Sand Dunes: They Are What You Think They Are

Sand dunes are exactly what you think they are. But still pretty interesting. Learn all about them right now!

Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

See omnystudio.com/listener for privacy information.

Episode Transcript

Speaker 1 (00:00):
Attention, Chicago and Toronto. We're coming to see you guys soon,
so we better hurry up and buy your tickets because
they're going fast. Yeah, man, Chicago at the Hairs Theater July.
We've actually sold a lot of tickets now, yeah, you
guys listen, thank you, thanks for stepping up. In Toronto
at the Danforth Music Hall the next night, July. It
may be sold out by now. Yeah. Well, there's only

(00:21):
one way to find out. Go on to s y
s K live dot com and you'll find links to
the ticket sites and all the show info you need,
and we will see you soon. Welcome to Stuff You
Should Know, a production of I Heart Radios How Stuff Works. Hey,
and welcome to the podcast. I'm Josh Clark, and there's

(00:43):
Charles w Chuck Bryant, there's Jerry over there, and this
is Earth Science Time. Baby. I love this stuff. Yeah,
this one was a little well, it's about dry. I
just caught myself at the last second. Thank you. It
was a little dry though, Uh it was, But I

(01:03):
mean we're talking sand dudes. There's just so much you
can do with something, do you know what I mean? Yeah,
But it's also one of those is kind of neat,
and that when next time I go to the beach
or the desert, I will I'm armed with a little
more knowledge, which is always nice. Are you gonna go
do some sandboarding? I don't think so, although I did
look at some videos. It sounds pretty awesome to me.

(01:24):
It looks like a great way for a forty eight
year old to break his knee. Did you, oh man,
breaking your knee? Can you imagine? No? Did you, um
listen to the sound of dunes singing? Uh? Yeah, and
I've heard that sound like in person? What kind of
life have you lived? I mean a life wire been

(01:45):
around some sand dunes? Wow, that's neat. I think I
heard the dune singing on a TV commercial shoot out
in the desert. That's where I heard it. Well, what
were they singing? Do you remember they were singing? Uh?
Fresh friends? No, No, these were not European dunes. So

(02:05):
you've been, um nice, you've been around dunes that were
not beach dunes, because my only experience has been just
beach dunes. Standards, stay off the dunes, beach dunes. These
are desert dunes. That's pretty neat. Yeah, it looked like
in fact, I believe they had even done some Star
Wars reshoots in this area of California. Wow, it wasn't Tunisia,

(02:30):
but it stood in for Tunisia. So I was told,
just like those hills stood in for Korea and mash
that's right. But this is a Michael bay Chevy commercial, okay.
And I got to stand around and watch him scream
at everybody that's neat man, what a good guy? Um Like,
I said, I've only been around dunes on the beach,

(02:52):
coastal dunes, right, coastal dunes. But I was talking to
you me, and I guess these would constitute coastal dunes.
But she said she taught in Japan, you know, um
years and years ago, and a prefecture called to Tori,
which is the least populated prefecture in Japan, and they
actually had some amazingly beautiful dunes which look like desert dunes,

(03:15):
but it's coastal. So I guess they're coastal dunes. But
they don't look like coastal dunes. They look like desert
dunes in South Carolina. No, it's definitely not. And I
was like dunes in Japan that doesn't make any sense.
But I saw him with my own eyes. And unless
she photoshopped these pictures they were real, which would have
really been something because they weren't even her pictures. They

(03:36):
were posted on the internet. It would be a weird thing.
I suppose she could have photoshop the pictures, started a
website with an unrelated name uploaded um and then made
it look like she was searching just Google images, which
she was just to fool me. And then she's like,
I got you on a dune fake burn right, classic

(03:56):
dune fake fake but she um. She also, by the way,
she when she taught in Japan, um, she taught with
our buddy Raymie, who we're going to see in Toronto soon.
That's great. Which, by the way, if you haven't gotten
your tickets to Chicago, it's probably too late for Toronto
by the time this comes out. How about this. If
you're listening to this and you haven't bought your ticket

(04:18):
for Portland's Maine, shame on you. Okay, So sand dunes.
I love this article, by the way by Debbie Ronka yep,
And she basically says a sand dune needs three things
to form. You need loose sand because that's the kind
that can blow around you need wind to blow a

