In this illustration, seawater flows deep below the surface into an actively opening ice shelf rift in Antarctica. New research shows that such rifts can open very quickly, and that the seawater rushing in helps control the speed of ice shelf breakage. Credit: Rob Soto
There’s enough water frozen in Greenland and Antarctic glaciers that if they melted, global seas would rise by many feet. What will happen to these glaciers over the coming decades is the biggest unknown in the future of rising seas, partly because glacier fracture physics is not yet fully understood.
A critical question is how warmer oceans might cause glaciers to break apart more quickly. University of Washington researchers have demonstrated the fastest-known large-scale breakage along an Antarctic ice shelf. The study, recently published in AGU Advances, shows that a 6.5-mile (10.5 kilometer) crack formed in 2012 on Pine Island Glacier — a retreating ice shelf that holds back the larger West Antarctic ice sheet — in about 5 and a half minutes. That means the rift opened at about 115 feet (35 meters) per second, or about 80 miles per hour.
“This is to our knowledge the fastest rift-opening event that’s ever been observed,” said lead author Stephanie Olinger, who did the work as part of her doctoral research at the UW and Harvard University, and is now a postdoctoral researcher at Stanford University. “This shows that under certain circumstances, an ice shelf can shatter. It tells us we need to look out for this type of behavior in the future, and it informs how we might go about describing these fractures in large-scale ice sheet models.”
The Significance of Rift Formation
A rift is a crack that passes all the way through the roughly 1,000 feet (300 meters) of floating ice for a typical Antarctic ice shelf. These cracks are the precursor to ice shelf calving, in which large chunks of ice break off a glacier and fall into the sea. Such events happen often at Pine Island Glacier — the iceberg observed in the study has long since separated from the continent.
Satellite images taken May 8 (left) and May 11 (right), three days apart in 2012, show a new crack that forms a “Y” branching off to the left of the previous rift. Three seismic instruments (black triangles) recorded vibrations that were used to calculate rift propagation speeds of up to 80 miles per hour. Credit: Olinger et al./AGU Advances
“Ice shelves exert a really important stabilizing influence on the rest of the Antarctic ice sheet. If an ice shelf breaks up, the glacier ice behind really speeds up,” Olinger said. “This rifting process is essentially how Antarctic ice shelves calve large icebergs.”
In other parts of Antarctica, rifts often develop over months or years. But it can happen more quickly in a fast-evolving landscape like Pine Island Glacier, where researchers believe the West Antarctic Ice Sheet has already passed a tipping point on its collapse into the ocean.
Challenges in Observing Glacial Changes
Satellite images provide ongoing observations. But orbiting satellites pass by each point on Earth only every three days. What happens during those three days is harder to pin down, especially in the dangerous landscape of a fragile Antarctic ice shelf.
For the new study, the researchers combined tools to understand the rift’s formation. They used seismic data recorded by instruments placed on the ice shelf by other researchers in 2012 with radar observations from satellites.
Glacier ice acts like a solid on short timescales, but it’s more like a viscous liquid on long timescales.
“Is rift formation more like glass breaking or like Silly Putty being pulled apart? That was the question,” Olinger said. “Our calculations for this event show that it’s a lot more like glass breaking.”
The Role of Seawater and Future Research
If the ice were a simple brittle material, it should have shattered even faster, Olinger said. Further investigation pointed to the role of seawater. Seawater in the rifts holds the space open against the inward forces of the glacier. And since seawater has viscosity, surface tension, and mass, it can’t just instantly fill the void. Instead, the pace at which seawater fills the opening crack helps slow the rift’s spread.
“Before we can improve the performance of large-scale ice sheet models and projections of future sea-level rise, we have to have a good, physics-based understanding of the many different processes that influence ice shelf stability,” Olinger said.
Reference: “Ocean Coupling Limits Rupture Velocity of Fastest Observed Ice Shelf Rift Propagation Event” by Stephanie D. Olinger, Bradley P. Lipovsky and Marine A. Denolle, 05 February 2024, AGU Advances.
