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>> Earth, a unique planet,

restless and dynamic.

Continents shift and clash.

Volcanoes erupt. Glaciers grow

and recede. Titanic forces that

are constantly at work, leaving

a trail of geological mysteries

behind. This investigation

ventures deep into remote

Russia in search of a vast sea

of stone called the Siberian

Traps. Experts will dig deep

into Earth's ancient past to

discover how this rocky

wilderness formed, and unearth

evidence in surprising places

to prove how deadly volcanic

eruptions in Siberia wiped out

nearly every living thing on

Earth. The most dramatic

episode yet in the story of

"How the Earth Was Made."
S02x11 Earth's Deadliest Eruption
Original Air Date on February 9, 2010

-- Sync, corrected by elderman --
-- for www.MY-SUBS.com --

The investigation into the

cataclysmic event that

radically changed planet Earth

begins in the deep frozen land

of Siberia. 50% bigger than the

entire United States, this land

is locked in ice for most of

the year. Temperatures plummet

to minus 90 degrees fahrenheit

and below. But in summer, the

ice melts and reveals one of

the largest and most mysterious

geological formations on Earth.

The Siberian Traps. Nearly 5%

of Earth's land mass is covered

by this ancient sea of rock.

Deep canyons expose layers

hundreds of feet thick. These

giant stepped formations are

called traps, from the Swedish

Word for "stairs." They were

discovered under unusual

circumstances. Polish geologist

Aleksander Czekanowski was

exiled to Siberia in 1863 for

"political crimes" against

Russia. While banished, he

surveyed the landscape and

stumbled upon this unique,

unexplained expanse of layered

rock. Today, the journey to

fully understand how this

strange stone formation was

made begins in a swamp.

>> I'm not sitting in this

swamp just for fun. This

swamp's actually very

characteristic of what Siberia

was probably like before the

Siberian Traps formed. This

vegetation, this shallow,

stagnant water is very

different to the environment we

see in Siberia today.

>> The clue that enabled

scientists to figure out that

Siberia was once a swamp came

from a particular kind of rock

found beneath the traps.

Coal... trillions of tons of it.

>> This rock here is coal. It's

very important in Siberia. It

forms when plant matter, trees,

the thick vegetation dies and

falls into a swamp, and over

millions of years of geological

time, they're compressed into a

hard rock substance like the

one I'm holding in my hand

today.

>> The age of the coal was

determined by dating the plant

fossils trapped inside the

rock. The process revealed that

the coal was formed more than

300 million years ago. It

continued to collect and be

compressed over the next 50

million years.

>> So, the environment was very

stable--swamps, thick

vegetation. Then suddenly, 250

million years ago, it all

stops, and you have the

Siberian Traps lying on top of

the coal. So, something fairly

dramatic must have happened at

that time, so we really need to

study this phenomenon to

investigate the geology and see

what we can find out.

>> But investigating the

geology of the Siberian Traps

is no easy task, because

they're located in one of the

most remote and least explored

areas of the planet. It's an

arduous journey for Howard and

his team, a 1,000-mile trek

through Siberia over land and

water, camping out in

mosquito-infested forests.

>> It's taken us nearly 7 days

to get to this remote corner of

Siberia, but this afternoon,

we've finally found the rocks

that we were hoping to study.

>> These towering pinnacles of

rock mark the edge of the

Siberian Traps. Even from a

distance, without leaving their

boat, the geologists can

identify this distinctive

formation.

>> The rocks you can see behind

me are basalts forming

wonderful towers. We've stopped

and studied these in several

locations. And what we've seen

is only a tiny part of the

basalt which covers such a large

part of Siberia.

>> This evidence unlocks the

mystery of how the traps were

made. Basalt is what geologists

call "igneous rock." and that

only comes from one source--a

volcanic eruption. The Siberian

Traps must once have been a

vast, red-hot lava field.