(04:40):
sand dune around, and then you need an obstacle, which
can be anything. It can be a bed of pebbles,
it can be a big rock, can be a tree,
but it's something for the sand to hit and say, oh,
I can't go any further. And then as more and
more sand hits that obstacle, the sand dune starts to build,
and then the sand dune itself becomes the obstacle. In

(05:04):
one of the most zen processes around on Earth. It
really really is. It's a true like uh layering effect
that if you see sped up with the time lapse camera, yeah,
it's pretty remarkable. Well, that actually reveals maybe the fact
of the podcast to me, sand dunes move. I thought

(05:27):
you're gonna say time lapse photography is possible, right if
but if you watch the sand dune over a long
enough exposure, you would see it moving forward. And here's
the thing. It doesn't just move in that like the
sand gets blown around and and you know, the sand
dune takes all these different shapes. It keeps its shape
and just moves forward depending on the type of dune

(05:50):
and the type of what's called wind regime in the area.
That's right. I just think that it is amazing. They're
clearly alive and can feel pain. So you really shouldn't
walk on the sand, dude. And the shape is so
dictated by the fact that, you know, maybe the wind
always blows in one direction where you are maybe opposed
in two directions only maybe it blows from many directions,

(06:13):
and that's all gonna dictate this malleable living, breathing, breathing, feeling,
emotional beast right, that will kill you if you don't
treat it right. It has. It's killed a couple of
people at least. So let's talk about how wind can
move sand around. Uh. It's generally a few different ways.

(06:34):
There's uh saltation, which is mostly like of sand. Grains
move like this and that's just the wind is just
bouncing them along. Yeah, I thought these percentages were pretty specific.
Four percent, one percent, Like who who came up with
those percentages? Okay, all right, well then they probably are accurate.

(06:58):
There's creep, Yes, creep I'd never witnessed or heard of before,
of you, I don't think. So that's the four percent
um of sand moves this way, and this is when
grains are colliding with other grains um, like you know,
maybe gravel or something causing them to move. It's like
sand croquet. Yeah. Um, salmon croquettes, No, those aren't the

(07:23):
best croquettes if you ask me. Frankly, I'm just gonna
come out and say it. The only way to eat
salmon is raw. I'm sorry. Oh I love a grilled
salmon with that crispy skin. M m mmm. I like
grilled fish. It's just when salmon is cooked, it undergoes
a taste conversion that I'm not a fan of. I

(07:43):
prefer it raw. No, I love raw salmon for sure,
but I love that crispy skin so much. Hey, i'm
not yucking your young man. If you like cooked salmon,
have at it. And I do like fish skin, crispy
fish skin. I'm with you, but I'm more like a
cooked trout fish skin kind of guy. Yeah. Uh. When
I was a kid, a very big seventies meal um

(08:04):
in my household was the canned salmon croquettes. Oh yeah,
I've had those. Yeah, it's just the bones, you know,
Like I don't like there to be bones in my food.
I'm with you. I'll eat something off the bone. I
just don't want to be expected to actually eat the bone.
I guess I don't know at a good butcher or

(08:25):
a good fisher. Okay, but don't that. But aren't there
still really really tiny little bones. It depends on the salmon.
But sure with you. I don't like bones either, so um.
Obviously we're talking about sand dunes still. Yeah, but the
suspension is the third way. We gotta finish that up

(08:46):
right right, Um, that's where that's where the wind blows
very strongly, um, so strongly and from enough different directions
at once that it actually lifts the sand into the air.
And this is what a US storm is, or a
sandstorm or um any number of Basically, if they're sand
blowing around in the air, that's this is the suspension

(09:08):
movement of sand up though in the air. Like when
you go to the beach. Sometimes you'll see sand in
the right conditions blowing along the ground that couple inches
off the ground. That's not the same thing, man, No,
that's saltation. That hurts. That's really painful. Yeah, I guess
it can hurt, can it? Oh? It can hurts. So um,

(09:32):
we've kind of already described like how a sand dune forms, um,
sort of sort of, but the there's there's a lot
of different kinds of sand dunes. We're gonna get into it,
don't worry. But there's a general way that a sand
dune forms where the sand blows along hits a something

(09:54):
that stops. It's for momentum, and then it starts to
pile up. And when this piling up happens, a sand
dune typically undergoes a fairly predictable um evolution, I guess,
whereas more and more sand builds up, the sand dune
gets bigger and bigger, and the sand just kind of
smacks into the back of the sand dune, and the

