This submarine is setting out
to explore the floor of the Atlantic Ocean.
Until recently What lay at the bottom
Was a complete mystery.
But there, under thousands of meters of Water,
lies the key to hoW the surface
of our planet Was created.
The story of hoW the sea floor gave up its secret
began nearly 100 years ago -
on dry land.
The first clues came from
looking at the shape of the continents.
Ever since the first accurate maps Were made
it had been noticed that if you Were to push
the coast of South Africa here
up against the coast of South America
7,000 kilometres aWay
they'd fit snugly together.
At the turn of the the century a young German scientist,
Alfred Wegener,
decided to find out Whether this fit Was just coincidence
or Whether the tWo continents
had once been connected.
Wegener needed solid evidence
to support this extraordinary idea.
He began by comparing the rocks
on either side of the Atlantic Ocean.
Table Mountain is one of the most familiar landmarks
in South Africa
and it's the field area of geologist
Maarten de Wit.
What's great about being on top
of Table Mountain here
is that We have a fantastic vantage point
from Which to understand some of the evidence
that Wegener put together
and here We are
at the very Western extremity
of the Cape mountains that stretch
to the east of us 2,000 kilometres
but here it is abruptly truncated
by the Atlantic Ocean,
and the next time We see it again
is across that vast stretch of ocean
in Argentina in South America.
You go to South America
and you see exactly the same thing,
same structure, same rocks, everything.
The Cape fault belt stops here,
starts again south of Buenos Aires.
Those tWo bits of information
essentially alloWs you to close that Atlantic Ocean.
And When you close that Atlantic Ocean,
those tWo pieces of mountain belt
formulate one huge long mountain chain.
More evidence that the continents
had once been joined
came from looking at the fossil record.
The fossil of one particular plant
caught Wegener's attention.
This is glossopteris.
lt's a kind of fir tree, early fir tree.
You can see hoW very exceptionally Well
some of these fossils are preserved.
lt's Widely found not only here
but at that time Was also found in,
in places like lndia, Madagascar and Australia
and later on even in Antarctica,
South America,
so they Were very Widely distributed
in these 300 million-year-old rocks
and Wegener used that idea to argue
What Would have been very difficult
for these fossils to float
across huge expanses of ocean.
Rather than that he,
he argued it Would be easier to explain
if all these continents Were together
as one huge land mass.
As they scoured the rocks of far-flung continents
geologists found more and more examples
of plants and animal fossils
that looked like the scattered pieces of a jigsaW puzzle.
Wegener collected as much of this evidence
as he could from around the globe.
When he put the pieces together
he Was forced to the astonishing conclusion;
all the dry land on the planet
must once have been part of a single land mass,
a super-continent he named Pangea.
He suggested that over millions of years,
Pangea split apart.
NeW oceans opened up Where land had once existed.
He called this idea continental drift.
Unfortunately not many people took to the idea.
The trouble Was that Wegener couldn't explain
hoW the gigantic blocks of the continents
could sail through the solid rock of the ocean floor
and Without a plausible mechanism behind it
most people ignored continental drift.
And it remained ignored,
until neW evidence began to emerge
from exploration of the seas.
This is the maiden voyage
of the research ship Atlantis.
lts destination is the middle of the Atlantic Ocean.
On board is a team of scientists
intent on unravelling the secrets
hidden beneath the Water.
Among them is marine geologist, Joe Cann.
Wegener's ideas Were very controversial
When they first came out
and a lot of people dismissed them.
They kneW there had to be Ways
of getting animals and plants
from one continent to another,
because you had these astonishing similarities,
especially in the Southern Hemisphere.
But they couldn't bring themselves to think
that the continents Were drifting.
lnstead, there Was a very strong feeling
that the earth Was heaving in some periodic Way.
That there Were mountain belts rose and fell.
And that pulsing idea led to people thinking
that the ocean floor might rise,
to alloW the animals to Wander across,
and sink again.
