[PrestonSturges]

http://www.allglacier.com/history_museu ... _flood.php

Peak of the Last Ice Age
As a section of the Cordilleran ice sheet moved south, a huge ice dam came about and blocked the Clark Fork River, forming a huge lake that was 2,000 feet deep – Glacial Lake Missoula. The lake contained more than 500 cubic miles of water.

End of the Last Ice Age
The Glacial Lake Missoula was an inland sea, stretching for 200 miles. It had more water than Lake Ontario and Lake Erie combined. The ice dam that held it back finally broke from the pressure, flooding down the Columbia River, sweeping what are now Montana, Idaho and Washington State. It is said that the flow was ten times the flow of all rivers in the world put together. A towering cascade of water and ice stripped away soil, cut canyons, moved boulders and shook the world as it raced almost 65 miles per hour across and through the land.

Over the next 2,500 years, this Cordilleran ice sheet continued to move south and the Clark Fork River became blocked over and over again, creating the Glacial Lake Missoula again and again. The ice dam would rupture periodically, with floods rushing once more through Montana, Washington and Idaho.

[gandolf]

http://www.allglacier.com/history_museums/missoula_flood.php

Peak of the Last Ice Age
As a section of the Cordilleran ice sheet moved south, a huge ice dam came about and blocked the Clark Fork River, forming a huge lake that was 2,000 feet deep – Glacial Lake Missoula. The lake contained more than 500 cubic miles of water.

End of the Last Ice Age
The Glacial Lake Missoula was an inland sea, stretching for 200 miles. It had more water than Lake Ontario and Lake Erie combined. The ice dam that held it back finally broke from the pressure, flooding down the Columbia River, sweeping what are now Montana, Idaho and Washington State. It is said that the flow was ten times the flow of all rivers in the world put together. A towering cascade of water and ice stripped away soil, cut canyons, moved boulders and shook the world as it raced almost 65 miles per hour across and through the land.

Over the next 2,500 years, this Cordilleran ice sheet continued to move south and the Clark Fork River became blocked over and over again, creating the Glacial Lake Missoula again and again. The ice dam would rupture periodically, with floods rushing once more through Montana, Washington and Idaho.

Has anyone got a video of that cause that would be great to see. Better even than the movie 2012

[vtsnowedin]

Got the name wrong on the Conn. river lake and I thought Lake Agasszi drained out the St. Lawrence and certainly some areas would have had to at some time or another. Lake Champlain was a bay of the ocean and covered with shelf ice. The bottom of the lake is well below sea level even today but the outlet has rebounded after the ice weight was removed and is now about ninety five feet above sea level.
I found this bit about lake Hitchcock in an article by Larry Coffin talking about dams on the Connecticut.

Glacial Lake Hitchcock was formed behind a giant earthen dam at Rocky Hill, Connecticut about 15,000 years ago. Before it drained away about 3,000 years later it had reshaped the valley for almost two hundred miles upstream. (Map Umass Geoscience

and this

Within the heritage of the Abenaki, who peopled this valley before the coming of the Europeans, are legends of Odzihozo, the earth-shaper and Ktsi Amiskw, the Great Beaver.

This Great Beaver held back the waters of the Kwanitekw, or the Connecticut. But a cousin of Odzihozo broke the back of the beaver and released the captive waters.

http://larrycoffin.blogspot.com/2010/09 ... aters.html
All interesting stuff but not something that is likely to happen in Greenland in our lifetimes.

[hillsidedigger]

I wonder if the energy of a sudden burst of water from Greenland might somehow set off large tidal waves.

[Newfie]

No, no danger of tidal wave. But lower six meters in a month is startling, if true.

I surely don't know all the physics but that would seem to imply that the ice is going through a phase change and that generally doesn't happen unless all the ice has a similar amount of energy stored. Given the amount of ice stored on the cap I suppose it could be that the inner ice is very well insulate. But still, this would seem to mean that the cap has absorbed a huge amount of energy.

If I've go my physics right, it would sort of indicate a larger and accelerating melt.

Is this right?

[vtsnowedin]

No, no danger of tidal wave. But lower six meters in a month is startling, if true.

I surely don't know all the physics but that would seem to imply that the ice is going through a phase change and that generally doesn't happen unless all the ice has a similar amount of energy stored. Given the amount of ice stored on the cap I suppose it could be that the inner ice is very well insulate. But still, this would seem to mean that the cap has absorbed a huge amount of energy.