>> I think the Siberian Traps

would have been 1,000 times

more intense than anything

I've seen doing my own

fieldwork. And if I could go in

a time machine and watch it all

happen, it would be really just

fantastic to see the scale of

it. The length of the lava

flows, and the height of the

fire fountains would have been

really something to see.

>> There are several types of

lava rock. This basaltic lava

is a free-flowing liquid when

it first erupts from the

ground.

>> Just looking at how fluid

this rock appears gives us some

of the clues what it might have

been like in Siberia if we

could have gone there. There

would have been really gooey,

goopy, runny lava flowing

across the land surface for

1,000 miles in all directions.

>> This semi-liquid lava gives

these rocky plains their

name--flood basalts. They still

erupt today in Kilauea in

Hawaii, currently the world's

most active volcano. After 25

years of constant eruption,

the basalt lava field has

engulfed more than 4 square

miles of Hawaii's Big Island.

But the Siberian traps are

bigger--500,000 times bigger.

Each distinct step is laid down

by an individual lava flow.

Layer pours out upon layer

until the traps are more than a

mile deep in black hardtop,

over an area nearly the size of

the continental U.S.

>> So, imagine the entire United

States covered in a lumpy,

uneven parking lot, like

asphalt, everywhere as far as

the eye can see, and that is

what the Siberian Traps looked

like when it first formed.

>> Geologists have discovered

how the traps were made. The

next step is calculating how

long this vast Siberian super

eruption lasted.

>> Fortunately, volcanic rocks

contain little minerals that

formed when the rock

crystallized--when the rock

cooled and solidified. And some

of these minerals are

radioactive, and they decay

over time. And so they're like

little time clocks. They start

when the rock cools, and then

when we measure them, the clock

stops. And we know how much

time has passed

since that rock formed.

>> Dating the oldest lava here

reveals that the Siberian traps

first ripped the landscape

apart 250 million years ago.

And by also dating the youngest

lava, scientists can figure out

exactly how long the eruptions

lasted. The results are

surprising. They show that lava

carried on pouring out and

building up into ever-deeper

layers for an almost

unimaginable one million years,

forging the largest lava flow

on land. The next step in the

journey is to figure out why

this vast eruption happened

here in Siberia. Most volcanoes

exist at plate boundaries, thin

spots on Earth's crust where

the floating plates that

support the continents jostle

together as they drift across

the face of the Earth. Yet, the

Siberian Traps are right in the

heart of a huge continent. So

experts have to come up

with an explanation.

>> This is a mantle plume. It

may not look like it. And you

have to imagine that this is

going on over about 1,500

miles, rather than a bottle. But

it's quite a good simulation of

how mantle plumes work. They're

heated from below. This candle

is the Earth's core supplying

heat. And this is the bottom of

the mantle. And the heat is

heating up some of the mantle.

And it rises up as these blobs

up towards the Siberian Traps

which are up at the top here.

>> Mantle plumes are one of

geology's great mysteries. No

one knows why they switch on or

off. But their shape is a

crucial clue as to why plume

eruptions are so fierce

and so massive.

>> That mushroom head in

reality can be 1,500 miles

across. And so, the volcanic

eruptions can cover huge

areas--hundreds of thousands of

square miles. And also, the

actual head is a very

short-lived phenomenon that

probably erupts in hundreds of

thousands of years, at most, a

million years.

>> Evidence has been uncovered

to reveal how and when the

Siberian Traps formed. 250

million years ago, a vast magma

bubble burst, cracking and

slashing open Earth's crust.

And for life on Earth, a new

devastating era began. Two

types of rock are proof of very

different landscapes in ancient

Siberia. Coal reveals that

before the traps existed, this

area was a swamp. Basalt lava

is evidence this era ended with

a bang--a super volcanic

eruption. But now, geologists

have evidence that the Siberian

super volcano was about to

become Earth's greatest-ever

killer. The deadliest million

years in Earth's history

were about to begin.

