South Pole Episode 19. Cold Dirt, Permafrost, and the Greening of Antarctica

Explore the secrets locked in Antarctica’s permafrost as we dive into soil formation, ecosystem changes, and climate impacts in the world’s coldest desert. Guest Dr. Joe Levy, a geomorphologist and planetary scientist, shares insights from years of fieldwork in Antarctica’s dry valleys and how studying “cold dirt” offers clues about Earth’s past and Mars’ potential. Discover how warming temperatures and permafrost thaw could transform this frozen landscape into a carbon sink—or trigger unforeseen consequences. Join us as we learn about ancient soils, microbial mats, and the surprising parallels between Antarctica and Mars in this fascinating episode of South Pole.

Episode Guest: Dr. Joe Levy

Learn more about Dr. Levy here

Browse Dr. Levy’s publications here

Follow Dr. Levy on X

Learn more about the Cold Dirt Lab here

Episode Transcript  and more information on the Pine Forest Media Website

Follow Pine Forest Media on Instagram @pineforestmedia

Hosted, produced, written, and edited by Clark Marchese 

Cover art and PFM logo by Laurel Wong. 

Theme music by Nela Ruiz

Transcript:

[00:00:09.220] - Clark

Hello, and welcome back to another episode of South Pole, the podcast that explores everything Antarctica. I am your host, Clark Marchese, and today we are talking about cold dirt, Antarctica forests, permafrost thaw, marsh and climate change, space exploration, and the world's largest desert. Okay, it is Dirt Day, everyone. Finally, we made it. Today, we're talking all about dirt and permafrost in the Antarctica. The research question is that scientists are asking about it, how the dirt is changing, how old the dirt is, what the dirt can tell us about the past, are we getting more dirt soon, is that a good thing or bad thing? We will find out all about that in just a moment. Today's guest is Dr. Joe Levy, an Associate Professor of Earth and Environmental Geosciences at Colgate University. Dr. Levy is a geomorphologist and a planetary scientist with a passion for studying permafrost landscapes on Earth and beyond. His research spans both terrestrial and planetary science, focusing on the surface processes and geological-ecological interactions. He has led significant research initiatives, including fieldwork in Antarctica and investigations into glaciers on Mars. He is also part of a research laboratory called the Cold Dirt Lab, which we will learn more about today.

[00:01:33.790] - Clark

We have a lot to cover and a lot of vocabulary words in this episode. Buckle in, and I will see you on the other side. All right. Hello. We are recording. Well, the first question I have for you is if If you could just introduce yourself and tell us a bit about your research.

[00:02:03.390] - Dr. Joe Levy

Sure. I'm Joe Levy. I'm an Associate Professor of Earth and Environmental Geosciences at Colgate University in beautiful central New York State. I'm in the business of figuring out how soil and water and ice and salt and life all interact in cold landscapes, from Antarctica to Mars and anywhere there's cold dirt in between.

[00:02:23.050] - Clark

Amazing. We are definitely going to be talking about Antarctica, and we're going to be talking a little bit about Mars, too. But one question I to ask on the top of the show is, I don't think you've been to Mars, but it's possible you've been to Antarctica. If you have, can you tell us about some of the research projects that took you down there?

[00:02:39.850] - Dr. Joe Levy

Sure, yeah. I've been going to Antarctica since 2004. I started as a graduate student, and I've been back probably 13, 14 times at this point, going through all the stages of an academic life cycle as a postdoc, and now as a faculty member. I've worked on a wide variety of things, mostly with the United States Anartic program, a little bit with colleagues at Anartic and New Zealand, doing everything from mapping permafrost landscapes with high-resolution laser scanners to using delta deposits left behind by Paleo Lakes during the last Ice Age to try and reconstruct ice sheets. So a little bit of everything. But what unifies all these projects is working in the McMurdo dry valleys of Antarctica, which are this tiny corner of the continent that's not completely covered by ice sheets. And so there's exposed rock, there's exposed soil. And so right now, I'm finishing a five-year project with the National Science Foundation, trying to figure out how soil is born in this cold desert. How do you take a little bit of snowmelt every summer and have that water percolate into the ground and form these underground streams called water tracks? Is that a place where soil is being born in the Nordic continent?

[00:03:45.970] - Clark

Okay, I'm taking notes because there's probably some vocabulary words that we will need to work through. But first, let me just ask you, what made you interested to study soil and sediments?