(10:16):
lighter sand will just continue up and over the sand dune.
And then once it makes it down the other side,
which is called the slip face, which is the side
that's protected from the wind, the um the sand dune
just kind of gets bigger and bigger. But eventually enough
sand will pile up on the back side that it
forms a crest where it basically piles up and forms

(10:40):
a peak or crest or something like that. And then
this crest can get so so big and so pronounced
that it will actually crumble under its own weight. Yeah,
I mean, it's just it's like raw physics before your
very eyes. These layers, those light sands blowing over and
it's layer after layer building up. Then that crest gets

(11:00):
super tall, like you could mess around with it if
you had a big bucket of dry sand with your
own hand. Sort of see this effect as you drop sand. Eventually,
when it does collapse, it's gonna avalanche down the slip
face and there is an angle it's called the angle
of repose, where it's sort of where that beautiful, Um,

(11:21):
what's the word I'm looking for. Not symbiosis, but when
when something's pushing against something, the other things pushing right back,
and it all agrees that just to stop there in
the middle. I don't remember what it's called, but I
know what you're talking about. It is beautiful, that's basically it.
It's about thirty to forty thirty four degrees in general,
and that's when it just reaches that perfect angle of

(11:42):
steepness that it's all just stable and solid. Right, So
now you have a dune. It's no longer being born.
It's now living, and it's it's it still can keep growing,
but it's going to keep growing along these lines where
you know, if if enough gets built up, it's gonna
fall down into the angle of repose. More likely, the

(12:03):
sand will just continue going over the edge and then
being built up on the back side too. It's a
rump will grow basically. Yeah. And if you're like, winds
are really strong, it's probably gonna be taller. If the
winds are really gentle, it's probably going to be more
spread out. And the direction of the wind, the angle
of the wind um and like we mentioned earlier, whether

(12:23):
or not its unidirectional, bi direction or multidirectional, that's all
gonna play a part into what kind of dune you're
gonna get. So let's take a break and then we'll
come back and talk about the different kinds of dunes. Okay,
all right, Chuck. Have you ever read the book Dune? Nope?

(13:00):
I haven't either. Have you ever seen the movie? Nope?
Me either. That's interesting. You know they're making they're making
it again. Uh, that's great. That Dennis villaenieu guy. So
oh he's good. Yeah, he's amazing. He did the arrival, right,
I think so? Yeah? Or just a arrival. The arrival
is like old Charlie Sheen movie. I think, I think

(13:22):
it's just a arrival. Okay, yeah, so, um, neither one
of us has seen or red dune. We're gonna get
some email about this, I think. Yeah. And I'm not
knocking David Lynch either, of course, I want to throw
that in there, or Frank Herbert. Yeah, I'm just kidding.
I don't know anything. So um. So, like you were saying,

(13:43):
dunes are the result of the winds that are im
prevalent in the area, and the most common dune on
Earth and um, little known fact, well maybe not little known,
but interesting fact. Um, the most common dunes on Mars
or what it called a cynic or crescent shaped dunes
and these are far and away the most common. Um,

(14:05):
which means that more often than not, in any given area,
the wind is going to be blowing in the same
direction basically all the time. Yeah. And this got a
little confusing for me because the more I researched the
types of dunes, like I saw one place it said
there are five main types of sand dunes Barkin, transverse, blowout, linear,

(14:28):
and composite. Who said that a website that seemed very
educational and reliable. Weird, But I believe they are just
different words for some of these, and some of these
are subtypes of the main five. Because I believe a
crescentic is a bark in dune. Yes, if I'm not mistaken,

(14:50):
you're not horseshoe shaped front facing the wind, I guess. So. Yeah,
that's the big thing is where is the curve pointing
is the big differentiator for chryscentic. Yeah, Like I look
these up online, all these pictures, and like when I
saw the chriscentic, uh, these look like sort of those
big beautiful dunes from Star Wars or Lawrence of Arabia. Yeah,

(15:13):
it's what most people think of when they think of
a dune. It's like a desert dune, right, exactly, thank you.
So chryscentic is if you imagine it is like a
U shape or a V shape. The underside or the
bottom of the U or the point the outside point
of the V is going to be pointing in the
direction opposite the wind, so it's pointing up wind. So