>> 300 million years ago,

Siberia was a swamp. But deep

underground, a plume of hot

mantle rock was rising. 250

million years ago, the bulging

crust burst open, and boiling

lava erupted onto the surface.

The most cataclysmic and

destructive million years in

Earth's existence was about to

begin. With every eruption,

basalt lava surged across

Siberia in rivers and waves.

Terrifying forest fires raged.

Animals were burnt alive.

A new deadly Earth story was

underway, one which would have

catastrophic consequences for

all life on Earth.

To figure out what chaos this

mega-eruption caused for the

Planet, geologists are taking a

closer look at Siberia's

ancient lava rocks.

>> This rock is very typical of

what you see in flood basalt

provinces. And we have many

what we call vesicles. They're

small holes in the rock, and

those suggest that gases left

this rock. They escaped from

this rock when this rock

started cooling at the surface

of the Earth.

>> The search for what kind of

gas Siberia was producing

begins nearly 8,000 miles away

at Mammoth Mountain in

California. This is an ancient

dormant volcano. For years, it

was thought to be harmless. But

then in 1989, a ranger had a

terrifying experience.

>> It was wintertime, and a

ranger was just checking on the

area. And he wanted to take a

break from the wind, so he

crawled in through a hatch

that's in the roof of this

cabin. And he became very dizzy

inside and didn't feel well.

And he had the commonsense to

think that maybe there was some

bad air in the cabin, and he

crawled back up the ladder and

got out safely. But it always

kind of remained a mystery

initially.

>> Then just a few months

later, the trees here began to

die. Clearly, something strange

was happening.

>> So it required an

explanation of what could

combine with making a person

feel dizzy and disoriented, and

what would also kill trees at

the same time.

>> Farrar's research revealed

that a poisonous gas was to

blame, one that was seeping

upwards out of the ground.

Analysis proved that the gas

was carbon dioxide, a byproduct

of volcanic activity. It's

released when magma rises from

deep underground.

>> So, just like this bottle of

soda water, the magma beneath

us contains dissolved carbon

dioxide. And when it reaches

the surface of the Earth, the

pressure is released. Just like

this, when you... open the

water, the pressure is released

and carbon dioxide is coming

out of this bottle of soda

water, and that's the same gas

that's coming out here at

Mammoth.

>> Today, lava deep beneath

Mammoth Mountain pumps out

1,000 tons of carbon dioxide

every day. This suggests to

scientists that trillions of

tons of gas could have been

released into the atmosphere by

one of the Earth's largest

eruptions in Siberia 250

million years ago. And evidence

comes from an unlikely source.

>> Well, this is a ginkgo tree.

And ginkgo trees are very

special, because the ginkgo

family has been around for a

very long time--270 million

years. And it's remained fairly

unchanged over the course of

Earth's history.

>> Because the ginkgo changes

so little over time, it is the

ideal specimen for comparing

the present with the past. The

leaf's surface is peppered with

microscopic pores called

stomata. Plants use these

stomata like tiny mouths to

breathe in carbon dioxide.

>> The number of stomata on the

leaves of a ginkgo indicate how

much carbon dioxide is

available to them in the

atmosphere. When there's a lot

of carbon dioxide in the

atmosphere, they only need to

have a few. When we look at

fossils of ginkgo leaves that

formed 250 million years ago,

we notice that they have very,

very few stomata to take up

carbon dioxide. And this means

that there was a lot of carbon

dioxide available

in the atmosphere.

>> Investigators have studied

ancient leaves from locations

all over the world

and calculated that there was 3

times more carbon dioxide in

Earth's atmosphere 250 million

years ago than there is today.

This was a deadly and global

gas disaster. And the only

culprit capable of producing

such substantial quantities of

carbon dioxide is volcanic

activity, on a truly massive

scale.

