Record of Antarctic Ice Sheet Response to Climate Cycles Found in Rock Samples

The effects of global climate cycles on Southern Ocean temperatures drove cycles of melting and freezing in the East Antarctic Ice Sheet every few thousand years, according to a new study

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA – SANTA CRUZ

Rock Sample MA113
IMAGE: UCSC RESEARCHERS ANALYZED TWO ROCK SAMPLES COLLECTED IN EASTERN ANTARCTICA IN WHICH ALTERNATING LAYERS OF CALCITE AND OPAL REFLECT CYCLIC CHANGES IN THE SUBGLACIAL ENVIRONMENT. SAMPLE MA113 IS 9 CENTIMETERS THICK AND COMES FROM MOUNT ACHERNAR MORAINE ON THE SIDE OF LAW GLACIER. view more 
CREDIT: GAVIN PICCIONE

By analyzing unusual rock samples collected years ago in Antarctica, scientists at the University of California, Santa Cruz, have discovered a remarkable record of how the East Antarctic Ice Sheet has responded to changes in climate over a period of 100,000 years during the Late Pleistocene.

The East Antarctic Ice Sheet is the world’s largest ice mass. Understanding its sensitivity to climate change is crucial for efforts to project how much sea level will rise as global temperatures increase. Recent studies suggest it may be more vulnerable to ice loss than previously thought.

The new study, published September 15 in Nature Communications, provides evidence of changes at the base of the ice sheet over a broad area in response to cyclic changes in climate during the Pleistocene. The changes are reflected in the types of minerals deposited at the base of the ice sheet.

“One of the key findings is that the ice sheet was responding to temperature changes in the Southern Ocean,” said coauthor Terrence Blackburn, associate professor of Earth and planetary sciences at UC Santa Cruz. “The warm water eats at the edges of the ice sheet and causes the ice to flow faster, and that response reaches deep into the heart of the ice sheet.”

The rock samples analyzed in the study consist of alternating layers of opal and calcite that formed as mineral deposits at the base of the ice sheet, recording cyclic changes in the composition of subglacial fluids.

“Each layer in these samples is a manifestation of a change at the base of the ice sheet driven by changes in the motion of the ice streams,” said first author Gavin Piccione, a Ph.D. candidate working with Blackburn at UCSC.

By dating the layers, the researchers found a striking correlation between the layers of mineral deposits and the record of polar sea surface temperatures derived from ice cores. The opal was deposited during cold periods, and the calcite during warm periods.

“These climate oscillations are causing changes in ice sheet behavior such that the chemistry and hydrology beneath the ice is changing,” said coauthor Slawek Tulaczyk, a professor of Earth and planetary sciences at UCSC who has been studying the behavior of ice sheets and glaciers for decades.

The climate cycles that match the mineral layers are relatively small fluctuations that occur every few thousand years within the more pronounced glacial-interglacial cycles that occurred every 100,000 years or so throughout the Pleistocene. The glacial-interglacial cycles are driven primarily by changes in Earth’s orbit around the sun. The smaller millennial-scale climate cycles involve oscillations in polar temperatures driven by weakening and strengthening of a major ocean current (the Atlantic Meridional Overturning Circulation, or AMOC) which transports large amounts of heat northward through the Atlantic Ocean.

Tulaczyk said the new findings reveal the Antarctic Ice Sheet’s sensitivity to small, short-term climate fluctuations.

“As important as the Antarctic Ice Sheet is—it’s responsible for close to 17 meters of sea level rise since the last glacial maximum—we really know very little about how it has responded to climate variability,” he said. “We know the last 20,000 years pretty well, but beyond that we’ve been almost blind. That’s why these results are so mind-blowing. People have been banging their heads against the wall over this for decades.”

The two rock samples analyzed for this study were collected from glacial moraines separated by more than 900 kilometers (560 miles), and they formed over different periods covering a total of more than 100,000 years. In other words, they record similar cycles of mineral deposition beneath the ice occurring over a broad area and over long periods of time.

“The chemistry of the two samples matched, even though they came from so far apart, which gave us confidence that some large-scale, systematic process was going on,” Piccione said.

The mechanism behind the formation of layers of opal and calcite is a bit complicated and requires an understanding of not only mineral chemistry but also the unusual hydrology beneath the Antarctic Ice Sheet. Heat from Earth’s interior (“geothermal heating”) causes melting at the base of the ice sheet, which is insulated from frigid polar temperatures by the thickness of the ice. Where the ice gets thinner toward the margins of the ice sheet, subglacial meltwater begins to refreeze, concentrating dissolved minerals and eventually forming hypersaline brines.

Mineral deposits form as the water becomes concentrated by refreezing, and the first thing to precipitate is calcite, the most common form of calcium carbonate. Opal (amorphous silica) will eventually precipitate from older, supersaturated brines that don’t have any carbon left in them.

“Antarctica has these interesting brines with no carbon in them, because it all precipitated out earlier, so when those brines are isolated from other sources of water they form opal,” Piccione explained.

To get a layer of calcite on top of the opal requires an influx of carbon-containing glacial meltwater, which occurs during warm intervals in the climate cycles, when the AMOC slows down. That leads to warming in the Southern Hemisphere and brings warm water into contact with the floating ice shelves at the edges of the ice sheet. As the warm water eats away at the bottom of the ice shelves, the “grounding line” where the ice contacts land begins to retreat and ice flows more rapidly from the interior out to the edges.

Tulaczyk explained that the motion of the ice over the bedrock generates heat, increasing the amount of meltwater at the base of the ice sheet. “If you imagine a map of where there is meltwater under the ice sheet, that area expands in warm periods and contracts in cold periods, like a heartbeat,” he said.

