New findings on why Antarctic ice sheets melt

Jan 17, 2011

Research from Victoria University has revealed new findings on why Antarctic ice sheets have melted in the past, as well as how future melting may affect sea levels.

Victoria researcher Dr. Andrew Mackintosh is the lead author of the research published today in the prestigious journal Nature Geoscience. Victoria researchers Dr. Nick Golledge and Dr. Dan Zwartz also contributed.

"Our research looked at how ice sheets behave, in particular the East . The retreat of this ice sheet at the end of the last has previously been attributed to both sea level rise and ocean warming," says Dr. Mackintosh.

"We found that although the initial stage of retreat may have been forced by rise, the majority of the ice loss resulted from ocean warming. Increasing ocean warmth seems to be the main driver of ice sheet retreat.

"This means that we should be particularly concerned about the present-day warming of the oceans around the Antarctic periphery. Our findings suggest that a substantial contribution from melting ice sheets to global in the near future is very likely.

"As a caveat though, we also show that the response of an ice sheet margin can vary significantly between locations, depending on the geometry of the land beneath the ice. This makes it challenging to predict the actual response of the ice sheet without detailed computer modelling."

Dr. Mackintosh says that researchers study past records of ice sheet behavior to help understand current change.

"It’s very difficult to tell what might happen with modern observations such as satellite imagery because they cover a very short period of time, so we look at past information, asking questions such as ‘What caused the retreat of ice sheets thousands of years ago?’.

In particular, we use computer models, which are tested against geological data, to help answer these questions."

Dr. Mackintosh leads a glacier modelling group in the Antarctic Research Center at Victoria University and he says that this paper represents the most significant publication of the group to date.

Explore further: Huge waves measured for first time in Arctic Ocean

More information: Paper online: www.nature.com/ngeo/journal/va… nt/abs/ngeo1061.html

Provided by Victoria University

4 /5 (15 votes)

Related Stories

New structure found deep within West Antarctic Ice Sheet

Sep 23, 2004

Ice sheet more susceptible to change than previously thought Scientists have found a remarkable new structure deep within the West Antarctic Ice Sheet which suggests that the whole ice sheet is more susceptible to future ch ...

Search for ice sheet 'tipping point'

Jan 13, 2010

(PhysOrg.com) -- A new study examines how ice sheets, such as the West Antarctic Ice Sheet, could become unstable as the world warms.

Greenland and Antarctic ice sheet melting, rate unknown

Feb 16, 2009

The Greenland and Antarctica ice sheets are melting, but the amounts that will melt and the time it will take are still unknown, according to Richard Alley, Evan Pugh professor of geosciences, Penn State.

Warming oceans threaten Antarctic glaciers

Mar 15, 2007

Scientists have identified four Antarctic glaciers that pose a threat to future sea levels using satellite observations, according to a study published in the journal Science.

Scientists observe drumlin beneath ice sheet

Jan 23, 2007

Scientists have discovered a warehouse-sized drumlin – a mound of sediment and rock – actively forming and growing under the ice sheet in Antarctica. Its discovery, and the rate at which it was formed, sheds new light ...

Ice shelves disappearing on Antarctic Peninsula

Feb 22, 2010

Ice shelves are retreating in the southern section of the Antarctic Peninsula due to climate change. This could result in glacier retreat and sea-level rise if warming continues, threatening coastal communities ...

Recommended for you

Huge waves measured for first time in Arctic Ocean

7 hours ago

As the climate warms and sea ice retreats, the North is changing. An ice-covered expanse now has a season of increasingly open water which is predicted to extend across the whole Arctic Ocean before the middle ...

New research reveals Pele is powerful, even in the sky

13 hours ago

One might assume that a tropical storm moving through volcanic smog (vog) would sweep up the tainted air and march on, unchanged. However, a recent study from atmospheric scientists at the University of Hawai'i ...

Image: Wildfires continue near Yellowknife, Canada

13 hours ago

The wildfires that have been plaguing the Northern Territories in Canada and have sent smoke drifting down to the Great Lakes in the U.S. continue on. NASA's Aqua satellite collected this natural-color image ...

Excavated ship traced to Colonial-era Philadelphia

14 hours ago

Four years ago this month, archeologists monitoring the excavation of the former World Trade Center site uncovered a ghostly surprise: the bones of an ancient sailing ship. Tree-ring scientists at Columbia ...

User comments : 21

Adjust slider to filter visible comments by rank

Display comments: newest first

plaasjaapie
1.5 / 5 (22) Jan 17, 2011
More AGW crap.
Skepticus_Rex_
2.2 / 5 (13) Jan 17, 2011
I read on Anthony Watts page (our god ;)) that humans aren't causing the Antarctic ice to melt but penguins are. They produce methane during the winter and their droppings are dark particles that absorb sunlight and cause melting....nothing to do with us! Save the ice sheet by removing the penguins!
Moebius
2.5 / 5 (11) Jan 17, 2011
More AGW crap.


More plaasjaapie crap, if only stupidty was terminal (it is but just not quick enough to matter)

Don't forget their warm little feet. And aren't they large dark particles themselves when they are standing on the ice?
geokstr
1.8 / 5 (10) Jan 17, 2011
I think it was the wooly mammoths and all their SUVs.
jscroft
2.3 / 5 (9) Jan 17, 2011
You guys are all a bunch of racists.

