Hot Mantle Plume Is Melting Antarctica From Beneath, NASA Study Finds

[Judi Lynn]

BY HIMANSHU GOENKA @HIMGOJOURNO ON 11/08/17 AT 11:17 PM

When Antarctica lost an enormous iceberg from the Larsen C ice shelf in July, it set off alarm bells about the future of the shelf itself, as well as about the region in general, which like other ice repositories on Earth, is faring badly under the onslaught of global warming. But this atmospheric threat from above, made worse by anthropogenic carbon emissions, is only half the problem.

A study by NASA has found new evidence to support a three-decades-old theory that said a geothermal source deep underneath the icy continent was melting it from below. The heat source is called a mantle plume, and its role in affecting volcanic activity and topographic features on Antarctica was first theorized about 30 years ago by a scientist at the University of Colorado, Denver.

Hélène Seroussi and Erik Ivins of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, studied this mantle plume idea through numerical modeling, since getting direct measurements from under the ice is difficult. The JPL researchers created a model that accounted for the physics of the ice sheets, sources of heat in the region and how heat is transported, changes in the altitude of the ice sheet surface, among other factors.

After that, they simulated a number of different scenarios for the size and location of a possible mantle plume, since both those factors were unknown, and compared the effects with observations of Antarctic melting, as recorded by satellites in space.

More:
http://www.ibtimes.com/hot-mantle-plume-melting-antarctica-beneath-nasa-study-finds-2612488

[Judi Lynn]

1. There's a Huge Plume of Magma Bulging Against Antarctica

By Rafi Letzter, Staff Writer | November 8, 2017 12:55pm ET


Imagine drifting over Antarctica's icy expanse. A white continent extends below you, and it's smothered in enough frozen water to drown every coastline in the world in a 216-foot (66 meters) wave if it were to melt. But scientists now believe that, deep beneath almost 1.2 miles (2 kilometers) of ice and a relatively thin slice of rocky crust, one region of the frozen continent hides a column of red-hot magma, straining toward the surface, according to a new study.

Usually, magma nears the surface only at the edges of tectonic plates. And West Antarctica's Marie Byrd Land, where the plume is suspected to exist, is far from any such border regions. However, there are places in the world where magma reaches toward the surface far from any tectonic border regions, NASA scientists said in a Nov. 7 statement. Yellowstone National Park is one. Hawaii is another. All that magma pushes against the crust in those parts of the world, causing it to bulge and pumping heat up through the ground.

That heat offered scientists the first clues that the Antarctic plume exists.

Despite its apparent icy stillness, Antarctica is alive with motion. Huge masses of frozen water slip, slide and grind with enormous pressure against the continent below, their constant motion lubricated by a complex system of rivers and lakes below the ice.

More:
https://www.livescience.com/60885-antarctica-map-river-water-melt-magma.html?utm_source=notification

[JayhawkSD]

2. Extremely misleading article, utterly false headline

The "mantle plume" is a theory and only a theory. There is no direct evidence. It has not been detected, observed, discovered, or proven. There is nothing, repeat nothing more than a mathematical model calculating how such a mantle plume might create the observed effects.

Even if the mantle plume does exist, it has been there for hundreds of centuries, and there is not the slightest suggestion that anything about it is in any way likely to change, nor that its effect on melting the ice cap will change from what it has been doing for tens of thousands of years.

The NASA study has done nothing more than measure the thickness of the ice. It has not detected any mantle plume nor did it measure or detect anything that would tend to confirm the theory.

[Duppers]

3. I tend to agree with you.

This is conjectural.

And likely a convenient divergent for ignorant gop pols who want to ignore anthropogenic global warming.

[JayhawkSD]

5. I'm not sure about "ignorant gop pols"

I did not mean to provide fodder for climate change deniers, nor to fuel any sort of political diatribe.

I happen to think that climate change is happening even faster than we know, and that it is at least partly, perhaps mostly, due to the influence of human activity. I strongly suspect that the human part of the cause is in large part sheer numbers, so if you want humans to stop contributing to global warming you need to kill about five billion of us.

But I am fascinated by science and discovery, and am disgusted by the manner in which the media treats it, partly to distort the climate discussion (on both sides), and partly out of laziness and unskilled writing.