The resulting “freeze-flush cycles” at the base of the ice account for the alternating layers of opal and calcite in the rocks.

The findings point to water temperatures in the Southern Ocean as the main mechanism driving the response of the Antarctic Ice Sheet to changes in the global climate. Temperatures in Antarctica are so cold that a few degrees of warming won’t cause surface melting of the ice, yet scientists know the ice sheet has melted in the past and parts of it have collapsed, Blackburn said. “It’s been hard to understand, but this shows clearly that ocean warming is the driving mechanism,” he said.

“If you look at the places that are losing ice today, they are concentrated along the edges of the ice sheet where it is in contact with the warming ocean,” Tulaczyk added. “The primary driver of ocean warming now is atmospheric carbon dioxide, not the AMOC, but I don’t think the ice sheet cares what causes the warming.”

Tulaczyk said the findings do show that the ice sheet can retreat during warm periods and then recover during subsequent cooling. “In the context of the threshold question—is the ice sheet sitting on a threshold beyond which there would be runaway melting and it will all go—that’s not what I see here,” he said. “The ice is sensitive to these short-term fluctuations, but the magnitude of ice loss is small enough that it can recover with cooling.”

In addition to Piccione, Blackburn, and Tulaczyk, the coauthors of the paper include Mathis Hain, Chloe Tinglof, and B. Cheney at UC Santa Cruz; Troy Rasbury and Paul Northrup at Stony Brook University; D.E. Ibarra at UC Berkeley and Brown University; Katharina Methner at Stanford University; and Kathy Licht at Indiana University-Purdue University Indianapolis. This research was funded by the National Science Foundation.


JOURNAL

Nature Communications

DOI

10.1038/s41467-022-33009-1 

ARTICLE TITLE

Subglacial precipitates record Antarctic ice sheet response to late Pleistocene millennial climate cycles

ARTICLE PUBLICATION DATE

15-Sep-2022

COI STATEMENT

The authors declare no competing interests.

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Brad-DXT
September 18, 2022 10:35 pm

 “The primary driver of ocean warming now is atmospheric carbon dioxide…”
They had to add that line to get funding, right? It’s not like they have proof.

PCman999
Reply to  Brad-DXT
September 18, 2022 11:16 pm

You don’t have to assume dishonesty – Tulaczyk could just be indoctrinated into the climate cult after years of exposure to the BBC.

Brad-DXT
Reply to  PCman999
September 18, 2022 11:49 pm

I didn’t mention dishonesty, I suggested grant harvesting (moral ambiguity?).
By the way, is it dishonest to make a claim in a scientific paper without proof?

Drake
Reply to  Brad-DXT
September 19, 2022 10:43 am

YES!

Tom Abbott
Reply to  Drake
September 19, 2022 12:20 pm

It’s definitely dishonest to claim you have proof of something when you don’t have the proof.

It’s dishonest to claim assumptions and assertions are proof.

It’s dishonest to use “confidence levels” as proof.

There is a LOT of dishonesty in alarmist climate science. So much so, that you can’t believe a word alarmists say about the climate.

Duane
Reply to  Brad-DXT
September 19, 2022 4:58 am

The opposite is proven, of course. The oceans warm or cool the atmosphere, not the other way around. Due to simple physics (the ocean’s far larger specific heat content, mass adjusted, than the atmosphere, by more than three orders of magnitude). The sun’s variable insolation heats or lessens the heat of the oceans, and then the oceans warm or cool the atmosphere.

The warmunists literally claim that the tail wags the dog … or more proportionately, the rear end of the flea sitting on the tail wags the dog.

Brad-DXT
Reply to  Duane
September 19, 2022 8:14 am

Perhaps with their esteemed scientific accumen they can prove that the rear end of the flea sitting on the tail wags the dog.

That’s a nice turn of phrase, I’m going to steal that.

roaddog
Reply to  Duane
September 20, 2022 6:25 am

Oh come on, man. I’m certain that if I raise the temperature of my thermostat by 2 degrees, it will heat my bath.

marty
Reply to  roaddog
September 20, 2022 8:16 am

[invalid email-mod]

Peter Gardner
Reply to  Duane
September 22, 2022 5:35 pm

Actually he’s talking about surface water, which is heated by the sun and atmosphere. But anyway the causes of the water warming were not part of the study. It is just a throw away line to attract funding from scary headlines. The media will do the work for him.

Last edited 11 days ago by Peter Gardner
tgasloli
Reply to  Brad-DXT
September 19, 2022 7:37 am

They were doing real science but then ruined it with that line. Just sad they all have to recite the party line even when it is unrelated to their research.

Brad-DXT
Reply to  tgasloli
September 19, 2022 8:17 am

I wonder when they’ll do a retraction to edit that out.

Peter Gardner
Reply to  tgasloli
September 22, 2022 5:39 pm

Unfortunately it is typical of research in Antarctica, much of which is excellent, but ruined in publication by feeding the media with scary lines in order to attract more funding. It is not clear in this paper whether the authors even believe it themselves. No evidence or proof is needed since it is not part of their study.

Last edited 11 days ago by Peter Gardner
Indur Goklany
Reply to  Brad-DXT
September 19, 2022 9:19 am

You have to recite the catechism and say a few Ave Marias to deserve any funding, you denier!

Brad-DXT
Reply to  Indur Goklany
September 19, 2022 9:35 am

Since Ave Maria is associated with the Catholic Church, they’ll have to use another song.
James Taylor is popular with these folks so I think they should use Fire and Rain for their theme. After all, it’s a song about depression and suicide.

