Bill Nye the Science Guy - S04E14 Volcanoes

this is an ancient landscape

actually it's just a few weeks old but

some of the oldest land on earth came

from the same place this from is brought

to you by the law offices of magma lava

tephra and pumice making mountains out

of vent holes take a look at this

it's a mountain well actually it's a

volcano volcanoes are formed when hot

molten rock from deep inside the earth

finds its way to the surface this isn't

hot molten rock it's a mild acid and to

help it find its way to the surface

we'll add some sodium bicarbonate this

will be like hard rock right above the

molten rock from deep inside the earth

see the pressure builds up and it builds

up then eventually a volcano will erupt

it'll blow its top it'll write explode

with any time now

there it goes haha he's in bill you know

I've made volcanoes like that in my

kitchen maybe it's better I mean I mean

that's it

that's it I mean what's the big deal

what's the big deal

take a look volcanoes can blow down

entire forests in just a few seconds

they can reroute rivers and form new

Lakes carve new valleys transform entire

landscapes in a matter of hours and

that's what happened around here when

that mountain right there blew it's hot

it's mount st. helens and it erupted in

1980s in the Pacific Northwest of North

America

now there are different types of

volcanoes they don't always explode when

they erupt some volcanoes hooves

now when I say Jews I'm talking about

hundreds of thousands of tons of rock

and well over a thousand degrees Celsius

they come out of the earth and they cool

off to make new land land that you and I

live on see there are different types of

volcanoes but they all do the same thing

they all build up the Earth's surface

since the earth was young volcanoes have

hurled fiery rock from the planets

interior to its surface

volcanoes usually occur were two

tectonic plates run into each other like

here's mount st. helens where the

Pacific plate is colliding with the

North American plate but the Hawaiian

Islands right here in the middle of the

Pacific plate with no other plates

around and the Hawaiian Islands are made

of volcanoes so how did they get there

take a look at this

it's our drifting plate magma boom

simulator of science this is the Pacific

Ocean this is the Pacific ocean floor

the Pacific plate and this is a boat

near as we can tell

deep beneath the Pacific plate there's a

stream of extremely hot magma what we

call a magma pose see the magma in the

plume doesn't flow continuously instead

it sputters like smoke from a chimney

and it's always in the same spot so the

pressure in the poem builds for it to

punch through the Pacific plate please

this when the plate moves the pressure

builds and the plume punches through

again more plume punches through

volcanic rock and ash accompanied by

billowing clouds of steam shoot into the

air and build a new iron so this is how

the Hawaiian Islands were formed

we figured it out when we noticed that

the rocks on the northern islands are

older than the rocks on the southern

islands because the Pacific plate is

drifting this way we can detect so the

pressure in the plume built up and boom

nylons for pressure build up and boom

volcanoes erupted because there are

gases trapped in the magma deep inside

the earth lava is in constant motion

expanding gas is released from within so

when those gases get hot enough they

expand and explode expand and explode

see a volcano is kind of like a bottle

of soda there's a lot of carbon dioxide

in there so if you put one bottle of

soda on ice and you put the other bottle

under a heat source which one do you

think is gonna fit the most when we take

off the cap look I can't do everything

for you okay okay okay okay I'll do it

fine cold this is an active lava field

this is an active lava field a field of

lava and it is hot

the lavas falling under the surface

right along here hot hot hot

once in a while the surface collapse and

we can see in it's called a skylight the

lava here is really moving

that's the cinder cone of a volcano down

in the crater is a lava vent it's

letting lava that's under pressure vent

to the surface it's filling up it's

brand-new land the lava flows downhill

and channels the edges of the channels

cool into a hard crust

sometimes they form a lava tube a lava

tube like this one the volcano ends up

with a whole underground subway system

of lava building up new land and flowing

sometimes all the way to the sea

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here it is the lava is flowing into the

sea see it's turning the ocean into

steam and it's making brand-new land I'm

talking about waterfront property

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and lava solidifies

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new land is more

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the wind carries seeds all over the

volcanic landscape if they happen to

land in the right place some of them

start growing now why do you think

plants get started in these cracks well

that's where the water hangs out when it

rains so you getting started on these

smooth surfaces would be hard the water

just just runs away these plants are

growing in soil that's beneath the layer

of ash but in a few years with a few

more rains the plants will be getting

their nutrients from the ash itself the

volcanic landscape will turn lush this

is a brand-new lake so there are new

plants growing here that brings in all

kinds of new animals around here nature

as a way of regenerating itself

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holidays had magma box with balloons for

the kitties and hotdogs

beefy boy burgers flame boil

and as always balloons for the kiddies

and hot dogs for mom and

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this is the cone of a volcano call it a

