02x12 - Earth Explorations

[bunniefuu]

Today on Dragonfly TV, some kids get to

the bottom of sinkholes. I'm

not going down there. And two mountain

bikers take a gonzo ride on the slick

rock trail.

Major funding for Dragonfly TV is

provided by the Best Buy Children's

Foundation. We're excited to see kids

like you exploring the world of science

and technology because what you're

learning is going to change the way we

live. Best Buy the future looks fun.

And by the National Science Foundation,

supporting education and research in

science, mathematics and technology.

The National Science Foundation.

America's investment in the future.

This is DF TV. I'm Mariko and I'm

Michael. Today we're taking a journey

through talk. Exploring the jump. Or you

could just say we're digging in the dirt.

In cool places like sinkholes,

along with Margie, Meredith, and Caitlin,

who climb in for a closer look. But first

we're heading to Utah, where Ari and Jr.

do some rock hopping on mountain bikes.

On a rocky roller coaster called the

Slick Rock Trail.

I'm Ari. And I'm Jr. We ride our bikes

in some of the coolest rock in the world

in Moab, Utah, where the

rock formations look like they're from

outer space.

When you bike in Moab, you see some crazy

things. Natural arches! Giant

mesas. Fins.

Towers. And

precariously unbalanced boulders.

This totally reminds me of a Road Runner

cartoon.

These formations have been here for

thousands of years, and it took thousands

more for them to form. This whole place

is sandstone, which means erosion has

been at work here. Erosion can build

things up and wear them back down. Look,

I know the supernatural isn't supposed to

happen, but it does happen. We

love biking here. These are some of the

best trails in the world. Our question

is how the two separate trails at Moab

turn out so different.

This is the world-famous Slickrock

Trail. Slickrock is a type of sandstone

that got its nickname back in the pioneer

days, when burros and horses used to

slide around on it. But rubber tires love

it. Check out the steep angles we can

climb. Slickrock is a



difficulty, and the dark cliffs behind

drop straight down.

This is the Porcupine Rim Trail, a ride

that will rock your world. The

Porcupine Rim is 15.6 miles one way,

with a 34 mile loop for the truly

hardcore mountain biker.

To investigate the rock surfaces of these

two trails, we're going to test them up

close and personal with our bikes.

We'll ride one mile of each trail,

recording our voices on a video recorder

as we go. We'll record every time we get

air off a drop off a ledge, every time we

have to change gears, or every time we

get off to walk our bikes. And thenWe

started all out. I've got a bike

and you can ride it too

It's got a belt and it looks like it

First off, there's a k*ller fly just to

get to the part we want to test. Then we

turned around, hit record, and headed

downhill.

oh oh Very rugged, just hurling,

stopping. Holy gas, good

air. Oh, big risk.

Hey, I got air. I got air. We hit the one

mile mark and pulled all of our data off

the audio recorder. Then we headed off to

Sliprock.

Little bump, little bump. The air.

Air walk. I walk. Air.

I'm just keeping it right up.

I walk. My tires run out.

Got a sand pockets in the drain here. We

still have a half mile. Shift

down, steep hill.

Shift down for it. The legs

feel like they're going to fall off or

you walk. Shift up,

shift up. Yeah, that's

crazy right there. If I don't make it,

give my bike to my little brother.

Would you ever go over that drop off?If

it was my last day on earth, maybe.

I just don't know how they can make it

down in one piece, but stick with us to

see if they do. Serious bikers like Ari

and Jr. have their own dictionary of

slang. See if you can understand any of

this. On that gonzo ride, his

sneaker hit some death cookies right

before like a tombstone sent him endo

like Superman, which I got him a

hamburger and a potato chip. Translation.

On that extreme ride, his tire hit some

stones and then a rock that sent him

flying over the handlebars like Superman

really far. And then he got totally

scraped up. That's the hamburger. And he

bent his tire. So it looks like a potato

chip. So if your hobby has any really

confusing lingo, don't worry about it

because we can translate. Just send us

the details and we may put you on Dragon

We'll tell you how coming up.

Have you ever wondered what's way

underground?Look at this. What if we

could peel back layers of the earth to

see what's inside?Well, that's today's

riddle. How would you look deep inside

the earth?Try and figure this one out

before we bring you the answer at the end

of the show.

To float a boat, you'll need... A plastic

bottle filled with water, a plastic pen

top, and some modeling clay. Stick

the pen top in the piece of clay. Put the

top in the bottle and seal it tightly.

The pen top floats. Now

squeeze the sides. Squeezing the

bottle increases the pressure inside and

forces water into the pen top. This

compresses the air trapped inside the cap

and increases its density. What happens

if you squeeze hard enough?Will the cap

sink?Or float. What happens

if you release the sides?Don't just sit

there. Get to it.