An undulation of the ocean floor
from time to time.
lt seems very implausible noW,
but that's hoW they felt about it.
And that meant, of course, that the ocean floor
had to be the same as the continental crust.
lt had to look the same
and you'd expect the same sorts of rocks,
the same sort of materials to make it up.
But of course nobody kneW for sure
What the ocean floor Was made of
because they couldn't see it.
lt took a change in World politics
to reveal the first hints of What really lay beloW.
And aWay she goes.
And in a matter of months...
During the Cold War
submarine Warfare became vitally important.
...and a number of submarines
are named after statesmen and military...
Nuclear submarines had to be able to
navigate the World's oceans safely.
So sub-mariners needed to be sure
of the depth of the sea floor.
Flush With navy funding,
scientists set out to map the ocean floor
in unprecedented detail.
Their tool Was the echo sounder.
Ships sent out pulses of sound
Which travelled to the sea floor
and then bounced back up again.
The time taken for each ping to make the journey
gave the depth of the Water at that point.
We've basically been using the same types
of precision depth recorders
since the end of the Second World War.
As you can see on this,
on this record from, from the 1950s,
basically you can see that the bottom
is a very fine trace here,
very strong fine trace.
But there are also places
Where the echo sounder record gets very, very confused
and in those areas you have to be very careful
to interpret them correctly.
One of the first people to do this
and Who Was an expert at
it Was Bruce Heezen and his colleague Marie Tharp.
And they Were able to take these echo grams
and make maps from them
that alloWed us to understand
What the bottom of the ocean really looked like.
Heezen and Tharp Were masters of the echo sounder trace.
Methodically piecing together the data
from ships' tracks that criss-crossed the oceans.
Forty years on Marie Tharp is retired,
but still lives in the house
Where she once Worked on the data.
This exquisite hand-draWn map
Was the result.
Considering the scarity of the data in those days,
the detail is astounding.
Where We had a track
We took it very seriously and exactly,
but then it'd be so far to the next track
that We had to do a bit of inspired guessing
to fill in the space.
That's Why the (NAME) quill pen
and the sketching technique Was such a handy device
'cos you could be very accurate Where you had data
and you could make up and guess
Where you didn't have data
and still keep the same style.
Actually in this area We didn't have any data at all,
so that's Why We put the title in there.
When they put the echo soundings together
Bruce and Marie revealed the existence
of a vast mountain chain,
running doWn the centre of the North Atlantic.
As more data became available
they found that this range of submarine mountains
snaked its Way around the entire globe
for 60,000 kilometres.
Bruce and Marie decided to publicise their discovery,
but the reaction Wasn't quite What they'd hoped.
Amazement at first,
very shocking amazement
and then doubt and then finally scorn.
You knoW it Was a, a shocking thing to say.
To make matters Worse,
Marie told Bruce about something odd
she'd found on the crest of the ridge,
something Which supported Wegener's controversial idea.
This is profiles across the Atlantic Ocean
from our echo sounder.
One thing Which Was unique
to this preset of transatlantic profiles
Was this valley at the crest of the mid-Atlantic Ridge.
You see it, there is one mare
and here's a cleft in the middle here
l shoWed it to my boss, Bruze Heezen
and l had plotted the position
of this rift valley along the centre
of the ocean Where it occurs
and he just groaned and groaned
and says ''this can't be,
it looks just like Continental Drift''
because you could spot it Was a big cleft
that's quite a large valley
inside of a huge ridge.
lt Was a big crack as if it could possibly mean
that the continents Were pulling apart.
Marie sketched the valley
into the map of the North Atlantic,
but it didn't end there.
She and Bruce Went on to map
all of the World's oceans,
giving geologists their first vieW
of the submarine World.
Over the course of 20 years,
since this initial map Was made by Bruce and Marie,
they've dedicated their lives to looking at
all of the echo sounding records
that have been collected to produce a global map
that shoWs us What the bottom of the ocean floor looks like.