If I've go my physics right, it would sort of indicate a larger and accelerating melt.

Is this right?

You have to look at the qualifiers and limits to that six meter measurement. Look at the quote.

A British research team studying the Greenlandice has discovered that the ice sheet in their region had lowered six metres in just a month

Notice they don't tell you what region that was. Top of the ice cap in the middle of the island? Doubt it. Within snow cat distance from the coast and sea level? Probably. Left vague to alarm the easily led and create a dramatic story? Of course! Is there real science behind the story? Yes they would not risk their professional reps. on telling a complete lie.
I'm betting that one of their final conclusions in their paper is "That more research is needed"

[PrestonSturges]

FWIW the story about the "ice sheet" was from a single location. Something is definitely up with the glacier those guys are studying, but it was not the whole ice sheet.

[basil_hayden]

Looks like the name will match the conditions soon, as it did 400-900,000 years ago.

[Newfie]

But to take a second data point at Illustat (sp? - near Disco Bat) the sun came up two days early this year. One theory on why was that the height of the ice cap had lowered so much that it didn't block the sun as long. Atmospheric conditions was another theory.

[americandream]

You have to look at the qualifiers and limits to that six meter measurement. Look at the quote.

A British research team studying the Greenlandice has discovered that the ice sheet in their region had lowered six metres in just a month

Notice they don't tell you what region that was. Top of the ice cap in the middle of the island? Doubt it. Within snow cat distance from the coast and sea level? Probably. Left vague to alarm the easily led and create a dramatic story? Of course! Is there real science behind the story? Yes they would not risk their professional reps. on telling a complete lie.
I'm betting that one of their final conclusions in their paper is "That more research is needed"

Character assasination at it's most absurd. Assuming that these fellows would be stupid enough to use a sample region that was prone to this sort of behaviour, (the inference from your argument being that they probably used such a sample to cause alarm), how long would they survive as salaried professionals? Why, some sleuth in the vast industry holding AGW to account would be onto them like s#*t on a blanket. Such sampling methodology would quite rightly be exposed for the incompetency it was, incompetent on so many levels, I would not even know where to begin.

The jury is out on climate issues, agreed, given the lack of hard evidence that conclusively shows that the climate is entering volatility in preparation for a transition to a new range. AGW sleuths have gone to great pains to shout this out to the world at large and much mitigational effort at reigning in capitalism (which is something of an oxymoron anyways) has flopped by the wayside. To think that said sleuths, many of whom are industry veterans, would let anything dent that impasse without a challenge is either naive or stirring.

[Hinterlander]

Astonishing record-smashing 600-billion-ton ice-sheet mass-balance loss on Greenland during 2010


http://climatechangepsychology.blogspot ... llion.html

Latest GRACE data: record ice loss in 2010

Posted on 29 January 2011 by John Cook


The GRACE satellites continue to measure the change in gravity around the Greenland ice sheet. Here is the latest data showing the record amount of ice loss Greenland experienced in the 2010 summer.

see chart here:

http://www.skepticalscience.com/Latest-GRACE-data-record-ice-loss-in-2010.html


It's interesting to compare this data to previous blog posts in May 2010 and November 2010. The ice loss in 2010 is the greatest in the satellite record - around 600 billion tonnes of ice mass loss over the 2010 summer. More importantly, the rate of ice loss continues to increase, more than doubling since 2002.

Around two decades ago and for some time before that, Greenland was probably in approximate mass balance - with ice gain in the interior matched by ice loss at the edges. Around one decade ago, the ice loss increased to around 100 billion tonnes per year. Currently, it's losing ice at over 200 billion tonnes per year.

[PrestonSturges]

A billion tonnes equals a cubic kilometer of water?

How many gigatons per millimeter of sea level rise?

[vtsnowedin]

A billion tonnes equals a cubic kilometer of water?

How many gigatons per millimeter of sea level rise?

Get your slide rule out. The surface area of the worlds oceans is 361000000km^2

[PrestonSturges]

A billion tonnes equals a cubic kilometer of water?

How many gigatons per millimeter of sea level rise?

Get your slide rule out. The surface area of the worlds oceans is 361000000km^2

What's a "slide rule?"

[PrestonSturges]

OK...