Hi, I'm Margie. I'm

Caitlin. And I'm Meredith. And

we're into sinkholes. Sinkholes are holes

that form in the ground. We live in

southeastern Minnesota. Around here,

sinkholes open up every year. Wow!

But you know, sinkholes aren't a laughing

matter. A farmer around here didn't find

this one sinkhole until after his pigs

disappeared. In the

cornfields, you can tell where the

sinkholes are. Here's one, here's

one, and here's one. The farmers just

plow around the sinkholes, and over time,

trees grow up inside them. So we're

going to figure out what makes sinkholes

sink.

We're going to look for several

sinkholes, measure how big they are, and

look for clues to see if we can find an

answer. Some sinkholes can be dangerous,

so we never explore them without

supervision. That's Arrow. He's from the

Department of Natural Resources.

It's a great day to go out looking for

sinkholes. Do you

remember where that sinkhole was?Oh, I

remember one was over there.

Maybe if we call for it. Here's Tinkle,

Tinkle, Tinkle. It's right here.

Yeah. It's small, though. Yeah. Here,

Margie, let's take a measurement. OK.

It's 29 feet. I'll measure the depth.

It's a little more than five feet,Margie.

What are these rocks here for?There's a

lot of limestones in the case, so maybe

it's a limestone. I know one way you can

find out. Look for a fossil. Hmm

OK. What's that?I

know it's not a fossil. How pretty.

Oh, here's a rock. Here's a rock.

Yeah, there it is. Oh, there it is. It's

got spirals. Looks like a carrot to me.

Oh, cool. Oh, wow. I think this one's a

snail. I wonder if anything was ever in

here. They must have all been underwater

at one point. Let's go look for a bigger

sinkhole. OK.

Well, we found a bigger one. Sure did.

Look at the weird shape, you guys.

This'll be fun to measure.

Okay, Margie, it's 69. 69?

Okay. Oh, I can't.

I'm having troubles. No. Kaitlyn,

it's about seven and a half feet. Okay.

Hey, you guys, why is there so much junk

down here?It looks like all the gunk that

gathers in the drain. Well, it fills up

with water, so the water has to go

somewhere. So there must be a drain under

here, right?Have fun looking for it.

Hey, look, some limestone. Maybe that

means there's more limestone underneath.

Come on, you guys, let's find an even

bigger sinkhole. Okay.

Whoa. Have fun,

Caitlin. Yeah, I'm not going down there.

There's a lot of limes down here. Yeah,

the water must have dissolved. It away,

and then it just kept that little shelf.

The ground above probably got too heavy,

so it all caved in. Check out that

drainage hole. I wonder where it leads

to. Maybe to a cave. We really should

have found it out. One next floor.

Well, I don't think we're going to take

measurements at this sinkhole. Yeah,

especially that cave really deep. It's so

dark. I don't think there's enough hole

to even cover that. You don't even know

where it ends.

Let's see your drawings. They're all

different shapes. Like the first one's

shallow. Yeah, the second one is oblong.

And the third one's really deep. You

don't even know where it goes. What else

did we find in the three sinkholes?We saw

limestone in all of them. Maybe that has

something to do with it. We didn't see

any standing water in any of them. The

water must all drain out somewhere. In

the second one, all the logs are crowded

around, so that must have been where the

drain was. So we've got water that runs

out of a sinkhole and eventually

dissolves the rock. So that creates

little caverns that eventually fall in.

Using the clues we found, we built the

mile to show how a sinkhole might form.

We built up layers of sugar cubes and

Graham crackers. That represents the

limestone. The next layer is foam rubber

with a hole for water to drain. On top of

that, we put. A layer of topsoil. Let the

rains begin.

Oh, there it goes. Yeah, cool. You can

see the... There it is, there it is.

There's the spots. Look at that. Oh my

gosh, there's like a drain hole right

there. Oh, this was right there. It is

like the number three sinkhole. Ohh

So the sinkholes around here need

limestone underneath them in order to

form. Just add water.

You know, some sinkholes lead into caves,

like this one. So what are we waiting for?

Okay, the girls used a model to show us

how a sinkhole works. Well, Earth

scientists use models a lot to see how

things happen on a bigger scale. Like

this one. Here's a model of how a rock

moves in an earthquake fault line. layers

of the Earth's crust try to push past

each other, stress builds up until

suddenly they slip. And that's when an

earthquake happens. Sometimes the rocks

just move a little bit and buildings

wobble. Sometimes they move a lot until

the building falls over. Now it's

time to see some kids who don't need

models, 'cause they're working hands-on.

Snakes have gotten a bad rap, but we

think they're just misunderstood. If we

can slither onto DFTV, you can too.

Surf on over to the Dragonfly TV website.

It's at PBS online at pbskids.org.

