Stuff You Should Know - How Ocean Currents Work

Episode Date: June 4, 2015

It's easy to overlook the importance of ocean currents - they move along out at sea, while we stay mostly on land. But we are globally affected by them every day. Currents form the base of the food chain, drive weather and keep life as we know it going. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

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on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts. Welcome to Stuff You Should Know, from HowStuffWorks.com. MUSIC Hey, and welcome to the podcast. I'm Josh Clark with Charles W. Chuck Bryant and Jerry. And this is Stuff You Should Know, the one about ocean currents.

We should start titling our episodes like friends did. Yeah, the one where Ross talks about ocean currents. Yeah, the one where Chuck's eyes glazed over. I love this stuff, man. Yeah. Like, Earth Science really gets me jazzed. That's good. It really does.

Like, it's so... Like, it's very detailed. Yeah. There's a lot to it. It's often oversimplified, but it's also very understandable. And when you really, like, learn about it, you realize what an elegant system the whole thing is. Sure.

Maybe not necessarily a living organism, but I could see how someone would characterize it as such. Yeah. I like that. It's a good intro. Yeah, that's what I got. So yes, title, ocean currents. Well, not title.

That's part of the ocean current system. That's a type of current. Yeah. It's under the current umbrella. I've misspoken the first 10 seconds. I think it's funny that in this article, the word current refers to the motion of water when speaking of water.

Is that what it says? Yeah. When speaking of water, the word current refers to the motion of the water. Yeah. Yeah. That was a little clumsy. Merriam's defines...

Yeah. Well, this is about ocean currents. There are all kinds of currents. River currents. Yeah. There's currents in marshes and swamps and currents all over the place. But this is about ocean currents.

Yeah. As long as water is not stagnant, there's currents present. Yeah, if it's stagnant, bad news, jack mosquitoes, disease, sure. But then again, you can make the case that if it's not stagnant, if there's a current, it'll carry your car away in the blink of an eye.

Don't even think about it. Boy, did you see the photos of the downtown connector the other day in Atlanta when it flooded? No. Apparently, the storm drains backed up. And the downtown connector of Atlanta was a lake. Wow. Like it literally stopped traffic.

I can believe that. Yeah. People in Atlanta don't know how to drive in the rain to begin with. Oh, I don't know about that. Really? Yeah, that's all we do is drive in the rain. Man.

People in LA don't know how to drive in the rain. Seems to me like everybody's brain just drops a couple of gears when rain starts. And everyone starts bumping into everybody else and driving at two miles an hour. You just pedal to the metal. Yeah. What's different?

All the time. I got good tires. Yeah. What's this? You like tire stores. I don't like tire stores, but I'm willing to spend time there to get good tires that move water away from my car so I can drive really fast

no matter what the weather. You should start your retirement. I want to point out Jerry just sighed heavily at this tangent. I think your retirement business should be Josh's tire house. Emporium? Yeah, and then have a really sweet setup. It would be like buying tires here is like no place else on earth.

Oh, yeah. You've got Wi-Fi. You've got a coffee machine. Well, there's coffee machines. Well, no. I mean a barista. Oh, gotcha. Like a little mini Starbucks right there in your tires shop.

Sure. Games have ice breakers, meat and greets. Yeah. I could serve ice breakers gum, too. You get a tender, tender day. OK, what else? Well, I don't know. That's all I got.

Aromatherapy would be good. Yeah. It'd be a big one. Massage. Yeah. All right, that's my plan B. All right. Josh's tire warehouse Emporium, I think,

is what we came up with. Sure. Josh's big house of tires. Our house of big tires. OK, so ocean currents. Yeah, we're back to it. So one of the things that I did not realize Chuck when researching this is that ocean currents,

they're old, but they aren't permanent. They haven't always been around. Yeah. Currents change. Some currents have been at it for thousands and thousands of years. Other currents change month to month. They're a fickle in some cases.