(15:36):
the wind is blowing and hitting that outside point of
the V or the bottom of the U, which doesn't
really make sense um to me. The parabolic, which we'll
talk about later, makes more sense. But anyway, the parabolic
the same as a blowout, because a blowout dune is
the opposite of a bar can, and that the curve,
the horseshoe curve, faces away from the wind. Yes, okay,

(15:59):
it's gonna take five minutes to undo the confusion we
just created. Well, and there are some who studies this,
what kind of geologists I believe, desert ecologists. Yeah, I'm
sure they are having a ball with this one. Just
up a drink, everybody, Yeah, all seventeen of them, buckle up.
So crescent shaped ones again, say they're U shape or
V shaped, and the bottom of the U or the

(16:20):
point of the V is pointing facing the wind, so
pointing up wind, the wind blows it. The wind the
sand that it's blowing onto the backside, onto the rump
of this dune blows up, it falls down avalanches, uh
under the slip face which is the inside of the
U or the V, and it's not as protected from

(16:44):
the wind. And what's amazing about this is because the
crescent shaped dune is the result of a wind regime
where the wind is blowing in one direction basically all
the time. These are the dunes that can actually move
and they can move pretty fast. They're one of two kinds,
but they can move pretty fast across the desert, so

(17:05):
much so that sometimes these dunes, when there's many of them,
will catch up to one another, and they'll do some
pretty amazing things when they catch up to one another. Yeah,
and so much so that they can threaten uh like villages,
and people have to try and stop these dunes. Yes,
some people have been known to pour motor oil on
dunes to keep them from moving. Because it winds the

(17:26):
sand without it drying out. It's not a good one. Um.
You could plant vegetation, although if you're in the desert,
that's not a great great thing because your plants are
just gonna die. Um more often than not. If you
just put up fencing, that that becomes an obstacle for
the dune, and the dune will stop in its tracks
and it will just keep building up on the back side.
Eventually it might be big enough to overcome the dune,

(17:49):
but it will certainly slow it down for a good
many years for sure. But the thing about that crescent shape,
when when a small one catches up to a bigger one,
a lot of things can happen. One thing is that
it can appear as if the small one passes straight
through the big one. It is amazing. And then another
thing that can happen is to to um dunes. I

(18:12):
don't remember how if they're the same size or different
size when they come together, so that the arms are
the wings of the horns of that crescent shape, right,
not the main part, but the points that come out.
Those are called the horns of actually seen arms too.
There's all sorts of different names. It's a giant mess.
Nobody can agree on anything with dune ecology. But when

(18:34):
a different dune catches up and merges with it, it
can actually go from two dunes to three, which is
called breeding and the two So there's the one dune
that remains and then the other one basically splits into
two dunes that come out. The arms are the points
of the original dune. So when you had two, now

(18:54):
there's three, which is pretty astounding if you ask me,
because we're talking sand dunes here and breeding new dunes. Amazing.
I think it's pretty amazing too. So among the five types,
there's also enlisted as a transverse dune. I didn't understand
them at all. Well, I think these are the ones
that their long lines of rigid dunes and they're perpendicular

(19:16):
to the wind. Uh. They have really steep slip faces
at the backsides, and they're kind of wavy. So there's
a lot of sand and not a lot of plants.
And I think the dunes that like you see um,
like behind the beach are a lot of times are
transverse dunes. Okay, if I'm not mistaken, my understanding was

(19:38):
that parabolic we're the most um coastal dunes, maybe not
the most coastal, right, and I think there are different
kinds of dunes even along the coast, right, Yeah, yeah,
for sure. Again, it just depends on what the wind
is like in an area. And because wind regime is
going to be different for every kind of area, there's
different kinds of dunes. And um, what we're talking about

(20:01):
are the standard simple kinds of dunes. Dunes can like
we like we were just saying, can merge with one another.
Winds can change and different types of dunes will start
to form. You've got um compound and complex dunes to
which can be two different kinds of dunes merged together. Um.
So there's a lot of weird things that can happen

(20:23):
with dunes. They're they're very rarely just a simple, straight up,
straightforward kind of dune. Yeah, there are linear dunes. Uh.
These are mostly parallel to the wind, and these form
these long straight ridges and they think geologists think that
they are caused by wind that blows in one They
are definitely bi directional as far as the wind goes,