>> When you have an eruption

the size of something like the

Siberian Traps, you imagine

something almost apocalyptic in

nature--ash blocking out the

sun. But then you have a kind

of double whammy where you also

have the release of volcanic

gases from the eruptions. And

these gases trap in the heat,

so it gets hotter and hotter.

>> Lava from the traps turns

Siberia into a lifeless

disaster zone. But carbon

dioxide can mingle and mix in

the atmosphere, trapping heat

inside like a parked car on a

hot day.

7,000 miles away from

Siberia is South Africa's Karoo

Basin. Here, evidence in rocks

gives geologists a tip-off that

carbon dioxide from the

eruption provoked a climate

disaster that wasn't confined

to Siberia. An old river

channel slices through the

landscape, exposing the layers.

These rocks have been dated to

just before and just after the

Siberian Traps began to erupt.

These are mudstones. They form

on lakebeds from squashed mud,

so they're evidence that, just

as in Siberia, the land was

once swamp-like and covered in

water. But they're also

evidence of change.

>> These rocks beneath my feet,

which are green in color, are

the older rocks here. And then

these rocks, which have got a

more red color, are the younger

rocks. And the red color

indicates that there's an

environmental change. That the

climate was possibly drying out

and becoming warmer.

>> The mud is rich in iron.

When it is shaded by plants or

covered by water, it stays

green. When it's exposed to the

sun, it turns rusty red. So the

red stones are evidence that

plants and water, which shaded

the mud, had disappeared. 250

million years ago, as Siberia

spewed volcanic gases into the

air, South Africa was drying

out, warming up, and turning to

desert. The Karoo Basin is also

where the first evidence was

discovered that it was not just

the plants that were dying.

>> Well, this animal was found

in 1934. My aunt, who was then

a little girl at school--she

came home from school one day

and she said to her father,

"daddy, what is a fossil?" and

my grandfather's response was,

"let's go off into the hills

for a picnic and see if we can

find one." so they went off to

the hills. And amongst other

bones, they found this.

>> In their own backyard, the

Rubidge family had unearthed

yhe remains of an animal

completely unknown to science.

This creature is a gorgonopsid.

It was a carnivorous lizard 10

feet long which roamed South

Africa during an era called the

Permian, hundreds of millions

of years before even dinosaurs

evolved. But dating these

fossils reveals that as Siberia

began to erupt, these animals

were dying.

>> Gorgonopsids are the

dominant predators of the

Permian period, and we find

them in all these different

layers in the Permian rocks.

Gorgons lived in this area

about 260 to about 251 million

years ago. And then suddenly,

when you get higher up at this

sort of level in the Permian

sequence, they disappear.

>> And the gorgonopsids were

not alone. There are virtually

no animal fossils here younger

than 250 million years. 7,000

miles from the Siberian super

volcano, something caused the

land to dry up, plants to die,

and nearly every land animal to

go extinct. And one critical

cause of this global disaster

is carbon dioxide from the lava

rocks. Yet, this deadly,

million-year-long chain

reaction, triggered by Siberian

eruptions, is only just

starting. The investigation has

uncovered how volcanic activity

in Siberia created a global

catastrophe. Fossil leaves of

the gingko tree reveal evidence

that the atmosphere was full of

volcanic carbon dioxide.

Gorgonopsid skulls show animals

were dying out at the same

time. But worse was to come.

The catastrophic Siberian

eruptions were about to unleash

a new murderous nightmare.

>> 300 million years ago,

Siberia was a waterlogged,

swampy bog. 50 million years

later, Earth's biggest-ever

volcanic eruption on land was

smothering Siberia in layer

after layer of solid, silvery

basalt lava hundreds of feet

thick. An atmosphere saturated

with volcanic carbon dioxide

had raised global temperatures

by around 10 degrees

fahrenheit. Life on land was

dying. Now the hunt is on to

uncover evidence of how

Siberia's super volcano

precipitated a marine

catastrophe in all of Earth's

oceans. But scientists aren't

looking for answers in the sea.

