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Wipneus

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Re: PIG has calved
« Reply #850 on: November 10, 2018, 11:09:17 AM »

Would you mind to combine this photograph with the one you posted on Reply #767 on: September 21, 2018, 09:11:33 AM? Is this the same crack or a new one?

Thanks a lot!

It is the same (suspected) crack. These Landsat images are just able to show the dent in the snow, very much depending on the Sun elevation and direction.

I am downloading a clear Landsat image from 7 November now, which is really a night image so has a low Sun position. See how that shows.

I intent to closely follow any developments of this crack of course, but surprise (to me) calving do happen.

FredBear

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Re: PIG has calved
« Reply #851 on: November 10, 2018, 12:52:33 PM »
NASA Ice has put up some photos of the PIG area on FaceBook, some are :-

No.4. Crevasses in Pine Island Glacier show where the ice is drifting apart. (Brooke Medley/NASA)
No.3. In this close-up of Iceberg B-46, the crumbling edge of the cliff are visible. (Brooke Medley/NASA)
No. 5. The shadow of NASA's DC-8 provides scale for the massive Iceberg B-46. (Brooke Medley/NASA)

Wipneus

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Re: PIG has calved
« Reply #852 on: November 10, 2018, 12:53:10 PM »
Here is that nightly Landsat image from 7 November. It is the same as the NASA image reported some posts above. NASA did succeed to give it a "sunny" look, but the sun's elevation above the horizon is only 1.15 degrees. So I don't mind a more shadowy appearance after some contrast enhancement.

Those shadows bring out more linear features of which the middle one (of three most prominent) is the one I mentioned before.

1400x1400 pixels (15m/pix) : click for that hi-res image.

Shared Humanity

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Re: PIG has calved
« Reply #853 on: November 10, 2018, 04:01:37 PM »
As soon as it calves, the berg begins to break up at the rifts that run parallel to the calving as well as perpendicular where the pronounced rifts are. The PIG is in a slow motion disintegration and those rifts further south from the new face will result in additional calving soon.

AbruptSLR

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Re: PIG has calved
« Reply #854 on: November 10, 2018, 05:23:26 PM »
As soon as it calves, the berg begins to break up at the rifts that run parallel to the calving as well as perpendicular where the pronounced rifts are. The PIG is in a slow motion disintegration and those rifts further south from the new face will result in additional calving soon.

Remember (per the attached diagram) that this 'rifts' parallel to the calving face first form way upstream as the grounded glacial ice accelerates downhill, and then these rifts close-up as the angle of the surface slope decreases.  Further, I believe that as the ice velocities continue to increase (with continued global warming) these parallel rifts will have less time to heal themselves before they are subject to calving when they move down into the ice shelf.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
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Shared Humanity

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Re: PIG has calved
« Reply #855 on: November 10, 2018, 08:44:06 PM »
Thank you for posting that again. Now I get it.

oren

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Re: PIG has calved
« Reply #856 on: November 10, 2018, 09:24:41 PM »
Thanks to all for the detailed images and info in this thread. The PIIS indeed seems to be in a slow motion disintegration. Very bad.

Sleepy

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Re: PIG has calved
« Reply #857 on: November 11, 2018, 07:35:29 AM »
Since Pine Island used to calve on decadal timeframes it's insanely bad.
I almost printed out that last image posted by Wipneus...
Omnia mirari, etiam tritissima.
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Stephan

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Re: PIG has calved
« Reply #858 on: November 11, 2018, 07:45:04 AM »
I think we all should thank Wipneus and ASLR for important and impressive contributions to this thread.
PIG / PIIS seems to be the canary in the coalmine concerning the WAIS stability and must be continuously observed.

AbruptSLR

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Re: PIG has calved
« Reply #859 on: November 11, 2018, 04:14:47 PM »
I would like to express my appreciation for the many contributions that A-Team made to this thread in 2015 & 2016 (before he stopped posting here), particularly with regard to the upstream ice dynamics for PIG, by reposting a very few of his numerous scientific grade images:
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

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Re: PIG has calved
« Reply #860 on: November 12, 2018, 09:37:33 PM »
All,

Due to Neven's management style in this forum I have decided to stop posting here,

Sayonara,
ASLR
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

solartim27

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Re: PIG has calved
« Reply #861 on: November 12, 2018, 10:00:00 PM »
All,

Due to Neven's management style in this forum I have decided to stop posting here,