[00:03:55.140] - Dr. Joe Levy

I've always loved to hike and be outside. When I discovered I could to be paid to do that for a living, it seemed great. But actually, my super nerd origin story goes back to college and sitting in a biology class, a chemistry class, and a geology class, which the last one I took totally on a lark All of them began the very first day with four and a half billion years ago, the Earth accreded out of dust and ice all blobbing together. I thought, Whoa, that's the beginning. That's where life, as we know it, that's where the elements that make up life, that's where everything started. So Maybe I should become a geoscientist because that's where all this stuff began. Since then, I've become one.

[00:04:37.600] - Clark

One word that I've seen associated with your work is geomorphologist. Do you identify as a geomorphologist?

[00:04:43.910] - Dr. Joe Levy

Yeah. I wear a lot of hats, but geo morphologist is great. That's someone who studies the geo, the Earth, and the morphology of the geo, so the shape of the Earth. It's a term I really like because it means I study landscapes and how they evolve, what they're made out and particularly how climate affects them. The surface of the Earth is awesome because it's the Earth, but it's in contact with the atmosphere, it's in contact with water and the water cycle. If you're interested in climate change, if you're interested in water resources, Everything's going on at the surface of the planet. That's where geomorphologists spend most of their time is studying those interactions between the solid Earth, the liquid Earth, the gaseous Earth, and for me, the icy Earth.

[00:05:25.270] - Clark

Awesome. You work also with an organization called the Cold Dirt Lab. Is this the The work that you do there?

[00:05:31.460] - Dr. Joe Levy

Oh, yeah. The Cold Dirt Lab is just the name for my lab group. I've moved from multiple institutions over the years. It's nice to have the Cold Dirt Lab group and alumni and colleagues who can always move with me. We're interested in how climate interaction with landscapes on time scales from seasons to years to millions of years. Really, anywhere in the solar system that ice is part of the landscape, there's someone in the Cold Dirt Lab doing some work. I think we're all really keen on ice in the landscape because where you have ice, you have melting or sublimation, where the ice is furtive away into gas. What it means is those landscapes with ice in them change really quickly. Other geologists might look at a landscape that changes a mountain range that changes over millions of years. But for me, It could be weeks, it could be years. Maybe I'm just not very patient, but I study quick-changing landscapes in the cold dirt lab. Right now, the cold dirt lab is at Colgate University, and I work with a team of outstanding undergraduate researchers on these projects.

[00:06:30.760] - Clark

Okay, there's a lot to unpack, and I'm taking even more notes, so we'll circle back to a couple of things you've said so far. But one phrase that stuck in my mind was about soil being born. What does it mean for soil to be born?

[00:06:42.890] - Dr. Joe Levy

So soil is a living thing. It's composed of sand grains and mineral grains, but also organic matter, also the water in the soil, the gasses in the soil. When you go outside and dig a hole, there's worms, there's beetles, all these things you can count it. There's no doubt that that soil is alive. But in Antarctica, it's this Mars-like cold, polar desert. It is super important that people understand that Antarctica is a cold desert. That's what really makes it special. It's below freezing most of the year. It's particularly way below freezing most of the year. It's all sediment grains that have been dropped off by glaciers and ice sheets grinding over the landscape for the last several million years. Basically, it looks like a gravel pile. It looks like sand and dust all mixed together. It's like there wouldn't any life in it at all. In the McMurdo Drive valleys, where I do most of my work, there is this tiny fragile ecosystem that has Nordic forests or microbial mats, like algae that's growing on the damp soil or in the little seasonal stream channels. Then the lion and tigers of the dry valleys, like Kyrie Byer and Adams calls them that, are nematodes and tardigrades and organisms that 100 of them could fit on your pinkie nail.

[00:07:55.390] - Dr. Joe Levy

So tiny, tiny creatures. The question here is, how do you go from sand and dust and gravel to something that looks like a living, breathing soil. How does organic matter build up in that soil? Right now, in most places in Antarctica, that's not happening. But as you look to the future, as the world warms up, as an Arctic permafrost thaws, those soils are going to be born. We're going to get organic matter mixed in. We're going to get organisms living in there. What we really want to know is, is there a place we can go now to look for a preview of what's going to happen across the whole continent as it deglaciates? That spot for previews now are these Nordic wetlands that I study, the water tracks, because they're the places that today have water and have seasonal melting in summer and are beginning to go from gravel to something that's smelly and full of organisms and really quite wonderful.