They're climbing 10,000 feet

above sea level up into the

Dolomites Mountains.

>> Here in the mountains of

northern Italy, these rocks

give evidence of one of the

greatest crises in the history

of the planet.

>> Crack open the layered rocks

and fascinating secrets are

revealed. Mysterious and long-

extinct sea creatures called

trilobites are preserved in

their millions. Their existence

here proves these peaks were

once a seabed. The trilobites

were trapped in sediment

settling on the ocean floor.

over millions of years,

geological upheavals have

thrust them two miles up in the

air. The rock layers here are a

oerfect record of life in the

ancient oceans.

>> What we can see is, just

below the level of my hand,

there's lots of nice fossils, a

big diversity of things we can

find in here. And then these

younger rocks just above, just

a little bit higher--basically,

there's very few fossils in

here, and a much lower

diversity.

>> In between the two different

layers of life, Wignall hacks

into a black band. In here,

there are not just fewer

fossils. Here, there are none

at all. This is what geologists

call the extinction zone. It

has been dated as 250 million

uears old. Worrying evidence

that, having killed off most of

the life on land, the Siberian

super volcanic disaster was

spreading to the seas. This

black clay contains microscopic,

glittering clues--crystals of a

mineral called iron pyrites.

Its shiny appearance has earned

this rock the nickname "fools'

Gold." it's worth just a few

cents, but it holds priceless

information about ocean waters

where the rock formed

250 million years ago.

>> This mineral, this iron

pyrites will only form in the

absence of oxygen. And so

therefore, it's a nice, very

direct line of evidence for

what's going on at this time.

>> The presence of fools' gold

is evidence that the water in

which it formed had no oxygen

at all. And scientists believe

the warming effect of volcanic

carbon dioxide from the

Siberian eruptions was directly

to blame for this lack of

oxygen.

>> The ocean circulation is

driven by the fact that we have

a good temperature gradient.

It's cold at the poles and it's

warm at the equator. And so,

the water circulates between

the poles and the equator, like

a conveyor belt. But if you

make everywhere warm, the

conveyor belt turns off, and

the water just sits there and

stagnates and no longer has the

ability to sort of resupply

oxygen.

>> The ocean had become as

still and warm as bath water.

And warm water absorbs less

oxygen.

>> It's possible to recreate

these nasty conditions in a

fish tank, in fact. All you need

do with a fish tank is to put it

in the window on a bright,

sunny day. The sun will warm

the water up, and the water

will start to lose its oxygen,

and it'll--basically, it'll

stagnate. If you leave it for

too long, your fish will die,

and you'll have a sort of

mini-recreation of one of the

greatest extinction events of

all time.

>> As volcanic eruptions tore

Siberia apart, life was

fighting for survival in the

oxygen-depleted seas. But the

Siberian eruptions were about

to flood an even more deadly

poison into the oceans. To find

out what happened next,

researchers hunted for a

modern-day location that could

recreate life in the

Siberian-damaged Permian Ocean.

Unexpectedly, they found it in

central New York state--Green

Lakes State Park. This unusual,

little lake is extremely salty,

and nearly 200 feet deep,

making it a model in miniature

of the ancient seas.

>> We get asked, "why do you go

to a lake to study the Permian

Ocean?" It turns out this lake

is a lot like the ocean,

actually. It's fairly salty.

and its circulation

system--the process that brings

oxygen down deep into this

lake--is shut down, just like

we think happened to the

Permian Ocean.

>> The top layer of the lake is

healthy and thriving. But deep

down, the bottom layer is

stagnant and still. By lowering

a water sampler 150 feet down,

Kump's diving deep into the

past to a time when the

Siberian Traps were erupting.

>> Well, we have a couple clues

from this water that's telling

us about what's going on down

there at the bottom of the

lake, one of which is its

color. And this water is pink

because it's loaded with tens

of millions of purple bacteria

cells in each ounce of water.

