Latest Antarctic Ice Reports

[Gray-Wolf]

I've now E-mailed Mr Grumbine with my concerns. We'll see what he has to say (as a leading expert on sea ice and it's processes).

[AtlanticFlamethrower]

Stop spamming the thread with posts nobody can understand without a headache and links that nobody can download without putting their browser in a coma.

I remember when you wrote to the Antarctic group. They replied there was nothing to worry about. However I also remember that despite me highlighting that specific paragraph of their letter which said this to you, you completely ignored it.

Why am I not surprised?

Now tell me that isn't one heck of a mess down there with lots of open water between the cracks and coasts! Greatest extent ever recorded? Pah!

It is obvious you do not fully understand the process by which these cracks in the ice form, yet you continue to attribute them to global warming. It may have little or nothing to do with warming.

This winter there has been a lot of cold air in the Antarctic, and some extra sea--ice. One might speculate the weight of the sea ice can push into the ice-shelf and in concertina fashion crack up its near edge.

I don't claim that to be a complete explanation. But its one that doesn't require warming. It would happen under a cooling regime.

[Gray-Wolf]

Shall we just await Mr Grumbine's reply then? I take it you will accept the word of one of the worlds leading Authorities on the processes of sea ice and how this years 'Anoms' apply?

Douglas R. MacAyeal actually wrote

"My off the cuff view is that the cracks in the Ross Ice Shelf are not subject to a "catastrophic" collapse of the ice shelf at this present stage, as these cracks are "normal" and part of the system....

However, that's assuming the present climate regime and that the processes of crack propagation will remain in "slow mode" in spite of any potential for global warming effects, etc."

All before the revelations of ice lake 'uplift' of central ice sheets, NASA imaging of 2005 snow ablation, surface pooling on the ice surface and rapid bottom freshening in the Ross sea...all indicators of things not being in 'slow mode'. Anyhow , I thought you'd decided 'historical' info didn't belong on this thread? Oh yeah, your changeable aren't you?

Spamming up the thread! I seem to recall your good self demanding images not 12hrs ago and now that I do? Do folk have difficulty keeping up with you or is consistency not your thing?

What has 'cold air to do with subsurface processes and 'fluid' oceans??(I believe we've been here before) That is akin to saying, from inside your centrally heated house "its snowing outside so I'm cold"

Again, I have given you what you demanded of me and now you don't want it, I have patiently tried to explain what I see occuring and you still will not take on board today's visible evidence (concertina fashion LOL, take a look, please!)

Any how, we shall await the opinion of one of the lead authorities eh?

[Gray-Wolf]

http://rapidfire.sci.gsfc.nasa.gov/realtim...060000.250m.jpg

very nice image from 05:55 UTC . Just around from the Weddell sea showing the continent, the weddell ice shelf and the broken up sea ice. Note the shadows cast by the edge of the shelf ice onto the fragmented sea ice below.

Edited September 19, 2007 by Gray-Wolf

[AtlanticFlamethrower]

1. Note this part of the reply: "the cracks in the Ross Ice Shelf are not subject to a "catastrophic" collapse of the ice shelf at this present stage, as these cracks are "normal" and part of the system."

2. Unable to access your image. I accessed a smaller version. The sea ice is not broken. It is at 100% concentration. This is confirmed by satellite of the region (September 18). Ice in this region is slightly thicker in the Weddell sea than on the same day in 2006.

3. The temperature in the Weddell sea region is not above freezing at any hour of the day. This is a significant fact one needs to grasp before one can understand the formation of the cracks in the ice.

What has 'cold air to do with subsurface processes and 'fluid' oceans??(I believe we've been here before) That is akin to saying, from inside your centrally heated house "its snowing outside so I'm cold"

Again, I have given you what you demanded of me and now you don't want it, I have patiently tried to explain what I see occuring and you still will not take on board today's visible evidence (concertina fashion LOL, take a look, please!)

Ice no matter what its thickness - 1 centimeter or 10 meters in height - will rise and fall with the tides. I don't understand what you're trying to say if this is not it.

Seeing as I'm thick, you'll need to try again.

Edited September 19, 2007 by AtlanticFlamethrower

[Gray-Wolf]

Oh my dear Boy A.F. you do seem to need a little help!