Pat from Kerbob
Reply to  Brad-DXT
September 19, 2022 3:45 pm

They have no proof because its not possible for the the atmosphere to heat the ocean. I think in order for the atmosphere to heat the ocean 1C the atmosphere would have to be 10C hotter for at least 100 years? That math might work out. This is just more of their “hidden heat” BS.

AGW is Not Science
Reply to  Brad-DXT
September 20, 2022 1:12 pm

Same immediate reaction – “Objection! Facts not in evidence.”

September 18, 2022 10:38 pm

Does not change the fact Antarctica is refusing to warm, and “climate science” does not understand why.. 😉

Reply to  E. Schaffer
September 19, 2022 2:57 am

In Antarctics, CO2 is more cooling than warming.

Pat from Kerbob
Reply to  Krishna Gans
September 19, 2022 3:47 pm

That’s because its upside down, basic climate science.

This stuff is easy

Javier
Reply to  E. Schaffer
September 19, 2022 3:40 am

Climate science does understand why even if you don’t. In Antarctica, the surface is colder than the atmosphere. More CO2 means warmer molecules producing more radiative cooling.

Essentially the greenhouse effect works in reverse in the polar regions.
van Wijngaarden and Happer explain that.

https://arxiv.org/pdf/2006.03098.pdf%C2%A0%C2%A0%C2%A0Dependence

Last edited 14 days ago by Javier
The Dark Lord
Reply to  Javier
September 19, 2022 4:33 am

CO2 has nothing to do with warming or cooling …

Last edited 14 days ago by The Dark Lord
Javier
Reply to  The Dark Lord
September 19, 2022 5:45 am

It does, even in The Dark.

Gene
Reply to  Javier
September 19, 2022 7:40 am

Notice the quotes around “climate science.” Here, we see “climate science” is a thinking entity that understands something. In earlier times science was a subset of philosophy where logic and language matter. Science is a methodology not club. Anyway, what about the sun and volcanoes? We always ignore these things. Few years ago, there was “climate science” hysteria over the earth’s temperature rising. Of note, Mars’ temperature rose exactly in line with that and my car has never been there. Correlation can mean there is mutual causation elsewhere.

Javier
Reply to  Gene
September 19, 2022 10:31 am

Here, we see “climate science” is a thinking entity that understands something.

No. Here “climate science” is a way of expressing the accumulated knowledge by humans of how climate changes, whether correct or incorrect.

roaddog
Reply to  Javier
September 20, 2022 1:54 am

Sometimes known as accumulated ignorance. Ref: Galileo

Gene
Reply to  Javier
September 20, 2022 10:26 am

Javier, your comment is scary. Climate has a meaning, which is not weather. Science has a meaning. It is not expressing your beliefs. Our culture promotes superficial and emotional posturing. Accumulated knowledge? Think about that. What does it mean? Research shows in the distant past that CO2 FOLLOWED warming trends. Is this part of your accumulated knowledge? Aren’t we told CO2 is supposed to cause warming? (Let’s leave the idea that correlation is not causation as a hopeless conversation)

Greg B
Reply to  Gene
September 22, 2022 8:06 pm

Let’s leave the cliché ‘correlation is not causation’ behind forever. It’s misleading. Correlation is sometimes causation. The more accurate aphorism would be ‘correlation is a necessary but insufficient condition for causation’.

Richard M
Reply to  Javier
September 19, 2022 11:41 am

It is true that more CO2 leads to more radiative cooling. However, this is not limited to Antarctica. It is true everywhere. And, as W/H indicated on page 15, doubling CO2 raises the emissions height to a warmer altitude. That is also true everywhere.

Reply to  Javier
September 20, 2022 10:18 am

It is theoretically a sound explanation, don’t get me wrong. The GHE over Antarctica is indeed negative and if you increase CO2 there you should not expect any warming, if at all. However, as any good chess player, I am thinking a few steps ahead before making a move.

Antarctica is engulfed by a much larger area (all south of 45S) showing equally no warming. There this reasoning holds no more true. And of course you have convection. Antarctica is not isolated, just as the Arctic is not.

Also you have inversion especially in the Arctic winter. There and then CO2 should not provide much warming. But guess what, the Arctic winter is heating much more than anything else. In the bigger picture, this seemingly simple explanation fails.

“Climate science” favours another position anyhow. That is extreme heating of the Antarctic, but it is all concentrated around Byrd station. Sure its got nothing to do with poor, incomplete temperature records there, that have been suplemented with state of the art models…

comment image

September 18, 2022 10:59 pm

Interesting. They found the evidence for the millennial cycle that is clearly in the records….
https://breadonthewater.co.za/2021/03/04/the-1000-year-eddy-cycle/

Now. Where did that warming in the past millennials come from????
Click on my name.

Pat from Kerbob
Reply to  HenryP
September 19, 2022 3:48 pm

Is that like “pull my finger”?

Alastair Brickell
September 18, 2022 10:59 pm

Generally an interesting paper but with both sense and nonsense:

Sense:

“The glacial-interglacial cycles are driven primarily by changes in Earth’s orbit around the sun. The smaller millennial-scale climate cycles involve oscillations in polar temperatures driven by weakening and strengthening of a major ocean current (the Atlantic Meridional Overturning Circulation, or AMOC) which transports large amounts of heat northward through the Atlantic Ocean.”

  • SO ITS NOT OUR FAULT THEN!