200 km3=200 gigtons actually a bit more when the ice melts

360,000,000 km2 / 200 gigatons per year

1,805,000 km2/gigaton

1 gigaton = 1x106 mm per km2

1.8x106 km2/1x106 mm per km2

= 1.8 mm

If 600 cubic kilometer melted last year, sea level should go up a quarter inch world wide.

[vtsnowedin]

A billion tonnes equals a cubic kilometer of water?

How many gigatons per millimeter of sea level rise?

Get your slide rule out. The surface area of the worlds oceans is 361000000km^2

What's a "slide rule?"

If you are that young and really don't know check out the movie Apollo 13. It is the little widget Tom Hanks has in his hand and uses to figure out how long to burn the engine to get his crew back to earth without a working computer. Not much margin for error. For that matter the whole race to the moon was computed or at least back checked using slide rules.Post peak oil we will have to go back to them or an abacus.

[PrestonSturges]

No that's the one thing we won't have to give up - there will be solar powered calculators no matter what. People will be swapping them for beads and rabbit pelts in a hundred years.

I have a (nonsolar) Casio that I have been using for 25 years, and all I've done is soak it in distilled water a few times, which makes it like new.

[Hinterlander]

Arctic Report Card 2010
http://www.arctic.noaa.gov/reportcard/greenland.html

October 19, 2010

Greenland Summary
Greenland climate in 2010 is marked by record-setting
~ high air temperatures,
~ ice loss by melting,
~ and marine-terminating glacier area loss.

Summer seasonal average (June-August) air temperatures around Greenland were 0.6 to 2.4°C above the 1971-2000 baseline and were highest in the west.
A combination of a warm and dry 2009-2010 winter and the very warm summer resulted in the highest melt rate since at least 1958 and an area and duration of ice sheet melting that was above any previous year on record since at least 1978. The largest recorded glacier area loss observed in Greenland occurred this summer at Petermann Glacier, where 290 km2 of ice broke away. The rate of area loss in marine-terminating glaciers this year (419 km2) was 3.4 times that of the previous 8 years, when regular observations are available. There is now clear evidence that the ice area loss rate of the past decade (averaging 120 km2/year) is greater than loss rates pre-2000.

Record melt from Greenland icesheet in 2010
http://news.yahoo.com/s/afp/20110122/sc_afp/scienceclimatewarminggreenlandicesheet

PARIS (AFP) – Greenland's icesheet, feared as a major driver of rising sea levels, shed a record amount of melted snow and ice in 2010, scientists reported Friday, a day after the UN said last year was the warmest on record.

The 2010 runoff was more than twice the average annual loss in Greenland over the previous three decades, surpassing a record set in 2007, said the study, published in the US-based journal Environmental Research Letters.

Ice melt has now topped this benchmark every year since 1996, according to the paper, derived from long-term satellite and observational data.

[Adelaidewonderer]

Whilst fully understanding the vastness of the oceans coverage, it always astounds me that people only concentrate on the increase in sea level height from melting ice from the Antarctic and Greenland. Man plays around with teh waters in the oceans alot more, which also affects ocean levels. Whilst I am not saying it affects it to levels as much as ice melt, but the activities have some effect, an dmust also be considered in sea level rise calculations.

On the decreasing sea level side- examples like
To extract oil, saudia Arabia pumps down 2 barrels of sea water to extract 1 barrel of oil. 15 milion barrels (approx 2 million cubic metres) a day are used by the saudis just to extract oil. Not including what they use for their desalination plants etc.

On the increasing sea level side - examples like
Billions of cubic metres of top soil and rubbish are washed into the seas each year, from rivers, and more importantly floods. One just had to see the recent queensland floods to see that the water was 95 percent water, and 5 percent crap. The 5 percent crap just sinks to the bottom of the sea, not even to rise again for evaportaion.

You got huge carriers (and millions of small leisure craft) being added to oceans each year (displacement). Permanent stutures like breakwaters etc being added. Volcanic fallout.

[dissident]

Yes, 2 mm of sea level change is nothing to write home about and is in the noise of whole pile of other processes. But it is looking more and more like we will have over 3 meters of sea level rise by 2100 most of it from the Greenland ice sheet. That completely overshadows the other processes.

The title of this thread is absurd. The ice sheet lowered by six meters in one location and its overall change is nowhere near this large. But the ice loss is accelerating driven by the increasingly warm waters, year round, which surround it. There has also been an interesting atmospheric circulation pattern in the last couple of winters (at least) where southern Greenland has seen above freezing temperatures in December and January.