Shelf ice is the extension of multiple glaciers as they extend into (or over) ocean basins. Glaciers, by nature of their movement and the terrain they negotiate become very laterally fragment into crevasses as the encounter changes in gradients or overcome obstacles. These lateral fissures do not 'heal' but they do close up. The way Shelf ice disintegrates is along these inbuilt weaknesses (as with my 'crack'). My crack outlines an area 4 times larger than the largest known berg to calve off a shelf (B15). In the Ross the 'floor' is well below sea level but the ice stops the sea from encroaching (which is why it would be a very bad thing for it to float up and off the sea bed as this would facilitate the rapid deposition of the rest of the shelf back to the fringing mountain ranges) by means of these multiple lateral fractures.

here is a little snippet of the MODIS image that your browser cannot process annotated as you requested.

Now the 'shelf ice' is solid ,as all can see. But what's this beyond the shelf? Solid or fractured? and the collapsed section of shelf? solid or fractured?

I'm sorry you are unable to view in the detail necessary to see these features but every single image I've linked you to shows the same picture all around the Antarctic continent.

Are you still willing to maintain that the open water between cracks, when all added together, is 'negligible'?

Edited September 19, 2007 by Gray-Wolf

[Gray-Wolf]

And just to 'spam on' A.F. should we let the good folk of NW decide if they can see 'fragmented areas, solid areas and coastal areas' in case you need further reinforcement from the masses as to the meaning of these terms?

[BLAST FROM THE PAST]

And just to 'spam on' A.F. should we let the good folk of NW decide if they can see 'fragmented areas, solid areas and coastal areas' in case you need further reinforcement from the masses as to the meaning of these terms?

Give it up GW, we don't subscribe [not to say you POV is invalid but not agreed with]

There is no iminent collapse, Antarctica has been cooling for 30 years and now is/was in three year blip. only sea ice is affected...ONLY sea ice as Oceans warm. That continent is safe according to many scientists and me too. Folk should make up their own mind with their own sites and assessment available from different scientists and reports and one to peruse and search as one pleases. Never mind GRUMBLE as there are others to oppose him [although ineresting to see what his words are..exactly]. His view maybe valid but so may others. Antarctica isn't going to collapse IMO...in fact it will start the opposite affect to what you prescribe to.....and we are starting to see that with this last SH Winter.

BFTP

[Gray-Wolf]

Give it up GW, we don't subscribe [not to say you POV is invalid but not agreed with]

There is no imminent collapse, Antarctica has been cooling for 30 years and now is/was in three year blip. only sea ice is affected...ONLY sea ice as Oceans warm. That continent is safe according to many scientists and me too. Folk should make up their own mind with their own sites and assessment available from different scientists and reports and one to peruse and search as one pleases. Never mind GRUMBLE as there are others to oppose him [although interesting to see what his words are..exactly]. His view maybe valid but so may others. Antarctica isn't going to collapse IMO...in fact it will start the opposite affect to what you prescribe to.....and we are starting to see that with this last SH Winter.

BFTP

As the thread I instigated on the Enviro section states this is a 'mechanical process' and so independent of inner continental upland cooling. I would have asked A.F. but you seem adequate enough. The temps folk paddle regarding ice sheet/shelf, are these standard 2m temps? Obviously below the single year ice the water temps are all positive...heck of a range over 3m don'tcha think?

Whilst NASA were imaging snow ablation on the mountains fringing Ross the temps there were quoted at -15c???? strange old world eh?

At the end of the last period of 'ice shelf free Ross sea' the girdle that interrupted the 'emptying' of the E.A.I.S. km high rucks and buckles formed in the ice backing up at the rear of the embayment (as ground penetrating radar showed us 2 yrs ago) would you imagine that the potential energy somehow dissipates over time or is there already a 'coiled spring' pushing at the Embayment there? I'd love for you to walk me through your notion of this phenomena.

The warming Ocean, The sub ice waters are all penetrating under the Ross from both front and back, how much would you imagine is needed to resist both the gravity feed from your thickening interior on E.A.I.S. and the coiled,km high rucks pressing onto the rear of the shelf area?

Doug MacAyeal suggests that B15 fell prey to undercutting to the point where gravity and wave lifting 'toppled' the section of shelf at the nearest available lateral fracture (in the glacier feed to the west of Roosevelt island), my crack has been in slo mo topple for two years (the photo's are there for all to route out).

