Puzzled.

[Digit]

"a normal process that happens all the time".

It is indeed Tom, all glaciers that terminate in the sea must break up at the tail.

Roy.

 

[Tom K]

Petermann Glacier spawned smaller ice islands in 2001 (34 square miles) and 2008 (10 square miles).
Roy if open water were so unusual here how could this happen on a regular basis? Surely the islands just sit there surrounded by frozen sea water?

 

[CHJ]

Yes Roy but is not what you are seeing as sea ice actually a high percentage fresh water ice due to precipitation not frozen sea water?
The coastal rock water interface may well have started a warming that is indeed accentuated near the coastline by sunlight impact on the water itself, I know I have flown over parts of the coast in summer time when there appears to be the equivalent of a river between the land mass and the sea ice pack with calving iceburgs streaming out from glaciers through the sea ice and out in to open sea, very difficult to determin which is sea ice and fresh water ice and sea temps from 15,000 ft though. :lol:

 

[Digit]

Apparently the Fjord is free of ice by mid July Tom.
I've just read an article on the Petermann that is driving me nuts!
Apparently the flow rate has accelerated, this apparently pushes the floating ice further out into the Fjord so that larger areas can and will continue to break off.
Fine, but they don't explain why it has accelerated!

Roy.

 

[Digit]

With temps low enough to freeze sea water Chas just how much precipitation would you get?
Also any precipitation would also fall on the ice, it seems to be due to the glacier Chas 'cos if you look at the smaller glaciers in the pic they also have open water ahead of them.
If it is precipitation why does it not freeze at those low temps and if it is melt water why does it not freeze and can you get glacial melt water when temps are low enough to freeze sea water?
Hence I am puzzled.

Roy.

 

[CHJ]

I think the process tends to be self perpetuating with glaciers, the ice rock interface is fluid water due to friction heat/pressure, the quicker the movement the more heat the greater the water cushion the faster the ice flows ----- somewhat like an avalanche I suspect there comes a time when things let go then it all starts up again.

The precipitation is snow and hail, it's already frozen when it impacts and stays frozen that's why it's 600ft + thick.

 

[CHJ]

.....and can you get glacial melt water when temps are low enough to freeze sea water?
Hence I am puzzled.

Roy.

Get yourself a trip up to the base of a glacier when it's cold enough to freeze your breath and you may well see the melt water cascading out from under the glacier ice.

 

[Digit]

see the melt water cascading out from under the glacier ice.

Granted, and that is what I think must be the reason as all the glaciers in the pic show the same feature.

Roy.

 

[CHJ]

Here, you have the headache with the problem I'm off to bed. :lol:

2
MOVEMENT OF WATER IN GLACIERS*
By R. L. SHREVE
(University of California, Los Angeles, California 90024, U.S.A.)
ABSTRACT. A network of passages situated along three-grain intersections enables water to percolate
through temperate glacier ice. The deformability of the ice allows the passages to expand and contract in
response to changes in pressure, and melting of the passage walls by heat generated by viscous dissipation
and carried by above-freezing water causes the larger passages gradually to increase in size at the expense
of the smaller ones. Thus, the behavior of the passages is primarily the result of three basic characteristics:
(J) the capacity of the system continually adjusts, though not instantly, to fluctuations in the supply of melt
water; (2) the direction of movement of the water is determined mainly by the ambient pressure in the ice,
which in turn is governed primarily by the slope of the ice surface and secondarily by the local topography
of the glacier bed; and, most important, (3) the network of passages tends in time to become arborescent,
with a superglacial part much like an ordinary river system in a karst region, an englacial part comprised
of tree-like systems of passages penetrating the ice from bed to surface, and a subglacial part consisting of
tunnels in the ice carrying water and sediment along the glacier bed. These characteristics indicate that a
sheet-like basal water layer under a glacier would normally be unstable, the stable form being tunnels:
and they explain, among other things, why ice-marginal melt-water streams and lakes are so common,
why eskers, which are generally considered to have formed in subglacial passages, trend in the general
direction of ice flow with a tendency to follow valley floors and to cross divides at their lowest points, why
they are typically discontinuous where they cross ridge crests, why they sometimes contain fragments from
bedrock outcrops near the esker but not

 

[Jason Pettitt]

There was a congressional select committee meeting held after Petermann shed the 2010 ice island which may be of interest.
http://youtu.be/Wr6AIlwZg2Q

 

[Benchwayze]

This might help.

http://www.second-opinions.co.uk/wilkins-ice-sheet.html

I have long suspected something like this might have occurred, in addition to natural global warming.

I don't know if Barry Groves has an agenda, other than he doesn't like being taken for a fool by the 'Powers that Be'. However, whatever your stance folks, it is appropriate to read conflicting views, even if only to reinforce your own. Quite bluntly, I don't trust politicians, and I know whom I would prefer to believe.

And when a High Court Judge criticises Al Gore's report...