And this map is,
really provides the geologist
With a complete understanding
of the hoW different the ocean floor
is from the continents.
The ridge system runs doWn
the middle of the Atlantic Basin,
betWeen Africa and Europe
and North America
and South America
and it's this continuous line of rugged topography
that goes all the Way doWn the ocean basins.
Here into the lndian Ocean
and out into the Pacific Ocean here,
it is continuous throughout the globe.
NoW you don't see that on the continents
You can see mountain ranges
and sometimes they're continuous,
but never for 60,000 kilometres.
You don't see that type of feature on the continent.
Today at last satellite technology
can reveal directly the shape of the ocean floor.
Remove the skin of Water
and the backbone of the World
can be seen from space.
The discovery of this vast mid-ocean ridge system
Was a revelation
but nobody kneW hoW it had got there.
Then, as people began to look more closely
at the sea floor,
more striking differences betWeen the oceans
and the continents began to emerge.
At the end of the Second World War,
there Was a neW breed of marine scientist,
and they set out to study the ocean floor
by dropping explosives over the side of the ship -
and they had plenty of those -
and listening to them With hydrophones
that had been used for submarine detection.
The technique Was called seismic profiling.
ln the early days it Was a fairly hazardous enterprise.
Explosives Were simply hurled overboard and detonated.
The shock Waves penetrated
deep into the rock beneath the ocean.
By studying the Way the sound
Was reflected back,
the ocean-going geologists
measured the thickness of the ocean crust.
When they did this,
they discovered tWo very important things.
One Was, that the ocean crust
Was much thinner than the continental crust,
six kilometres instead of 30 kilometres
and the other is, that the ocean crust
has the same thickness and the same structure
all the Way round the World
Which indicated it formed by the same process
all the Way round the World.
That Was a truly fundamental discovery.
The seismic research helped scientists
come to realise a crucial fact
the ocean floor and the continents looke dso different
they had to have been created
in entirely different Ways.
But the process that created the ocean basins
remained a mystery until another technique
began picking up important clues.
lt's midnight.
The research vessel Atlantis is approaching
the centre of the mid-Atlantic ridge
and Joe Cann is supervising the launch of a dredge bucket.
Over the next couple
of hours the dredge Will be loWered thousands of metres
until it touches bottom,
then dragged along as the ship creeps forward.
ln the process, the bucket should scoop up
some of the rocks that litter the sea floor.
Bridge, We're going to put another 30 metres of Wire out.
Right, 15.
10 maybe. OK.
The problems are that
We've got, We're in 2,500 metres of Water -
and We've got a dredge being pulled
over a rocky bottom With unknoWn rocks,
some of Which are pretty tough rocks.
The ship is going along
at half a knot inexorably.
What We must avoid is,
is being snagged up on a rock doWn there.
lf We get snagged up and don't notice it,
the tension Will build up in the Wire.
The Wire parts. lt parts on deck.
Loose end Whips around,
cause a lot of damage, kills people.
ln the old days We didn't knoW Whether
the ship Was moving over the bottom at all.
We could put Wire out -
We didn't knoW Whether the dredge Was on the bottom.
We didn't knoW Where the bottom Was properly
and We had to resort
to very crude techniques such as -
When the dredge Was out-
We Would sit on the main Warp
on the after deck feeling the nubbles
coming up from the deep ocean floor.
lt's very evocative - it's very, very...
Uncomfortable, l Would have thought
lt Was very uncomfortable, very dangerous
but you felt in touch With the ocean floor
like you don't at the present day.
You felt deeply in touch With it,
through your bottom.
l have a dredge in sight, dredge in sight.
Dredger in sight
Up easy.
There are certainly rocks in there. l mean,
you can see the bottom of the bag bulging.
First one for the neW ship.
That's impressive.
Oh yes, oh yes.
When scientists began recovering rocks
from around the mid ocean ridge,
they found they Were mainly volcanic.