The alarming increase of glacial movement on the W.A.I.S. since the removal of it's shelf girdle seems to suggest that your 'thickening at the head of the glaciers is a very bad thing, much more so on E.A.I.S. (have you any idea the area of glaciers that is the Ross ice embayment and from whence they hale?)

Any hoo, all of that is for the environment thread.

So , you along with A.F. have stood up and declared you see no fragmentation of sea ice on the latest image posted, nor do you see slumped shelf ice at the coastal fringe. If you'd care to look at the earlier images of the rest of the Antarctic ice pack do you feel that you will also see no evidence of fragmentation of ice (and it's outward drift) in those images too? Time to pin your colours to your new found flag my boy for the rest of our community to see!

Edited September 19, 2007 by Gray-Wolf

[BLAST FROM THE PAST]

So , you along with A.F. have stood up and declared you see no fragmentation of sea ice on the latest image posted, nor do you see slumped shelf ice at the coastal fringe. If you'd care to look at the earlier images of the rest of the ice pack do you feel that you will also see no evidence of fragmentation of ice (and it's outward drift) in those images too? Time to pin your colours to your new found flag my boy for the rest of our community to see!

GW

I declare that Antarctica is growing...in ice and cold. That's my view but as expressed I will not diss or dismiss your view. Glaciers have slowed and this is down to the 'mud' freezig hence lubrication is less so I see no glacier collapse in progress.

regards

BFTP

Edited September 19, 2007 by BLAST FROM THE PAST

[AtlanticFlamethrower]

Gray-Wolf, I'm sorry you cannot share your knowledge without assuming a patronising tone that one should already be well aware of, or agree with, what you know.

Sorry but this is all new to me and probably new to most people who would be interested in following this thread.

Your latest image with annotation was excellent. If you kept posting those monitoring the status of Antarctic ice that would be very interesting.

Whatever the rights and wrongs of your motivation to do it, it would be interesting to see what happens as we move into the Antarctic summer.

Edited September 19, 2007 by AtlanticFlamethrower

[Gray-Wolf]

Thanks for that A.F., maybe we could start again with just the images and none of the agro?

I've tried to isolate the same area as before but now it is 11:30 UTC so the sun is higher/brighter and the shadows start to bring depth to the image.

The Nunatac's to the bottom right are the tops of mountains poking through the Antarctic ice sheet. I feel they help with the scale of things.

You can also start to grasp the scale of the slumping of that chunk of Weddell ice shelf and the wacky angle it is resting at.

I'll try and upload similar each day (if I can) as the melt progresses and the other shelf features reveal themselves so we can all 'get our eyes in'.

The Modis images are an excellent resource and I suggest folk track down a U.K. image at the 250m resolution to really help you bring some scale to the images I'll post.....I know they're bloomin' big!!!

Edited September 19, 2007 by Gray-Wolf

[Gray-Wolf]

here is Cypres at the same resolution

[AtlanticFlamethrower]

The scale definitely helps get one's eyes tuned to the image. It doesn't look much but the collapsed ice area must be larger than the area of London.

My first observation would be that the area of the collapsed ice is a "corner."

Two lines meet at an angle - 2 o'clock from the top right, 8 o'clock from the bottom left, collapsed section in the middle.

http://www.netweather.tv/forum/index.php?a...st&id=45892

I wonder which way the tide/currents go along the shore. From the picture I'd suggest the pressure comes from the bottom left - 8 o'clock - on the basis that is the side where the collapsed ice is.

NB: No more agro as long as you go at a pace slow enough to get newbies interested and don't sound like a global warming lunatic.

Edited September 19, 2007 by AtlanticFlamethrower

[Gray-Wolf]

Morning!,

Yes A.F. it is so easy, without a reference , to scale down the size of these features but once you see them then , even the tiny cracks in the ice, start to occupy a large surface area!

When I've zoomed in over that collapse you can see that the sea ice fringing it is well mangled, something you wouldn't see if it was an old 'slump' from years back.

Doug MacAyeal, who studies shelf collapse/glacier front collapse has sea swell and basal penetration by sea waters (enabling pneumatic hammering by 'wave action') as some of the major players in the mechanical erosion of the ice. So if you imagine enough of a gap at the base for sea waters to push under then storm swells start to rhythmically waggle (like pulling your baby teeth) until it (the shelf) snaps off.