Sayonara,
ASLR

Well, that sucks.  Thanks for all the input.
FNORD

Sleepy

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Re: PIG has calved
« Reply #862 on: November 12, 2018, 10:07:38 PM »
Agreed. ASLR's posts around Antarctica was the reason I started reading here in late 2013. I don't follow the political threads. All the best whatever you decide ASLR.
Omnia mirari, etiam tritissima.
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SteveMDFP

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Re: PIG has calved
« Reply #863 on: November 13, 2018, 04:51:30 AM »
All,

Due to Neven's management style in this forum I have decided to stop posting here,

Sayonara,
ASLR

You've been tireless in presenting an astonishing diversity of scientific information and of thoughtful contributions.  We're losing a star.

bligh8

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Re: PIG has calved
« Reply #864 on: November 13, 2018, 05:01:17 AM »
Agreed. ASLR's posts around Antarctica was the reason I started reading here in late 2013. I don't follow the political threads. All the best whatever you decide ASLR.



+1

Pmt111500

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Re: PIG has calved
« Reply #865 on: November 13, 2018, 05:17:01 AM »
All,

Due to Neven's management style in this forum I have decided to stop posting here,

Sayonara,
ASLR

Too bad, but the republican nutjobs make any forum nearly intolerable to follow. I might follow the suit, not willing to compromise on political threads.
« Last Edit: November 13, 2018, 06:44:20 AM by Pmt111500 »
Amateur observations of Sea Ice since 2003.

magnamentis

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Re: PIG has calved
« Reply #866 on: November 13, 2018, 05:29:01 AM »
All,

Due to Neven's management style in this forum I have decided to stop posting here,

Sayonara,
ASLR

a real pity while i would be very interested to understand what happened that was so serious that it was leading to such a decision. i found your input precious and educating but i also can side very well with most things that neven is doing and contributing.

i find it always pitiful to see how people with similar goals in similar or the same fields part for personal IMO petty discrepancies. with petty i don't mean that the discrepancies are not important but considering the task at hand here, to make >7'000'000 people and their leaders aware of what's going to happen if we don't change our life-styles a forum management should not be important enough to stop the real working on the real task at hand which is to reduce the impact of our evildoings to planet earth to a possible minimum.

apparently personal disputes once more help to kill the process to steer the vessel of the cliff, not good.
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Juan C. García

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Re: PIG has calved
« Reply #867 on: November 13, 2018, 06:34:30 AM »
All,

Due to Neven's management style in this forum I have decided to stop posting here,

Sayonara,
ASLR


Did Neven lost his temper for once in 5 years? Well, he is human, like the rest of us.
I want to thank Neven for all the effort on this Forum and on the ASIB. And I want to thank AbruptSLR for the same reason. It is happening to several of us. Just a lot of psycological pressure, with all that it is happening on climate change and feeling that the governments are not reacting well enough. So, thank you both.

AbruptSLR, I will ask you to reconsider your decision. Hope to see you around here soon!
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

Stephan

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Re: PIG has calved
« Reply #868 on: November 13, 2018, 07:35:23 PM »
All,

Due to Neven's management style in this forum I have decided to stop posting here,

Sayonara,
ASLR
This is really hard. Is there a chance that you change that decision? We need you here!
Anyway, thanks a million for your posts, your well-researched information and for giving us the opportunity to share your experience and knowledge.

uniquorn

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Re: PIG has calved
« Reply #869 on: November 13, 2018, 08:15:25 PM »
...sigh...

Wipneus

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Re: PIG has calved
« Reply #870 on: November 19, 2018, 07:04:53 PM »
I posted the first attached image before, here

Second is the same suspected crack pictured by Sentinel 2B, same resolution different orientation. The improved quality still shows not show much more than a dent in the snow.


Wipneus

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Re: PIG has calved
« Reply #871 on: December 09, 2018, 01:08:46 PM »
Detail of some break-up of the latest (September) Calving in this Sentinel 2B shown in native 10m/pix resolution. The preference for square angles is obvious.

Stephan

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Re: PIG has calved
« Reply #872 on: December 18, 2018, 09:51:58 PM »
I watch Thwaites and PIG carefully on EOSDIS worldview.
Please look at the big gap of open water that has appeared behind the 2017 PIIS calving remains. Unfortunately the "calving crack" of Oct 2018 is shaded by thin clouds. But it must have widened massively yesterday and today. I will keep an eye on that.
The movement of the icebergs of the 2017 calving remains from day to day is amazing (I do not know how to create a short video).  There must be strong currents beneath the ice.
Upper picture from Nov 29, lower pic from today (Dec 18, 2018)

Tor Bejnar

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Re: PIG has calved
« Reply #873 on: December 19, 2018, 12:14:07 AM »
Arctic ice is healthy for children and other living things.