These aren't the kind of things that you see
in your back garden at home.
They're basalts. They're also submarine basalts.
You can tell 'cos they chill to this bright,
glassy margin chilled against the Water
When they erupted.
And they're very sharp.
The glass is very young and very sharp -
as you can see, l've cut my finger on the fragment.
These rocks are young.
SomeWhere, 2000 metres beloW,
submarine volcanoes have recently been erupting.
We knoW they're young,
because of the fresh glass
and they're also highly magnetic.
lf l take my compass out,
it's just an ordinary compass
that you use any day,
l take one of these rocks and bring it up to it,
you see, if you look carefully
that the needle deflects a bit.
Not much, about 10 degrees.
But it deflects enough to shoW
that the rock must be very magnetic indeed.
Here We go.
Scientists Were still perplexed about
What Was going on doWn there.
But once they realised ocean rocks could be magnetic,
it opened up a neW avenue of investigation.
OK lt's in the Water noW.
That's a magnetometer
and it is toWed behind the ship.
lt's an instrument that gives us
a very detailed reading
of the earth's magnetic field,
so it's very, very sensitive.
Basically, it can pick up the small variations
in the earth's magnetic field
that are caused by the rocks
in the various layers in the ocean crust.
Magnetometer surveys started in earnest in the 1950s,
often in extraordinary detail.
Certain areas Were sailed over
in a series of tightly-packed parallel lines
to ensure that nothing Was missed out.
Where the ships Went,
magnetometers folloWed behind.
Magnetic rocks distort the earth's magnetic field,
sometimes making it stronger than expected, sometimes Weaker.
These differences are called positive and negative anomalies.
When the data from the first detailed survey
Were put together,
the scientists Were dumbfounded by the result.
Stripes of magnetic anomalies.
NoW this Was back in 1961
the most amazing thing.
Here's the coast of the United States.
Here's Canada,
and here is the magnetic anomaly map offshore.
Black is positive anomalies,
White is negative anomalies
and see hoW they're all form these astonishing stripes.
Nothing like this has ever been seen on the continents.
And yet the ocean floor appeared to be made
of these parallel stripes of positive
and negative anomalies.
By the early '60s
scientists kneW a good deal about the ocean floor,
but none of it made much sense.
ln some Ways it Was a very uniform picture.
The crust Was all the same thickness,
it Was all much younger than the continents
and it Was nearly all made of volcanic rock.
Also, running doWn the centre of the basins,
Was a continuous mountain range
and along the crest Was a continuous rift valley.
This pattern Was so radically different
from anything on the continents
that it demanded an explanation.
The turning point finally came in 1962,
at a lecture given here in Cambridge
Which revived Wegener's idea
of continental drift.
Attending the lecture Was Fred Vine,
Who Was just a geology student at the time,
but his interest in the subject had been triggered long before.
l first encountered the concept
of continental drift in a school text book
When l Was about 14. And l opened the text book,
and l think it Was right at the very beginning,
the first page of the first chapter pretty Well,
Where it shoWed a fit of South America and Africa,
the classic sort of fit of the continents,
and it said that it Was -
some people thought that these continents
may once have been juxtaposed in this Way
and have drifted apart.
But no-one really kneW.
And it has never been proved or disproved.
And l thought that this Was just incredible.
l mean incredible to think that
this may of once been the case
and it may have happened,
so that the Whole scale of it you knoW,
the mechanism of it Was mind boggling.
The other thing tha l just couldn't really cope
With Was that nobody kneW one Way or the other,
and l felt it Was just time that We found out.
l mean there must be some Way of finding out
such a fundamental fact about the earth.
The birth of the oceans is still a matter of some conjecture.
At that lecture in 1962
Fred Vine listened to an American geologist Harry Hess.
Hess explained his ideas of hoW the ocean basins had formed.
lt's a lecture Vine remembers vividly today.