cone because it's round and cone-shaped

when volcanoes stopped erupting a lot of

times they form a little bowl in the

middle nice a little it's huge

it's two kilometers across this is

called a caldera and under here is a

chamber of met when the magma chamber

fills up the bottom of the caldera Rises

the locus when the magma chamber greens

the bottom goes down some volcanoes

other volcanoes explode please consider

please consider please can see consider

the fall take a look at this this is

molten let its liquid it flows just like

lava

just like magma no matter how long we

let it sit there it just sits there it

doesn't boil it won't overheat and blow

its top but this is boiling water it's

only at a hundred degrees Celsius for

LEDs at 300 degrees Celsius we let it

sit there long enough eventually the

pressure will build up inside here watch

it blew up that's because the water

turns to steam water vapor a gas that

could expand the lead still just sitting

there now this is what happens in

volcanoes some losing volcanoes form

when a hot pocket of magma magma plume

finds its way to the surface through

some cracks in the plate other volcanoes

happen when one of the Earth's plates

slides underneath another plate if it's

under the ocean the plate gets soaked

with water then later when the Earth's

heat warms it up enough to form a

volcano it explodes

come on volcanoes come in different

shapes depending on how they're formed

the shield volcano was formed by hot

lava that flows down the sides quickly

the lava comes out hot and flows a long

way before it hardens that's why this

volcano sort of flat like shield

miss your cinder cone volcano it erupts

explosively the cinder ash so it ends up

tall and sort of flat on time well

there's a third shape it's like a combo

of the other to call it strata cone

sometimes it spews lava and other times

cinders

Strada cone is tall with a symmetrical

cone shape so there you have is your

three flavors of volcanoes this is a

shield

cinder cone and strata cone yum yum yum

could I have some dough there's any

extra Vesuvius is a composite cone or

stratovolcano built by many eruptions of

ash cinders and lava Vesuvius erupted

violently in 1944

the whole world watched in awe as

newsreels showed villages at the foot of

the mountains crumbling before the

advancing lava

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[Applause]

honey

what does this remind you of

honey you know what that reminds me of

come on honey you want to hear you say

it what does this remind you of honey

it's embarrassing okay if you insist it

reminds me of a strata cone volcano

which builds up in the Earth's crust to

make it big and strong

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[Applause]

now please be excused from the table

sure how hot is lava oh yeah

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that hot

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now hot as lava it's over a thousand

degrees Celsius

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the lab says these rock samples all came

from underneath the Earth's crust and

get this they used to be hot goo over

1,000 degrees centigrade hot bucum guató

can't exactly book them sir they're

volcanic rock

volcanic rock and people say you know

why study volcanoes why bother why go to

all this trouble I'll tell you why

well yeah I'll get our cool oh yeah

that's no problem but I'll tell you what

else there a window on the underworld

there a window on what's inside the

earth where all the land on earth once

came from look at it right now flow is

flowing underground through a system of

lava tubes and it's coming out right

here at the sea

in Italy great love the knowledge on

revolutionary protective suits in hopes

of getting a closer glimpse of the

volcanic activity exploding forth from

out Stromboli govision naka Dhaka was

formed about five or six thousand years

ago within the school ever since then it

has been a very active volcano with

glucose the most recent large eruption

occurred in 1990 if you count the

smaller eruptions

the most recent one occurred in January

1995 about 50,000 people live on the

caldera right now so at this museum we

are always using scientific methods to

monitor the caldera activity to study

the effects of the volcano on the

environment

what's up fishtank you're not okay take

a look at this

this one's called pahoehoe the other one

is ah and this ash and cinder goes by

the street name Li Aloha bandit no

tephra how do they get here

what kind of sicko would take molten

rock from under the Earth's crust and

spit it out like so much mouthwash could

be that big volcano down the street I've

got it the volcano

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this is a treat it used to be alive

all of these trees used to be alive but

they were killed just like that when a

hot stone wind from Mount Saint Helens

blew through this valley now a stone

wind is a wind loaded with pumice

volcanic ash exploding from the volcano

at over 350 degrees Celsius a stone win

instantly knocked trees down that were

close to the explosion and then it

continued on for many kilometers

completely scorching thousands of

standing trees along the way just like

that honey we're out of soap again don't

get in a lather dear try some ah where's

it from from under the Earth's crust

silly any other questions just one scrub

my back

there are some volcanoes that may never

erupt again these are called extinct

volcanoes like Mount Kenya in Africa it

hasn't erupted in millions of years

the magma plume where the lava used to

come from has cooled to a solid Mount

Kenya is extinct so feel free to build a

house on it'll probably be okay for

centuries a volcano that hasn't erupted

in two hundred years is called dormant

like Mount Rainier in Washington State

it's just sleeping there's no magnet

flowing right now but it could easily

just snap out of it snap and you

probably shouldn't build a house there

then of course there's everyone's feet

the active volcano Stromboli postive

Italy

active volcanoes are almost always

shaking and rumbling and shooting off

steam or erupting I probably don't have

to tell you do not do not want to build

a house right there

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Sam

[Applause]

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oh yeah you have us

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big predictions mother's way we in case

the big ones

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until the chest

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well that's our show thanks for watching

- excuse me I've got some airborne de

site particle levels to measure see yeah

look at that

pumice plane then add a site the artists

in association with the National Science

Foundation

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[Applause]

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if it takes more time let me sum volcano

sit there for hundreds of years

centuries before they explode some just

you know a few hours

this one is was taking up longer than we

expected but that's one of the features

of volcanoes is the unpredictability of

the receipts this why we study them

that's why we're doing a whole show

trying to figure out when exactly

volcanoes will erupt

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