And the other is the smell. So

if I open up the lid here and

take a whiff, it's a very

potent smell of rotten eggs.

And that's a very

characteristic smell of hydrogen

sulfide.

>> Oxygen is toxic to purple

bacteria, so stagnant water is

a perfect breeding ground.

These single-celled

survivalists flourish where

other sea life suffocates. But

they have a nasty side. They

produce a noxious and pungent

poison gas called hydrogen

sulfide. The tiniest amounts

can be fatal. The same bacteria

live in sewers, so workers

there must carry gas detectors.

>> Hydrogen sulfide deprives

your body of oxygen. It's also

a strong neurotoxin, so it has

that detrimental effect, as

well. And the really insidious

thing about hydrogen sulfide is

that it paralyzes our olfactory

nerve. In other words, we can't

smell it anymore. And that's

what's so terrible, because

right after you stop being able

to smell it, if the level keeps

building up, it can become

instantly poisonous.

>> Kump's trying to figure out

if the same lethal microbes

plagued the seas stripped of

oxygen by the Siberian

eruptions. He's searching for

proof in rocks from 250 million

years ago. But bacteria don't

leave fossils. So instead, he's

pursuing the chemical traces

they leave behind.

>> So, the clues we're looking

for are compounds called

biomarkers. These are chemical

fossils. They're fragments of

the organism that have been

preserved over long periods of

geologic time in these rocks.

And from these fragments--from

these chemical fossils, we can

try to identify what organisms

might have been involved in

this mass extinction.

>> Like a fragment of bone or

shell, a chemical fossil is a

fingerprint identifying the

micro-organism which made it.

And Kump's struck lucky.

>> This is it. This is the clue

we've been looking for. This is

the chemical fossil, the

biomarker that tells us that

these organisms were existing

at the time of the greatest

mass extinction of all time.

>> As Siberia erupted, the

purple bacteria were in

paradise, vigorously poisoning

the water with hydrogen

sulfide. The sea became a

suffocating, toxic cesspool.

The trilobites and virtually

every other species of sea life

died out and never returned.

The evidence is building up as

to how massive volcanic

eruptions in Siberia wiped out

nearly all marine life on

Earth. Fools' gold shows the

sea lost its oxygen. Biomarkers

show it was also poisoned with

lethal hydrogen sulfide. The

Earth was choking. Life could

no longer depend on its two

most vital resources--air and

water. But a new threat loomed,

as Siberia's underground coal

reserves added fuel

to the flames.

>> 250 million years ago,

a sudden violent volcanic

eruption began in Siberia.

The traps erupted over the next

million years, forging basalt

lava layers thousands of feet

thick. Buried underneath the

basalts were 5 trillion tons of

coal. As Siberia erupted, a

powerful fuel was about to

catch fire. For geologists,

coal is a crucial clue in

figuring out how a huge volcano

wiped out nearly all life on

Earth.

>> Coal is the remains of dead

plant material. And when coal

burns, the volatile materials

are released, and these include

gases such as methane.

>> And lava from the volcanic

eruption was the ultimate

source of ignition. It was like

pouring gasoline on a barbecue.

Now Saltzman is hunting for

evidence of how this colossal

coal fire damaged the planet.

His search begins in a barren

blacktop wasteland. But this is

not Siberia. This is a town

in Pennsylvania.

>> I'm standing here in what

looks like a war zone. It's hard

to believe this was the main

road into a thriving community

of several thousand people.

These cracks and these gases

all around me are a clue not

only to what extinguished this

town, but also provide one of

the key clues into the mystery

of the greatest mass extinction

of all time.