[00:08:47.600] - Clark

Okay. Maybe before we go any further, let me ask you about the term permafrost itself. In my understanding, that just means frozen soil. Is there anything more technical to the definition than that?

[00:08:59.200] - Dr. Joe Levy

Great question. There's a reason I chose cold dirt as the name of the lab. It's a real simple explanation. But it's a permafrost, strictly speaking, is soil that has remained frozen. That's an important thing. So it never thaws for at least two years. That's the official sparkling wine, champagne, dividing wine there. But most permafrost has been frozen for much, much longer. All the permafrost in Antarctica has been frozen since at least the last Ice Age, and probably for millions of years, actually, prior to that. But that doesn't mean that no soil thaw is there. So the very top of the soil, and I'm walking around in the dry valleys in summer there, it's like December, January, the upper part of the soil has thawed, it has melted, and that's called the active layer. That's the seasonally frozen and unfrozen part of the ground.

[00:09:43.270] - Clark

Is there a standard depth where the active layer starts and stops, or does it just depend on how much has thawed in a given area?

[00:09:49.930] - Dr. Joe Levy

It varies across the landscape. One thing we spend a lot of time doing is measuring the active layer thickness because that tells you, is the soil thawing more? Is that permafrost melting from the top down? You'll see us going out across the landscape, but it looks like minesweepers or something. We have these big long tea probes, a big steel rod, a little handle on top. Basically, it's like we're probing for, I don't know, whatever, water, gold, you name it. Or maybe it looks like the Dynamite Plunger from Black and White Movies, where we're poking the probe in the ground because that way when it hits something solid, that's something solid is frozen ground, is the ice. We can then measure that depth. Of course, in the water tracks and these wet soils and these wetlands, these Nordic marshes, it's falling really deeply. Wet soil thaws really deep, whereas the dry soils in the dry valleys, which are most of the soils, are like an insulator. They're like a pot holder. Mostly the Nordic permafrost is really stable. It's been resisting warming. It's been resisting thawing. For the long time, we've really thought that it's not going anywhere, although that is maybe changing.

[00:10:49.440] - Clark

Okay, we'll discuss that because you touched on something that I've heard from a number of scientists who work in Antarctica, whether they study the oceans or a species that lives there. Basically, they're telling me that the The Antarctica climate, the ecosystem, what have you, it used to be extremely stable, and now it seems like it's not necessarily as stable as it used to be. I want to check my understanding based off of what you said. I'm hearing that with increased hauling, more soil will be boring. But I also know that with ice in Antarctica, for example, there's some level to which it's supposed to melt and refreeze with the change of the seasons, and that's part of this stable system, right? My question is, in the era of global warming, are we seeing a trend of more thawing of the permafrost than there should be to maintain that stable system?

[00:11:35.140] - Dr. Joe Levy

Yeah. Folks have been looking for this smoking gun of climate change in the permafrost record in Antarctica a while now. People have been probing active layer and saying, Okay, is the active layer thickening? Are we getting deeper and deeper thaw every summer? In the early 2000s, into the 2010s, it was like, No, they're really consistent, they're really consistent. They're really consistent. So folks measured the permafrost temperature underneath that active layer. They would drill down in bore holes and say, Okay, is where is the permafrost warming up? Because that would be another sign that it's still below freezing, but it's warming up. Maybe one or two places it was beginning to look like that. But really in the last 5 or 10 years, one thing we've been seeing is that the amount of summertime heat that's available has been increasing. The summer is beginning warmer, the peak temperatures are beginning warmer. That's potentially following the permafrost from above. It's expanding those active layers. But one thing we started looking at just this past year that was really interesting is we have this 30-year record of weather station records from the McMurdo Drive Alley's long-term Ecological Research Group, emphasis on long-term.

[00:12:38.530] - Dr. Joe Levy

One thing I was really curious about is what's going on in winter. No one is there in winter, so we have to rely on our instruments. If you look over the last 30 years of winter, winters have actually been warming up in the dry valleys. Now we're still talking minus 20, minus 30, minus 40 degrees celsius, but they've been getting warmer and warmer and warmer. What that means is the permafrost is not cooling off as much as it used to. I'm beginning to wonder if this permafrost is actually in a vise, like where it's being squeezed from both sides. It's falling more in summer, it's freezing less in winter. If you project these calculations forward for what's going to happen to the permafrost and just put that straight line into the future. There are patches of Antarctica that could become permafrost-free as early as the early 2100s, and that's way earlier than anyone thought. Again, everyone had this vision that Antarctica was insulated or isolated from global systems, and it's not. It's coming for the ice, too.

