What’s hidden under the Greenland ice sheet? | Kristin Poinar

What’s hidden under the Greenland ice sheet? | Kristin Poinar

When was I was 21 years old, I had all this physics homework. Physics homework requires taking breaks, and Wikipedia was relatively new,
so I took a lot of breaks there. I kept going back to the same articles, reading them again and again, on glaciers, Antarctica and Greenland. How cool would it be to visit these places and what would it take to do so? Well, here we are on a repurposed Air Force cargo plane operated by NASA flying over the Greenland ice sheet. There’s a lot to see here, but there’s more that is hidden, waiting to be uncovered. What the Wikipedia articles didn’t tell me is that there’s liquid water
hidden inside the ice sheet, because we didn’t know that yet. I did learn on Wikipedia
that the Greenland ice sheet is huge, the size of Mexico, and its ice from top to bottom
is two miles thick. But it’s not just static. The ice flows like a river
downhill towards the ocean. As it flows around bends, it deforms and cracks. I get to study these amazing ice dynamics, which are located in one of the most
remote physical environments remaining on earth. To work in glaciology right now
is like getting in on the ground floor at Facebook in the 2000s. (Laughter) Our capability to fly airplanes
and satellites over the ice sheets is revolutionizing glaciology. It’s just starting to do for science what the smartphone
has done for social media. The satellites are reporting
a wealth of observations that are revealing new hidden facts
about the ice sheets continuously. For instance, we have observations
of the size of the Greenland ice sheet every month going back to 2002. You can look towards the bottom
of the screen here to see the month and the year go forward. You can see that some areas
of the ice sheet melt or lose ice in the summer. Other areas experience snowfall or gain ice back in the winter. This seasonal cycle, though, is eclipsed
by an overall rate of mass loss that would have stunned
a glaciologist 50 years ago. We never thought that an ice sheet could
lose mass into the ocean this quickly. Since these measurements began in 2002, the ice sheet has lost so much ice that if that water were piled up
on our smallest continent, it would drown Australia knee-deep. How is this possible? Well, under the ice lies the bedrock. We used radar to image the hills,
valleys, mountains and depressions that the ice flows over. Hidden under the ice sheet are channels
the size of the Grand Canyon that funnel ice and water
off of Greenland and into the ocean. The reason that radar
can reveal the bedrock is that ice is entirely
transparent to radar. You can do an experiment. Go home and put
an ice cube in the microwave. It won’t melt, because microwaves, or radar, pass straight through the ice
without interacting. If you want to melt your ice cube,
you have to get it wet, because water heats up easily
in the microwave. That’s the whole principle
the microwave oven is designed around. Radar can see water. And radar has revealed
a vast pool of liquid water hidden under my colleague Olivia, seven stories beneath her feet. Here, she’s used a pump to bring some of that water
back to the ice sheet’s surface. Just six years ago, we had no idea
this glacier aquifer existed. The aquifer formed when snow melts in the summer sun and trickles downward. It puddles up in huge pools. From there, the snow acts as an igloo, insulating this water
from the cold and the wind above. So the water can stay
hidden in the ice sheet in liquid form year after year. The question is, what happens next? Does the water stay there forever? It could. Or does it find a way out
to reach the global ocean? One possible way
for the water to reach the bedrock and from there the ocean is a crevasse, or a crack in the ice. When cracks fill with water, the weight of the water
forces them deeper and deeper. This is how fracking works to extract natural gas
from deep within the earth. Pressurized fluids fracture rocks. All it takes is a crack to get started. Well, we recently discovered that there are cracks available
in the Greenland ice sheet near this glacier aquifer. You can fly over
most of the Greenland ice sheet and see nothing, no cracks, no features on the surface, but as this helicopter
flies towards the coast, the path that water would take
on its quest to flow downhill, one crack appears, then another and another. Are these cracks filled with liquid water? And if so, how deep
do they take that water? Can they take it to the bedrock and the ocean? To answer these questions, we need something
beyond remote sensing data. We need numeric models. I write numeric models
that run on supercomputers. A numeric model
is simply a set of equations that works together to describe something. It can be as simple
as the next number in a sequence — one, three, five, seven — or it can be a more complex
set of equations that predict the future based on known conditions in the present. In our case, what are
the equations for how ice cracks? Well, engineers already have
a very good understanding of how aluminum, steel and plastics
fracture under stress. It’s an important problem in our society. And it turns out
that the engineering equations for how materials fracture are not that different
from my physics homework. So I borrowed them, adapted them for ice, and then I had a numeric model
for how a crevasse can fracture when filled with water from the aquifer. This is the power of math. It can help us understand
real processes in our world. I’ll show you now
the results of my numeric model, but first I should point out that the crevasse is about
a thousand times narrower than it is deep, so in the main panel here, we’ve zoomed in to better see the details. You can look to the smaller
panel on the right to see the true scale
for how tall and skinny the crevasse is. As the aquifer water
flows into the crevasse, some of it refreezes
in the negative 15 degree Celsius ice. That’s about as cold
as your kitchen freezer. But this loss can be overcome if the flow rate in from
the glacier aquifer is high enough. In our case, it is, and the aquifer water drives the crevasse
all the way to the base of the ice sheet a thousand meters below. From there, it has a clear path
to reach the ocean. So the aquifer water is a part of the three millimeters
per year of sea level rise that we experience as a global society. But there’s more: the aquifer water
might be punching above its weight. The ice flows in complex ways. In some places, the ice flows very fast. There tends to be water
at the base of the ice sheet here. In other places, not so fast. Usually, there’s not water
present at the base there. Now that we know the aquifer water
is getting to the base of the ice sheet, the next question is: Is it making the ice itself
flow faster into the ocean? We’re trying to uncover these mysteries
hidden inside the Greenland ice sheet so that we can better plan
for the sea level rise it holds. The amount of ice
that Greenland has lost since 2002 is just a small fraction
of what that ice sheet holds. Ice sheets are immense, powerful machines
that operate on long timescales. In the next 80 years, global sea levels
will rise at least 20 centimeters, perhaps as much as one meter, and maybe more. Our understanding
of future sea level rise is good, but our projections have a wide range. It’s our role as glaciologists
and scientists to narrow these uncertainties. How much sea level rise is coming, and how fast will it get here? We need to know how much and how fast, so the world and its communities can
plan for the sea level rise that’s coming. Thank you. (Applause)