>> In 1962, the mining town of

Centralia was a community of

4,000 people. But an accidental

fire ignited a coal seam and

caused an uncontrollable

underground blaze. Dangerous

methane gas began to seep from

the ground. Today, the

residents have abandoned the

town. The fire still rages

underneath Centralia... and

methane is still released into

the air. The situation raises

the question of whether the

burning of Siberia's far

greater coal reserves, set

alight by lava 250 million

years ago, also released

catastrophic levels of methane

gas into the air.

>> The volcanoes in Siberia

would have erupted through the

coals to get to the surface. On

their way, they would have

cooked these coals. And this

burning of coal would have

released methane, amongst other

gases, and this methane would

have had an extreme effect on

the global climate.

>> As Siberia continued to

erupt, temperatures all over

the planet rose by a further 10

degrees. It's a climatic change

too dramatic to be caused by

carbon dioxide alone. There

must be an additional culprit.

Methane is top of the list,

because it's over 20 times more

effective in trapping heat in

the atmosphere than carbon

dioxide. Today, scientists are

analyzing rocks for proof that

methane from the Siberian coal

fire was the culprit. They've

discovered a telltale chemical

clue: light carbon. It's a

fingerprint of methane gas, and

it has been recorded in every

extinction zone all over the

globe, from Antarctica to

Italy--proof of the eruption's

global reach. The levels of

light carbon geologists have

discovered are so incredibly

high, it equates to the sudden

release of a trillion tons of

gas. Temperatures surge as the

methane from Siberia spread

across the globe, leaving every

part of the planet devastated

by climate chaos and mass

extinction.

>> This would have been a very

nasty place to live. There

would have been less oxygen in

the oceans. There would have

been much warmer and drier

conditions on land. There would

have been problems with the

depletion of the ozone layer as

a result of this methane-rich

atmosphere. And so it just

would have been a very, very

inhospitable place to be.

>> But burning coal isn't the

pnly possible source of the

methane gas that warmed the

world a quarter of a billion

years ago. At the Brookhaven

Energy lab, scientists are

making ice. But this is ice that

burns--methane ice. In nature,

it's buried beneath seabeds and

locked into permafrost. Its

discovery got geologists very

excited, because there's more

energy locked inside methane

ice than all Earth's other

fossil fuels put together.

It could be the fuel of the

future, but it could also be

the key to the past. After

hundreds of thousands of years

of eruption, burning coal and

melting ice together released

enough methane to raise

temperatures by some 20 degrees

fahrenheit. Life on Earth was

heading for total wipeout.

Finally, a million years after

the Earth's deadliest eruption

began, the most catastrophic

event in the planet's history

is at an end. But life on Earth

paid a high price. Over 95% of

species have been driven to

extinction. The investigation

reveals the reach of the

volcanic eruption and how

Planet Earth continued to

change. Light carbon found in

rocks is evidence of a methane-

rich atmosphere. Burning coal

in Siberia is thought to be the

source of this gas. The Earth

is a different place from just

a million years ago, from the

air to the land to the sea. The

few species that have survived

are pioneers in a brave, new

world. They are about to change

the course of history.

>> 250 million years ago,

a volcano erupted into life,

paving Siberia with basalt lava

layers a mile and a half thick.

At the end of the worst million

years in Earth's existence, as

life teetered on the brink of

total wipeout, the eruptions

finally stopped. Now geologists

want to find out whether the

volcano died, or whether it

simply changed location. The

place where a mantle plume hits

the surface is called a

"hotspot." The plume's shape is

a clue to the hotspot's

activity over time. The head is

a huge lava bubble which feeds

short-lived, but massive,

eruptions. When the lava plume

head is all used up, the mega

eruptions stop. But the narrow

tail can live on, like a

chimney spouting small

eruptions for hundreds of

millions of years, while

Earth's tectonic plates are

shifting above it.

>> Here is a mantle plume.

It could be Siberia, it could be

Hawaii. And here is the plate.