[00:13:33.810] - Clark

Then I have a series of questions about the consequences of that thawing. Let me first ask you how the thaw affects the soil properties itself, such as, I don't know, salinity, oxygen levels, maybe, and then also how any of those changes might affect the soil biota, anything living in the soil in any way?

[00:13:52.660] - Dr. Joe Levy

Oh, great question. As the soil is warm, they become more habitable, more hospitable to life. There are corners of the dry valleys that are actually too cold and too dry for anything to live. As the soils warm up, it's possible for microbes to colonize them, for these microbial matss to spread. The microbial matss really need water. They're a plant-like organism. The wetter the soils get, the more they fall them over that ground ice can wick up like a wet sponge that you use to keep a plant going if you were transplanting it somewhere. That's going to be good for primary producers. That's going to be good for the Nordic forests that are going to be pulling carbon dioxide out of the air and putting it into the soil. Many of the microbes and larger organisms that live in the soil like warmer temperatures, too. Some of them don't. They're, of course, adapted to live in Antarctica. But if you just add water, these things start metabolizing, they start eating the microbes. Really, warmer, wetter soils in Antarctica will probably mean more clement conditions, more critters living in the soil. That's the point where I say I'm a geomorphologist, not a real biologist because I call them critters.

[00:14:58.200] - Dr. Joe Levy

From their perspective, The warming conditions are probably better if you want to multiply and thrive and really inhabit the soil and create a thriving soil ecosystem. Right now, the soils there are limited by water and by temperature. But as the soils get wetter, what you're going to notice is that you start flushing out all of the salts that are in the soil. Right now, the Nordic desert is unusual because it's cold, because it's dry, but also because it's extremely salty. It's been so cold and so dry there for the last, in some cases, 3 million years, in some cases, 8 million years. That salt is built up in soils. As those salts get flushed out down through these underground streams, these water tracks into the wetlands, sometimes it's like pickle juice. I mean, it's like actually too salty for organisms to live. There's this real competition between the soil is getting warmer, the soil is getting wetter, and then also the soil is getting saltier. The real tug of war we're trying to figure out now is which is going to win. Is the soil eventually going to flush itself out of all these salts and become something more like Arctic soils, which are grasses throwing in them, and you could have mastodons walking across the tundra during the last Ice Age.

[00:16:06.740] - Dr. Joe Levy

Or are we talking basically that this is going to be a salt flat in the Salt Lake situation, and it'll be very hard for organisms to live there?

[00:16:15.650] - Clark

Okay, interesting. There may be a bit of scrambling of which species can live where, if any, and if they can, which species thrive, which new ones get introduced, how they interact with the ones that are already there. I guess we have to keep an eye on that. But I'm also curious, will the washing of these minerals in the soil, will that be at a large enough scale to actually affect the surrounding ocean water, too? Because we know that marine life is adapted to current conditions and might be affected by a change like that if it's at a large enough scale.

[00:16:42.650] - Dr. Joe Levy

Sure. The interesting thing about this, again, is that the dry valleys are a small part of Antarctica, but they're connected to the Southern Ocean. They're connected to all of Antarctica. So some really neat work that my colleague, Barry Lyons, has been doing, has been looking at how iron from the soils is washed out to sea and actually could fertilize offshore organisms, so plankton living in the ocean. So any funding that makes Antarctica interesting from a geologist's perspective is that it's a place where there's almost no chemical weathering. If you've had an Earth science class, most people think back to third grade, they're like, Oh, physical weathering, that's when a rock break down a little pieces because you hit them like with glaciers or other rocks. Chemical weathering is when they dissolve and chemically change. For years, people said, Oh, there's no chemical weathering in Antarctica. It's too cold, it's too dry. Now we're seeing actually that it's happening everywhere, particularly in these Nordic wetlands. That's how that iron is getting leached out of the soil and washed out to sea. There is a real potential for more export of iron and other nutrients into the Southern Ocean, which are otherwise a pretty nutrient-poor place.

[00:17:46.570] - Dr. Joe Levy

That's going to mean more plankton living in those waters.

