Talk:Antarctic ice sheet

Latest comment: 23 days ago by EMsmile in topic Introduction, geography, lead

Wiki Education Foundation-supported course assignment edit

  This article was the subject of a Wiki Education Foundation-supported course assignment, between 7 January 2019 and 9 April 2019. Further details are available on the course page. Student editor(s): Barackdrea.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 14:24, 16 January 2022 (UTC)Reply

Numbers that don't add up ? edit

If Antarctica is 5.4 million square miles and contains 6.4 million CUBIC miles of ice, this implies the ice is on average over a mile deep. But according to bedrock elevation maps, such as this one: http://nsidc.org/data/atlas/news/bedrock_elevation.html, this is not the case. Here is a cite that states that antarctic ice averages to be about 3 to 6 feet thick: https://nsidc.org/cryosphere/seaice/characteristics/difference.html. Am I missing something? Perhaps there is a typo and the correct measure is actually 6.4 million SQUARE miles of ice? — Preceding unsigned comment added by 96.82.57.209 (talk) 20:03, 2 March 2017 (UTC)Reply

For future interested readers: while sea ice is only 1 or 2 m thick, the land ice on Antarctica reaches multiple kilometers. Femkemilene (talk) 13:45, 23 January 2019 (UTC)Reply

"Recent" studies edit

The article says, "Recent satellite data reported by NASA shows evidence that the total amount of ice in Antarctica has increased in the past few decades." However that data is now about four and a half years old (from August, 2002,) so it is hardly "recent." Also, more recent data suggests that the Antarctic ice sheets are actually melting now. See "Antarctic Ice Sheet Is Melting Rapidly" and "Antarctic ice sheet losing mass, says University of Colorado study" from March, 2006. Do we have an expert who can update this? If not, I'll do it, but I thought I'd check first. -- HiEv 12:12, 7 January 2007 (UTC)Reply

Wikipedia doesn't need experts to update articles. Measuring the net gain or loss of ice over an entire continent is not an easy thing to do, even with satellites. The article should reflect the fact that these are individual studies, each of which is saying something slightly different. Such is science. But feel free to update the article yourself. -- BlueCanoe 01:52, 24 August 2007 (UTC)Reply

East Antarctic Ice Sheet edit

Where is the article on the East Antarctic Ice Sheet? The West Antarctic Ice Sheet has its own article, and rightly so. The two "halves" of the Antarctic Ice Sheet are very different from each other with respect to geography, origin, age, stability, climate, etc. If I get time I'll start the article but anyone else should go for it! -- BlueCanoe 01:52, 24 August 2007 (UTC)Reply

Am new to contributing here, please forgive any faux paus.

This page http://en.wikipedia.org/wiki/Ice_sheet says "Around 90% of the fresh water on the Earth's surface is held in the ice sheet" and this page http://en.wikipedia.org/wiki/Antarctic_ice_sheet says "approximately 61 percent of all fresh water on the Earth is held in the Antarctic ice sheet"

What is the procedure for correcting the discrepency? —Preceding unsigned comment added by Nf one (talkcontribs) 19:50, 25 May 2010 (UTC)Reply

Ice Density and Ocean Levels edit

This article states that because the density of freshwater ice is different from saltwater, the ocean levels will still rise if the floating ice melts. However, my understanding is that the effect on ocean levels depends not on the density, but on the weight of the ice or water, and how much seawater that weight of ice displaces. My understanding is thus that it doesn't matter how dense freshwater is compared to saltwater. Is this the case? Eunsung (talk) 02:01, 22 January 2009 (UTC)Reply

I agree with this, I believe its because of Archimedes principle of buoyancy.
the original paper says this:
1g of ice would displace 1g of salt water(0.98cm3) when the ice desolves it will add 1.0cm3 of fresh water this is the volume increase. but in my opinion this fresh water woudl then uptake salt of its own from the sea increasing its own desity to that of salt water (you wouldnt have a section of fresh water floating in salt water) However because alot of the ice is not floating but resting on a solid land mass (at least that is what i understand from this article) then it would be based on density (ice is less dense than water so therefore you would get an increase in volume..dunno by how much though)

let me know if you believe me :D --Paddycolver (talk) 09:52, 22 January 2009 (UTC)Reply

I'm willing to believe anyone who knows what the hell they're talking about, haha. If that's you, could you edit the article with a clear explanation about this, or maybe take away the comment on the matter entirely? Cheers. Eunsung (talk) 05:38, 23 January 2009 (UTC)Reply

OK i tried to explain it a bit better. however my writing skills are really bad so it might need a touch up by someone of greater skill :D. also would be handy to find out whether the density change of salt water is linear with concentration, to give an idea if there would be a volume increasePaddycolver (talk) 09:51, 23 January 2009 (UTC)Reply