But there are some really ancient currents, some ancient ocean currents out there that are very old and have been this way since, say, like the Gulf Stream has been around for about 5 million years, ever since the Isthmus of Panama closed. Yeah. Pretty cool stuff, huh? Yeah, I think what I found the most interesting

was that ocean currents, they have a purpose. It's not just like water moving around willy-nilly. Right. If it wasn't for ocean currents, there would be no life in Antarctica. Right. Well, maybe not all of Antarctica, but no ocean marine life.

They make that possible. But that's an important point. If there's no ocean marine life, then there's no phytoplankton. Sure. There's no phytoplankton. There's no fishies eating the phytoplankton. There's no fishies around to eat the phytoplankton. There's no seals to eat the fishies.

If there's no seals, everything finds its support, its basis, in that ocean life. Absolutely. That's all supported by the currents. That's right. So the fact that it has purpose, it's very teleological of you, Chuck. Thank you. So let's not put this off any longer.

Let's talk about different types of currents. You can't talk about tire stores anymore? No. OK. We're done with the tire stores. Like, I started to get nauseated just talking that much about tire stores. Oh, really?

Man, I don't feel good. Well, let's start with surface currents then, buddy. I'll bring you back to the ocean. Earth science? You're home, earth sciences that you love. Surface currents occur about 300 to 400 meters deep and above. Yeah. They're called surface currents.

Right, and they're driven by the wind. Yeah, they'd make up for about 10% of the ocean. And if you've ever gone to the beach, you've seen coastal currents, surface currents. There's a couple of types. Coastal is one of them. You see them in action. Right.

Like, playing in the sand as a little kid or as an adult. You're seeing coastal surface currents at work. Right. So let's step back one more degree. So surface currents are created by wave action. That's right. Especially coastal currents are created by wave action. Yeah, which is created by wind.

Waves are created by wind. And you know Buckminster Fuller, the inventor of the geodesic dome among other great things? Sure. He was the person who pointed out that the wind doesn't blow. The wind sucks. That's a good point. Right.

And so if coastal currents begin with waves, waves begin with wind, wind begins with heat. Because at the equator, you have a lot of sunshine all year round. And it's very warm. Yes, it is. And as anyone who's been near the equator can attest. And that heat heats up air. And as the air heats up, it moves away from the equator.

It's like, I've got to go cool off. Yeah. It moves toward the poles, north and south. And as it moves toward the poles, it cools down and turns back around as like I need to heat back up at the equator. Yeah. Right. And as a result of this, you have wind.

And this wind pushes on the surface of the water, transfers some of its energy in the form of friction to the water surface, and creates waves. And those waves transfer the energy to the shoreline. And when they come in at an angle, that's when you get that coastal current, right? Yeah, like with you, again, if you've ever been to the beach and you see the tide or the waves coming in at that angle,

and you see it moving with the beach, like if you've ever been out playing on a raft as a little kid, you look up an hour later and your parents are like half a mile down the beach from where you started. It's a bit of a panicky situation. It is. And also, you're like, what kind of parents do I have that they just let me drift half a mile?

Yeah, they're passed out in the sand at that point. Yeah. So that is called when a wave breaks on the beach at that angle, it's going to pull sediment and sand and water down in what's known as a longshore current. That is, it's directed off parallel, also perpendicular, but the parallel movement is the longshore current. Yeah, it's like when a wave comes in at an angle to the shore,

it distributes its energy. Part of it directly onto the shore, part of it parallel to the shore. That's that longshore current, like you said. And one of the things that it does, you also said, is it takes sand and other stuff and deposits it elsewhere further down. And along the way, it creates things like barrier islands

and sandbars and all that stuff and this ever shifting, ever moving, eroding and depositing of sand and sediment. And those little underwater and sometimes above water deposits create other types of current, specifically a riptide current. Yeah, that's the longshore drift. And like if you've ever seen the beach curve back in pretty hard, the water can't make that turn really.

So it's just going to deposit stuff and sort of drop it off there at the end of that point. And it'll build up in what's known as a spit. Right. And so all of those obstructions, all of those deposits form obstructions for waves when they're going back out. Once they transfer their energy, they're like, oh,

I'm pretty far inland. I need to get back out to the ocean. And so it backs up, right? And as it does, it encounters these underwater barriers that it itself have deposited. It's kind of a big, ironic moment. And so it can't get back out to sea as fast as it wants because it's running in these obstructions.