And the hotspot, obviously, is

stationary, but we're going to

see that the plate is actually

moving above it. So the plate

is continuously moving. The

hotspot's staying put. And

you've goto imagine lots and

lots of lavas are erupting out

at the same time. So I think

what we've achieved is actually

a rather good representation of

a hotspot track. At this end,

the old end, that's where the

plume had first hit the top of

the mantle. Over time, it's

left a track that would in

reality have been lots of other

volcanoes just like the one

that we find in the Hawaiian

Islands today.

>> The Hawaiian chain was

forged by a plume as the

Pacific Plate passed above

it--at a speed of 30 miles

every million years. But

scientists searching for a

plume track in Siberia are left

scratching their heads, because

there's no evidence of a trail.

The investigation has

discovered Siberia's hotspot

caused a million years of

worldwide chaos and

destruction. But after that,

the hotspot trail goes cold.

>> The Siberian Traps would

have left a line of volcanic

landforms that relate it to

that movement. But over such a

long period of time, the

geological processes have

hidden the evidence, buried it,

and parts of it may have been

subducted back into the Earth's

mantle.

>> What happened to the hotspot

after it forged the Siberian

Traps is a mystery that may

never be solved. The dynamic

Earth has wiped away all trace

of the evidence. One thing is

certain. Siberia didn't succeed

in destroying all life on

Earth. But it was a very close

call.

>> This is the worst extinction

of all time. And a part of the

measure of that is just how

long it took to the planet to

recover from this. We estimate

8 to 10 million years later,

there was still only the very

beginnings of recovery, the

increasing diversity of

life on Earth.

>> Coal, which opened the

investigation into the Siberian

Traps, testifies to the

volcano's devastating effects.

No new coal formed for another

25 million years--not just in

Siberia, but around the entire

world. It's conclusive proof

that, although tree life

survived the mass extinction,

it could not and did not thrive

for tens of millions of years.

And the same is true for South

Africa's land animals. On his

family's land, Rubidge has

discovered yet another fossil

crucial to the investigation.

If burrow holes fill up with

sand or mud, they can

themselves become fossils.

Anything trapped inside is

fossilized, too.

>> This is the plug of an

ancient burrow. But the

exciting part about this

particular specimen is that it's

got a little animal actually

curled up, preserved in the

burrow. This animal died here

in this burrow about 250

million years ago, and that is

what he looks like. There you

can see is the head, and you

can see there's his little tail

over there.

>> Amazingly, this tiny

creature plays an enormous role

in the last 250 million years

of life on this planet. This

fossil represents the future of

life on Earth.

>> This burrow has huge

significance for our presence

here today. Because this little

animal is one of the distant

ancestors of mammals. This is

our ancestor. And the reason

why he's preserved in a burrow

after the extinction event is

because this burrow maybe

protected him from what was

causing other animals to go

extinct. And so maybe it's

thanks to a hole like that that

you and I are here today.

>> The eruption of the Siberian

Traps triggered a brutal race

for survival. Over 95% of the

competition was eliminated.

Only the well-adapted and the

lucky made the finish line.

It was Earth's worst million

years. But from the perspective

of life on Earth today, it was

the best thing that ever

happened.

>> This was the greatest crisis

that life has ever suffered.

But if it wasn't for this, then

evolution would have taken a

different course, and humans

wouldn't be here today.

>> The million-year eruption of

the Siberian Traps drastically

altered the entire Earth. From

the atmosphere to the ocean

depths, the planet changed at a

rate so rapid, evolution could

not keep pace. In this new

geologic world, life was

hopelessly outdated. The few

animals that survived shaped

the future, passing adaptations

on to their descendants.

Dinosaurs, birds, mammals, and

humans. The tree of life had

undergone some drastic pruning,

but it allowed our branch to

flourish, and humans to evolve.

Yet, today, 250 million years

after Siberia erupted, life is

still fragile, still at the

mercy of the ever-changing,

volatile, and unpredictable

Earth.

-- Sync, corrected by elderman --
-- for www.MY-SUBS.com --