Or you can write us at Dragonfly TV,





It's time for a clue to our riddle. How

can you tell what's deep below the

surface of the earth?Edgar and Donald are

doing some digging of their own.

Hey, Don, look how far you have to go to

reach the center of the earth. About



far, but I bet we can see pretty deep if

we find somebody drilling a well. Let's

go. This drill is working in my

neighborhood.

Look, you can see rock and dirt being

brought up. Hey,

how far are you drilling?140 feet.

That's pretty far, but it's barely a

start to get to the Earth's core.

How else can you see what's deep under

the Earth's surface?

I'm kind of surprised that a giant drill

like that doesn't go down even farther.

Whoa, maybe there's something you can do

above ground. Well, there's a big hint,

so try another guess. And stick around,

'cause the answer's on its way.

How many moons are in our solar system?







Let's go.

Hi, I'm Liz and I study rock.

Actually, I'm a mineralogist that

specializes in garnet, one of the three

most common minerals in the earth. And

what I'm really looking for in this rock

is water. And what you might not

know is that there's just about as much

water in the minerals of the Earth as

there are in all the oceans of the world.

I study rocks because I find them

extremely interesting. Rocks, rocks,

rocks. Rocks could be construed as a

history book. The rocks are billions of

years old. The best part of my job is

actually finding the minerals. Then when

I'm back in the lab, I study the samples

to find out what they're made of and how

they're made. That's another way of

learning how the Earth was formed. My

interest in minerals. Began while growing

up on the Big Island of Hawaii. I spent a

lot of time outdoors playing and hanging

out at the beach. When you grow up on an

island bubbling with lava, you feel

connected to the process that creates

more land and rocks. This is a pretty

interesting thing to to see first hand

how the earth is actually forming.

I love outdoor sports and adventure,

which is one of the reasons I love my

job. I skydive.

I bungee jump and I mountain

climb. Sometimes when I'm rock climbing,

people keep me busy identifying rock

types. My friends and family will come up

to me with rocks or minerals that they

found. What did you guys find here?Were

you looking outside?Yeah. So once I have

a mineral that is unknown, I have an

instrument called a Raman spectrometer.

Do you guys know what that is or have

heard about it?No. So basically what

we're going to do is stick these samples

in there. And a laser is going to hit it.

And from the way this mineral reacts to

the light, I can tell what it is. This

mineral is actually quartz.

Cool. I

love my jaw because my jaw rocks.

So minerals aren't just cool to look at.

Like Lisa says, they're pages right out

of the Earth's history book. Take this

hematite, for example. It forms when iron

dissolves in water and drops from one

surface to another, leaving behind this

cluster of minerals. And the name

hematite comes from the Greek word

meaning blood-like, because when you

smoosh it, the powder looks blood red. Or

this apatite in calcite. The calcite

was originally sandstone before it was

morphed by heat from nearby molten rock.

And the cool thing about this purpley

green stuff, apatite, is that apatite is

a mineral that makes up teeth and most

animals. Get it?Appetite.

Food. Teeth. Oh my gosh.

Great story, Mariko.

How many active volcanoes are located in

Alaska?1080



More than 140.

You don't have to be a scientist to

collect cool rocks. Check out what Jesse

and Gordon found in the Colorado Rockies.

You get so high up that you don't

actually realize you're above the ground.

You just kind of get used to it.

When I'm going up really, really high, I

get this really big

fast run. I'm Gordon. And I'm

Jesse. And we both love to rock climb.

Here in Aspen, we're very lucky. We've

got lots of different types of rocks to

climb. Lucky?Those are actually

complicated. Crystal this, that, all

that. What are we going to do about it?

Well, we've got to learn more about the

rocks. It'll make us better climbers.

Gordon and I will climb three types of

rock to see how their differences affect

our climbing. Three rock types will look

at two factors in our climbing, one being

hand paint, and the second being how well

our feet stick to the rock.

Rock type number one is igneous. That's

nice. Woo-hoo! I'm not

afraid to fall. But I'm

afraid to

fly The rock felt good.

My feet stuck really well. Didn't have

any problems. It was a really greatclimb.

There's sure a lot of gear in climbing,

isn't there?Yeah, we forgot the most

important thing. You know what that is?

Safety?Bingo. That's why a lot of times

when we're climbing, we wear a helmet.

You'd much rather have a rock hit this

instead of your head.

Rock

tight, #2 is metamorphic. Make

sure you're tight. I'm all set to go.

There's a lot of pockets. My feet are

gripping well. It feels grainy under my

feet. It's very edgy. And

there's little chippy rocks that come

off. Last

of all, we're going to take a stab at

sedimentary rock.

Climb on. Good luck.

That's it, baby. Dude, give me

slack. Can you pop up to

the lunge?Yeah!