“Heat from Earth’s interior (“geothermal heating”) causes melting at the base of the ice sheet…”

  • SO ITS STILL NOT OUR FAULT THEN! (good to finally see someone actually admitting that there is geothermal activity under the ice and that it can cause warming/melting)

“In the context of the threshold question—is the ice sheet sitting on a threshold beyond which there would be runaway melting and it will all go—that’s not what I see here,” and:

“…the magnitude of ice loss is small enough that it can recover with cooling.”

  • END OF THE WORLD PANIC CANCELLED!

Nonsense:

“The primary driver of ocean warming now is atmospheric carbon dioxide, not the AMOC…”

  • SOME PROOF PLEASE…
Reply to  Alastair Brickell
September 18, 2022 11:03 pm

Agreed. It is geothermal that caused our earth to heat a bit.
https://breadonthewater.co.za/2022/08/02/global-warming-how-and-where/

Old Man Winter
Reply to  Alastair Brickell
September 19, 2022 1:07 am

Thanks for the great summary- it confirmed my understanding of what I
thought I had read.

RickWill
September 18, 2022 11:00 pm

The Southern Ocean is cooling and will continue to cool for the next 9kyr. So not much to worry about if it was warming but of zero concern since it is cooling.

The real concern should be focused on the cooling NH winters and eventual glaciation around the North Atlantic.

Given the observed rate of fission energy development, glaciation poses a serious threat to inhabitants around the North Atlantic.

Reply to  RickWill
September 18, 2022 11:17 pm

Not to worry. Just spray the advancing ice with carbon soot.

RickWill
Reply to  RickWill
September 18, 2022 11:21 pm

To make it very clear. The December Solar EMR at 60S is now 489W/m^2. 1000 years ago it was 493W/m^2. In another 1000 years it will be 484W/m^2.

There is no way the Southern Ocean is going to suddenly start warming up. The cooling trend observed throughout the satellite era will continue.

NCEP_Three_Trends-2.png
Alastair Brickell
Reply to  RickWill
September 18, 2022 11:33 pm

I agree with your general thesis but what are the error bars on those EMR figures?

RickWill
Reply to  Alastair Brickell
September 19, 2022 4:01 pm

The EMR values above are purely related to geometry assuming constant solar output. The solar output varies by about 1W/m^2 in decadal time frame. The orbit is precise and predictable. The precession cycle of 23kyr dominates the shorter term orbital changes and is the dominant factor in century scale climate change. Attached shows frequency analysis for historical reconstruction of sea level.

There is strong evidence for solar variation in the Nino34 region in the centre chart above but these changes have time frame of decades not centuries. Sea level has been trending up for a couple of centuries now as the ocean retains more heat and is expanding thermally.

Sea_Level_Cycles.png
Old Man Winter
Reply to  RickWill
September 19, 2022 1:39 am

In a previous comment on another post, you mentioned that the NH
would be getting warmer & drier, with the drier is counterintuitive
to me as I had assumed a warmer Earth would also be a wetter
earth since it was both colder & drier 18k yrs ago
(map below).

Question: What drives it to be drier? In the SH, you’re showing
cooler Ts. Will that make it wetter or is the drier/wetter level
being driven by something other than T?

18kyadst.jpg
Last edited 14 days ago by Old Man Winter
RickWill
Reply to  Old Man Winter
September 19, 2022 3:49 pm

Most ocean evaporation occurs in January and December when the sun is over the SH. However that is when least water is in the atmosphere because it converges to the higher convective towers over land. PNG has the most powerful convective towers but Amazon and Congo best known. This is because moist land warms faster than wet ocean so the towers are more powerful.

The most water in the atmosphere occurs in June and July. However that is when ocean evaporation is lowest and the NH land masses are warmer than the oceans. The atmospheric water over the land is too low (<35mm) to support convective instability. So the land just gets hot and dry without any mid level convergence from the oceans.
https://earth.nullschool.net/#2022/07/19/2200Z/wind/surface/level/overlay=total_precipitable_water/orthographic=-133.97,42.46,343/loc=-109.947,43.942

India and parts of China are usually the exception where there is enough moisture over the land to support convective instability and the land towers are more powerful than those over the ocean so the water diverges from ocean to converge on land:
https://earth.nullschool.net/#2022/07/19/2200Z/wind/surface/level/overlay=total_precipitable_water/orthographic=74.16,20.97,343/loc=73.464,31.771

Land biomass is really important to convective instability over land because this ensures that surface and near surface moisture is greater than 45mm, which is needed for cyclic instability.

If the trees in the Amazon were all cut down then the place would eventually look like the Sahara as the regional climate changed.

John Gorter
September 18, 2022 11:23 pm

Volcanoes?

Loydo
Reply to  John Gorter
September 19, 2022 10:33 pm

Oceanic warming is occuring from the surface down, not from the floor up.

PCman999
September 18, 2022 11:31 pm

Is there any non-woke glaciation expert reading this article that can help me understand something: why do these scientists believe that loss of sea ice or ice around the edges, on land, of the ice pack in Antarctica will somehow speed up the rate of the ice flow to the sea?

Alpine glaciers that are melting recede, looking like they are moving back up the mountain. They don’t slip down the mountain because of melting ice possibly lubricating the way, and certainly they are on more of a grade than the average ice in Antarctica.

Are they so brainwashed that they can’t accept the idea that the ice calving at the edges is from the production of more ice than from melting?

If the waters around Antarctica are aiding the supposed melting, why does it take several years for a broken off sheet to melt? There was a very large section that broke off and was compared to the size of some island, Rhode Island I think, and there was all kinds of doomsday angst and such in the news. However the sheet was monitored for years via satellite and stayed the same size for years as it went around in circles in a bay. Once it finally meandered further north away from the shore it finally started to melt.