Uh... wait... DENIERS! You're deniers! Sheesh.
Caliban
4.2 / 5 (5) Jan 18, 2011
A related bit of interesting news I came accross on another site. You may find it interesting:

h(DELETEME)ttp://www.dailymail.co.uk/sciencetech/article-1346936/The-sun-rises-days-early-Greenland-sparking-fears-climate-change-accelerating.html
Skepticus_Rex_
1.4 / 5 (9) Jan 18, 2011
I think the polar bears caused the horizon to dip, remember according to climategate (remember that :) ) they farmed for breadfruit and coffee as it was much warmer then before they ate all the vikings. I have written on previous posts about 2012 and the effect of gravitation of planetary alignment causing the poles to shift :)
madrigal
3.4 / 5 (5) Jan 18, 2011
Skepticus Rex- are you for real? I really don't think Physorg is the forum for your kind of misinformation. If you have links for the tropical fruits in Greenland then please do share them.
Caliban- thankyou for the most informative link, the only credible reason for the early sun rise would be from the ice sheets sinking, linking with eye-witness and satellite readings.
lengould100
2.8 / 5 (5) Jan 18, 2011
research published today in the prestigious journal Nature Geoscience.
Any time any of you wackos get a paper describing one of your theories published in there, come here and tells us about it.

All that fruit and nuts in greenland must be the reason there's so many nutbars around to talk about it.
MikeyK
3.7 / 5 (3) Jan 18, 2011
LOL, the fruits and nuts seem appropriate!
Parsec
4.4 / 5 (7) Jan 18, 2011
Skepticus Rex- are you for real? I really don't think Physorg is the forum for your kind of misinformation. If you have links for the tropical fruits in Greenland then please do share them.
Caliban- thankyou for the most informative link, the only credible reason for the early sun rise would be from the ice sheets sinking, linking with eye-witness and satellite readings.

Ahh chill bro. I am pretty sure that post was completely tongue in cheek.
Paljor
4 / 5 (4) Jan 18, 2011
Would you guys stop talking about nutty stuff (Skepticus Rex that means you). As for the rest of you i have a question. If the ice sheets are melting then shouldn't they be COOLING the surrounding ocean? (It says in the article that it is contributing to warming the oceans.)
jscroft
1.5 / 5 (8) Jan 18, 2011
@Paljor: GENIUS!!!

AGW nuts always put the cart before the horse. They claim that high CO2 levels cause warming via a hypothetical "greenhouse effect" when the reverse hypothesis--that warming causes CO2 levels to rise--is well supported by the ACTUAL effect of ocean heating on dissolved CO2 (namely, outgassing).

Now these dimwits are claiming that melting ice packs will cause ocean warming, when the cause-and-effect chain--IF it took place at all--would CLEARLY run in the opposite direction.

Anyway, all of this would trouble you FAR less if only you would drive a more sensible car. Try a Prius... I hear the Tooth Fairy picks up nearly a third of the sticker price!
Cave_Man
2.6 / 5 (5) Jan 18, 2011

What you need to be worried about is the carbon MONoxide that has clearly dealt your brain a fatal blow. If you believe the systems at play on earth are as simple as that you must still be in gradeschool.

Don't you think that its possible an equilibrium of carbon output and uptake by the earth has been upset by humans and now we are seeing runaway release of carbon.

Remember it only takes one match to start a fire that will burn down an entire forest.

Or we're you just being facetious?
geokstr
1 / 5 (4) Jan 18, 2011
What you need to be worried about is the carbon MONoxide that has clearly dealt your brain a fatal blow.

Then why aren't you the least bothered that our lakes, rivers and oceans are all heavily polluted with one of the most deadly chemical compounds known to man, Dihydrogen Monoxide. It is documented to kill hundreds of thousands every year all over the world, both by inhalation and ingestion. It is dumped into our aquifers and water tables at prodigious rates constantly by greedy capitalist corporations who care about nothing but profits. Yet not a peep from the environmental whackos, or the Obama administration. Why is that?

Maybe it's because the military-industrial complex that Eisenhower warned us about all the way back in the 1950's desperately needs this noxious substance.

When you have a plan to deal with this deadly menace, then get back to me.

But not before.
ekim
3 / 5 (2) Jan 18, 2011
Would you guys stop talking about nutty stuff (Skepticus Rex that means you).

That's not Skepticus Rex.
It's his doppelganger Skepticus_Rex_.
Notice the underscore.
No?
It's pretty low.
treemikey
4 / 5 (4) Jan 19, 2011
Is there any difference, both clones seem nuts to me
Skepticus_Rex
1.5 / 5 (8) Jan 22, 2011
treemikey is another one of MikeyK's merry band of sockpuppets. Skepticus_Rex is for real but not Skepticus_Rex_, who is one of MikeyK's creations when he finds he cannot deal with things he doesn't like to read. So, he has to resort to his typical stupidity to sow confusion and inanity, as well as his enjoyable pasttime of suckering people into believing people are posting things that they are not.
MikeyK
1 / 5 (2) Jan 22, 2011
Me thinketh you complaineth too much!
Skepticus_Rex
1.6 / 5 (7) Jan 22, 2011
Actually, it is enjoyable to see your antics, sockpuppeteer. Believe it or not they were missed for a while.

As to Cave Man's remarks, no, we are not in a state of runaway carbon. We do not have enough carbon in the atmosphere or enough density in the atmosphere to do that. Yes, we are pumping quite a bit into the atmosphere. Yes, it likely has some influence on climate. No, I doubt very seriously the alarmists' claims about CO2 wreaking havoc on the world anytime soon as the debate is not over as to how much CO2 would actually do what they claim. They have been surprised several times over because their models are not complex enough to account for the climate's feedbacks that do not stand in line to obey.

I highly doubt that the exaggeration factors used by the IPCC and their supporters are accurate because their models still leave much to be desired.
MikeyK
not rated yet Jan 23, 2011
Ahhh, I've been giving him the attention he craves for. Enjoy it no-mates Skepty while it lasts!