(20:45):
but they think they're cause when wind blows from one
direction in one part of the year and then another
direction and another part of the year, right, So they're
they're like long lines basically. Yeah. But it's interesting that
you know, the winds will shift over you know, like
the course of a year, so it's not like every
day they're shifting, no, but it's enough and they're powerful

(21:06):
enough that they're blowing any any kind of um rump
or base of these and it's just a big long
line of saying sometimes very sharp depending on you know,
just how sharp the bi directionality of the wind is.
Um star ones. This is one of my favorites. These
are pretty cool. So if you tell what you would think, Yeah,

(21:26):
if it's like a sand dune that looks a bit
like a star, they have a pyramidal mound that goes
up in the middle um and then at least three
arms with um slip faces, you know, the avalanche face
radiating out from that middle And these are the results
of a bunch of different wind directions throughout a year

(21:48):
building up. So rather than moving along the face of
the earth, these things is kind of build up in space.
And they're actually some of the tallest ones. I think
there's some that are like fivet tall in deserts in China, um,
which is pretty pretty amazing. I mean that's tall, especially
if you're a sand border. Yeah, I mean you can

(22:08):
simulate all this stuff, like you can make your hand
the wind if you're at the beach and you're playing
with sand. I mean you just think about if you're
pushing the sand in one direction only, it's gonna look
a certain way. If you push then in another direction,
that's gonna look a certain way. And then in the
case of a star, if you're using your hand pushing
sand in and all these different directions, it's gonna grow

(22:29):
upward and it's not gonna grow laterally. Right right. We
should have probably said at the outset that it helps
a lot if you go look up images of the
different types of dunes we're talking about. Help me and
look up. Look up dune porn. Yeah, I'm sure it's
out there. Um okay, Now there's parabolic or parabolic I say.

(22:54):
You say parabolic, I say parabolic. So these are basically
the opposite of crescent shaped, where this time, the inside
of the U or the inside point of the V
is what the wind is blowing into, and then the
outside of the U or the outside of the V
is what's facing in the direction that the wind is going.

(23:16):
But it's down wind, right. It's what you would think of,
like if you're just thinking about moving sand with wind
via physics. This this one makes the most sense. But
the thing about parabolic that really distinguishes it from crescent
is that usually they're made of sand that is, has
some sort of water attached to it or vegetation so

(23:37):
that the arms are anchored, So the arms stay in
the same place. They just get longer and longer as
the bulk of the dune the middle part keeps moving
further and further away, which is pretty cool if you
especially if you imagine this stuff on a like a
time lapse or you know, happening really quickly. Yeah, I mean,

(23:58):
it can be a little treaty shrubs, grasses and what
we'll talk more about what can grow in dunes. But
these things very much served as the anchor on those arms. Uh.
And these are not gonna be very tall obviously if
you think about like the way they're going to form,
the fact that those arms are anchored down, they're not
gonna be super tall. Um. And then where that vegetation

(24:21):
is gonna stop, it's gonna slow the advance of that
sand accumulation. Right. They used to think it was strictly
just the vegetation um that anchors the arms, but they
apparently have discovered recently that no, it's actually more water
logged sand like in the arms than than we previously thought.
And it's probably the water it acts as motor oil,

(24:44):
that's right. And then on this original nost of five
main types, the composite dunes were the last one listed,
and this is just sort of a combination of two
or more types of other dunes. Um, these are really big,
they're very tall. Uh. They form these big hilly forms
called draws d r a a s and they're mostly

(25:05):
transverse in linear dunes, and they can be like taller
than fours. They're they're gigantic. Wow, that's really cool. What
makes them so big? I think just the combination of
the dunes I was just just running together. That's pretty neat. Um.
There's another one I want to give a shout out
to Chuck is lithified dunes or slick rock, like the

(25:29):
kind of that you see like in a painted desert
or whatever. That's actually like a hardened sand dune that
over time water has flown, has moved through, and as
it moved through, it basically fossilized the sand dune because
it deposited minerals of different types. And these minerals can
create like layers or strata um that that have different colors.