And when there's like a break in the obstruction, like a sandbar or something like that, a break in the sandbar, it provides a natural funnel. And that creates a riptide current. Yeah, like, hey, look at that little narrow channel. I'm going to take all this water that would normally just flow out nice and easy. I'm going to send it through there.

And I'm going to grab your little kid and take him with me. Right. It creates basically suction, just like when you open a drain in a bathtub and it starts to drain. It drains pretty quick. Yeah, it's dangerous. That's how you drown when you're swimming in the ocean. You hear about strong rip currents and inclement weather.

And it's no joke. Even really good swimmers can get caught in a riptide. Oh, yeah. And it's bad news. Riptide, very bad news. And then there's some other currents that are created that don't just occur at the shore, but they do occur in the ocean and at the shore.

There's this thing called upwelling. Yeah, I like this stuff. And upwelling can happen in a few different ways. But as far as the coast is concerned, when wind comes in and it basically blows water away from an area. Yeah, like from the shore. Right. Water likes to try to even itself out.

So as some water is blown away from the surface, the stuff that's below it, the deeper water, will come up and basically replace it. Yeah. And that's upwelling. Yeah, it's another, like what strikes me when you look at wind and all these currents, everything is circular almost.

Right. So there's a lot of spinning going on. Yeah, there's a really distinct relationship between wind and water. It's inseparable, especially when you're talking about global winds and currents together, right? Yeah. But both of them are broken down to fluid dynamics.

And they do form these circles and cycles and clockwise motions and counterclockwise motions depending on where you are in the world. Yeah, and in the case of upwelling and downwelling, a horizontal spin, but it is a vertical from top to bottom and then from bottom back up to the top. Yeah, and you want to talk about that was which one? Well, both.

It's the same pattern from top to bottom and bottom to top with upwelling and downwelling. Right, and the whole thing about upwelling and downwelling, whether it's at the shore or in the ocean, is that the ocean is kind of, it's not, like if you take a slice of ocean at the top, and you take a slice of ocean at the bottom. Very different.

And you look at them, yeah, under a microscope or test them for whatever, using some sort of spectroscope, maybe some sort of oscillator, glaven or something like that. Yeah, or just look at it. Yeah, you're going to find that it's like two different types of water, even though it's from the same section of ocean, right? Yeah.

And the stuff at the top is going to be very oxygen rich. There's going to be a lot of life phytoplankton, that kind of stuff, but not too many nutrients. The stuff at the bottom is going to be lousy with CO2. Yeah, cold. Yeah, very cold, and a lot of nutrients, right? And when both of these things are needed at different spots. Yeah.

So the upwelling and the downwelling creates this kind of gas exchange and nutrient exchange throughout the ocean. And the oxygen at the top, when it's deposited down lower, thanks to downwelling, all of that oxygen circulates downward through the ocean. And all the fishies that need oxygen in their gills get to breathe it in, right?

Yeah, and with upwelling, like I mentioned earlier, in Antarctica, where it's super cold, and you would not expect marine life to do so well, it is because of the upwelling that brings that nutrients from the bottom up to the top in that cycle, and that's called life. And one other really neat thing about upwelling and downwelling is that oxygen that's at the top of the ocean

were to just sit there for very long and dissolve. We would have a very big problem, because all of that life, once it dies, would decay very quickly up top. Yeah, that's not good. No, it wouldn't, because anaerobic bacteria would begin to thrive, and we'd have a overabundance of hydrogen sulfide, which would lead to ocean acidification, which

would mean the end of the world, basically. Yeah, so that nutrient swap is very important for everybody on the planet. Yeah, and there's this elegant solution to the oceans that happens every day, everywhere in the ocean, thanks to upwelling and downwelling. All right, well, that's a good start, my friend. Mies are not glazed over, actually.

Good. They're sharp, full of life. We will talk after this break about some more surface currents. Woo-hoo. I'm Mangesh Atikular, and to be honest, I don't believe in astrology. But from the moment I was born, it's been a part of my life.