100 thoughts on “What’s hidden under the Greenland ice sheet? | Kristin Poinar”

  • What about the coming ice age? Energy shortages? Global famines. Oops that's what was predicted in the 1970's.. this is all bs. Science can change any model they want.

  • There is way too many " i dont knows" within the science community. She went from 20cm to 1m in 20 years.. What happened to the world ending in 12 years? There is something somewhere in science that is wrong and has spiraled out of control.. Ancient theories physics and math was way superior.. Where is the 1 wrong thing we all think is right? This makes no sense… Roman concrete is superior to all.. The way they cut stone for the pyramids is superior to all… Apparently Nikola Tesla had the technology to harness free energy.. So with all these therioes and conclusions in science something is not adding up..

  • Superman’s cave of solitude is also located here. Superheroes can't fight crime and save lives around the clock. Sometimes they need a place to go to get away from it all, a place that is all their own, where they can relax and do the things they want to do.

  • Will Mathieson says:

    doing what humans have always done, adapt to change. Using fear of change to extract $$ from our pockets is political/corporate greed.

  • The Vikings swapped names between Greenland and Iceland to fool invaders – who, upon landing in Greenland discovered it was mostly Ice and that Iceland was likely the same (which it is not) The end result? The invaders moved on, arriving at North America long before Christopher Columbus, leaving volcanic Iceland to Icelanders and frozen Greenland to the Inuits. Tectonically, Greenland is part of the North American plate but is geographically closer to Canada than the USA – you hearing this Justin? Greenland – Canada's 11th Province makes more sense than becoming a US territory or her 51st State. I don't think the Danes would like that – and rightly so – leave Greenland be Captain America – she don't belong to you and hopefully never will.

  • Let's think about this moment. According to the science of calculus, if a snug belt were over the equator – and was increased in length by 7 feet.- could you crawl under it? Yes. So that's the science of calculus. So let's think about the geophysics of this- a bit more complex.