(25:52):
And that's but it's actually originally it was a sand dune. Gorgeous.
I've been you talk quite a few times, yep. Uh.
And we to talk about the subaqueous too, because those
are pretty great. They're underwater dunes and uh, if you've like,
you see these a lot in natural channels like rivers
and stuff. Um, but they can also form and you

(26:14):
know in a canal that man has built, which is
pretty interesting. They moved downstream always and they tend to
be of the same height and the same wavelength the
same frequency, like they're they're equally spaced apart. And I
didn't realize this, but it makes total sense. The presence
of um dunes on the bottom of like a channel

(26:35):
or a river or something. It increases the river's likelihood
of flooding because it decreases um flow. It increases resistance,
decreases flow, and so the water actually piles up and
overflows because it's running into sand dunes at the bottom. Amazing,
It is amazing. I don't know if we've gotten this
across yet or not everybody, but sand dunes are a

(26:57):
little more amazing than you might have thought, certainly more
amazing than say, Jackhammers. You want to take another break, Yeah,
let's do it. We're going to take a break everybody,
in case you didn't here, and we will be right
back with coastal dunes. Okay, So the dunes that I

(27:38):
am probably most people have seen more than any our
coastal dunes, the dunes at the beach, the dunes that
have a science says stay off the dunes. There's probably
some plants growing on them, and UM didn't protected. They
are protected and they're protective too, that's right, But really
I was I realized this as I was researching this

(28:00):
tuck they really protect human interests. They don't really do.
They don't. There's not a whole lot that they're doing
besides replenishing the sand that makes up the shore ecosystem
after a storm. They're basically like a reserve sand um pile,
so that when a storm happens that the sea goes,

(28:20):
give me some of that, and it takes the sand
out and replenishes it and then starts this process over again.
Because that's where the sand dune originally comes from. Is
waves bring sand ashore, and the sand starts to blow
inward inland and runs into something in the way, And
like I said, at the outset, it could be a
bed of pebbles, it could be shells, it could be

(28:42):
some vegetation that's already growing there, and it starts to
build up. And that's where coastal sand dunes begin. Yeah,
it's really cool they have. First of all, uh, an
embryo done is a real term, which is really kind
of funny and kind of like I imagined, is like
sticky in Yoki Cross. But how how these things uh like,

(29:06):
how vegetation comes to um to work with dunes, and
they kind of scratch each other's backs. Uh. In this
case is rotting seaweed will will come in from a storm,
let's say, because a sand dune in itself originally doesn't
have like a ton of nutrients to allow stuff to grow. Yeah,
it's just minerals basically, like like quarts and ground up

(29:28):
calcium carbonate and not much else. Yeah, so you would
be surprised if anything grew there. But what will happen
is the tide will bring in plant life and like
rotting seaweed and added, you know, they dump their nutrients
there and that allows what they call a pioneer species
to colonize because all of a sudden there's some nutrients there.
And this can be mainly grasses, like all different kinds

(29:49):
of kinds of sea grasses and uh, these plants, you know,
these are sea grasses. So they you know, they can
grow well in really harsh conditions like super salty area
as um they're getting beat by wind and they really
typically have these big, deep, long roots. They're gonna go
all the way down to the water table and that's
we're gonna they're gonna get there, uh their drink, and

(30:12):
they're gonna just bind that sand together. And it's like
I said, they kind of work together to make the
sand makes the plant stronger. The plants make the sand
stronger or the dune rather yeah. Yeah, And once those
pioneer species of grasses are established, they start to change
the actual like composition of the dune and they make
it more um. Yeah to other kinds of species that

(30:36):
aren't quite as pioneering but are still pretty hardy compared
to say like you're you know, your your rosebush or something.
They there's you know, woody perennials like um beach elder.
There's heaths and heathers UM in the UK, they grow
on on coastal dunes and UM. All that these do

(30:58):
is create uh an eve and stronger, more nutrient rich
type soil as these things live and grow and fix
nitrogen and turn more seaweed into even more nutrients UM.
And they also allow it to retain water. Although I
think basically to a species, any plant that can grow
on a sand dune is is basically developed UM techniques

(31:22):
to resist losing water. Like they have small crinkly leaves
that that don't evaporate water nearly as easily. So the
name of the game is to get as many nutrients
out of unfriendly um soil as possible and keep as
much of the water as you can get from the
water table. Yeah, which is why they protect dunes. I mean,

