Talk:Greenland ice sheet

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Contents

[edit] To Do

  • history and age of the ice sheet (110,000 year old ice vs. reports of millions of year old ice cap?)
  • fix exact percentage of Greenland's area covered by the ice cap (estimates range from 79 to 85%)
  • some nice images, preferably of ice melt, or mass balance (see for example [1])
  • adding a bit more on mass balance, precipitation, processes.

Jens Nielsen 18:57, 21 February 2006 (UTC)

[edit] loosing mass = melting? in year 2007?

"It was estimated that in the year 2007 Greenland ice sheet lost 592 km3 of its mass. [11]" Actually the source says that greenland MELT during the SUMMER that amount. It also gained mass by snowfalls etc. According to the source, net lost was only 65 km3. However, I guess that only counts the melt/snowfall, but not icebergs etc. —Preceding unsigned comment added by 213.216.199.26 (talk) 20:29, 21 April 2008 (UTC)

[edit] Post-melting archipelago ?

  • "If the ice would disappear, Greenland would most probably appear as an archipelago."

This is somehow misleading, without taking into account the Post-glacial rebound. The melting of such a mass of ice will certainly been followed by isostatic ajustment, like currently in Scandinavia. universimmedia 22:38, 27 June 2006 (UTC)

[edit] The melting ice sheet

  • "According to the study, in 1996 Greenland was losing about 96 km3 per year in mass from its ice sheet."

I hope I'm not just being anal, but isn't it incorrect to say "in mass" there, since km3 is a measure of volume?

~Murftown, 21 July 06

[edit] Time frame of the melting ?

I know scientists are very careful not to say anything about this, but what are the estimates of the time Greenland Ice Sheet takes to melt ? 1500 years (as in the end of the last ice age) - 150 years (as there's ~10 times less ice than in the last ice age)? —Preceding unsigned comment added by 91.153.60.138 (talk) 07:23, August 26, 2007 (UTC)

- Quick answer: We don't know. Between 50 and 1500 years.. —Preceding unsigned comment added by 87.86.252.131 (talk) 10:21, August 28, 2007 (UTC)

Great example of scientific innumeracy from questioner and answerer. Time frame = amount of ice/loss rate = 3 million / 200 = 15,000 years roughly. Of course this calculation is not done in the article because the answer is not sufficiently alarming. —Preceding unsigned comment added by 128.243.220.42 (talk) 15:04, 8 October 2007 (UTC)

It's actually more complicated than that. There can be strongly non-linear effects, such as pools of water forming that absorb sunlight much more efficiently than ice, and liquid water build-up below the ice that carries large blocks out into the sea. But even without such effects the ice-loss rate is going to change significantly due to climate change. It could increase (due to higher temperatures) or decrease (due to increased precipitation at high altitude). The most pessimistic scenario in the IPCC graph shown in the article has most of the ice gone by the year 3000. (The graph shows a 600 cm sea level rise, and a 720 cm rise would correspond to all of the ice sheet.) --PeR 19:59, 9 October 2007 (UTC)
Side-effects of ponding were important with the Larsen Ice Shelf collapse. While that was over sea, the role of ponding is somewhat measured in the Greenland ice sheet -
  • Surface Melt-Induced Acceleration of Greenland Ice-Sheet Flow Originally published in Science Express on 6 June 2002, Science 12 July 2002: Vol. 297. no. 5579, pp. 218 - 222 "The near coincidence of the ice acceleration with the duration of surface melting, followed by deceleration after the melting ceases... provides a mechanism for rapid, large-scale, dynamic responses of ice sheets to climate warming."
  • Evolution of melt pond volume on the surface of the Greenland Ice Sheet GEOPHYSICAL RESEARCH LETTERS, VOL. 34, L03501, "estimating the depth and hence volume of surface melt ponds... show large intra- and interannual changes in ponded water volumes, and large volumes of liquid water stored in extensive slush zones."

Then add the tracking of accumulated changes by ponding causing accelerated change in the ice sheet in the earthquake record ....

Another dynamic of melting ice happens with such events as the Missoula Floods.--Smkolins (talk) 01:14, 12 January 2008 (UTC)

[edit] Sentence needs reconsideration

"Because the overwhelming majority of humans in the world live near the water, it would inundated almost every major coastal city in the world, absent heroic mitigation." does not make sense. 1) IF TRUE? then regardless of the number of people living near water, it would still inundate (not -inundated) almost every major coastal city in the world. 2) also "absent heroic mitigation" does not reflect any fact, and thus does not belong in an encyclopedia. My suggestion is: 1) delete it altogether, or 2) change it to: "This would inundate most coastal cities in the world and remove several small island countries from the face of Earth." —Preceding unsigned comment added by 24.106.210.234 (talk • contribs)

I've noticed that too... I've followed your suggestion. --Bletch 14:39, 1 October 2006 (UTC)

[edit] Mass loss is more due to flow of ice though outlet glaciers than melting

It's worthy of note that the mass loss is due more to the ice flow in the outlet glaciers than to melting on the ice sheet (at least since 1996). [2] Should the section on melting be rewritten to reflect this? 71.32.19.55 (talk) 01:31, 25 May 2008 (UTC)