DOI: 10.1029/2023AV001023
The research was funded by the National Science Foundation. Co-authors are Brad Lipovsky and Marine Denolle, both UW faculty members in Earth and space sciences who began advising the work while at Harvard University.
“There’s enough water frozen in Greenland and Antarctic glaciers that if they melted, global seas would rise by many feet.”
That is true. However, what isn’t mentioned is that the best extrapolations of melting time are several multiples of the length of time that civilization has existed. Tectonic plates move about 10X faster than current sea level rise! That gives plenty of time to adapt, as the Dutch have done, or to explore the risky route of climate modification — assuming that the climate doesn’t reverse on its own. Those pesky irreversible Tipping Points have a habit of ‘untipping,’ as happened in Greenland after the Eemian Interglacial.
“A critical question is how warmer oceans might cause glaciers to break apart more quickly.”
The unstated assumption is that warming has an effect on the brittleness of ice. Is there any evidence, theoretical or empirical, to support the assumption? Perhaps the above quote should have been, “IF warmer oceans could cause glaciers to break apart more quickly.” Strangely, there is no mention of the role of tides, particularly higher than usual Spring Tides in semi-enclosed areas, in flexing an unsupported extension of brittle material. Why is it that these newly-minted PhDs have trouble thinking ‘outside the box?’ Do geology curricula no longer require reading T. C. Chamberlain’s ‘The Method of Multiple Working Hypotheses’?
Also, do you really think the elite would be investing billions of dollars on coastal real estate if this was a real possibility? No, they would not.
The “elite” are dumbasses. Do not imagine that they know what they’re doing. They don’t.
This is where we have to remember it wasn’t till the late 1970’s when the semi conductors made the equipment small and light enough to fly over the poles and scare everyone for more funding scientists are like gypsies they need good money for jobs so their kids can go to good schools What scientist doesn’t want a Tesla like their boss zipping around watching a computer screen for the next juice stop it’s only right we keep the worlds slave labor busy digging for battery minerals like cobalt yep dumbasses
ExxonMobil knew before the 70’s, their scientists were the first ones to raise the alarm about putting so much carbon back into the atmosphere. Up until the early 2000’s Republicans were on board searching for solutions. It wasn’t until the carbon tax proposal that the naysayers got loud and started hiring their own scientists, which they paid to contradict the regular scientists and claim that there was no such thing as climate change, and we’ve been at odds ever since. The whole thing is really tragic because there is no going back, we can’t put the carbon genie back into the bottle.
Unless they inherited the money, they have to be somewhat intelligent.
Yes they would and they do. Look at Florida for example. These people have enough money to take the risk for their beautiful views.
We deserve just what is happening, we don’t listen to the scientific truth, so learn how to treat water.
Are you seriously questioning the effect that warm temperatures have on ice? Let me explain: it melts. So considering the global warming trend that coincides with and is caused by the burning of fossil fuels, glaciers will continue to melt and contribute to sea level rise much faster that the plates will move to save the day. ((“…….a 6.5-mile (10.5 kilometer) crack formed in 2012 on Pine Island Glacier — a retreating ice shelf that holds back the larger West Antarctic ice sheet — in about 5 and a half minutes. That means the rift opened at about 115 feet (35 meters) per second, or about 80 miles per hour.))
Maybe John Kerry needs to quit jetting around the globe in a private jet.
“…, glaciers will continue to melt and contribute to sea level rise much faster that [sic] the plates will move to save the day.”
An assertion without any support. The oceans are rising about 2.5mm/year, while tectonic plates move on average about 2.5cm/year, sometimes much faster.
It is questionable that an ice tongue, named the Pine Island Glacier, squeezing out through a gap in the mountains, is holding back a continental glacier. The speed of an individual event such as a tension crack forming, or a boulder falling off the side of a mountain, has little bearing on the average long-term behavior of something that behaves like Silly Putty.