(31:42):
when you when you go to the beach, you're gonna
see signs that say stay off the dunes, and you
don't want to, you know, because the fear is that
humans will go in there, which is exactly what would happen,
and trample on these grasses. And then that little relationship
is busted apart when those grasses die off or even worse,
are pulled up, maybe because you want to take some

(32:05):
home or something, and then the sand dune is compromised.
Look at the girl from the beach, so one one.
Even without human intervention, these coastal dunes can turn into
parabolic dunes if something happens, like a storm search happens
and carves out like a significant portion of the sand

(32:27):
in front of the dune, because now there's nothing holding
that dune in place, and it's exposed to the wind
even further, and so the dune itself will start to
move forward, but the arms will stay in place, and
that's the coastal dune is just turned into a parabolic
dune too, and it's moving inland, which if you have
a house built there, that's a problem for you. But

(32:50):
one thing that I didn't realize, but I totally now
I've I've seen it all over the place, but I
never put tune two together. If you've ever noticed, um,
an established beach will almost always have like a conifer
like pine tree forest. And apparently that's like the end result,
like of the progressional evolution of a don ecosystem, is

(33:10):
a pine forest is going to grow because they're adapted
to grow in this this soil that's been prepared over
time that started out as a single piece of dead
seaweed and ended up into a whole pine forest. I mean,
for sure, there are a lot of pine trees in
the Florida Panhandle. Yeah, but you never think about it.
But that's that that's like a don eco system. But

(33:31):
that's part of the dune. That's like the I think
the climax ecosystem is what they call it. Yeah, And
I don't know if you've ever been to a beach
not so long after a hurricane is hit, but it, uh,
it's just devastating to look at. I mean, you always
obviously think of people in homes that are destroyed and
stuff like that, but if you look at the actual
beach itself, um, it's pretty brutal. Like it can take

(33:54):
decades for that beach itself to recover and for those
dunes to re cover. Um. Like I was in South
Carolina not a couple of years ago, not too long
after one of the hurricanes, and it was like you're
used to seeing these big broad beaches with these big
flowy dunes, and this was like a cliff. It was
just sand that eventually went up. Uh, you know, the

(34:17):
water line met just a hard like jeez a man,
some places like ten and twelve feet like a sand cliff,
and it just looks completely unnatural, like not like the
beaches that you're used to seeing. And selfishly, as you
know as a beach goer, some parts were just completely impassable,
Like you couldn't even get to the beach unless you
like repelled down the wall or something, and you certainly

(34:39):
couldn't get back up from what I could tell, though,
that's just part of this natural process. And like removing
and then slowly replenishing, and like I was saying earlier,
the dunes protect human habitation. Like you want a dune
if you live on a coastal beach area. It's like
a big stack of sandbags. It is, and and like

(35:01):
you build your house right behind it, and it provides
this buffer from storm surges and stuff like that. But
when it's when it's taken away, if it takes decades
to rebuild, you may want to move elsewhere. Apparently after
Hurricane Sandy, there's parts of New Jersey still that they're saying, like,
I don't know if this is habitable anymore. Maybe it
will be in like fifty years after the dunes come back.

(35:23):
But this is not like it's it's like we can't
live here anymore. It's because the dunes have have been removed.
And people in New Jersey said, have you ever been
to Newark? Yeah? At the New York's come a long way,
has it? Oh? Sure, okay? But when I first started
going there in the in the early to mid nineties,
it was it was a different story. I love Newark,

(35:45):
it's great. Do you really sure? Okay? I love all
of New Jersey. That's my second home, all right, there
you go. Speaking of second homes, we should talk about that.
What little critters make their home their first time them
in the dunes? M hm do you like? Well? I did?
It was pretty nice. That was a classic sk So

(36:08):
I mean kind of like we were talking about before,
like a big pile of sand is not an an
intuitive place for plants to live or animals to live. Um,
but because of all the nutrient dumps that the ocean
brings in, uh, it can, uh it can end up

(36:29):
being a really thriving ecosystem. There can be little little
flower dune flowers. There can be little rats and mice. Uh,
certainly snakes and lizards if you're in the desert. Um.
But obviously these are only going to be things like
you can't completely discount like nature. These all have to
be very very drought tolerant. Plants Oh yeah, for sure,