I think this whole section is in the wrong place. This is a wikpedia article on the Antarctic Ice Sheet, which means grounded ice on land not floating ice. The point about salinity is made on the page, Ice shelf. But could do with being expanded upon there along the lines of adding the academic references used here. The effect is very small. If you look at the Jenkins and Holland article, that is cited here, they mention that the extra 2.6 % due to salinity is offset a bit by the lower temperature of the ice shelves. The mass balance (changes in total amount of ice) info on the Antarctic Ice Sheet needs major updates as mentioned at the top of this discussion and it is confusing to have such a large section on an effect that is not directly relevant. Polargeo (talk) 19:11, 27 January 2009 (UTC)Reply

Ah now I get it. The point was initially added to the page over a year ago to explain why ice that is already floating could raise sea levels when it melts. This was a misconception (due mostly to confusion spread by global warming sceptics) that the melting of floating ice is the main issue here. The real issue is the amount of ice passing over the 'grounding line' from the land into/onto the sea and how much this is balanced by precipitation (mostly snow) falling back onto the continent. The change in sea level due to salinity differences is not directly relevant to this. Polargeo (talk) 19:34, 27 January 2009 (UTC)Reply

First paragraph states if all the ice sheet melts, it would raise sea levels by 70m, with no reference. New report using ESA's Cryosat data shows melting twice the rate as last measurement, leading to 0.43mm sea rise per year, and mentions 58m if all the ice melts. Reference BBC News 19th May 2014 [1] If nobody has objections, I will update page with this new info shortly. Tony Spencer (talk) 14:56, 21 May 2014 (UTC)Reply

References

Ice density section removal edit

I would like to suggest removal of this paragraph based on the comments above. In doing so the similar section on the ice shelf page (where this information is better placed) should be beefed up a bit. Any thoughts. I will leave it for a while Polargeo (talk) 14:44, 28 January 2009 (UTC) Another thought. Maybe a sentence on this effect can be left in this page somewhere, with a link to the ice shelf page of course. Without having a huge discussion on the issue on this page where it is not as well placed. Polargeo (talk) 09:30, 30 January 2009 (UTC)Reply

Done Polargeo (talk) 23:03, 4 February 2009 (UTC)Reply

Warming edit

I actually don't think that the prominance of recent melt and warming on this page, including two images is particularly helpful. It gives the impression that this is in some way affecting the whole mass balance of the Antarctic Ice Sheet. It is not. At present changes in surface temperature are tiny and have negligable effects on the ice sheet. It sends a confusing message. There are many more important factors at work on the ice sheet at present. That big red blob in the warming image over West Antarctica represents around 1 degree over half a centuary, with average temperatures in this region somewhere between -20 and -30 degrees. Then add on the melt image which just repesents the small amount of surface melt Antarctica experiences (Mostly a mere glazing of the ice surface). This melt does not reach the base of the ice sheet, does not run off into the sea and has no direct effect on the movement or mass balance of the ice sheet. Therefore this page, whilst not being inaccurate, is simply getting confusing to the general public and needs more balance. Polargeo (talk) 13:27, 20 February 2009 (UTC)Reply

Location, here best? edit

99.181.152.187 (talk) 02:57, 10 June 2012 (UTC)Reply

How about in the Filchner-Ronne Ice Shelf article? It is the central topic related to Sea level rise due to climate change from global warming.
The two Nature (journal) (May10 & April 26) and Nature Geoscience (May 9) references would be useful also. 99.181.155.96 (talk) 19:56, 10 June 2012 (UTC)Reply

Sea Ice? edit

Suddenly talking about sea ice makes it confusing that this is distinct from the ice sheet if the reader is not familiar with the terms.

I think that this needs to be prefaced with a sentence about what an ice sheet is, or moved to it's own section about sea ice. RobinGrant (talk) 04:59, 16 October 2013 (UTC)Reply

Right. These are often confused. For example, this Forbes article The Antarctic Ice Sheet Is Growing, But It Doesn't Mean Global Warming Isn't Real. The definition in the introduction should explain the distinction between (floating) sea ice and (grounded) ice sheet. Keith McClary (talk) 15:36, 30 October 2016 (UTC)Reply

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Metric gigatonnes?? edit

Someone clean this up please. Scientific notation would help. Grassynoel (talk) 13:59, 24 July 2023 (UTC)Reply

Introduction, geography, lead edit

I am thinking that there could be a better way to structure the intro to have more descriptive information about the ice sheet, its geologic history, its importance in climate, etc. Right now there is a lot of geographic information, and a lot of stats. In the future, the geography could be moved or expanded on in the geography section, and the stats could be located in a box on the sidebar like in North America, Nile, Mount Fuji, etc. Puddlesofmilk (talk) 20:30, 31 January 2024 (UTC)Reply