Your obvious outrage at someone saying something you don’t agree with is not justified in the light of your demonstrated poor understanding of glaciology.
If the shelf ice is resisting the forward motion of the Pine Island Glacier, shouldn’t there be compressive forces acting on the ice? How then does a tension fracture form and stay open once it formed? Shouldn’t the accelerating ice close the gap?
“Let me explain: it melts.”
At zero degrees Celsius. “The mean annual temperature of the interior is −43.5 °C.” [Wikipedia]
Someone better tell the Obamas!! They just paid 27 million for an ocean front mansion in Martha’s vineyard 😎
“Ice shelves exert a really important stabilizing influence on the rest of the Antarctic ice sheet. If an ice shelf breaks up, the glacier ice behind really speeds up,”
This is a commonly made claim. However, I think that the theoretical underpinnings are weak. The slope of the land and the friction with bedrock over tens of miles are the primary determining factors of ice velocity. In turn, the relief of the bedrock topography, the type of rock, and the presence or absence of basal meltwater modify the net friction. If there are barriers to simply sliding over the bedrock, the ice is capable of shearing over the top of the obstruction(s). If a barrier should suddenly fail, the bulge behind it (upstream) will relax and allow a temporary surge. All one has to do is look at fjords, or Yosemite NP, to see that glaciers can remove all obstacles to their forward motion, given sufficient time. One should look at and compare the forward velocity of ice shelves with and without grounding lines that are otherwise similar.
There was a recent article here in SciTechDaily that showed an animation of a claimed surge after a major calving event. I watched it several times and could not discern any obvious change in speed. One would also expect tension fractures immediately upstream from the break at the presumed grounding line. They are notable by their absence. There seem to be many assumptions about the behavior of Antarctic ice that are poorly supported by theory or observations.
All points well made and settled facts within the various ranges of sciences involved. Just as global warming is conventional wisdom well beyond the debating stage when the study was an idea and no more than a theory in its infancy.
Here is another fact…this one couched in the conventions of Oceanography. When glaciers melt the resulting fresh water lowers the salinity of the Earth’s Oceans. Specifically, the Pacific Ocean is home the the North Pacific Gyre…which is responsible for the relatively temperate climate enjoyed by North American Continentals. Change the ph level of the Pacific Ocean enough…and the Gyre STALLS! Now weather patterns are given to brutal extremes like Russia and the Middle East experience. Watch any given nightly newscast in any town of the USA… it has already begun… Lives are daily being lost.
Debate global warming? Your either pathologically selfish and playing dumb; or you are a coward to the point of medically reduced intelligence quotient.
Psychology is full of established facts as well, and if you deny climate change, then at least accept the help of modern psychology. Science is real.v Go ahead ask around!
I would expect that a considerable amount of sub-glacial erosion occurs by sub-glacial water (rivers) carrying rocks that have dropped off the adjacent mountainsides. These start as angular blocks and end up as well-rounded pebbles and cobbles that emerge from the glacier’s snout. As for speed of propagation of glacial fractures. Simple physics would suggest that once a crack initiates the stress concentration at the point of the developing crack would further enhance rate of fracture. Albeit that the behaviour of ice is not that of rock, glass or steel.
Rocks tumbled in a channel will end up getting rounded. As observed today, these streams are typically confined to a relatively narrow, sinuous path. The last time I visited the Fox Glacier (NZ) the park service had built a path and bridge over the singular stream exiting the ice front. However, while in Greenland, the roar of a meltwater stream well above the bedrock was a sufficient incentive to stop the upward driving of an intended air shaft in the Army tunnel (Camp Tuto). Pleistocene under-ice streams are evidenced by what are called eskers, in contrast to a ground moraine that is reworked by inadequate water to move all the material, and results in braided streams. However, water isn’t necessary to deepen a glacial valley, as shown here: https://www.scenicusa.net/images/MY08GlacialGroovesPD.jpg
Concerns over ice sheets melting and raising sea level are probably not as important as the changing salinity having adverse effects on variety of sea life and also on how the oceans tend to control environmental response such as carbon and heat retention.