In India, it's like smoking. You might not smoke, but you're going to get secondhand astrology. And lately, I've been wondering if the universe has been trying to tell me to stop running and pay attention, because maybe there is magic in the stars, if you're willing to look for it. So I rounded up some friends, and we dove in,

and let me tell you, it got weird fast. Tantric curses, major league baseball teams, canceled marriages, K-pop. But just when I thought I had to handle on this sweet and curious show about astrology, my whole world came crashing down. Situation doesn't look good. There is risk to father. And my whole view on astrology, it changed.

Whether you're a skeptic or a believer, I think your ideas are going to change, too. Listen to Skyline Drive and the iHeart Radio app, Apple Podcast, or wherever you get your podcasts. On the podcast, Hey Dude, the 90s called David Lasher and Christine Taylor, stars of the cult classic show Hey Dude, bring you back to the days of slip dresses and choker necklaces.

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Oh, oh, oh, oh, oh, oh, oh, oh, oh, oh, oh, oh, oh, oh, oh, oh. All right, Josh, there's more than one kind of surface current. We covered the, I kind of like the first part, but there's also surface ocean currents. And again, the wind is the big contributor to how these babies form. And specifically, I guess we should talk about the Coriolis effect.

Yeah, this is a game changer, as people who read self-help books on airplanes would call it, right? Yeah, so again, it all starts with heat, and all that heat is found in its thickest part at the equator. My brain is broken. So at the equator, it's the hottest, right? That's right.

And it's also spinning faster at the equator than at the poles. Right, it is. OK, so it's the Earth, that is. So at the equator, it's hot. It's spinning faster. Because of the spin, because of the heat, the ocean is actually about eight centimeters higher here than at the rest of the ocean.

Yeah, that's so much higher. So there's a, right, it's just enough to make water flow away from the equator. Plus, you've got wind that's whipped up, because hot air at the equator starts moving northward and cools down, and that creates wind, right? So if the Earth didn't rotate, you would still have these things. But wind would travel in a straight line away

from the equator toward the poles, cool down, and turn around, and come back in a straight line. That's right, but that's not the case. No, it isn't, because the Earth does rotate, and it produces the Coriolis effect. Yeah, it's like a curve, basically. It curves to the right in the northern hemisphere, and to the left in the southern hemisphere.

Right, so it makes wind curve. And since wind drives surface currents, it makes surface currents curve as well, right? That's right. So what's really cool is the ocean has its own topography. Oh, yeah. It's definitely not flat. Anybody who's looked at an ocean can be like, oh,

that's pretty choppy. But if you could step back even further, and you had the right kind of topographical glasses on maybe, you would see that there's valleys and mountains, and maybe not mountains, but little tiny hills and valleys in the ocean. So like I said, it has its own topography. And this is created by those winds

that push on the water. And as they're pushing the water up, and the Coriolis effect is turning at some, water starts to kind of mound. So in some parts of the ocean, you have water that forms a mound that's about like three to six feet tall. Yeah, it doesn't sound intuitive.

No, I don't think. I think of water mounting up on itself. You think of it as flat. Yeah. But there is actually water that's mounted up into little hills. Yeah. And so that means that gravity wants to push this water

downward. Right? But it doesn't just go back down the hill because the Coriolis effect pushes it upward. And the net outcome is that instead, the water just says, how about I just go around instead? Yeah. You stay up here on the mound.

You stay down here. But I am going to just go around. And what it does is since a mound is roughly circular, it creates a current that goes around these things, around these mounds. And there's five major ones in the entire world. I know where you're headed. And they form what are called gyres.

That's right. G-Y-R-E-S. And they are the North Atlantic, South Atlantic, North Pacific, South Pacific. And then the Indian Ocean has its very own gyre. Yes. There were smaller ones around Antarctica, but those are the five major gyres. We talked about the Gulf Stream earlier.