  • Corn Fields, that the Vikings Planted. Why do you think the Vikings called it Greenland, if it was totally Frozen and covered in Snow and Ice? They left when the Climate Changed, it when from Green to Frozen Over.

  • I live near the ocean and it is the same level now that it was 45 years ago so maybe the ice sheet has always flowed like this

  • “Waiting to be uncovered”
    The chemtrails are warming the planet to melt the Greenland sheet and scare the world into accepting one world government.
    The USA wants the natural resources under the ice.

  • but you dont know what the future is. if it gets colder, then the glaciers will store more water and the ocean will drop.

  • Go down to the ocean and you'll realize that the seas are NOT rising as this alarmist is claiming. Why? Because the REAL oceans DON'T use computers!!! Think about it.

  • Kristin Poinar, the earth DOESN'T use computers so predicting Climate Change with a computer only means that your prejudices are the Climate Change not the real Climate.

  • Kristin, Good luck with your computer predictions however do NOT rely on them to predict Climate Change – which is what you are really trying to convince us of.

  • Kristin, howzabout one of the inventors of Climate Change – Barry the Fairy Obama?

    "Now is the time when the seas will lower…or something."–Barack O'Stupid claiming to be Jesus in 2008.

    If you side with that moron then will it Doom Obama’s new Martha’s Vineyard mansion?

  • kernow trebartha says:

    Why worry over the inevitable… Everything ends, Sun's, Planets, Plant Life, Animal Life… Human Life. Even the Universe as a whole will end and we will never change that, just enjoy the miniscule amount of time you have at being alive.

  • Augustson Seventy says:

    "What's hidden under the Greenland ice sheet?"
    Everyone who's watched the Young Pope already knows the answer to this question!

  • We have been hearing that sea levels will rise but these idiot scientist have been wrong every time. What they have succeeded in doing it to manipulate the data. Thats all they have done.

  • Anthony Martin says:

    Sounds like brainwashing climate chance…and NASA….líes and fake everything …a front …Darpa…thats Who know whats going on ….and the massive chemtrail fumigación continúes 24/7 in Europe …White fake cloud skies and covering the sun…or sin simulator…..u Burn now in 30mins…no ozone due to toxic skies…wake Up dear

  • How cool would it be to visit these places. Yeah let's bring pollution, invade animals environment let them eat plastic and disrupt local natural cycles.

  • Currencia Currencia says:

    THIS SCREWBALL GIRL SAYS IF ALL THE WATER & ICE ON Greenland WERE TO BE SHIPPED AND DUMPED IN Australia, the island would have 20 inches of water more on it. Yet, at the end she says that if all the water and ice melted and flowed South it would raise all of Earth's sea level by maybe 8 feet. The sky is falling she sayeth. Little does she know or care that 50 million years ago Iceland was a lush rainforest with ferns and crocidiles.

  • Mike Gunner Sisco says:

    Well I’m disappointed tried an ice cube in the microwave and every single one melted lol. Even grabbed with tongs to avoid slightly heating them. Within 30 seconds they cracked and started melting. It didn’t matter what it was on or in they all melted within 2 minutes.

  • Ismayil Arifoglu says:

    Wvaterr. Nothing extraordinary is hidden under ice there. Leave Greenland alone. Otherwise, you will turn it into a next plastics dumpster.

  • This is all theory. Call me skeptical; Sounds like a researcher making the case to attract funding her research. I was taught in the 80s that there were lakes under the glaciers.

  • Personally, I think man made climate change is bullshit, however, I have no problem with people conducting reasearch to try to determine how much, how fast and geographical effects. Humans are an adaptive species, and there's nothing wrong with foresight. The manetic pole shift that is occurring has more to do with it than man. The magnetosphere blocks UV rays to a varying degree and as it shifts, warmer areas will cool, and cooler areas will warm. Someone following an actual scientific disipline rather than alarmist, could stand to make exorbitant amounts of money in real estate by playing the long game. It's going to happen. Always has, always will. I'm fairly certain tjat there are scientists out there that are privately funded to do real research to answer the geographical questions, but not the government funded "scientists" whose only job is to scare people into believing that if they just give governments more money, the government can somehow fix something thats a naturally occurring cycle.