[00:17:50.690] - Clark

Okay. As far as the plankton they're concerned, they are currently fulfilling their given role in relation to their species-rich ecosystem. If there's a change, things could get shifted around. But when you mentioned that when soil thaws, organisms may colonize a new area, species colonization in the past has caused a lot of problems. Dr. Richard Phillips mentioned to us in our third episode that even sailors bringing mice to Antarctica accidentally in the ship cargo had some major consequences for Antarctica wildlife. But if these new organisms are going to be colonizing an area that was previously inhospitable, do you foresee any negative implications, or is that just a cool science fact that will soon start to Yeah.

[00:18:31.040] - Dr. Joe Levy

I mean, so right now, the dry valleys are home to organisms that have evolved over millions of years to this cold, dry environment. They've survived ice age after ice age. They really figured out how to survive. They're a wonderful model ecosystem for studying how organisms adapt to change over time, but also just how, fundamentally, how an ecosystem is structured. The same way I said, it's hard to make a living in Antarctica and to survive there, and that's why I like it. It's all very deliberate. You can really see the connections between the organisms that live there today. We actually do a lot of work to try and keep outside organisms from arriving in Antarctica and taking advantage of warmer or wetter conditions. There's real serious biosecurity to prevent that contamination. But on the flip side, change is happening. I think what we're going to see, the long term feature is the greening of Antarctica and the greening of Nordic soils. Organisms that don't live there today are eventually going to arrive. They're going to live in these soils. They're going to grow. I think that's another important lesson for what's that going to do for carbon atmosphere?

[00:19:40.360] - Dr. Joe Levy

Are we actually going to have a carbon sink in Nordic soils as they bulk up and become more arctic How much? Is it enough to matter? We really don't know. We're just in the beginning of trying to figure that out because there's a whole continent's worth of soil underneath the ice that is going to start playing in global systems. And outside organisms are going to do that. The organisms that live there today really aren't up to that task. They're too adapted to the cold and the dry. But when we start seeing someday grasses in Antarctica, it was described by the earliest explorers as a great place to grow potatoes. We'll see.

[00:20:12.540] - Clark

Okay, I think I have more follow-up questions in this conversation than I might have ever had on any other episode, but I do have a couple more.

[00:20:19.380] - Dr. Joe Levy

I'm glad you like dirt, too.

[00:20:21.430] - Clark

It's so much fun. You mentioned a term called Antartic Forests. I'm wondering, is that just a word we use to describe the microorganisms organisms in the soil, or is that projecting into the future where there actually will be forests in Antarctica, like we understand forests today?

[00:20:38.630] - Dr. Joe Levy

I think I'm actually probably the only one who calls these microbial mats, Antartic Forests. You're so used to working on barren, rocky, gravely landscapes. When you encounter one of these things, it's like walking to a forest. It's just teeming with microbial life. The question is, why is it right there? What makes this place special, and how can that environment expand?

[00:20:57.680] - Clark

Got it. Then I'm wondering, you mentioned that maybe we could see the soil and the growth from it become a carbon sink. But isn't there also a concern that thawing could contribute a climate feedback loop in a way that intensifies the amount of carbon that's trapped in the atmosphere?

[00:21:14.790] - Dr. Joe Levy

Yeah. In most places, permafrost thaw is a real problem. It has the local problem that if you have ice on the ground and that ice thaws, then it destabilizes the ground surface. If you have infrastructure or houses or power lines, it wreaks havoc with those. There's It's also the climate feedback problem with thawing permafrost. Especially in the Arctic, permafrost is full of methane gas. When that permafrost thaws, that methane is released to the atmosphere. That's a powerful greenhouse gas. There's actually a positive feedback loop where thawing leads to methane release. Methane release leads to more warming, more warming leads to more thaw, which leads to more methane release. This has been called the permafrost carbon bomb. It should keep people awake at night. It's a potential really fast feedback in the climate system. Nordic Permafrost is not really part of either of those two problems. First of all, there's not a lot of people living there, and so certainly the bases are worried about Permafrost thaw and settling, and there's a lot of infrastructure around McMurdo Station and Scott Base and all the bases. But it's not like all communities living in the Arctic. Then also, because Antarctica has been covered by ice sheets for the last 34 million years, there's really not much organic matter in the soils at all there, as we can tell.