Stephan

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Re: PIG has calved
« Reply #874 on: December 19, 2018, 10:36:34 PM »
Thanks for that screen shot. Now it is evident that the "calving crevasse" of the October 2018 calving event has widened in the last days. This ice is not buttressing the PIG no longer. Can a specialist check the ice velocity and compare it with values of last summer and two years ago to see whether it has already increased? Thank you!

Stephan

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Re: PIG has calved
« Reply #875 on: December 29, 2018, 11:57:46 AM »
The SW tributary glacier flowing into the PIIS shows new cracks and a NE-directed movement (a little hard to see, please use the time lapse in EOSDIS worldview where I took the photos from). The upper photo comes from Nov 17, the lower from yesterday (dec 28, 2018)

solartim27

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Re: PIG has calved
« Reply #876 on: December 31, 2018, 04:21:09 AM »
Interesting development in the notch area, and lots of tabular berg breakup action in the first picture.  The second picture shows the large chunk of fast ice at the head of the tributary peninsula starting to break off.  I woder how much calving can happen with the bay jammed with sea ice this year (unlike 2016 and 2017).
From  https://www.polarview.aq/images/105_S1jpgfull/S1B_IW_GRDH_1SSH_20181230T092631_FDC0_S_1.final.jpg  (44 MB)
FNORD

IceConcerned

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Re: PIG has calved
« Reply #877 on: January 02, 2019, 12:11:30 PM »
Another calving in preparation ?
A big central crack appears to be opening, quite visible on this sharp image :
https://www.polarview.aq/images/105_S1jpgfull/S1B_IW_GRDH_1SSH_20181230T043510_02A2_S_1.final.jpg

oren

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Re: PIG has calved
« Reply #878 on: January 04, 2019, 12:34:28 PM »
Welcome, IceConcerned.

Stephan

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Re: PIG has calved
« Reply #879 on: January 05, 2019, 07:42:36 PM »
I keep on watching the Amundsen Sector of Western Antarctica carefully. The last two days a large chunk of fast sea ice broke off in the Pine Island Bay. I have added a picture generated by the EOSDIS "Start Comparison" button. The right half was photographed on Nov 19, the left half is from today. Try this comparison option out by yourself!

IceConcerned

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Re: PIG has calved
« Reply #880 on: January 08, 2019, 11:48:23 AM »
Many changes in that area in the past few days.
Here are 3 successive screen shots from Sentinel :
* loss of the iceberg on the east side that were in advance to the main big new iceberg
* on the west side, tremendous outbound movement of the icebergs floating in front of the SW tributary, with additional calving
* movement of the main iceberg towards the exterior

Stephan

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Re: PIG has calved
« Reply #881 on: January 08, 2019, 06:49:27 PM »
Thanks a lot for these images. Are there two new cracks (one already open) in the PIG and how long are they already?

IceConcerned

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Re: PIG has calved
« Reply #882 on: January 09, 2019, 04:51:17 PM »
Indeed, there two new cracks on the main flow's edge. The one further inland could point to the crack currently appearing at the middle of the flow.

IceConcerned

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Re: PIG has calved
« Reply #883 on: January 09, 2019, 05:11:53 PM »
Further movement : dislocation of the main iceberg going on the east side, and rotation of the whole, opening the front to more open seas.

FredBear

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Re: PIG has calved
« Reply #884 on: January 10, 2019, 02:40:52 PM »
It is interesting that the remains of the last 2 major calvings are slowly pushing northwards through the sorrounding sea ice (which has been growing since May 2017). I assume that up-welling water at the front of the glacier propels the icebergs?

oren

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Re: PIG has calved
« Reply #885 on: January 10, 2019, 09:20:05 PM »
It's possible that there is an underwater current that is pushing the deep-keeled bergs but not the sea ice.
It could be certainly be upwelling, but there is also some input of meltwater + glacier advance that flows into the bay.
In any case, the bergs are usually flushed out rather quickly if there's no sea ice, unless they become grounded.

FredBear

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Re: PIG has calved
« Reply #886 on: January 19, 2019, 07:55:10 PM »
In many places a polynya appears at the end of a glacier - I suspect deep warm water is melting the lower parts of the glacier and the fresher melt is rising up the front. This flow would also explain why calved icebergs often drift away quite rapidly.