John 8)

 

[Jason Pettitt]

Wilkins isn't Petermann - it's on the other side of the globe. The clip I linked to of Ricahrd Alley's testimony (he's an actual glaciologist who specialises in ice stability) touched on the fact that the two are different.

But they're not that different.

Barry's argument - that it's ridiculously cold down there, isn't true across the entire Antarctic region. The coast is typically only about -3 degrees C in summer (and warming). The idea that because it's so cold in the interior that warmer water can't have impacts on ice at the exterior is just clumsy thinking on his part.

One of the things that always arouses my suspicions, aside from espousing views wildly differing from established evidence based knowledge, is when someone flaunts specialist academic qualifications - effectively saying "I'm an expert" - in areas unrelated to their area of competence - that's academic bad form.

And once suspicious, it's fun to discover from his 'about page' that Barry got his nutrition PhD from an unknown American distance learning institution, most likely here.

I know whom I would prefer to believe.

Me too.

 

[Digit]

However, i think what we're asking is, what was going around when HE discovered that fire and or hot water made some foods easier to eat/digest and allowed new foods (starchy roots, etc) to be added to their diet.

Since being puzzled by what I now know the answer to I have been doing a lot of reading to learn more about glaciers, and from that I could off a number of scenarios to explain the loss of ice on the Petermann that have nothing to do with GW, whether man made or otherwise.
Before others saddle up their hobby horses I do not exclude GW. None the less studying both views is the proper cause of action IMO, hence....

An ice island four times the size of Manhattan broke off from one of Greenland's two main glaciers, scientists said Friday, in the biggest such event in the Arctic in nearly 50 years.

The new ice island, which broke off on Thursday, will enter a remote place called the Nares Strait, about 620 miles south of the North Pole between Greenland and Canada.

The ice island has an area of 100 square miles and a thickness up to half the height of the Empire State Building, said Andreas Muenchow, professor of ocean science and engineering at the University of Delaware.

Muenchow said he had expected an ice chunk to break off from the Petermann Glacier, one of the two largest remaining ones in Greenland, because it had been growing in size for seven or eight years. But he did not expect it to be so large.

"The freshwater stored in this ice island could keep the Delaware or Hudson Rivers flowing for more than two years," said Muenchow, whose research in the area is supported by the National Science Foundation.

"It could also keep all U.S. public tap water flowing for 120 days."

Global warming?
He said it was hard to judge whether the event occurred due to global warming because records on the sea water around the glacier have only been kept since 2003. The flow of sea water below the glaciers is one of the main causes of ice calvings off Greenland.
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"Nobody can claim this was caused by global warming. On the other hand nobody can claim that it wasn't," Muenchow said.

Image: Satellite image of calved ice island
Andreas Muenchow, University of Delaware
Satellite image from Aug. 5, 2010, shows the huge ice island calved from Greenland's Petermann Glacier.

Scientists have said the first six months of 2010 have been the hottest globally on record. The El Nino weather pattern has contributed to higher temperatures, but many scientists say elevated levels of man-made greenhouse gases are pushing temperatures higher.

The initial discovery of the calving was made by Trudy Wohlleben of the Canadian Ice Service.

The ice island could fuse to land, break up into smaller pieces, or slowly move south where it could block shipping, Muenchow said.

The last time such a large ice island formed was in 1962 when the Ward Hunt Ice Shelf calved an island. Smaller pieces of that chunk became lodged between real islands

Roy.

 

[Benchwayze]

Hi Jason....

I know when I meet the impossible situation, so not this time; not this debate I'm afraid... [-( :-# Self-applied.



John

 

[Digit]

in areas unrelated to their area of competence - that's academic bad form.

Very true. Al Gore having studied politics, having dropped out of science.

Roy.

 

[Jason Pettitt]

Al-Gore doesn't present academic qualifications when he talks about global warming. He doesn't introduce his slide show as A Talk from Al Gore PhD.

Muenchow also testified at the sub committee hearing [clip]

 

[Digit]

Al-Gore doesn't present academic qualifications when he talks about global warming.

Never said he did, neither did Hubbard, didn't stop him from forming a new religion though.

Roy.

 

[Benchwayze]

Is Richard Alley the same Richard Alley whose ice-core research also shows a regular rhythm of climactic change dating back over millennia?
it isn't the research and the data that counts, it's how it is used. Just like a graph can be made to look more severe depending on the choice of which information goes where! I would wager Mr. Alley's research is paid for by his Government.

For the same reasons that research into whatever makes us obese, is funded by the grain and sugar industries, two of the largest producers in the world. I'd say they have a vested interest in keeping us all hooked on sugar and grain products.

Right now I really mean >>>>>>>>>>>>>>>>>>>>>>>>>> gagged :-#

John 8)

 

[Digit]

Nah! Couldn't be! :roll:

Roy.

 

[Jason Pettitt]

Yup, the same chap. If you can stand it there's an on line talk he gave on how all that stuff fits with the present.

http://www.agu.org/meetings/fm09/lectur ... A23A.shtml