[00:22:30.300] - Dr. Joe Levy

Really, it's coming in from above now. That's what I mean when I talk about the birth of energy soil is a top-down growth of carbon in the soil. So as that permafrost thaws, it's not releasing carbon to the atmosphere in any place we've looked. Really, what it's doing is starting to build up that organic matter. It's taking carbon out of the atmosphere. It's turning it into microbial mats, and then that's building up in the soil because it's a real short-growing season. Organisms can grow in December, January, into February, and then everything freezes up, so nothing eat them. Over time, that organic matter can start to build up. It probably is a carbon sink. If you deglaciated all of Antarctica, you would have a landmass the size of the US and Canada put together. Some of it's below sea level, but some of it is just waiting to become soil. I think that's not a silver bullet. I don't think that's like, Oh, the solution to climate change is just to remove all the ice from Antarctica. That is not the case. That's a lot of sea level rise to contend with. But I think what we really have to do is think about Antarctica in post-glacial world.

[00:23:31.010] - Dr. Joe Levy

What's the next step? How does Antarctica actually fit into that? Antarctica soils are going to be a big part of that story because in the same way, I look at my window in central New York, and 20,000 years ago, we were under two miles of ice sheet. All the soil that's out there today is new. It formed in the last 20,000 years. Right now, it's farm fields. It's full of carbon, and it plays a role in global climate systems and global chemistry. We should be doing the same thing for Antarctica. We should be thinking about what role is it going to play after the ice.

[00:24:03.450] - Clark

After the ice, that's ominous. Oh, gosh. Well, I didn't understand that there was so much methane in the permafrost, mostly in the Arctic, but that is alarming. But another thing that's kept me up at night, and this has even made me nervous before we had our last bubble pandemic, and maybe this is more of a problem in the Arctic as well, where it's closer to human civilization. But I read some papers where scientists are looking to see what organisms are frozen in the ice and then could come back to as it were, or come back into contact with our human civilizations. There might even be a concern that they could be pathogenic. I'm wondering if any of your research touches on that aspect, or if there's any organisms that we're discovering trapped in the Antarctica permafrost, or if you think that's something that could be an issue of concern in the Antarctica.

[00:24:49.220] - Dr. Joe Levy

Thankfully, there's very little that's pathogenic or dangerous in Antarctica. Actually, I always joke that it completely ruins me as a field scientist because there's no rattlesnakes, there's no dangerous organisms to speak of, at least in land. On the Coast, there's seals and orcas and things that you should keep an eye out for. But yeah, mostly the pathogens coming out of permafrost are in the Arctic. It's mostly in Siberia where this is happening. In Antarctica, the organisms that live there are so cold adapted and really have no adaptations from a warmer or more pleasant time. They're not particularly pathogenic. They're not dangerous to humans.

[00:25:24.300] - Clark

Okay, good news. I also wanted to ask you because we just had an episode a couple of weeks ago on ice ice corps, and we learned all about how they serve as a climate record since, I guess, as far back as we're able to reach the ice. I'm wondering what historical records are frozen in the permafrost and how they can be information that's useful for us today.

[00:25:44.140] - Dr. Joe Levy

The permafrost holds a lot of interesting climate data, but it's not in the way you would think of with an ice core. An ice core snow piles up and that gives you change over time with the gasses that are trapped or dust. In Antarctica, the Permafrost doesn't pile up like that, so you have look someplace else. Instead, what the Permafrost really does is it acts like glue, and it's like the people who super glue together their Lego creations when they're done with them. It really locks them into place. You get this wonderful record of landscapes that in other parts of the world would have blown away or been washed away by streams, and they're still there in Antarctica. They're in pristine condition. One thing we can do with permafrost, for example, is go and walk around Taylor Valley, one of the big dry valleys. Right now, it's this big open alpine valley. It It just looks like you're walking through, I don't know, Utah in winter. As you walk up the desert Valley walls, there's these river delta deposits, so places where a stream entered a lake and dumped a whole bunch of sediment, and it looks like a fan.

[00:26:41.870] - Dr. Joe Levy

There's no stream there now in many cases. There's certainly no big body of water that it flowed into. It's like, what's going on with these deltas that are struck to the walls? What's going on with the deltas is there are paleo-climate records. They're telling us that at some point in the past, and we can tell when in the past because we can radio carbon to date, algal nets and microbial mats that are trapped in the deltas, the Taylor Valley was filled up with water. How do you fill up this desert valley with water? Well, you stick a cork at the end. During the last Ice Age, when the ice sheets grew, they actually expanded and flutter up into the dry valleys and closed up the mouth of the valley. They melted, and as the local glaciers melted in summer, it produced this giant lake, like the Paleo Lakes in the desert Southwest of the US. During the last Ice Age, places that didn't have the standing bodies of water did. The deltas were deposited in that. Then as the ice sheets retreated, water level dropped. The Delta has got dropped sequentially, lower and lower down the valley walls.