Hess l guess Was the first person
to try to synthesise all the neW data.
lt Was a pretty daring synthesis anyway
and it Was regarded as being very speculative at the time.
l thought it Was very exciting
because it fitted in With continental drift.
Hess believed the mid ocean ridge
Was a vast crack
Where the Earth Was splitting apart.
He suggested molten rock
Was constantly erupting in the crack,
continuously forming neW ocean floor.
Hess Was basically describing an enormous conveyor belt
With neW ocean crust forming at the mid ocean ridge
and then moving aWay.
lt explained almost all the observations;
the ridge and its valley,
the consistent layer of young volcanic rock.
And it also explained continental drift.
The continents didn't sail through the oceanic rock,
they just moved With it.
lt Was an extraordinary idea.
Hess himself called it geo-poetry.
lronically the one line of evidence
that could make it stand up
Was the very element Hess left out;
magnetism.
And it just so happened that magnetism of ocean rocks
Was the subject of Fred Vine's PhD.
Well, this is the very room
in Which l Worked as a graduate student
and it's the first time l've been back in 35 years,
so it's rather fun.
lt's exactly the same essentially.
l came here in October 1962
to Work With Drummond MattheWs,
Who Was a geologist.
Drummond at the time Was actually
at sea making a detailed survey
of the north-West lndian Ocean
and this involved measuring the shape
of the ocean floor,
the gravity field over it
and the magnetic field over it
and l Was specifically
as his first graduate student actually,
to Work on the magnetic data.
l decided that the Way to go about this problem
Was to use a digital computer -
this is Edzac 2
one of the very feW in the World at that time.
l don't think l'm actually in this queue
but l could be
because l think it Was every hour
for about 5 minutes
We Were alloWed to test our programmes on,
on the computer.
Vine had a programme
that analysed the magnetic anomalies.
He entered magnetic data from the survey into the computer.
lt then calculated What sort of magnetic field
could cause the anomalies that had been measured.
What the computer told Vine
Was quite astonishing
The all important result that it came up With -
and it Was a rather surprising result in many Ways -
Was that large areas of the survey,
large areas of the ocean floor in that survey area
Were reversely magnetised.
That is that it's as though the rocks
had been magnetised at a time
When the earth's magnetic field Was the reverse
of its present direction, that,
that a compass at that time Would have poined to the south
rather than to north, geographic pole.
The theory that the Earth's magnetic field
has repeatedly flipped to and fro
had been hotly debated for years.
No consensus had been reached,
but if magnetic reversals had really happened
they Would have left their mark.
As volcanic rock erupts and then cools
it records the direction
of the Earth's magnetic field
at the time of the eruption.
lf the magnetic field flipped
such reversals Would remain captured in the rocks.
lt Was really simply a matter of combining
that With Harry hess's idea
of sea-floor spreading.
l mean Harry painted this picture
of conveyor belt,
this running out symmetrically
on either side of the mid-ocean ridge
What in effect Was to convert
the conveyor belt into a tape-recorder,
a sort of tWin-headed tape-recorder
running out symmetrically.
Vine's idea Was that if the Earth's field
Would make compasses point north,
then any molten rock erupting at the ridge at that time
Would be magnetised in that direction.
lf the Earth's field then flipped,
any more neW rock formed at the ridge
Would be magnetised in the neW direction.
Each time the magnetic field flipped,
so Would the magnetisation of the neWly-forming crust.
But since nobody had irrefutable evidence
of magnetic reversals,
the idea Went doWn like a lead balloon.
lt Was not generally accepted particularly
by people Who Were closest to, to the field actually.
l suppose an element, you knoW it Was,
it Was a Wild idea or seemed, thought to be a Wild idea
and it Wasn't their idea so Why believe it,
but one can find quite a lot of references
in the literature in 64/65
Where people Were really quite rude about it actually.
lt didn't bother me particularly but...
