
Preamble: I must admit that the use of the term "Destruction Zone", which I had accepted, was a bit disturbing to me. After a first reading, diagonally (for the moment), of Stef Lhermitte et al. 2020, I found the term "Damage Zone", which seems to me better (and whose acronym is the same).
The other thing that disturbed me was the use only of the direction from the center of the Ice Shelf relative to the PIG, for example north side: NEDZ and NWDZ.
I propose to distinguish them by using the indications "upstream" and "downstream" (which really characterizes it), which gives: NuDZ, NdDZ, SuDZ and SdDZ.

About Stef Lhermitte et al. 2020, there are two sentences that leave me rather perplexed:
> “In the northern shear zone of PIG, on the other hand, the observed damage evolution is absent or lim-ited due negative maximum strain rates (Fig. 1A) that result in closing of crevasses and rifts.”
> "whereas the north-ern shear zone remained largely intact after the unprecedented retreat and disconnection from the northern PIG ice shelf in2015 (6)"
But it is true that this article was written in 2018 that for the PIG already seems so far away...
Indeed, as many have commented here, there is in fact a NuDZ and, as we have seen since the big calving in February, there is actually a NdDZ!

A few months ago we thought (we hope) that the very narrow NE-IS, supported by the Ice Rise Evan's Knoll, could provide, at least temporarily, a pinning point to the PIG. It seems that this will not be the case.

Analysis :
> the speed of the PIG is very high
> the NE-IS is fed by ice from the PIG basin which, to the right of the main flow, overflows an Ice Rumple and by a small tributary to the north.
> the ice of this ice shelf, in the strip near the NSM, moves parallel to the PIG with a very high velocity gradient
> downstream the NE-IS becomes very narrow

Currently this gives very high stresses with the PIG on the one hand and with the stationary ice of the Ice Rumble Evan's Knoll on the other hand.  And the remaining part of the NE-IS downstream of the separation with the PIG cannot provide support to the NE-IS upstream: the shock cannot be absorbed by deformation and it tends to break and calve.

And the NE-IS is a funnel and further upstream will widen which should make things worse.
I don't see what could prevent the NdDZ from gradually expanding upstream until it reconnects to the NuDZ. One can hope that this process will be slow (slower than at present), but it is only a matter of a few years.

And the speed of the PIG is likely to increase with the reduction of lateral stress, which is not conducive to stability.

Things are not better in the south, but this will be for another post.

click to zoom in

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2541 on: September 26, 2020, 01:09:25 PM »
This animation is based on high-resolution images of yesterday and today.
I wanted to show the differences that can exist between one image and the other because of the different orbits.
In our picture we can just see the "joint2" in today's image, joint that was very visible in yesterday's image. Hence the importance, as soon as possible, to check the images of other orbits.

In any case there is a joint between cR1 and the "rift of P2".
For the future there are two hypotheses: either cR1 reactivates and P2 remains attached to the piece of the ice shelf downstream of cR1, or there is an extension to the front of the "joint1" and in this case there is a much faster calving of P2.

To be followed carefully

baking

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2542 on: September 26, 2020, 03:08:11 PM »
Here are the usual 6-day GIFs of the Southern and Northern Shear Margins for today.

oren

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2543 on: September 26, 2020, 06:42:10 PM »
With the large rift both widening and lengthening, P2 does appear to be calving soon.

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2544 on: September 26, 2020, 09:12:34 PM »
Oren,
History: cR1 before had been named ext smR1.  Indeed, it had been formed by extending the smR1 rift in the center (this rift became the north side of P2), but there had never been any connection of smR1 with the latter.
In May the existing tensions had found a weak point and a rift had opened (very abruptly) connecting smR1 with the front downstream of cR1 (this rift became the current front north of P2).
There was therefore a very resistant point between smR1 and cR1.
It is therefore possible that this point is still very resistant and in this case we will have to wait either that the part downstream of cR1 also calves, or that this point finally gives way, to be followed carefully ...

More info :
Maximum width of the rifts : cR1 : ~150m and smR2 : ~300m

baking

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2545 on: September 27, 2020, 12:45:53 AM »
I just noticed a suspicious looking "shadow" in the GIF above, a possible rift forming in the Southern Ice Sheet surrounding the remains of Cork 3.

HapHazard

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2546 on: September 27, 2020, 10:18:53 PM »
P2 looks like India to me, that's what I named it in my head quite some time ago.

Anyway, just wanted to say thanks to paolo & baking for the amazing work being done here. :)

paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2547 on: September 27, 2020, 11:32:30 PM »
You will find in this post:
> a history of the front for the southern half: an image containing the positions of the front between 17/02 and 20/09 by 12 days interval, but the positions of the front of 29/02 and 03/08 are missing (no PolarView image). The image is very busy, hence the use of a white background.
> an image containing only the lines related to major calvings, as well as the front line as of 20/09.
> an image containing only the positions of the front on 17/02 and 20/09 to highlight the totality of the losses
> an image containing only the positions of the front on 08/09 and 20/09 to highlight the changes that occurred during this last period Added: you can notice the speed of P2 as well as the mini calving on the SIS side.

click to zoom in


paolo

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2548 on: September 28, 2020, 10:57:07 AM »
P2, arrivederci, aurevoir, aufwiedersehen, goodbye

oren

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Re: Pine Island Glacier (PIG) Calving and Discussion
« Reply #2549 on: September 28, 2020, 11:04:17 AM »
With the large rift both widening and lengthening, P2 does appear to be calving soon.
I am mightily surprised LOL, normally I predict something on this thread and the reality is the complete opposite.