[00:27:36.970] - Dr. Joe Levy

Then they're locked in place by the permafrost, by this super glue. Now they're there 20,000 years later, and we can actually go and date them and figure out how quickly ice sheets retreat in Antarctica or how quickly they retreated during the last ice age by looking at these permafrost deposits and dating them. They're landscape clues that tell you something has changed, and they're beautifully preserved by the permafrost. When you put those two together, you have a record of climate change in the dry valleys, which is really better than almost anywhere else that doesn't have ice cores. I'm a little jealous of the ice core people.

[00:28:11.320] - Clark

Okay, that's fascinating. The ice cores have a record of how the climate changes over time. The Permafrost record has a record of how the Earth changes. If you cross-reference those data sets, you can get an understanding of how the Earth responds to changes in climate. That's so smart. Wow. I'm curious. One thing I read when I was reviewing in your work was that one concern with permafrost thaw is that some data that you were just mentioning will be lost, will no longer be available to us. How much of a concern is that? What questions might we not be able to get the answers to if the data in that permafrost gets melted away.

[00:28:48.880] - Dr. Joe Levy

Yeah. The permafrost holds the landscape together and it preserves the deposits. If you thaw a Paleo Lake Delta, for example, that's been held together by ice for 20,000 years, it just turns into mud. Then all of the datable material in it, those algimats that you're radiocarbon dating, trying to figure out how old it was, it all mixed together, they get destroyed. The real game now is trying to figure out what do we still need to know. There are many, for example, Paleo Lake Deltas that haven't been dated in the dry valleys. They're telling us something about the rise and fall of the lakes, and that's telling us about the ice sheets waxing and waning. Again, if we're interested in how quickly ice sheets can vanish, for example, because of climate change, We should look at the most recent time, ice sheets were much bigger and how quickly they vanished to their present state. That information is in these coastal Nordic deposit. We need to find those. We need to figure out which ones are most likely to thaw first. That's really the ones closest to the coastal line where it's warmest. That's the one that's at the lowest elevations.

[00:29:48.030] - Dr. Joe Levy

It's just like in temperate environments, that's the warmest spot. Those are the ones that are going to be turning into mud. There's also the search for the oldest ice. If we have not just the last ice age, but if we have multiple life sages or really historic moments in Earth history, nearly 10 million years ago, we want to capture what's preserved in those landscapes before they thought to, because that's really a once in a lifetime, once in a species opportunity.

[00:30:11.400] - Clark

Wow, once in a species. It seems like the cold dirt lab has a lot of work to do really quickly. For anyone interested in soil, it looks like there's a need for you to become an Antartic soil scientist quickly. I think we're going to take a hard left in the interest of time because there's one thing left that I really want to talk about with you today, which is outer space. I saw a bit of your research touches on Mars. Can you tell us about how all of this ice frozen kilometers underneath Antarctica has to do with outer space?

[00:30:39.220] - Dr. Joe Levy

I actually got into Antarctica because of Mars. I was a planetary geology PhD student My advisor had an opportunity to come collaborate with an Antarctica, and I came along and been doing it ever since. But the reason that folks who are interested in Mars want to go to Antarctica is it really is the most Mars-like place on Earth. It is the coldest dry driest desert on the planet. A cold day in Antarctica, minus 50 Celsius, is an average day on Mars. It's as close as you can get to the red planet without having a holacious commute. The other thing that makes it really similar is that it's really dry. It is the driest desert on Earth. When you put these two together, there are landforms that exist in only two places that I know of in the solar system. One is the dry valleys in Antarctica and the other is Mars. As we're getting more information about Mars, particularly from satellites that are taking high-resolution images of the ground, particularly Mars as polar regions, we start seeing these landforms that look just like permafrost features in Antarctica. Why should people care about that? Well, the permafrost features in Antarctica have ice in them.

[00:31:41.920] - Dr. Joe Levy

They're made out of ice and soil and salt. That means that the Martian features are very likely made out of ice and soil, too. If you're in the business of wanting to establish a city on Mars or even just a base on Mars, it's much easier to bring just the tools that you need to generate water than to bring a whole community's worth of water with you. It's much too heavy. If you can take that ice on Mars and melt it and capture it, then there's your city's water supply. That now is in ice, and that ice is in Martian permafrost.