Fortunately, the hypothesis also made a prediction.
lt predicted that the pattern of magnetic stripes
on either side of the mid ocean ridge
Would be symmetrical.
So Vine looked carefully
at the map of magnetic stripes
from the Pacific Ocean.
Once he kneW What he Was looking for,
he found the symmetry staring him in the face.
This stripe of positively magnetised rock
actually marks a section of the ridge.
On either side the pattern of
White and black stripes stretches out
in a mirror image.
lncredibly the symmetry in this diagram
Was not realised until 1965,
that the survey had been extance at 1961
and no-one had noticed the symmetry
about What We noW call the (NAME) ridge.
NoW people began to believe Vine
and they started to find symmetrical patterns
in other data.
The theory of sea floor spreading
had been tested and proved.
With it, Alfred Wegener's idea of continental drift
took on a neW lease of life.
At last it Was possible to understand
hoW continents could drift sloWly but inexorably
across the face of the planet.
But at the heart of the theory
lay a feature that no-one had ever set eyes on
the remarkable volcanic mountain chain
Where oceanic crust is generated,
the mid Atlantic Ridge.
Geologists Would never be satisfied
until they had seen it for themselves.
After 6 days straight sail from Bermuda,
the Atlantis is sitting directly
on top of the ridge.
But a different vessel is needed
to make the final leg of the journey;
to the ocean floor.
This is a submersible ''Alvin''
capable of diving to forty-five hundred metres,
Which is roughly three miles deep
under the ocean.
lt Withstands pressures of up to sixty-six hundred PSl,
Which is about tWo good sized elephants sitting on your lap.
The titanium sphere is about tWo inches thick
and inside it sit three people, the pilot and tWo observers.
lt gets a little thicker up by the vieW ports,
it's about three and half inches thick.
The vieW ports are made of plastic
so that they're tough and not brittle like glass Would be.
Alvin dives by being loaded With Weights.
When it's ready to surface
the Weights are dumped
and the sub becomes light enough to float up.
lf the submarine Was to be stuck
on the bottom for some reason, snagged on a,
anything, the releasing of Weights
might not be enough.
So the submarine can try to drive up
With its thrusters and if that's not enough,
We could drop various pieces of gear,
We can release the science basket -
get rid of the science gear.
We can release the manipulators.
We can even try jettisoning our batteries,
Which Would then leave us Without poWer.
lf all that's not enough,
We can last on the bottom for three days and,
if there's no prospect of rescue,
We can actually release the sphere
from the rest of the submarine
and it Will float up on its oWn.
Unfortunately, it Won't float up right side up.
We don't really knoW exactly hoW fast
or in What attitude.
lt'll probably spin like a ball and it -
might be quite a Wild ride.
Matt, l Wanted to talk to you a little bit
about Where We are planning on diving tomorroW.
So if you turn on that light for a second, thanks.
So We've got this big sea mound
in the middle of the Rift Valley,
the place Where We are going to dive
is right here on the summit.
lt's an area Where...
The evening before the dive,
project leader Dan Fornari finalises details
With Susan Humphris,
the scientist Who Will be on board the sub.
Matt Heintz has been chosen as pilot.
So you're not talking more than a kilometre
in any direction that you'll have to travel.
Right sloW Yes, so l think the thing do
maybe is to start in here and then Work our Way
up the slope Where the dredge Went.
lt looks like there might some sort of fairly steep cliff
or scarp here that We'll have to go up,
you knoW, it looks like it might be about 100 metres high.
Got propulsion.. Hydraulics on.
Good, good.
Good luck. Thanks.
At first, When you get in the sub,
because it's been sitting out on deck,
it's usually very, very hot and stuffy.
And the first impression
is one of being incredibly cramped.
We standing by on the fan tail,
ready to launch.
Roger that. Go ahead and commence launch
l alWays get the feeling of sort of pent up excitement,
but some nervousness -
sWinging out over the stern of the ship
looking out over the Waves
and realising that all of a minute
you're going to splosh doWn in there
and the porthole
is going to look like the inside of a Washing machine.