That is a part of the North Atlantic gyre. And it carries 4,500 times the water of the entire Mississippi River, as the Gulf Stream does. Yeah, the Gulf Stream is the hero of all gyres. It is. Let me see. I've got to find this one because this is so amazing. So the Gulf Stream, at any given point,

it moves water at a rate of 15 superdome's worth per second. So you remember the superdome? In Louisiana. Yes. Sure. Say you filled it with water. OK. And then you took that and copied it 15, 14 more times.

So you have 15 superdome's full of water. That's how much water passes through any given point per second in the Gulf Stream. All right, that's a lot of water. How many Big Macs is that? It's trillions of Big Macs. Billions and billions served. But the Gulf Stream itself is actually,

it's technically the Western boundary current of the North Atlantic gyre. Yeah, and it's going to carry warm water. It has a big impact on the world. It's going to carry warm water up north from the Gulf of Mexico. And that's why if you're living on the east coast of Florida, you're going to have cooler summers and warmer winters. Western Europe is going to be a lot warmer than other places

on its exact same latitude. And this is all because of the Gulf Stream. Right. You can deposit bodies in it if you're a dexter. Yeah. And those things are going to, yep, see you later, body. Yeah, it'll probably get carried to England. And they'll be like, blimey, what is this?

So that's just the Gulf Stream. There's actually at least four major currents that form the boundary current of the North Atlantic gyre. Yeah. And the North Atlantic gyre is just one. We've also talked about gyres before with the Great Pacific Garbage Patch. Yeah, we covered, did we do waves or did we just do rogue waves?

We did rogue waves too, but we covered waves and surfing. OK. Yeah, yeah, I remember that. But these boundary currents are created, again, in part, by the winds flowing away from the equator, the Coriolis affect turning the waves and the mounds of water circulating the waves around them. So you've got these like just clockwise or counterclockwise,

depending on which hemisphere you are, currents that are just massive that move water around. And again, they cycle nutrients. Like you said, they affect the weather because they deposit warm water from the South all the way up to England. Apparently, so England is on the same latitude as some glacial parts of Canada.

Yeah, that makes sense. But their winners are like nothing compared to that. Thank you, Ocean. Same thing as Bermuda is very temperate. It has very nice climate. And it's on the same latitude as North Carolina, which is, it can get kind of cold there. Oh, yeah, sure.

That's all thanks to the Gulf Stream. Thank you, Gulf Stream. And if you want to thank the Gulf Stream, Chuck, you can thank Ben Franklin, because he's the one who named it. Oh, really? Yeah, as the first postmaster general of the United States, he wanted to figure out why Mail took so many more weeks longer to get from England to the US than it did from the US to England.

Because they're going against traffic. Exactly, but he didn't know that. And he found out, and he took some measurements and roughly charted the Gulf Stream back in the 18th century. Man, he was a smart dude. He really was. That's pretty amazing. I didn't know he dabbled in oceanography.

But again, the Gulf Stream, amazing. And it's just one boundary current of one major gyre. Yeah, it's kind of hypnotic if you look at these motion maps of global motion maps of trade winds and ocean currents. Yeah, I could watch those videos all day. Yeah, it's just stuff spinning around and traveling around. And it's really soothing.

And especially when they do like heat gradients or topographical gradients. So it's really colorful too, and it's ever shifting. Oh, yeah. You can just get a little jewel out of the corner of my mouth when I watch those. It's about as good as watching Fantasia. There's one other thing we should say

about those surface currents is they drag on the water below them, right? So the wind is transferring its energy to the surface of the water. Yeah, and it drags a little bit less as the deeper you go. Right. Apparently, though, the current, the motion of water usually goes in opposition to the motion of wind.

So what you end up having, if you could take a column slice from top to bottom of the ocean, you would find that the water ultimately is making a very long downward spiral. So and that's called the Ekman spiral. Yeah, there's a graphic of that that looks pretty neat as well. Pretty neat. Again, mesmerizing stuff.

Yeah. So Chuck, after this, we will talk about the global conveyor belt. It's my favorite part, I think. OK. Come on. I'm Mangesh Atikular. And to be honest, I don't believe in astrology.