So how does that jive with the tale that ocean warming is causing Antarctica to melt?

Duane
Reply to  PCman999
September 19, 2022 5:50 am

The warmunists have it all wrong on this point, in addition to many others.

Glaciers are simply slow moving water bodies – slow moving because they have extremely high viscosity compared to liquid water. Meaning that glaciers obey the same laws of physics that govern water flow, and it is all about gravity. In order for a glacier to move faster, it has to have a higher hydraulic grade line – i.e., the upstream surface of the ice pack must be higher (i.e, thicker ice) to drive it at a higher velocity downwards. The bottom surface profile of the underlying rock does not change or become steeper, if anything the bottom surface profile gets flatter over time (see typical U-shaped mountain valleys, like Yosemite, that have been gouged out by previous glaciers) which would tend to reduce the velocity of ice flow.

Just look at any river’s performance. When the upstream water shed gets a large input of precipitation runoff, what happens? The upstream water surface profile gets higher, providing greater gravitational force, and as a result the river flows faster as well as higher. Conversely, having an extended dry period in the upstream watershed, the river levels drop, and the velocity of the river also drops commensurately.

Ice works just the same, just that it’s responsiveness to higher upstream ice thickness is less than for rivers due to the much higher viscosity of ice than liquid water.

Clyde Spencer
Reply to  Duane
September 19, 2022 10:42 am

Friction plays a much larger role with ice than it does with water. However, the unstated assumption for the glaciers is that the bedrock is relatively planar, and melted water will act like a lubricant. However, the bedrock is often quite irregular, (As observed where the glacier has receded.) creating barriers to the forward motion of both the ice and the basal water. In the case of transverse barriers, the ice has to either shear over the top of barriers, or be deflected upwards and lifted in elevation, depending on the relief of the barrier. In both situations, any basal meltwater that might be present will have a negligible impact on the apparent friction.

To say anything intelligent about the behavior of the Eastern Ice Sheet, it is necessary to have far more detail about the bedrock gradient and relief than is generally available.

Duane
Reply to  Clyde Spencer
September 19, 2022 12:21 pm

Friction actually plays a far smaller role with moving glacial ice than it does with water in rivers or streams. In a river or stream, the natural irregularities in the bottom surface represent a far greater proportion of the water column depth than any irregularities in the bedrock below a moving glacier … the former generally being no more than a few feet to perhaps a few tens of feet water column depth, while glaciers typically measure in the hundreds to even thousands of feet thick. Friction only affects the boundary layer of the flow, or very close to the boundary layer … beyond that, there is no effect due to surface friction.

Besides water is not a great lubricant when it comes to impeding flow by large rocks, boulders, ravines, canyons, and such that make up the typical hard surface beneath a glacier. Water works great as a lubricant when dealing with extremely small, microscopic surface irregularities, not with boulders.

Clyde Spencer
Reply to  Duane
September 19, 2022 5:47 pm

In a river or stream, the natural irregularities in the bottom surface represent a far greater proportion of the water column depth than any irregularities in the bedrock below a moving glacier …

The “all other things being equal” caveat here is the depth of the river and the size of the bed load components. In a shallow mountain stream with boulders, there is a substantial effective friction during Summer low water. Hundreds of miles downstream, with only sand, silt, and clay size particles, the friction is much less.

On the other hand, the only thing that keeps an alpine glacier from falling (flowing) off a mountainside is the basal adhesion and viscosity of the ice.

There are many problems with generalities about glaciers, because almost every glacier is a unique situation.

Javier
Reply to  PCman999
September 19, 2022 5:59 am

Is there any non-woke glaciation expert reading this article that can help me understand something: why do these scientists believe that loss of sea ice or ice around the edges, on land, of the ice pack in Antarctica will somehow speed up the rate of the ice flow to the sea?

It would help you understand it if you would make an effort to at least look at the figures in the paper.

It is the rock at the BASE of the ice they are looking at. Bottom of the ice-sheet melting does speed up the ice flow. That’s why this paper is important. They find the base of the ice-sheet responds to climate changes affecting also the ocean.

Reply to  Javier
September 19, 2022 6:35 am

Javier

Why would melting speed up the ice flow? Glaciers flow by growing at the head and pushing ice down stream not much different than water in a river growing and speeding up when its raining up stream.

Craig

Javier
Reply to  bob boder
September 19, 2022 7:40 am

Frictional force does greatly affect glacier flow. Bottom melting makes a huge difference.

Reply to  Javier
September 19, 2022 10:38 am

Javier

If the glacier is melting then you will have melt water running under the glacier to the sea or where ever, but I don’t see the force that we be causing the Glacier to flow down stream while it is melting. This really seems counterintuitive what is being said here. But perhaps I am missing something.

Clyde Spencer
Reply to  Javier
September 19, 2022 11:06 am

I would say that bottom melting can make a difference, but it is an ice-bridge too far to say that it always makes a difference.

I have observed striations on glacial polish in New England that strongly suggests the direction and velocity of basal ice was turbulent, and even stagnant in some locations. The upper levels of ice undoubtedly had radial motion away from the Labrador accumulation center, but with considerable variation in local directions as the sheet passed over and around the stream-dissected White Mountains of New Hampshire and the Green Mountains of Vermont. The ice tongue moving down the Connecticut River Valley surely behaved differently than the ice going passed Mt. Monadnock.