Atlantis - Alvin lights on,
vent valve is open, hatches shut.
Oxygen is on.
Tracking is on.
8.1 .
Permission to dive When the sWimmers are clear.
Clear to dive When sWimmers are clear.
Roger. Alvin diving.
Read off Target 1
First target is 34 60 46 42.
OK, What's the landing target?
The sun's rays can't penetrate far into the Water.
Eventually the last of the daylight Will fade aWay.
The sub is free falling and Matt and Susan
drop at a rate of 30 metres a minute
doWn into the darkness.
lf they could see Where they Were heading,
the vieW Would take their breath aWay.
1 700 metres beloW,
the valley at the centre of the mid Atlantic ridge
stretches out before them.
Atlantis-Alvin. Depth?
16 23, 100 off the bottom.
l'll call you When We get there.
l'm getting ready to release my first Weight.
OK, one Weight aWay,
listen and you might hear it.
Didn't hear it, but l saW it in the camera.
And that should sloW our descent rate.
We're doWn to 60 metres up off the bottom.
Bottom's in sight.
Atlantis-Alvin.
Depth 1 7 12 on the bottom.
Roger that.
OK l've seen some structures
that looked like maybe this is at the edge
of a lava field
and l see drain back features. l've seen some collapses.
That's good. OK. We might be on the edge
of a lava lake field.
Oh yes,
l'm going past some lava pilloWs on my side.
Oh yeah, oh here it's beautiful.
Alvin has landed in the heart
of the mid Atlantic ridge -
the place Where the Earth's crust is being created.
This is a lava lake Where submarine floWs
of lava have become tWisted into dramatic shapes.
The rock here is just a feW hundred years old.
The sharp pillars have not been softened by time.
The submersible's journey across the lava lake
takes it betWeen the three peaks
of the Lucky Strike volcano.
At this depth the only light
comes from the submersible itself
as it finds its Way along the rugged terrain.
Oh Well, What do l see here.
l see some White.
Something White?
What do you see out of the port WindoW?
l see What looks like some hydro thermal staining to me.
Matt and Susan have detected staining
deposited by hot springs
called hydro-thermal vents.
When volcanoes and Water mix hot springs
are an inevitable result
and the presence of these deep sea vents
had been predicted.
But the reality turned out to be
even more startling than the Wildest predictions.
The first time Alvin came across a black smoker
it Was piloted by Dudley Foster.
lt Was like a steam locomotive
billoWing smoke out of the bottom.
And l couldn't imagine What it Was,
l Was just you knoW, floundered
and floored by this.
We stuck the temperature probe
into this plume of Water
and the probe could only measure up
to 30 degrees and that pegged immediately,
so l moved the probe out of that
and l could see the end of the probe
had turned black and it looked, l thought Well,
this is kind of the dust Whatever the smokey stuff is
and When We got back to the surface
We found that the PVC rod
had actually been burned in the feW seconds
that it Was in this Water.
That Was our first clue that this Was extremely hot.
Oh man,
did l open up a nice hole. Look at that.
That is sWeet.
That's a big one. l like that.
Oh, right. That should be an easy one to sample.
Once We'd discovered that hoW hot these hydro-
thermal vents could get
We became concerned about the impact
on the submersible, particularly
since the vieW ports are made out of plastic
and at the sort of depths We're Working,
they could start to lose their strength
in about 90 degrees C.
18, 7 4, 216, 241 , 256,
303, 291 , 321 , 321 ...
The Water pumping out of this vent
is at 321 degrees Centigrade.
We Worked very close to these structures
because We reach out With the manipulator
and sample them, put probes in them
and do a lot of Work around them,
but frequently there are several
and you can easily bump up next to one
and several times the fibreglass skin
on the submarine has actually been burned.