With the shelves that are a collection of glacier snouts squished together then they already posses the lateral fractures that they then fail along and drop into the ocean.

Edited September 20, 2007 by Gray-Wolf

[Gray-Wolf]

Ian wrote:

> Hello Mr Grubine!

> we spoke earlier in the year regarding

> my concerns over a crevasse/crack on the East Ross Ice Shelf.

>

> I have another query that's more in your field. I've been studying the

> MODIS images (Tetra and Aqua) of the sea ice around Antarctica since

> the reports of record ice extent only to find what seems to be a mass

> of framented sea ice surrounding the continent with clear water

> between cracks and coast.

>

> Am I right in my observations?

-------------

I haven't checked out MODIS, but this is the normal sort of thing for

this time of year.

------------

> I guess that the 'single year ice' was no match for the tides around

> the full moon on Aug 28th and that they (the tides) are responsible

> for the fracturing of the sea ice and that, in fact, the software

> measuring ice extent has really been witnessing the pack slowly

> drifting apart over the weeks since then. Does this sound reasonable?

>

> Another teeny question. Does the ice extent calcs take into account

> the 'new' sea areas available for freezing that were once shelves and

> glacier snouts?

-----------------

That will depend on exactly who is doing the computation and how

recently they've been able to update their land masks. The main source

I use is too old to include the disintegrations of the Larsen ice shelf

parts, and some of the more recent major iceberg calving events. The

amount of area involved is small compared to the total Antarctic ice

extent. And it's not clear what to do for ice extent calculations.

-----------------------

Such areas _would_ have been ice covered, if they weren't ice tongues or

the like back then.

------------------------

To go back, extent is computed by considering grid cells in the

analysis. If a grid cell has any ice in it, the area of the cell (not

of the ice, the whole grid cell) is added. Repeat this over the entire

grid and you have the hemispheric ice extent. The coastal separation

you're seeing is expected this time of year -- it is now too warm to

freeze up new ice. The winds blowing away from the continent carry the

ice away. The ice doesn't move fast, and there are onshore winds as

well, and other effects, so the gap is limited and typically smaller

than my grid cells (obviously this one will depend on the size of

people's grids).

Ice area is done cell by cell also, but if a cell is only 30% ice

covered, only 30% of the area of the cell is added. Extent is always

greater than area. Usually the two track each other pretty well. But

they don't have to -- the pack could lose a lot of area, as it undergoes

a swiss cheese style of melting (the normal in Antarctica) while extent

remains fairly constant.

Cheers,

Robert Grubine

--------------------

> I guess you'll be a tad busy at present so I'll not be dissapointed if

> you are unable to respond any time soon!

>

> Take care!

>

> Ian Ballantine-Gray

--

No virus found in this incoming message.

Checked by AVG Free Edition.

Version: 7.5.487 / Virus Database: 269.13.25/1018 - Release Date: 19/09/2007 15:59

Wow he was quick again! The reply is slotted into my origional E-mail so I've separated the two by spaces and dashes , the rest is how it arrived.

I suppose my concerns are somewhat allayed now but he does show us how limited the sea ice observation technique's can be in calculating total ice concentration.

Also , his point about the overlaid 'mask' of land /shelf and glacier show us just how dated some of their 'current' info is.

Right, time to duck below the parapet...........

Edited September 20, 2007 by Gray-Wolf

[jethro]

You can duck if you like GW but I for one have a higher regard for anyone who will post stuff which counter-acts or disagrees with their opinion; you could have kept it under your hat and claimed the guy must have been too busy to reply. Good on ya.

[Gray-Wolf]

Thanks for that Jethro!

I kinda hope that all the other 'hard hitters' over on the enviro threads would do just the same though!, if not? well I've always thought that you lead from the front!

Bob and the others show us that ,if we have questions, we shouldn't be afraid to go to the horses mouth rather to rely on other folks opinions (which are often just culled from 'old' reports/data sets). Every time i've approached a 'world expert' they have always been more than happy to reply and put you straight or, if necessary, try and address your concerns with actions (like the seismometers they placed at the end of 'my crack')

So far as the Antarctic and it's evolution MODIS is one of the tools they use. It's hard to get teams out to inspect on a yearly basis so they do just as I do and study the visible images for changes in the ice cover and it's condition. The more eyes they have aiding them in this then the better!