In the last 2 days the sea ice has been breaking up in front of Pine Island glacier, the bits of the last two icebergs are drifting away   .   .   .

wdmn

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Re: PIG has calved
« Reply #887 on: January 19, 2019, 08:36:57 PM »
In many places a polynya appears at the end of a glacier - I suspect deep warm water is melting the lower parts of the glacier and the fresher melt is rising up the front. This flow would also explain why calved icebergs often drift away quite rapidly.

In the last 2 days the sea ice has been breaking up in front of Pine Island glacier, the bits of the last two icebergs are drifting away   .   .   .


Since I had to look it up I figure someone else will have to also...


Stephan

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Re: PIG has calved
« Reply #888 on: January 19, 2019, 08:38:22 PM »
A big change occured with the sea ice in front of PIIS within the last days. Please compare the two pictures from Jan 09 (above) and today (Jan 19, 2019), both taken from EOSDIS worldview.
It looks like a complete break-up and partial collapse of the sea ice, combined with a massive NW movement of the calved icebergs from Oct 2018 and the remains from the calving in 2017 (don't remember the month).
PIIS and the NW tributary fronts are now completely exposed to open water...

Stephan

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Re: PIG has calved
« Reply #889 on: January 19, 2019, 08:56:22 PM »
Also at the NE edge of Pine Island Bay a massive disintegration of the fast ice occurred last week. See the new cracks (marked in red) and the little island (is that Pine Island?) at the bottom (marked in green), now freed from ice. Please be aware that these two pictures show the changes that happened last week (upper pic Jan 12, lower pic Jan 19)
Taken from EOSDIS worldview

Andreas T

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Re: PIG has calved
« Reply #890 on: January 19, 2019, 10:17:28 PM »
Pine Island Bay and Pine  Island Glacier were named after a ship involved in the mapping of this area in 1946. https://en.wikipedia.org/wiki/USS_Pine_Island_(AV-12)
The ship in turn was named after an island off the coast of Florida, a more likely place to find pine trees I guess ;)

Stephan

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Re: PIG has calved
« Reply #891 on: January 20, 2019, 12:14:42 PM »
Maybe, when climate change has fully set in (T > 5°C than today), our ancestors may plant some pine trees on that island in a wind sheltered and sunny corner, if it is not inundated until then...  ;)

crandles

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Re: PIG has calved
« Reply #892 on: January 20, 2019, 12:50:09 PM »
Maybe, when climate change has fully set in (T > 5°C than today), our ancestors may plant some pine trees on that island in a wind sheltered and sunny corner, if it is not inundated until then...  ;)

That would be remarkable even if you mean descendants.  ;)

Wherestheice

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Re: PIG has calved
« Reply #893 on: January 20, 2019, 12:59:27 PM »
Maybe, when climate change has fully set in (T > 5°C than today), our ancestors may plant some pine trees on that island in a wind sheltered and sunny corner, if it is not inundated until then...  ;)

Once we warm 5 C, there won’t be many people around to call ancestors
"When the ice goes..... F***

Stephan

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Re: PIG has calved
« Reply #894 on: January 20, 2019, 01:04:33 PM »
This sounds very pessimistic but unfortunately you may be right...

Stephan

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Re: PIG has calved
« Reply #895 on: January 20, 2019, 01:08:22 PM »
Even with a 9-day difference in the "Start comparison" mode in EOSDIS worldview you see a movement of the PIG. I have looked at other places in Antarctica by this method but haven't found any "as speedy as PIG" glacier or ice shelf. Only the fast ice along the Thwaites Ice tongue comes close to that.
May I ask the experts and the "pixel counters" to update their estimation about the velocity of this fastest glacier in Antarctica?
Thanks!

b_lumenkraft

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Re: PIG has calved
« Reply #896 on: January 20, 2019, 01:25:53 PM »
Maybe, when climate change has fully set in (T > 5°C than today), our ancestors may plant some pine trees on that island in a wind sheltered and sunny corner, if it is not inundated until then...  ;)

Once we warm 5 C, there won’t be many people around to call ancestors

Had the very same thought.

charles_oil

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Re: PIG has calved
« Reply #897 on: January 20, 2019, 03:31:14 PM »
Ancestors = descendants I hope - if not that's really spooky  ;)

gerontocrat

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Re: PIG has calved
« Reply #898 on: January 20, 2019, 04:21:23 PM »
Pine Island Bay and Pine  Island Glacier were named after a ship involved in the mapping of this area in 1946.
I wonder where one could find the map they made? Did they take photos? It would be interesting to compare with today.
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Stephan

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Re: PIG has calved
« Reply #899 on: January 20, 2019, 04:49:37 PM »