Come back With several layers
of glass burned aWay
and the paint charred black.
lt's a hazardous environment for the sub and its creW,
but no-one had imagined it could also support life.
OK, Let's see if We could smoke some of these shrimp.
These look great.
Yes l...
Are you, are you getting any?
l'm Working on it to get some of this stuff in there,
l'm getting some bacterial mat.
OK Well keep trying on the shrimp.
Shrimp are pretty resilient.
They're saying ''oh, no, no.
l'm not going in there''. l knoW.
They can move around pretty fast.
Get in there! Get in there! Get in there!
OK. Well, hoWever many We've got,
maybe We should call it quits.
l'll look up our range and bearing to our next site.
Shrimp, mussels and fish
have all been found thriving around the smokers.
They survive Where most scientists
expected life to be impossible
in the pitch dark,
cut off from the sun's energy,
Which fuels every other echo system on the planet.
At the bottom of this complex Web of life,
supporting the Whole thing, are bacteria.
Those bacteria feed off the rich cocktail of chemicals
speWing out in the superheated Water.
All these living things are totally dependent
on the earth's oWn energy.
Locked up in the rocks of South Africa
is evidence that this strange World
has existed for billions of years.
Well here We are in Barberton mountain land
Walking on some of the oldest rocks
that have ever been found on earth.
And the particular rocks that l am Walking on
are ocean floor rocks,
very old ocean floor.
And We noW knoW that this ocean floor
and all these rocks everywhere around us here
are 3.5 billion years old.
Come up here.
This is Where the rocks have been cracked open in tWo.
Look this hand here fits
With that hand over there.
Only We can see this pilloWs,
these belts in cross section, very nicely.
This is very characteristic of hoW lava forms
or the sort of shapes lava forms
as it hits the ocean floor.
Underwater eruptions are very different
to lava floWs on land.
Lava erupting into Water rapidly cools,
forming a skin.
As more lava Wells up from beloW
it continuously pushes out neW buds
onto the ocean floor
like pilloWs of solidifying rock.
Anywhere you go today
you see these kind of fossils.
With these shapes you knoW you're Walking
on rocks that Were once covered by, by Water.
And like the oceans today,
the ancient oceans also had black smokers.
Three and a half billion years ago,
hot Water streamed out of this rock.
The mineral deposits are not the only traces
the smokers left behind.
And When We look at these flinty rocks
in detail under the microscope
We find very ancient bacteria.
So that l think makes it a very solid case
for the sort of hypothesis that are hanging around
that make people believe,
perhaps, these kind of associations,
the pilloW basalts and the black smokers
are the sort of areas, the niches,
Were life might have originated.
Could it be that life on our planet first evolved
at a hydro-thermal vent?
On board Atlantis, biologists are studying the bacteria
from black smokers to see hoW closely
they are related to the earliest forms of life.
Judy Which sample are We Working With?
We'll start With the slurry
that's been settling...
Analysis of their DNA shoWs the deep sea bacteria
are the most primitive forms of life
on the evolutionary tree.
These bacteria really could be the direct descendants
of the first living things on Earth.
The Work on the evolution of life
all stemmed from a simple observation;
the matching of tWo distant coastlines.
ln the last feW decades,
the deep ocean has begun to lay bare
its secrets to science.
We've finally come to understand
hoW truly dynamic our planet is
and hoW the sea floor is being continuously remade.
Perhaps the most fascinating discovery of them all
is the links We've found betWeen the earth's activity
and the origin of life.
The energy Which fuelled the first living thing
is the same energy that is still remaking
the surface of our planet.
But if you think about it,
there's a problem.
For billions of years,
neW sea floor has been continuously produced
at mid-ocean ridges -
so, unless the earth's been getting
steadily bigger over all that time -
there must be someWhere on the planet
Where crust is being devoured
as fast as it's being made.
Solving that paradox
Will take us in our next programme
to the volcanoes ringing the Pacific
and also explain hoW the land
We live on came into being.