As the man said it is early in the season for the visible images and he hasn't had a look yet (relying on thermal images) so I might get an 'add on' once he's had a gander........

I've not had a chance to wade through this a.m's images yet but if I spot anything I feel is of interest I'll crop it and post it!

[BLAST FROM THE PAST]

Thanks for that Jethro!

I kinda hope that all the other 'hard hitters' over on the enviro threads would do just the same though!, if not? well I've always thought that you lead from the front!

Bob and the others show us that ,if we have questions, we shouldn't be afraid to go to the horses mouth rather to rely on other folks opinions (which are often just culled from 'old' reports/data sets). Every time i've approached a 'world expert' they have always been more than happy to reply and put you straight or, if necessary, try and address your concerns with actions (like the seismometers they placed at the end of 'my crack')

So far as the Antarctic and it's evolution MODIS is one of the tools they use. It's hard to get teams out to inspect on a yearly basis so they do just as I do and study the visible images for changes in the ice cover and it's condition. The more eyes they have aiding them in this then the better!

As the man said it is early in the season for the visible images and he hasn't had a look yet (relying on thermal images) so I might get an 'add on' once he's had a gander........

I've not had a chance to wade through this a.m's images yet but if I spot anything I feel is of interest I'll crop it and post it!

GW

No need to duck. POV are different with different folk. You went the extra yard with 'horse mouth' info. Excellent stuff and credit to you ....as it was much more than I did this time.

regards

BFTP

[Gray-Wolf]

Thanks B.F.T.P.

Crosphere today have retracted their 'Ice max' headline I see. Software glitch. Just goes to show (to me at least) that you can't beat your own eyes!!! (if you can trust the images!!!).......

[Gray-Wolf]

Still pretty blighted by cloud/fog over the dissapating pack but I'd say we are well beyond maximum cover/extent now and ,as Bob highlighted, large areas of open water are now appearing around all of the coast. From our 'Cyprus' guide some of the open coastal waters appear as large as Cyprus if not larger. The Pennisula is already in a ice free state. Cloud willing I'll post an image as the area of the penninsula is visualy stunning with it's mountains/Glaciers.

[Gray-Wolf]

http://www.sciencedaily.com/releases/2007/...70920122154.htm

Thought I'd stick this up before my daily gander 'Darn Sarwf'.

[BLAST FROM THE PAST]

http://www.sciencedaily.com/releases/2007/...70920122154.htm

Thought I'd stick this up before my daily gander 'Darn Sarwf'.

Important to read it because the headline is somewhat distorting. 2005 was that an odd year down there? let's see what this years report comes up with.

BFTP

[Gray-Wolf]

Hi B.F.T.P.!

I'd agree about the reading of it but it is not just highlighting the upland melting over the 2005 season (I'd imagine there were many more years with lesser melts, but still melts!) but the wide-scale melt over the Ross Ice shelf.

Step 1 in the breakup of Larsen was widespread meltwater pools forming which then penetrated the shelf and ,at depth under pressure, smashed the integrity of the base (and lubricated it) allowing for the rapid disintegration we witnessed in 2002. When Ross goes it will be slightly different (due to the sea water inundation 'lifting the shelf') but just as rapid (single season). When we see this occur we are really up pooh creek without means of propulsion as The E.A.I.S. will then not only have lost it's restraining 'girdle' of ice but also the anomalously warm waters of the Ross sea will increase melt at the snouts of the glaciers allowing for rapid acceleration of the glacier behind.

None of this is pleasant (and My personal fears....even though I'm a worrier! are greater than ever) but to solve any problem first you have to define the problem (as realistically as possible)

Edited September 22, 2007 by Gray-Wolf

[AtlanticFlamethrower]

Gray-Wolf, you're edging toward eco-lunacy again. Leave it out here.

The Larson B ice shelf last broke off 12'000 years ago - during the last ice age. It did not break up due to surface temperature then, there no reason to assume it was due to surface temperature now. Your theory is not proved. Your hypotheses are just hypotheses, this is not the right board to peddle them.

Leave the narrative for the Environmental Change board and just give us the facts about Antarctic ice, increase, decrease, in this thread.