Ask a science graduate anything...

[Archer]

But hold on, that 70m that gets quoted is the total volume of ice contained there. Of which roughly two thirds (or more) would already be underwater. So when it all melts the oceans would only rise by about 23m, still a lot, but at least not as devastating as 70m.

 

[BattleMoose]

But hold on, that 70m that gets quoted is the total volume of ice contained there. Of which roughly two thirds (or more) would already be underwater. So when it all melts the oceans would only rise by about 23m, still a lot, but at least not as devastating as 70m.

Antarctica is a continent, land covered with ice, any land based ice that melts will directly contribute to sea level rise. It is only free floating ice that won't lead to sea level rise. Ice shelves are a bit of both because on the land they rest is submerged, however, the amount of ice in ice shelves in Antarctica is a very small fraction of total ice on Antarctica.

Furthermore, while some of the ice shelves on the antaractic peninsula have collapsed, anatarcitc land based ice, is considered to be very stable (for centuries), indeed even with a global heating trend, Antarctica is not expected to get warmer anytime soon.

It is the Greenland landbased ice, and iceshelves and the arctic ice cap that are considered very vulnerable.

 

[Archer]

In East Antarctica, the ice sheet rests on a major land mass, but in West Antarctica the bed can extend to more than 2,500 m below sea level. The land in this area would be seabed if the ice sheet were not there.

Sounds like a bit of both, some ice on actual land, and some in the ocean. So the 70m figure might still not quite be true in terms of what would actually happen if it all melted. Perhaps somewhere around 30-50m?

 

[Guantanamo]

Looks like a lekker inland sea could be formed with the Himalyas as the backdrop. Cue Chinese factories to pump extra CH4 CO and CO2, for tourism benefits of course

 

[battletoad]

Sounds like a bit of both, some ice on actual land, and some in the ocean. So the 70m figure might still not quite be true in terms of what would actually happen if it all melted. Perhaps somewhere around 30-50m?

No. Still roundabout 60-65m, source. True, some parts are below sea level, but an overwhelming majority of Antarctic land is above sea level. Also something interesting to note, the mass of ice on Antarctica depresses it, if in the event some warming trend occurs over Antarctica and the glaciers melt, the continent will rise by a few meters(seems logical but will look for a source for this claim). These gained meters in height would add to the increase of sea levels if, as stated before, such a warming event occurs. But the average temperature is -34ºC so as BattleMoose said that ain't happening anytime soon.
Side note: If all the glaciers in Greenland melted sea levels would rise by more than 7m. thanks wiki.

Something else that I'm thinking about, its easy (and sometimes fun) to go about finding information these days to make better inferences, arguments, etc. for what have you. Sometimes its a bit too easy, could this be a reason why undergrads these days struggle a lot? With this course I'm tutoring in, they don't really go home and work on their own for long periods, sometimes when i hold impromptu sessions they cannot concentrate for more than 15mins on one exercise. Seems as if the information age is favouring quick answers over well thought out and precise arguments. I just hope and pray those that make it all the way into postgrad (our future leaders in their respective fields) have the commonsense to proofread and understand the information they source in its context.

For instance, there's an actuarial scientist by the name of David Li who wrote a paper on Gaussian copula models. Financial institutions then used his methods to price complex investments such as mortages. Although Li himself stated that his paper had limitations in 2005, investors proceeded to use his methods for all and sundry. Outcome?

...while in the aftermath of the Global financial crisis of 2008–2009, to which Li's model has been credited partly to blame,[1][2] his model has been called a "recipe for disaster".[2]

http://en.wikipedia.org/wiki/David_X._Li

 

[BigAl-sa]

This thread is geared toward undergrad science subjects.

I'm tutoring in some courses, and the calibre of students leaves much to be desired, maybe its OBE. Be that as it may, perhaps we [-]formites[/-]forumites can come together and help those suffering through these courses.

To those that need help, [-]im[/-]I'm pretty sure [-]you'l[/-]you'll ask your homework questions. Keep in mind, even if [-]i or[/-] someone else or I answers you, [-]its[/-]it's imperative that you work [-]thru[/-] through examples and exercises on your own to strengthen your understanding of the subject matter. Your textbook and lecturer [-]is[/-]are your best friends if you want to have an easier ride [-]on[/-]through varsity, so make time for [-]it[/-]them.