Modern day alpine glaciers, which experience surging presumed to be from basal meltwater, are not a good analogue for the behavior of continental glaciers moving across mountain ranges, such as is the case in Antarctica.

Clyde Spencer
Reply to  Javier
September 19, 2022 11:29 am

Note the authors’ rendition of subglacial topography for the study site:
comment image

ATheoK
Reply to  Javier
September 19, 2022 8:19 am

That’s why this paper is important. They find the base of the ice-sheet responds to climate changes affecting also the ocean.”

They selected two samples from locations 900 kilometers (560 miles) apart.

They then speculate the rest. Not science!

Javier
Reply to  ATheoK
September 19, 2022 10:28 am

Not science!

You don’t decide that. They produce evidence that hasn’t been produced before, therefore it is science.

Clyde Spencer
Reply to  ATheoK
September 19, 2022 11:27 am

I agree. Moraines are detrital material accumulations at the snout (or margins) of the glacier. Nothing was said about how the specimens were collected (core drilling?) or if they acquired orientation information. These could be cobbles from tens-of-miles upstream at a travertine deposit and not be related to what the oceans were/are doing.

Alastair Brickell
Reply to  Clyde Spencer
September 19, 2022 2:35 pm

Quite right…it would be good to have that clarified. It’s pretty basic to say where your samples came from and thus exactly what they are sampling.

Editor
September 18, 2022 11:41 pm

“The findings point to water temperatures in the Southern Ocean as the main mechanism driving the response of the Antarctic Ice Sheet …”. Well, the response should be a cooling:

“Southern Ocean Cooling in a Warming World” – http://oceans.mit.edu/news/featured-stories/southern-ocean-cooling-in-a-warming-world.html
“Going against the trend: Cooling in the Southern Ocean” – https://phys.org/news/2020-05-trend-cooling-southern-ocean.html
“there was quite strong overall [Southern Ocean] cooling” – https://wattsupwiththat.com/2019/04/10/the-curious-case-of-the-southern-ocean-and-the-peer-reviewed-journal/

Alastair Brickell
Reply to  Mike Jonas
September 18, 2022 11:50 pm

Are you trying to confuse the issue with facts??

DMacKenzie
Reply to  Alastair Brickell
September 19, 2022 6:44 am

Everybody knows the oceans are getting warmer. Just read some media articles…
/s

Javier
Reply to  Mike Jonas
September 19, 2022 6:02 am

“The findings point to water temperatures in the Southern Ocean as the main mechanism driving the response of the Antarctic Ice Sheet …”

Only if one confounds correlation with causality. Something could be driving changes in the ocean and the ice-sheet.

Steve Case
September 19, 2022 1:56 am

If you look at the places that are losing ice today, they are concentrated along the edges of the ice sheet where it is in contact with the warming ocean,”
_________________

In other news, the Sun will rise in the east tomorrow morning

Pat from Kerbob
Reply to  Steve Case
September 19, 2022 3:54 pm

You don’t know that, that is pure speculation.

AGW is Not Science
Reply to  Steve Case
September 20, 2022 4:54 pm

Ummm but the ocean isn’t warming…

fretslider
September 19, 2022 2:42 am

“”we really know very little “”

I agree with them on that. It seems the default setting now is ‘worse than was thought’ even when it patently is not

“”The primary driver of ocean warming now is atmospheric carbon dioxide””

No doubt the cheque is in the post

Cardimona
September 19, 2022 3:04 am

The James Webb space telescope is seeing Birkeland currents everywhere it looks.
That means the Big Bang theory has been falsified, and the electric universe theory is supported.
The 12,000-year galactic electromagnetic sheet reversal – and the associated crustal displacement here on Earth – explains the alternating layers of opal and calcite in this paper rather well.
Antarctica spends 6,000 years on the equator, then 6,000 years at the south pole in a repeating cycle.
The Sky Dragon Slayers were right all along…

Javier
September 19, 2022 3:33 am

“…the magnitude of ice loss is small enough that it can recover with cooling.”

Why would anyone want that to happen? It is not as if there is a shortage of ice for drinks.

Clyde Spencer
Reply to  Javier
September 19, 2022 11:44 am

And, I’m sure that there will be a lot more ice available in Europe come this Winter.

saveenergy
Reply to  Clyde Spencer
September 19, 2022 1:57 pm

So we’ll come around to your place for drinks then (:-))

Clyde Spencer
Reply to  saveenergy
September 19, 2022 5:50 pm

Unless all the roads in Europe go unplowed because of a shortage of gasoline.

roaddog
Reply to  Clyde Spencer
September 20, 2022 2:01 am

And damn little demand for cold drinks.

Duane
September 19, 2022 4:51 am

Great theory, until one understands that the oceans do not warm due to “global warming” or climate change, because liquid water is extremely insensitive to atmospheric temperatures, via simple physics which the warmunists simply don’t understand, or else purposely ignore.

Liquid water has a specific heat content four times greater than air per unit mass. Meaning that for any thermal energy input, 1 kg of liquid water will see its temperature change at 1/4 the rate of 1 kg of air. Then of course the mass of the oceans is several orders of magnitude greater than the mass of the atmosphere. So a 1 or 2 deg C change in atmospheric temperature at the sea surface will cause an unmeasurable change in sea temperature, particularly in the deeper layers that could affect the undersides of glacial ice shelves.

The bottom line here is that the oceans constitute a nearly unchangeable (with respect to atmospheric influence) heat sink, and indeed it is the transport of thermal energy by the oceans, from shallow (warm in the tropical latitudes due to insolation) to deep (cold) then laterally to shallow (warm, except in the polar latitudes) that controls the atmospheric temperature … and not the other way around as the warmunists claim. The sun warms or cools the oceans, along with geothermal processes, and then the oceans warm or cool the atmosphere.