How many people died as a direct result? Until you can answer that with a healthy-sounding number, what wake-up call?
Thats a dumb statement. Life on earth isnt all about how many people have died. People & animals dont have to die to be affected by climate change.
The extremes of a once temperate climate is a foundational change to the North American’s life. The brutal force involved along with a learning curve as we adapt to the new reality of killer storms–fire storms in California last summer, and now wind and snow storms are racking up body counts in the Sunshine State. Listen to the news on serious formats like NPR and the BBC… it irks me and makes me worry that folks like yourself are aggressively ignorant of the human condition taking a pretty heavy hit. The losses are occurring on the home team side for God’s sake. Wake up.
The North Pacific Gyre is in the process of stalling out and it is the one greatest cause of North America’s history of hospitable, temperate climate relative to the rest of the world.
The engine driving this Gyre is dependent on an unforgivingly exact balance of Salt vs H2O.
T when the glaciers melt the resulting freshwater added to the ocean create an imbalance in the pH level the salinity basically is lowered below the threshold necessary to run the engine of the North Pacific dryer
Certainly, fresh water can be problematic for marine life. However, there doesn’t seem to be any evidence that the end of the last glaciation was an existential problem for it. Perhaps that is because the freshwater floats in the mixing zone and the salinity is quickly restored, despite evidence for a 12m rise in about 1,000 years:
https://i0.wp.com/fabiusmaximus.com/wp-content/uploads/2014/08/holocene_sea_level.png?ssl=1
It can’t melt fast enough for me – the so called professionals don’t even know why we have glaciers or how we had an ice age.
This planet is about to get hot, very hot for the human race and I’m more thrilled than anything. Those of us that understand our world and what is happening know what it means to travail like a woman about to give birth. REVELATION 13 is about to happen. First though before mankind’s last test of love God is giving them a chance to reconcile REVELATION 14:6-12 & 18 – then REVELATION 16 will happen to those not ready… So exciting watching prophecy unfold daily globally. The “MESSAGE OF TRUTH” is going around the world right now – THEN THE END WILL COME! I WILL GIVE YOU ONE PEARL – GET READY FOR FORCED WORSHIP OF SUNDAY & BEING SEALED BY SATAN – Because those of us being Sealed by God on his holy Sabbath day are ready – HERE IS THE PATIENCE OF THE SAINTS THAT KEEP MY COMMANDMENTS AND TESTIMONIES OF JESUS CHRIST
This has been coming for thousands of years. Mankind has accelerated it but are not the cause. I recently read an article on the mammoth extinction and that it’s major cause was global warming. And other extinction events were also caused by it. Plus this has been evolving for thousands of years, look at sunken cities dating back thousands of years.
Read another article:
https://scitechdaily.com/humans-had-significant-role-in-the-extinction-of-the-woolly-mammoth/
Hey don’t get in the way of a trillion dollar scam & political talking point. Do you have any idea how much money people donate to fix this “man made” catastrophe? If people start thinking that could come to an end. 🙂
[trillion dollar scam & political talking point]
When global warming renders the food supply exiguous, environmentally aware citizens get to dispatch, dress & eat climate change deniers.
It is only fair. you were warned.
Keep in touch 😉
Excellent points you make. Thank you for marshalling good science and established fact in making your point. N I accept what you’re saying but aren’t we obligated to mitigate to whatever extent possible the deleterious effects upon human life. I consider human life Paramount to all others and therefore I personally find it incumbent upon myself to do everything I can to preserve and extend the quality and duration of human life whenever or wherever I see it threatened. It is not possible for me to do otherwise… And I don’t believe that I am special in this regard I believe the natural state of the way man is made means behaving as a jealous defender of the species and it’s survival.
My last comment was directed towards John McReynolds’ very credible statement.