[00:32:12.560] - Clark

Then if I'm understanding, I guess all the insights that we have from studying the permafrost and the soil in Antarctica can help us form hypotheses about Mars and maybe give us an understanding of what we might expect.

[00:32:22.830] - Dr. Joe Levy

Exactly, yeah. So Antarctica is very much the training ground for developing ideas about Mars. It's where our predictions come from, and then we send a spacecraft to figure it out and test those. When we send the spacecraft, whether they're landers that scrape away the dirt or radars, they can shine through the sediment. What they keep finding is between 30 degrees latitude, temperate latitudes on the Earth and the Pole, Mars has a thick pasted-on deposit of ice. It's like cream cheese on a bagel. It seems to have been deposited sometime in the last few million years. It's very young. It's trying to work its way the poles. Mars has ice caps just like Earth. That's where the ice is stable. This is Martian climate change. In the last 2-4 million years, the polar ice was destabilized on Mars. It deposited at lower latitudes, and now it's working its way back.

[00:33:14.790] - Clark

Wow. Okay, Martian climate change is another word that I have heard for the first time in this last however long we've been speaking. My next question is, because we had an episode where I spoke to an astrophysicist about research that he does out of Antarctica, and I was asking him, Why do we care? Why are we doing this type of research? The answer was basically just for the sake of better understanding the universe, which we hold space for that on this podcast, and I think it's super cool. But I just want to ask you about applying the research on Mars using these Antartic insights, because I was not expecting to hear that we're already at the stage where we're looking for water sources for a potential society. But what applied research is coming out of this space?

[00:33:54.310] - Dr. Joe Levy

You might be surprised to hear it, but I mean, a lot of people are interested in humans on Mars. Nasa has plans to send humans to Mars in small numbers. Elon Musk and SpaceX have plans for large numbers. And so, permafrost on Earth is not a growth industry, right? It's thawing. But permafrost on Mars, really is the... And Permafrost geomorphology is the key to unlocking where these deposits of ice are. There have been several meetings and workshops, landing site, selection workshops, where a bunch of us, Mars, Permafrost geomorphology types, from Mars, radar scientists all sit together and try and figure out where is the ice In particular, where is it accessible? There's plenty of ice, but the further towards the poles you get, the colder it gets. If you want something that's closer to the equator. That also makes it a lot easier to land. It also makes it a lot warmer. But the warmer it gets, the less stable the ice is, the deeper it goes underground. We're in this ICE prospecting business. The pure science, like Martian climate change, is really informing what could be the nuts and bolts of future human plumbing.

[00:34:55.830] - Dr. Joe Levy

It's the most important resource for space exploration.

[00:34:59.730] - Clark

Wow, I was not expecting that. But I guess here we are today, 2024, and this is what we're talking about. I think I've taken a lot of your time today, and I think we've covered quite a lot of topics. The last question I have for you is where can people find you and follow your work?

[00:35:12.780] - Dr. Joe Levy

I tweet from time to time at cold Cold Dirt on what is now X, I guess. I occasionally tell some science stories at the scua. Org, but mostly I publish a lot of what I write with my students. If anyone needs to find some polar science and they don't have access to it, shoot me email, and I'm always happy to talk about it and to share research results.

[00:35:33.630] - Clark

Okay, perfect. I'll make sure to include links to all of the above in the episode description so that people can find it easily. This is the part where I say thank you so much for coming on the show today. Thank you for teaching us about cold dirt and also for your very important research in this space.

[00:35:46.770] - Dr. Joe Levy

No worries. Thanks for getting in touch. This was tons of fun. Like you said, a giant polar dirt nerd, and so I'm always happy to talk about it.

[00:35:59.920] - Clark

You've been listening to South Pole. You can find more information about this week's guests and links to their work in the episode description. Cover art for the show was done by Laura Wong, and the music you're listening to was done by Nila Ruiz. I am your host, Clark Merkezi, and this episode was produced and engineered by me. If you found it interesting, send it to someone you know. South Pole is part of a larger network of sciencey podcast called Pineforest Media. We've got one on plastic, one on drinking water, and a couple of new ones coming out soon. You can find more information about us in the episode description or on our website at pineforestpods. Com. We're also on TikTok and Instagram at Pineforest Media. If you love the show and want to support science communication like this, a five-star rating across platforms and a review on Apple podcast is one of the best things you can do to help science reach more people and for the entire network to grow. All right, thank you so much to all of you who have made it this far, and we'll chat soon.