There weren't as many handholds as the

rocks we climbed before. I mean, it's

pretty rough. It wasn't really pointy. It

was rough.

So what are the results, Staz?Well, they

don't tell us a definite answer. What

they do tell us is which rock holds up

bestAnd which rock has the best foot and

handholds?

Doing these tests help, but we're not

geologists yet. But we are climbers.

Climbers who know their rocks. Yeah,

salute our hero.

Now back to Ari and Jr. and their

bone-busting bike ride. We

rode our mountain bikes in two very tough

but different trails in Ohab, Utah, and

we recorded our audio data as we went.

Hey, you made it. Oh, man, I'm going to

be sore. Let's take these melting charts

as bad boys. OK. We made

a chart to help us make sense of what we

recorded. We came up with a color code

for the chart. We used purple marks to

show when we shifted gears, blue marks

when we caught air, and brown marks for

when we saw debris on the trail.

Let's look at Porcupine Rim. Holy

cow, that's good air. Ohh

Look at all the blue marks. Yeah, we got

a lot of air. We went over 23 drop-offs.

That was a rough ride. We had to change

gears a lot. Nine times just in that one

mile. And we got off our bikes about four

times. Look at all the marks for debris.

There is a lot of stuff in that trail.

Rocks and sand. Now let's check

out Slick Rock. Little walks,

little lair, stair walks. I walk

air, shift down,

steep hill. There aren't very many marks

in this one. Yeah, we didn't go over many

drop-offs, and we only caught her seven

times. It was really hilly, though. Lots

of up and down. We changed gears seven

times. We had to get off our bikes three

times. Some of those hills were really

steep. Slick rock sandstone

was really fine-grained, and it didn't

have that much debris. There was some

sand, but not much else. The trail was

really smooth, kind of like a skate park.

What's missing here?It's just me.

Without my mind. So what does

this all tell us?Well, we only saw sand

on this lake rock trail. No big rocks.

The hills looked like petrified piles of

sand built up by the wind. This place

must have been like a giant desert before

the dunes turned into sandstone. So this

turned into this.

Porcupine Rim was full of rocks and

debris that the wind couldn't carry.

Porcupine Rim was a butt Buster. No

kidding. It's really rock ride.

The shape of it was different. The

erosion was really uneven.

We figured these trails must have been

formed by water.

How much more will the chills change?I

don't know. Guess we'll have to dig a

little deeper. Take a lifetime of writing

to find out the things we do for science.

So it's easy to imagine how a river can

erode stuff away as it moves along, but

wind is just as powerful. Wind blowing

at 15 miles an hour can carry sand

particles across the surface. So wind

with the help of the airborne dirt can

scour away at things. Check out the three

sides of this rock. They've been worn

away by winds coming from different

directions. It's called a ventifact,

which means made by the wind. And now for

some deeper geology, it's time to answer

today's riddle. How can you see far

beneath the Earth's surface?And guess

what?We're staying above ground for the

answer.

We use vibrations called seismic waves to

figure out what's below the Earth's

surface. It's like throwing a

rock into a pond and watching the waves

rippling out in all directions, except

the waves go down into the Earth. Seismic

waves are made by earthquakes, but we

make them with this machine. A 200 LB

hammer hits the surface and sends seismic

waves deep into the ground.

We monitor the sound waves that bounce

out the rock and come back. They're

called reflections.

Reflections indicate different rock

layers, how far down they are and what

they're made of. This system measures

depths of up to 1,000 feet. Feel the

rhythm now. But other systems,

like this truck, make a stronger sound

wave that can go as far down as 20,000

feet or more.

That's really deep. Think of it this way.

A jet airplane flies about 25,000 feet

overhead. Now imagine looking that deep

down below. Here I have a core sample

brought from underground. This quartzite

came from 1000 feet below and is more

than 1.8 billion years old. This

silt stone is from 500 feet down and came

from an ancient seabed. See, every way of

the earth really does have a story to

tell. So if you have any science projects

or ideas, make sure to tell us about it,

because if you don't, who will?

To find out more about Dragonfly TV, head

to PBS online at pbskids.org or

write us at Dragonfly TV. 772 E



See what's coming up this season on

Dragonfly TV. Whoa!

He ripped that color off. Yes, you did.

Coming up soon on Dragonfly TV.

Michael's got a k*ller test tomorrow.

Yes, I do. But we're also out of time. So

we'll see you next time for more

investigations across the nation. On

Dragonfly TV. Major funding for Dragonfly

TV is provided by the Best Buy Children's

Foundation. We're excited to see kids

like you exploring the world of science

and technology, because what you're

learning is going to change the way we

live. Best Buy, the futureLooks fun.

And by the National Science Foundation,

supporting education and research in

science, mathematics and technology.

The National Science Foundation.

America's investment in the future.