But from the moment I was born, it's been a part of my life. In India, it's like smoking. You might not smoke, but you're going to get secondhand astrology. And lately, I've been wondering if the universe has been trying to tell me to stop running and pay attention. Because maybe there is magic in the stars, if you're willing to look for it.

So I rounded up some friends and we dove in. And let me tell you, it got weird fast. Tantric curses, major league baseball teams, canceled marriages, K-pop. But just when I thought I had to handle on this sweet and curious show about astrology. My whole world can crash down. Situation doesn't look good.

There is risk to father. And my whole view on astrology, it changed. Whether you're a skeptic or a believer, I think your ideas are going to change too. Listen to Skyline Drive and the iHeart Radio app, Apple podcast, or wherever you get your podcasts. On the podcast, Paydude, the 90s, called David Lasher and Christine Taylor,

stars of the co-classic show, Hey Dude, bring you back to the days of slip dresses and choker necklaces. We're going to use Hey Dude as our jumping off point, but we are going to unpack and dive back into the decade of the 90s. We lived it, and now we're calling on all of our friends to come back and relive it.

It's a podcast packed with interviews, co-stars, friends, and nonstop references to the best decade ever. Do you remember going to Blockbuster? Do you remember Nintendo 64? Do you remember getting Frosted Tips? Was that a cereal? No, it was hair. Do you remember AOL Instant Messenger and the dial-up

sound like poltergeist? So leave a code on your best friend's beeper, because you'll want to be there when the nostalgia starts flowing. Each episode will rival the feeling of taking out the cartridge from your Game Boy, blowing on it and popping it back in, as we take you back to the 90s.

Listen to Hey Dude, the 90s, called on the iHeart Radio app, Apple Podcasts, or wherever you get your podcasts. All right. My favorite part of Ocean Currency, Ocean Currents, the deep ocean current, a.k.a. the global conveyor belt, is fascinating to me. If you're talking about this is about 90% of the surface currents are about 10%, about 90% of the ocean's water

is part of the deep ocean current. And we can't see it because we're up here on Earth, and we are not deep under the water. It's invisible to us. But it circles the globe at a force 16 times as strong as all of the world's rivers combined. Which is, again, still not as much as the Gulf Stream. Still pretty impressive.

It's pretty impressive. But it's slow. So it moves water a few centimeters a second. Whereas the Gulf Stream moves waters at a couple hundred centimeters a second. Yeah, I think the conveyor belt, like I said, one patch will take 1,000 years to complete the circuit. Yeah, the circuit.

And it takes 10 years for a water to make a full circuit on the North Atlantic gyre. Yeah, so 10 years, and then 1,000 years. Right. So the global conveyor belt, it is driven by density, which I think is pretty interesting. Yeah, because up to this point, it's all been driven by wind, which is ultimately driven by heat.

This is also driven by heat in a way, but in a completely different way. Yeah, heat and salt. Thermohalene circulation, thermo being heat, and halene being salt. Warm water holds less salt. So what happens is, like let's say you're in the Antarctic. And water freezes to form an iceberg, or water evaporates.

Either way, salt is not going to be a part of that equation. No, the salt is left behind as the water freezes. And you know, icebergs aren't salty. They're fresh water. Yeah, so the salt is left behind. It's got to go somewhere. It is going to be very dense at that point. So it is going to be cold and dense and sink

to the ocean floor. Right. So remember back when we were talking about, right, and we were talking about coastal currents, and upwelling and downwelling. Yeah, this plays a part. When water sinks, other water moves in to replace it. And so what starts off here, and this actually,

I think, starts around the North Pole, definitely in the North Atlantic, as that water sinks and moves downward, it creates, it starts this current that goes all the way around the world. And again, it takes 1,000 years to complete. Yeah, it just kick starts it basically. And it's called the conveyor belt, I think,

because it never stops moving, and it's super slow. Yeah, I kept getting that. Remember that, whatever, that Bugs Bunny assembly line song? It was always the same like, I can't remember it either. Now I have our theme song in my head. I'm trying to think about it. But there's like any time Bugs Bunny messed around on a conveyor belt or something,

they use the same composition. Oh, really? Yeah. I'll try to find it. All right. So once this water hits Antarctica, basically the same thing happens all over again. The cold water is going to split.