(36:50):
but there are adapted to grow on these dunes. And
you know when you add a plant and a lizard
and an insect and a bird or something like that, Um,
you got yourself a nice little ecosystem going. And they're
definitely dune ecosystems that have developed over time. Beatles, crickets, Yeah,
I was looking up. I was like, our dung beetles

(37:10):
a dune bug. Apparently, my friend, dung beetles are an
anywhere beetle there on every continent, in just about every
ecosystem except for Antarctica. Really, yeah, we're gonna have to
do at least the short stuff on the dung beetle
because it's a poop beetle. It gathers poop, and I
think that's pretty neat. Yeah. I remember watching those guys
roll those little poop balls around and the what was

(37:34):
it the Planet Earth videos? Yeah, for sure, pretty great,
or maybe it was micro Cosmos. I can't remember it was.
They they're I mean, they're they're pretty frequent TV gets
in a lot of movies. Remember when they're on the
Man Drill Sister Show. Yeah, man, that was brought the
House down, Man Drill Sisters. Did you watch that? No?

(37:57):
I grew up in Ohio. We didn't have that. Oh
it was nation wide, you kidd me? No, I'm I'm
sure this is when people in New York City watched
he haw Right. Yeah, I know. Everybody was on cebes
and acted like they were truckers, wore truckers shirts. Crazy.
That was a cool little period in the seventies, you know. Yeah,
it was a little weird trucker culture took over yeph

(38:19):
What else is gonna hurt dunes? Deforestation? It sounds weird
to use that word about um sand dunes, but yeah,
I mean there's those coda for forests. Yeah, you can
DeForest e conifer forest just like any other forest. You jerk,
not you, I'm saying the person who cuts down the
conifer forest. That's right. Yeah, what else you got anything else? Uh? Now,

(38:40):
we talked about the singing sand dunes, which if you
haven't heard, go listen. It's pretty neat and it's really
just sand, dry sand falling over itself in an avalanche,
and again proof positive that sand dunes are alive and
can feel pain. That's right. Uh, that's it for sand dunes.
I think the last thing we have to say is
stay off the dunes. If it says day off the dunes,

(39:01):
just don't go on them, especially with your dune buggy.
Yeah that was that was another seventies little fad to
doom buggies. Yeah. They they also have beaches still where
you can drive your car. I'm not a big fan
of that. No, because even if it's not eroding the beach.
It's small gone the beach. Come on, it's just ugly.
You don't want to go to the beach and see
someone's stupid car. Nope, I can barely stand seeing people's

(39:24):
bare feet. Agreed. Uh, Well, since we said that, it's
time of course, friends for listener mail. Uh. Chuck got
me out of a parking ticket. Hi, guys, my name
is Camber M a grad student at Indiana University, Go Hoosiers. Uh.
But I work in Indianapolis, A fairly new listener about

(39:46):
six months. But I have to drive a lot for
school and work and family, so I spent a lot
of time listening to you guys. Uh. And I need
to let Chuck know that he saved me hundreds of
dollars with so you. Winding back to Friday night, I
was driving to Louisville, Kentucky, about a two hour drive
and might have been going seventy and get fold over

(40:08):
and I think this is it. I'm gonna have to
take out extra loans, get another job, My insurance is
gonna go up. And then I remember what Chuck said
about getting out of his speeding tickets and just surrendering
myself to the law, so I thought, why not give
it a try, and it worked. Not only do I
did I not have to pay for a park or
for a speeding ticket, but you saved my insurance from spiking.

(40:30):
I'll always remember this in future situations. But of course
I'm gonna work in my lad foot first. Thanks so
much for the advice, and thank you for the podcast.
Guys listen almost every day. I don't know what my
morning commute would be without it. That is from Camber Soulberger.
Nice first of all, Camber, great name, Cambra Solberger, even
greater name, that's one of the great names. And then

(40:52):
uh yeah, Chuck getting you out of a ticket. That's
just an all around fantastic listener mail Charles Greed. Well,
if you want to get in touch with us, like
Cambert Limburger Camembert Limburger did, you can go on to
stuff you Should Know dot com and check out our
social links. Or if you want to write us an email,

(41:13):
you can fill it out, smack it on the bottom
and send it off to Stuff Podcast at iHeart radio
dot com. Stuff you Should Know is a production of
iHeart Radios. How Stuff Works For more podcasts For my
heart Radio because at the iHeart Radio app, Apple podcasts,
or wherever you listen to your favorite shows,