Yeah, super excited to see God’s rath rain down on those that belief differently than you. That sounds just like something Jesus would feel doesn’t it? Or maybe not and that should make u question if u really are one to be saved, I doubt it. Such a loving god u believe in. Keep waiting
Did Joe Biden type that for you? The coherency & grammar is just staggering.
A+ for the Joe Biden comment, Walter!
Once noticed why not implant anchors into both sides in order to keep it from going adrift .
Its will slow the inevitable process.
What a massive waste of time & money.
Do you have any idea what it would take to anchor & stop something of such a colossal size from splitting or even slowing it down?
Granted I have not been on the planet long enough to speak from experience but I have been around long enough to hear the same incessant babbling about the end the world. Wolf has been cried too many times for me to worry about wolves.
Why is its a wake up call for America. Why not China or Inda.
America had done a our part.
Because only the ‘evil’ white Western people are bad, duh.
There’s more heat in this comment section than in the actual atmosphere. Folks, don’t give in to the fear merchants. There’s nothing to worry about. And even if there were – there would be nothing you could do about it, anyway. So just chill and take this kind of news with a large pinch of salt.
And finally Jeff spicoli he’s heard from
There’s always a major ‘catastrophe’ going on supposedly from climate change, an issue that we have no idea how much is because of humans.
And people are losing their minds expecting us to stop use of all fossil fuels immediately. Well even if the US stops every single drop tomorrow; Africa, South/Central America & Asia won’t even consider the idea — so there is no point in completely tanking our economy & killings thousands if not millions of people for something that we alone can’t fix.
What a load of fabricated science fiction climate hoax BS you people will say and do anything to push your globalist agenda to brainwash people to live in fear fear fear you people are nothing but criminals soon you all will be arrested
[What a load of fabricated science fiction climate hoax BS you people will say]
We both know that is untrue.
When global warming renders the food supply exiguous, environmentally aware citizens get to dispatch, dress & eat climate change deniers.
It is only fair. you were warned. 😉
“We both know” is such a shallow attempt at persuasion here.
You, in fact, don’t know anything. You only think you know something. And your certainly don’t know what the guy you replied to knows.
Hope this didn’t strain your brain.
Liars. Most of Antarctica is either unknown or forbidden. Until “They” come clean with the truth, they will always be liars about whatever they try to sell us next.
Water expands as it freezes.it displaces fluids around it. Fill a glass with ice and water,let the ice melt the result will be a glass less than full. Your science and hypothesis are wrong, dumb and just dishonest.
The glacier sits on LAND. When it melts, the oceans rise. I don’t want anyone to live in fear, nor do I want anyone to stick their head in the sand.
The left panics over climate change, don’t they know that North America and south America was covered with ice for a very long time and it started melting at the end of the ice age and still melting like it always did. The way they talk, it like it started melting a few years ago. Now they panic because an ice sheet broke off like if it never happened before. How do they think the ice melted when NY and Canada was covered with a mile high ice sheet. Are these people serious? When will they start using their brain, they have no common sense, it’s laughable, they are really clueless
Natural, cyclical geological, and meteorological events are NOT evidence of AWG.
I heard that researchers just found out that water is wet.
It’s a really sad fact, that there IS NO WAKE UP CALL for the society. Somehow, the brains of most people are wired in a fashion to deny science and facts and common sense, just about anything that puts us into danger and require change.
Just look at things like alcohol or tobacco or obesity. We will perish from the surface of the Earth, and the society will still be full of deniers.
It’s the psychology of people en mass. Those who care and understand don’t have enough power, and somewhere deep inside they also just deny it. Otherwise how else we can explain the lax approach?
Yes, Ice was melting before, and temperatures were so much warmer, just these people forget that at that ages life was adapted to that and there was a balance.
All the great dying events, wiping out majority of life on earth, were caused by climate change, with the exception of one meteorite.
So asking stupid things like how do you prove that ice melts on higher temperature and such, is really the deniers’ defendsive psychology.
Planet is in great shape. Just keep planting trees
Planet earth is in great shape, keep planting trees.carbon will be taken care of.