Some of it heads to the Indian Ocean, some heads to the Pacific. And this upwelling and downwelling, this cycle, just starts all over again. Yeah, as it moves closer to the Indian Ocean and the Pacific, it gets closer to the equator, the water starts to warm up, it loses some of its salinity, it starts to thin out a little bit, and so it rises.

And when it does, it takes all those nutrients and all that CO2 up with it. And it's very much like the gas exchange that occurs in the human cardiopulmonary system, right? Yeah, it's not homeostasis, but it almost feels like that. If you took the whole system overall, yeah, it's homeostatic for sure. But it's like that by this exchange,

this transfer from one part to another, from the deep ocean to the surface. And as it reaches the surface and it depletes its nutrients, it's carried back around, it basically tries to go up, hits Alaska, Russia, Asia, North Asia, Northeast Asia, and turns back around and goes, ends up finally, back in the North Atlantic, up near the North Pole. And gets cold and starts all over again.

Right, and by the time it gets there, it's basically nutrient depleted and it sinks and it starts to recharge again. That's right, and that- Just like blood in your cardiopulmonary system. It gets depleted, it ends up going past the lungs, it transfers out CO2, it gets in oxygen. This is just the opposite.

This is transferring out oxygen and gaining CO2 in nutrients. That's a good way to feel connected to the earth when you start looking at things like that, you know? Yeah, it's not so different. It's, I mean, we're all connected, man. And again, there's a big nutrient swap meat happening as well with the conveyor belt, like we're talking about,

and basically kind of has the same effect as those surface currents do. As far as exchanging the oxygen and the CO2 and nutrients, and just moving everything where it needs to be. Yeah, I thought this was pretty cool. In this article, it talks about, there's also a density-driven, a thermohaline current in the Mediterranean,

because the Mediterranean is apparently saltier than the Atlantic. Oh yeah. And as a result, this gradient, anytime you have a difference in something, whether it's height, temperature, salinity. Yeah, density. Homeostasis is the ultimate goal,

so it's gonna try to go toward the middle from higher to lower, and this is the same thing. So it creates that oceanic current, and apparently in World War II, subs would run silent by going in and out of the Mediterranean without their engines on, just using that current. Oh really? Yeah.

So they would run silent? Yeah, like a glider? Run deep, run silent, run deep. Exactly. Wow. That's frightening. All right, are we at tidal currents? You don't have to be frightened, it was years ago.

Yeah, we're at tidal currents, I think. Did they still do that, no? There's no submarines anymore, they haven't been at war for years. They retired all the submarines. Yeah. All right, tidal currents are generated by the tides. We did talk about, like we said,

I think in the rogue waves and surfing about tides and waves. Yeah. And the gravitational pull of the moon and the sun, but more of the moon because the moon is closer, is what's gonna cause that bulge on the sides, and it's gonna drive the water level at that bulge. Basically, it's gonna decrease, it's gonna increase where it's aligned with the moon

and decrease at the halfway point between those two places. Right, and so, and it's always changing because the moon, the position of the moon and the sun and the earth are always changing, but they change in a very predictable manner so we can predict when the tides happen. But if you just took a snapshot at any given point of the tidal effect, right?

And if you imagine that the moon is on one side, the sun is on one side, and the earth is on the middle, the world's oceans around the earth stretch out on the sides and because of that gravitational pull. And just imagine that it's always like that. It's always just this elliptical oval shape the world's oceans are, and then the earth, the dry earth is spinning within that.

And so the land masses on the earth are always coming in and out of that bulge. And so they're going from higher to lower tide. It's kind of, it just makes it easier for me rather than to think of the oceans moving around the earth to think of the earth spinning within the ocean. And that causes the change in tides. That does something for you?

Does it, all the way. And these are different than the other currents we talked about because it's not a continuous stream and they switch directions. That's the high tide and low tide. And it doesn't impact like the ocean current that much. It's shoreline stuff. Yeah, but it's pretty important.