  • NASA and other scientists have scientific evidence that the sun is about to go go through a very cool period with sunspots increasingly disappearing. They have warned the governments of an upcoming ice age which is to be going to measurable levels in 2020. The global warming was a big hoax to implement huge taxes on commercial companies aircrafts and vehicles.

  • If you actually cared lady about the ice sheet melting you would call out all governments for heating up the ionosphere with hf technology and manipulating the weather.

  • Veritas Veilleux says:

    If you want true answers about the time it takes for the ice sheet to melt, stop lying about the time it took to build. The Vikings called it «Greenland», in other words a land that was green a few hundred years ago, not millions years ago as your faked sciences want us to believe!

  • Wow! A girl who likes math! I think I'm in love.

    Seriously, though, the projection that the sea level will rise at least 20 centimeters in the next 80 years is based on a recent trend. But the climate of the Earth fluctuates between hot and cold. In fact, the Earth was still in the "little ice age" less than 200 years ago. This tells us that the recent trend toward warmer temperatures will reverse in due time, the Greenland ice sheet will thicken up again, and the sea level will fall.

  • well, I grew up hearing that California was going to fall off into the sea and Manhattan Island would be totally underwater by the year 1999…

  • Instead of letting all that water go into the ocean, it could be contained for something useful like irrigation of dry areas.

  • Not very scientific to report only one half of the ice mass equation. Over the past three years Greenland has accumulated ice, that is, there has been more snowfall than there has been ice melt. The precipitation originated from evaporated ocean water. In other words, Greenland is currently a net consumer of ocean water, not contributing to sea level rise. And, the ice mass is so huge that even if there was to be no more snow henceforth, the current levels of summertime ice melt, would require 6000 years to melt the icesheet completely. Not gonna happen.

  • Jesus Christ of Newtonville United church says:


  • Jesus Christ of Newtonville United church says:


  • oooSoundOfLifeooo says:

    I liked the tone and the factual delivery. No hot air, no cataclysmic predictions based on green religious beliefs, just science. This is what we do, this is what we found, this is what we're investigating, open questions, no hot headed conclusions without data.
    Really refreshing! (In every sense…)

  • the earth has been ice-less many times in its geological history. what is stunning is the earth maintains a oxygen level of 20.95 regardless on how we hammer and destroy our own biosphere.

  • Well Nestle Tea will take full advantage of any of the run off I promise you that. Never worry about the oceans rising they got it all figured out to dollars and bills and Clinton's pockets hint hint…

  • Nestle Tea makes more money than NASA lol just think about that for a lunar moment ok folks before you open your lids think how big that company is and what they own. NASA owns diapers compared to Nestle Tea man I love stupid Americans lol

  • Well I don't think we have to worry aboutwhat she was talking about in our lifetime my grandchildren's lifetime, and my great grandchildren's lifetime it's just the cycle of Life get over…. It's a big waste of money to put in other people's pockets…..

  • Second of allwhy don't they just stop wasting their time in Greenland and go to Nevada and tell us what's under area 51………. 😁😄😃😀😁

  • It`s now 17 years on from 2002 and no significant increase in ocean levels and Obama just bought an Ocean Front home at Martha`s Vineyard for $15 million……. a couple of feet above sea level…… I guess he can walk on water huh? https://robbreport.com/shelter/homes-for-sale/obamas-marthas-vineyard-estate-15-million-2865341/

  • Sea levels used to be 400 feet lower than present. Have you figured out a ratio of the rise since that time to include in your data set. If not… you are pissing in the wind. Even if sea level don't rise at all…. the Eastern seaboard will eventually subside into the Atlantic….fact.

  • This feature under the ice is actually one of the great vents in Earth's crust through which 'The Fountains of The Deep' burst at the start of The Flood.
    The pressure of the supercritical piezo-electricity heated water under the crust made sure the vent was truly massive.
    And more to the point the amount of rock and soil in that 31 km – 19 mile crater now accounts for a lot of the comets, meteorities and asteroids circling Earth.
    Anyone care to calculate the volume of a 32 km crater of unknown depth?

  • Now…block corporations from taking that water for next to nothing, and bottling it to line their wallets…while emitting huge CO2 to ship it…like Nestle’s has done to the major aquifers under the plains of North America/Canada.

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