[-]Im[/-]I'm a maths (pure) major, [-]i[/-]I gather Edduck would only be too happy chatting about matters regarding microbiology and such, and [-]im[/-]I'm sure [-]formites[/-]forumites specialising in other [-]types of[/-] sciences would be happy to oblige. Just ask nicely and display some initiative on your part.

So... let the games begin

Can we trust you to use the language of mathematics properly?

Remember, there's a big difference between x and x'

 

[battletoad]

Can we trust you to use the language of mathematics properly?

Remember, there's a big difference between x and x'

Dude i used opera mini for that post (as i am now, looking forward to the corrections). But dont you worry, i respect every question i answer by being as lucid and precise as i possibly can be.

 

[Archer]

No. Still roundabout 60-65m, source. True, some parts are below sea level, but an overwhelming majority of Antarctic land is above sea level. Also something interesting to note, the mass of ice on Antarctica depresses it, if in the event some warming trend occurs over Antarctica and the glaciers melt, the continent will rise by a few meters(seems logical but will look for a source for this claim). These gained meters in height would add to the increase of sea levels if, as stated before, such a warming event occurs. But the average temperature is -34ºC so as BattleMoose said that ain't happening anytime soon.
Side note: If all the glaciers in Greenland melted sea levels would rise by more than 7m. thanks wiki.

The first wiki page that gave this info was not worded very well and it was unclear if the total ice present in Antartica contained the equivalent of 70m of water in the ocean, or if when its all melted it would actually raise ocean levels by 70m. And the continent below the ice would not add any more height to world oceans if all the ice melted. It is already below the ocean, meaning it is already displacing the maximum amount of water. So if anything, if all the ice melted and the continent breaks the surface of the ocean, it would lower the oceans levels since it would be displacing less water.

 

[battletoad]

The first wiki page that gave this info was not worded very well and it was unclear if the total ice present in Antartica contained the equivalent of 70m of water in the ocean, or if when its all melted it would actually raise ocean levels by 70m.

In the Geography section it states that if all ice melted, sea levels would rise 60m. Try for yourself (dont have a calculator):

(Area of Antarctica * average thickness of ice) / Area of World Ocean

The first two variables can be found under the geography section of the wiki link, a quick google for the third

That equation however is neglecting the change in the coastlines of continents so it should be a worse case scenario

And the continent below the ice would not add any more height to world oceans if all the ice melted. It is already below the ocean, meaning it is already displacing the maximum amount of water. So if anything, if all the ice melted and the continent breaks the surface of the ocean, it would lower the oceans levels since it would be displacing less water.

Not quite. If the land's (which breaks the surface) prior position is replace by water your statement would be correct. But this is not the case. Deeper ground would take the place of the continents old position.

 

[werries2]

DO YOU want a purple swimming pool? are u not thinking of sodium?

Potassium will have the same effect as Sodium... Possibly even react more.

 

[Archer]

In the Geography section it states that if all ice melted, sea levels would rise 60m. Try for yourself (dont have a calculator):

(Area of Antarctica * average thickness of ice) / Area of World Ocean

The first two variables can be found under the geography section of the wiki link, a quick google for the third

That equation however is neglecting the change in the coastlines of continents so it should be a worse case scenario


Not quite. If the land's (which breaks the surface) prior position is replace by water your statement would be correct. But this is not the case. Deeper ground would take the place of the continents old position.

Yes I understood the first bit, but just said the first wiki article was poorly worded.

Onto the land thing. What force would cause this deeper ground to shift upwards, and why would water then not go into the void created below the deeper ground? A mass of earth that large is not going to be water tight. Cracks will form, especially if an upheaval of the land is taking place. Not seeing a good argument for the land mass creating additional rise in ocean levels yet.

 

[UnUnOctium]

Didn't read the whole bit about the ice-shelf melting (a.k.a. thread). But if the land is displacing an x volume of water due to the weight of the ice on it and the ice melts and (for the sake of simplicity) we assume it all runs off into the ocean, if i remember correctly, geology says the continent will rise some amount (SiAl and SiMa). If the continent of antarctica is floating on water, this would actually decrease the water level (i.e. displace less) but would have a net increase due to the melted ice (vol. melted ice - [delta] vol. displaced antarctica). But since antarctica is NOT floating on water afaik. (i.e. there is solid ground all the way to the seabed) this will increase the sea level since more is displaced by the continent moving higher up (it tapers out to be wider, not narrower).