When you say "intro" do you mean the lead? If so, please check WP:LEAD if you haven't done already (just saying as you are quite new. Welcome to Wikipedia by the way!). The lead should be a summary of the article (with refs where they fit). I usually aim for 4 paragraphs or 500 words, no longer than that. It should be a bit like the abstract of a paper or the executive summary of a report. Most of your articles have quite poor leads which is a shame because most readers might not read further than the lead. So if you can improve the lead, that would be wonderful. EMsmile (talk) 23:20, 31 January 2024 (UTC)Reply
Yes thank you! I am new and still learning where and how to participate effectively.
I meant the lead. I have seen the style page about the lead before but that is helpful. Puddlesofmilk (talk) 01:37, 1 February 2024 (UTC)Reply
I have created the infobox and tried to add relevant, cited information that can provide context to the rest of the article. I think the lead needs a lot more work though. Looking at the Greenland ice sheet page, which has a higher article rating, may give some good guidance on how to structure the article and lead.
In particular, the information in the last few paragraphs of the lead about climate change has zero citations and may be better moved to the section on Ice loss and accumulation. Looking at the article on the Late Cenozoic Ice Age, which also needs a lot of work, there is also a need for including better information about the geological context of the ice sheet. Puddlesofmilk (talk) 18:47, 2 February 2024 (UTC)Reply
@Puddlesofmilk Sorry for overlooking this earlier. I must say that I really like the edits you made!
Regarding the climate paragraphs of the lead - I wrote them that way, and it's for a reason. I have been repeatedly told that most readers only see the lead, so I wanted ensure they would know about all the major impacts and timelines by the time they finish reading it. According to policies we actually do not have to include references in the lead, as long as information there matches reliably referenced information in the body of the article. Normally, I still reference every sentence in the lead, but this is an exception, because the body of the article consists of excerpts, so the citations are also present in the excerpts, rather than in the article itself. If you include the same references in the lead as what is in the excerpts, that just creates a list of references with duplicates. I think there is some way to avoid that issue, but I am not sure on this. If this article gets a GA (Good Article) review, they might suggest something, but for now, that doesn't appear necessary.
Speaking of GAs: I have been preparing the other ice sheet articles (GrIS, WAIS and EAIS) for those assessments since December. I am curious if you would like to take a look at the WAIS article in particular. I think it's a fairly good state after all my recent edits, but there is still an issue with "Description": the second paragraph of that section is completely unreferenced, and the other two could probably be a lot better as well. You might also decide it should have other subsections besides the Rift as well. And perhaps you would uncover some issue there. InformationToKnowledge (talk) 15:17, 13 February 2024 (UTC)Reply
Regarding If you include the same references in the lead as what is in the excerpts, that just creates a list of references with duplicates.: this is true but I think it's more important to have the refs in the lead than to avoid duplicate entries in the ref list. I know that the style guide says that refs in the leads are not mandatory. But I think if we use excerpts more widely, then this advice is not a good one anymore: if the lead of Antarctic ice sheet was transcribed somewhere else (by using the excerpt tool), then the third and fifth paragraph of the lead would show up without any refs which would be a pity. Apart from that it also looks strange that some paragraphs in the lead have plenty of refs whereas others have none. So I would opt for adding more refs to the lead.EMsmile (talk) 13:19, 4 March 2024 (UTC)Reply
Ultimately, I looked at how many other articles, including at a GA or FA status (i.e. Rice, New England, Pig, or Antarctica itself) do not use references in the lead, and I decided we should not have them here either. Besides, the most-referenced section of the lead had the kind of detail which really belonged in the geography section anyway. Finally, I really don't think we should be excerpting this article for anything, since the West and East Antarctic ice sheet articles are far more detailed anyway (and they do have referenced leads, for that matter.) InformationToKnowledge (talk) 06:29, 13 March 2024 (UTC)Reply
I still prefer more refs in leads than less but it might depend on the kind of article. Maybe with high level general articles like pig or rice it's less important then with the more detailed science type articles like effects of climate change. Anyway, doesn't matter for now.
I had a look at where excerpts from Antarctic ice sheet are used. Currently only at ice sheet. I have now lengthened the two excerpts there that are about the West and East Antarctic ice sheet articles. But I think having the excerpt from Antarctic ice sheet at ice sheet (first paragraph only) does make sense. Otherwise people might be confused why we say the Earth has two ice sheets but then list three: Greenland, West, East Antarctic ice sheets. So it needs to be clear that the two main ones are Greenland and Antarctic, and that the latter one is then split into two. EMsmile (talk) 09:27, 2 April 2024 (UTC)Reply