Here's the article that supports the lack of any actual evidence of any such plume.

[Duppers]

7. Wait.

I did not misconstrue your intent. Only observing that a repub politician could take this Article to further deny that Humans are the cause of warming.

And we're on the same side of the GW issue. (My PhD hubs is a NASA researcher, btw, and a neighbor of ours is in Antarctica now doing research.
http://www.vims.edu/features/programs/antarctica.php )

[Duppers]

8. Well, looks as if we were Wrong...

https://www.nasa.gov/feature/jpl/hot-news-from-the-antarctic-underground


Had my hubs read this (not his field) and he said this was the most reasonable explanation even though it is still modeling. (He is a theoretical physicist whose primary work is modeling, just not in this field but in material science.)


Also, see:
https://www.democraticunderground.com/10029821935

[JayhawkSD]

9. That article is utter nonsense.

Notice that actual quotes from your first citation:
"With few direct measurements existing from under the ice, Seroussi and Erik Ivins of JPL concluded the best way to study the mantle plume idea was by numerical modeling." Not, you notice by actual observation of physical detection of any actual heat source.
and
"To assure the model was realistic, the scientists drew on observations of changes in the altitude of the ice sheet surface made by NASA's IceSat satellite and airborne Operation IceBridge campaign." Again, they measured the ice, not any actual heat or sources of heat.

And from your second:
"Now, scientists from NASA’s Jet Propulsion Laboratory have created advanced numerical models..."
and
"The team developed a mantle plume model..."

So the headline, "Nasa Discovers Mantle Plume Almost As Hot As Yellowstone Supervolcano That's Melting Antarctica From Below," is directly a lie. They discovered nothing; they wrote a model to fit a theory that has been around for several decades. It is not new and is still entirely unproven.

Even if it turns out to be entirely true and 100% accurate to the model,
"The Marie Byrd Land mantle plume (if it exists, which is not proven) formed 50 to 110 million years ago, long before the West Antarctic ice sheet came into existence." Which would suggest that it has nothing whatever to contribute to the climate change discussion of present time.

"At the end of the last ice age around 11,000 years ago, the ice sheet went through a period of rapid, sustained ice loss when changes in global weather patterns and rising sea levels pushed warm water closer to the ice sheet -- just as is happening today." All of which has nothing whatever to do with any putative "mantle plume."

"Seroussi and Ivins suggest the mantle plume could facilitate this kind of rapid loss." If it exists. That's a long way from claims earlier in the article that the "mantle plume" has been discovered and that it is melting the ice cap.

[Duppers]

10. I got into that with my hubs earlier

Bringing up your points and he said their models offer a reasonable explanation only since they cannot better explain the greater temperature differentials.

It's NOT what the misleading science "journalists" at Newsweek wrote however. You are correct! There has Not been a discovery. Please post on that thread if you've not already done so.

Thanks!

[JayhawkSD]

11. I'm not saying the "mantle plume" is not there

It might very well be. It has, as you say, not been "discovered," and even if it is there the impact of it is far from clear. The explanation so far suggests very much to me that the impact of it is essentially zero. Other than when it blew, how much impact has the Yellowstone plume had? It's provided a nice tourist attraction, but other than that?

[B2G]

12. Climate change projections are based on models as well.

Are there specific models we should toss out and others we should take as gospel?

A cheat sheet would be helpful.

[hatrack]

4. Why does science reporting blow goats on such a consistent basis?

[JayhawkSD]

6. Sensationalism, partisanship, and lack of professionalism.

Sensationalism is what sells papers or, in the online media, sells advertising. In online media it's called "clickbait." You use the number of "clicks" to sell advertising on your site. You don't want your writers to write true things, you want them to write exciting things that many people will read and, more importantly, will get their friends to read by posting references to them on places like DU.

Partisanship leads media to care less about truth than about promoting their point of view. They are second only to politicians in this, and are a very close second at that.

Lack of professionalism is a cost issue. Science writers who can write informative articles because they are trained as scientists themselves have to be paid pretty high salaries. After all, they are educated in science as well as in journalism. Media has ditched them for writers who are not even trained in journalism. Saves a ton of money for the media companies, and they don't care that it results in an uninformed and/or misinformed public.