The warmunists have to ignore proven physics to get to their conclusions.

Last edited 14 days ago by Duane
Yooper
Reply to  Duane
September 19, 2022 6:26 am

Ya know, I would really like someone to do a calculation about Sea Level Fall as a result of ice formation.

Reply to  Duane
September 19, 2022 6:46 am

The influence is just vice versa
the ocean is warming the atmosphere, or in cases is cooling it.

Last edited 14 days ago by Krishna Gans
Duane
Reply to  Krishna Gans
September 19, 2022 12:31 pm

Yes. A simple test is this:

Meteorologists have always known that air masses take on the characteristics of the earth’s surface over which they pass, proportional to the time and distance spent by the air mass over a particular surface.

Hence, winds that move across large oceans are heavily influenced by the temperature of those waters, and of course also pick up moisture from such seas. These are referred to as “maritime air masses”, which are cool (if flowing over the polar seas, or those portions of the oceans wherein known cold currents – such as the Humboldt Current – prevail), and moist; or warm (if flowing over tropical seas or surface currents that are warmed by tropical seas, such as the Atlantic Gulf Stream) and moist.

Alternatively, winds that flow for long distances over land areas, referred to as “continental air masses” tend to be dry, and either cold (such as the Arctic and Canadian air masses that typically move south and east across the US in winter), while those that flow over more southerly low elevation areas, like the Sahara Desert, are warm and dry. Saharan Desert air masses moving west-northwest across the Atlantic Ocean this “hurricane season” have been suppressing Atlantic tropical cyclones in 2022.

Last edited 14 days ago by Duane
Sweet Old Bob
September 19, 2022 6:50 am

” UCSC RESEARCHERS ANALYZED TWO ROCK SAMPLES COLLECTED IN EASTERN ANTARCTICA IN WHICH ALTERNATING LAYERS OF CALCITE AND OPAL REFLECT CYCLIC CHANGES IN THE SUBGLACIAL ENVIRONMENT. SAMPLE MA113 IS 9 CENTIMETERS THICK AND COMES FROM MOUNT ACHERNAR MORAINE ON THE SIDE OF LAW GLACIER. ”

Only two ?
Did other samples differ ?

Did they “find” what they wanted to find ?

Like Yamal ?

ATheoK
Reply to  Sweet Old Bob
September 19, 2022 8:23 am

Exactly the right questions!

Especially, since the authors then fill their paper with boundless speculations as to the formation of the rock samples.

ATheoK
September 19, 2022 8:11 am

“One of the key findings is that the ice sheet was responding to temperature changes in the Southern Ocean,” said coauthor Terrence Blackburn, associate professor of Earth and planetary sciences at UC Santa Cruz. “The warm water eats at the edges of the ice sheet and causes the ice to flow faster, and that response reaches deep into the heart of the ice sheet.”

Classic climate illogic.
Discover a possible, (two physical samples, 900 kilometers apart (560 miles)), physical effect and immediately apply pure speculation as to cause and effect.

They assume what causes the physical rock depositions and what speculate what causes the water conditions that support rock deposition.

Clyde Spencer
September 19, 2022 11:39 am

I would say that they have done high-quality laboratory geochemistry and mineralogy. However, I don’t feel that their glaciology is up to the same level.

Their description of how they obtained their samples raises a number of questions.

KcTaza
September 19, 2022 1:14 pm

I wonder when they took their two samples?

Temperatures In Antarctica Tumble Back Below Multidecadal Average, As Satellite Data Reveals 40 Years Of Cooling and Ice Expansion
https://bit.ly/3IN8JyU
3/25/22

Eastern Antarctica saw unusually high temperatures for a few days last week, with Concordia station hitting a record -11.8C (10.8F) on March 18.
The record temperatures were the result of an atmospheric river that trapped heat over the continent — an entirely natural phenomenon, and one thought to have been aided by the historically low solar activity we’re currently experiencing as well as the ongoing magnetic excursion (aka pole shift), although the interactions of the mechanisms are poorly understood…

KcTaza
September 19, 2022 1:17 pm

Why no mention of this in their study?

Antarctica shock: Bizarre ‘heat source’ coming from three miles below ice revealed
 http://shr.gs/A08AAVP
2/15/20https://electroverse.net/antarctic-temps-fall-back-below-average/

February 15, 2020

The discovery was made at the southern Pole of Cold, on the icy continent’s East Antarctic Ice Sheet, near Russia’s scientific research station. Scientists drilled almost three miles into the ice after radars spotted an anomaly, discovering what is now known as Lake Vostok. The drills stopped just before they hit the water, due to concerns over spoiling what could be a “pristine” ecosystem.
But, they still made some remarkable finds, Amazon Prime’s “Forbidden Mysteries” revealed.
Narrator David Taylor said in 2018: “In the Seventies, via airborne radar, Russia began to suspect that they had inadvertently built their base at the tip of a large sub-glacial lake.
“In the years since orbital radar mapping, combined with surface seismological measurements have confirmed that Lake Vostok, under two miles of solid ice, is the largest lake discovered in the last 100 years.
“Roughly the size of Lake Ontario, but much deeper in places, more than 3,000 feet, and about four times the volume.