I mean, like fish, fishies lay eggs and a low tide will pull those eggs out into the open ocean and they'll hatch. It also brings food in from the ocean into like marshland and that kind of stuff. Or washes up jellyfish and to delight the children on the beach. Yes, but don't touch them.

You can just look. And when the tide is rising, that flow is directed toward the shore. That's called the flood current. We've heard about that flood in the ebb. And the ebb is when it's directed back out to sea. That's right. And that makes it all very predictable.

Like you said, we can go to the beach and listen to the tide report. It's also a very relaxing thing to do. Oh yeah? Oh yeah, listen to that. Like the AM, like fishing and charts and title reports. Yeah. It's very relaxing for me.

I like it. I remember growing up listening to like grain future reports and hog reports and stuff like that. Pork bellies. Yeah. Pork futures. Yeah. Chuck, just a couple more things.

So like there are plenty of other currents and there's also plenty of other wind patterns that drive these currents. They do things like create the El Nino. Yeah. Which basically takes weather, thunderstorms and stuff around the equator and moves them in different places that we're not used to, which can lead to droughts

and floods depending on where you are. And then also there's a lot of concern among scientists who know about this kind of stuff that changes, climate change is going to ultimately and negatively affect the global conveyor belt. Yeah. Because as the earth warms up, more and more icebergs are going to melt,

creating much less salinity and since the water will be less saline and warmer, it's going to sink less. And so that global conveyor belt that relies on cold, dense, salty water to sink to get it started is going to slow. And that could be bad because remember it's all, that's the global nutrient exchange. Yeah, that wouldn't be good.

No, because then the phytoplankton dies and again, when the phytoplankton dies, the fishes die, the seals die. Polar bears are upset. Well, the poor seals die either way. Yeah. That is very sad. Yeah.

You got anything else? No, that's it. That's ocean currents. If you want to know more about ocean currents, you can type those words in the search bar at howstuffworks.com. As I said, search bar is time for listener mail. I'm going to call this a French speaker.

Doesn't like our heavy metal music interludes. There's a few people out there who don't. So here we go. I'm going to read this just as it came. I like you very much. Sorry for my bad English, but I speak French, so it compensates. I have a little problem I feel like I need to tell you.

Please don't take it the wrong way. I have had problems to sleep for a while now, and I found that listening to podcasts helped me a lot. I put my iPod under my pillow while it plays, or I put only one head sound thing in one ear. I love your podcast because it's very interesting, intelligent, and also your voices are nice and you are never yelling.

So I do fall asleep every single time. This is a good thing, I swear. Of course, it takes me three or four times to listen to all of it. Usually I re-listen to it in the car. Now my problem, why do you have to put loud, heavy metal music for a break? I always wake up in panic when it starts.

I do want to continue to listen to you at night. I really do, so you have two choices. Either you don't change your music and think of me every time and laugh, or you change it for something, let's say, nicer. Maybe in exchange, I'm sorry, exchange, I could give you pickup lines in French. Au revoir.

Au revoir. Au revoir. Daniel. I have to say hats off, Daniel, because I could not write that in French. Oh, well, no, you don't speak French, do you? I'm Piquito. Ha, ha, ha, ha, perfect.

Thanks a lot, Daniel. We will consider removing the heavy metal music, which we did before, and then we brought back because other people are like, bring back the heavy metal music, so we're kind of caught between a rock and a hard place. Caught between an amp and a hard place. Yeah, yes, if you want to let us know

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Hey, I'm Lance Bass, host of the new I Hard Podcast, Frosted Tips with Lance Bass. Do you ever think to yourself, what advice would Lance Bass and my favorite boy bands give me in this situation? If you do, you've come to the right place, because I'm here to help, and a different hot, sexy teen crush boy bander each week to guide you through life.

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We're going to be talking to Nancy Rodriguez from Netflix's Love is Blind Season 3. Looking back at your experience, were there any red flags that you think you missed? What I saw as a weakness of his, I wanted to embrace. The way I thought of it was, whatever love I have from you is extra for me. Like, I already love myself enough.

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