The heat source was recorded in East Antarctic Ice Shelf (Image: GETTY/WIKI)
The find was made near the Vostok research centre (Image: YOUTUBE)
Clearly indicating a subterranean heat source
David Taylor
“The lake, which is still liquid and not frozen, has been isolated under the ice sheets since anywhere from 13,000 to 14 million years ago, depending on who you talk to.
“The water in the lake, determined by surface thermal scans ranges from 10C to 18C, clearly indicating a subterranean heat source…”

Sturmudgeon
Reply to  KcTaza
September 19, 2022 7:38 pm

Some pretty doggone wide ‘ranges’ in there…

KcTaza
September 19, 2022 1:24 pm

One must wonder why “scientists” ignore these findings and fail to take them into account when studying melting?

Multiple NASA Studies Confirm Bedrock Heat Flow Behind Melting Polar Ice, Not Global Warming
https://climatechangedispatch.com/nasa-natural-causes-behind-polar-melt/

NASA Antarctica Study 11/7/17
*
Hot News from the Antarctic Underground
http://go.nasa.gov/3ji40uc

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

This research study entitled “Hot News from the Antarctic Underground“ investigated West Antarctica’s subglacial geology.
It substantiates many previous research studies that have documented this region’s subglacial high-bedrock heat-flow, active faulting, and prevalent volcanism.
Recent research by the University of Rhode Island scientists confirms the premises of a previous Climate Change Dispatch article that subglacial, volcanic heat-flow is melting West Antarctica’s Pine Island Glacier (see here)…

Geoff Sherrington
September 19, 2022 3:15 pm

Almost the entire concept of this paper relies on the geological origins of the two rock samples, on their mode of formation.
As a geochemist for several decades, my boss was John N Elliston AO, a geologist who spent much of his career developing explanations for ore and rock genesis bases on colloidal mechanisms. There is abundant reason to invoke colloids in the formation of the 2 rock specimens here.
John rode on ahead this year, well into his 90s. He led one of the most successful mineral exploration teams in the world, with 14 new mines found in 30 years, many on greenfield sites, some of world class. He was another case of The Establishment of closed minds refusing to accept his studies, while unable to find fault with them. In his mid 80s he self-published:
https://www.connorcourtpublishing.com.au/THE-ORIGIN-OF-ROCKS-AND-MINERAL-DEPOSITS–John-Elliston_p_111.html
I once showed him an orbicular rock, formerly a sphere sliced in two. The exposed surface about 150 mm diameter had about 75 concentric circles, roughly like a gramophone record if you still remember vinyl. (The owner declined my substantial offer to buy, it was so elegant and rare). I looked through John’s work at hand but could not find his photo of it, so I selected some other examples of banding from colloidal processes.
http://www.geoffstuff.com/jne.jpg
……………………….
Until these authors above study and rule out a colloidal origin for their textures, their paper has no validity.

Geoff S

Loren C. Wilson
September 19, 2022 3:23 pm

Two samples – I would expect that they looked at a lot more to make these claims.

Philip CM
September 19, 2022 4:56 pm

(The findings point to water temperatures in the Southern Ocean as the main mechanism driving the response of the Antarctic Ice Sheet to changes in the global climate.)

Nothing on the role the changes in southern ocean currents have played, a more southwardly drop to the currents arc, hindering the northward movement of the Antarctic Circumpolar Current, read thermohaline circulation, keeping the warmer water around longer than usual.

TimTheToolMan
September 20, 2022 1:30 pm

“The chemistry of the two samples matched, even though they came from so far apart, which gave us confidence that some large-scale, systematic process was going on,” Piccione said.

Two samples. One sample each at two distant locations.

And from this and a bunch of assumptions about how the climate and glacial conditions impacted their chemistry comes a detailed picture of the regional climate.

I think I’m channelling Judith Curry when I suggest the uncertainty of that finding is unprecedented.

Peter Gardner
Reply to  TimTheToolMan
September 22, 2022 6:44 pm

Yes it is very dubious. A 3-D map of antarctica shows the terrain under the ice-cap is very mountainous although a surprisingly large proportion is below sea level. So the assumption of connection might be correct but in fact nobody knows with certainty beyond tossing a coin.

September 21, 2022 1:27 pm

The climate cycles that match the mineral layers are relatively small fluctuations that occur every few thousand years within the more pronounced glacial-interglacial cycles that occurred every 100,000 years or so throughout the Pleistocene.

Yet more evidence of big climate oscillation on timescales less than glacial-interglacial. Enough to change the type of rock deposited in Antarctica.

Who was driving SUVs 🚙 back then?

Peter Gardner
September 22, 2022 5:25 pm

So many studies of phenomena in the Antarctic are brilliant until they get to an enormous leap of faith with statements such as the one made here: “The primary driver of ocean warming now is atmospheric carbon dioxide…”
That enables the article to be publicised with alarming headlines and so to attract yet more money from taxpayers.
We had the same with Larsen B in 2002. They conveniently forgot to mention or even to consider the fact that it had been sitting over a very long chain of volcanoes stretching into the South Atlantic, many of which are active.
Before anyone says it, yes I know The Antarctic Peninsula is West and is not the Eastern Ice cap mentioned in the article. that is not the point.

Last edited 11 days ago by Peter Gardner
Peter Gardner
Reply to  Peter Gardner
September 22, 2022 6:40 pm

I forgot to mention that studies of ice cores from EPICA Dome C in 2014 covering 8 inter-glacial cycles (800,000 years) show that when temperatures are rising, the rise in atmospheric CO2 content lags temperature. So CO2 could not possibly be the cause of rising atmospheric temperatures. But for sea temperatures around undersea volcanoes and fault lines it’s different!

Last edited 10 days ago by Peter Gardner
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