All language subtitles for m.f.a.s02e04.1080p.web.h264-cbfm_track3_[eng]

NARRATOR: A lost relic from one of
history's darkest periods.

- What have they found hidden
under 61 metres of water?

NARRATOR: Cryptic ocean patterns
reveal a hidden talent.

- It's like a giant question mark,
begging you to answer its riddle.

NARRATOR: A post-apocalyptic
landscape lost at sea.

- It looks like it was hit by a
bomb.

NARRATOR: Mysterious markings dot
the deep abyss.

- The bottom of the ocean is the
last frontier. What dwells there?

We still don't know.

NARRATOR: Everywhere we look
on our planet,

there's evidence of the past.
In nature, in buildings, in relics.

Each holds a mystery that technology
now allows us to see from above.

What new secrets are revealed?

We know more about the topography of
Mars than we do about what

lies beneath our oceans and seas.

To decipher some of these hidden
mysteries we often need

a view from above.

The small island nation of Malta
lies in the central

Mediterranean sea.

In its capital city of Valletta, a
team of marine archaeologists

prepare for a mission.

Dr Timmy Gambin from the university
of Malta has spent a lifetime

searching for submerged secrets.

- When I hear the words
Mediterranean Sea,

I think immediately of the great
ancient empires that thrived

around it: the
Egyptians, the Greeks, the Romans.

The whole area is a treasure
ground for historians.

- 71% of the Earth's surface is
covered by water.

And, much of it, like the
Mediterranean Sea, has never

been fully explored.

- You've gotta ask what else is
hiding down in those murky depths?

There could be ancient treasure.
There could be buried cities.

NARRATOR: On this day, Dr
Timmy Gambin and his team

have only
one mystery on their mind.

A strange shape discovered from
above during a routine sonar

survey of the sea floor a
year earlier.

- The discovery was made possible by
a technology called side-scan

sonar that produces an accurate
record of the ocean floor.

- There's clearly something there,
but you gotta ask, what is it?

NARRATOR: The shape appears to be
roughly 8 metres in length.

- This thing, whatever it is, is
really pretty large.

I mean, it's about as big as a
London double-decker bus.

NARRATOR: Dr Gambin is no stranger
to finding fascinating things

around his home island.

- Marine archaeology is truly
unpredictable.

You never know what
you're going to find.

The sea is just full of secrets.

NARRATOR: In 2007, the Mediterranean
yielded one its greatest treasures.

Spotted during another offshore
survey, this anomaly turned

out to be a Phoenician cargo vessel
dating back to the 7th century BC.

- That Phoenician trade ship is
considered to be the oldest

shipwrecks uncovered in the
central Mediterranean.

- Could this be another vessel?

NARRATOR: That ship measured 12
metres in length.

This object is slightly shorter.

- So based on the measurements, it's
very possible that this, too,

is a ship.

NARRATOR: On the other hand, it
could be nothing.

- Not everything here is
of historic value.

Sadly, some of these waters are
absolutely choked with

debris, ranging from plastic bottles
to entire refrigerators, even

shipping containers.

NARRATOR: Luckily, the strange
object doesn't appear to be just

rusted out sea junk.

But what's more telling is it's
distinct shape.

- A closer look clearly shows the
unmistakable outline of an airplane.

- But what kind of plane? And how
long has it been there?

- Certainly this part of the
Mediterranean is under a very

busy flight path for countless
commercial and private planes.

And no doubt more than a few have
sadly crashed over the decades.

NARRATOR: But none of the recorded
crash sites are anywhere near

Dr Gambin's target.

- It's so frustrating to know that
something is down there but

you can't tell what it is.

And there's only really one way to
find out and that's to get a

view from above below.

- Okay, let's get into the water and
see what the site has to

offer, okay?

Let's remember we need to try and
see if we can identify what

type of plane it is.

NARRATOR: Their goal is to capture
enough images to produce a 3D

model of the plane so the team can
unlock the mystery of what it

is and how it ended up 61
metres underwater.

- Imagine the height of the
Leaning Tower of Pisa, that's how

deep down they have to swim.

NARRATOR: To accommodate for
decompression, the team will have

a short window to investigate
and film the wreck.

- As I'm approaching the wreck,
there's a massive sense of

curiosity.

I have a number of ideas of
what the aircraft could be.

However, there is nothing certain
until one sets one's eyes on

the wreck itself.

NARRATOR: As the divers descend
deeper,

the mysterious
shape finally reveals itself.

- The first thing that strikes you
is that it's sitting perfectly

upright on the seabed.

- It's as though its still taxi-ing
on the runway.

This means that the pilot did a
great job at ditching the air craft,

because there isn't a lot of
damage.

I'm swimming around the wreck
looking for telltale signs.

We're looking for small hatches
that are distinctive to a particular

aircraft. One has to retain a bit
of composure because I'm excited.

I'm seeing the tail of a plane
covered in marine growth,

sponges, some other barnacles.

- Now this suggests this plane has
been here a very long time.

NARRATOR: Up close, it's clear this
is not a modern plane.

Perhaps it's connected to Malta's
not-so distant past.

At the height of WWII, the
entire region was a deadly

battleground for control of
the Mediterranean.

- By July 1942, Hitler controls most
of Europe and he's gaining

ground in North Africa.

He needs to control the waterway
that links them, the

Mediterranean Sea.

- The only defence against Hitler
right there is this handful,

a mere handful, of RAF pilots
stationed in Malta.

And the Nazis are trying to make
sure they don't get in their

way by trying to bomb this small
island nation into submission.

- In summer of 1942, this makes
Malta the most bombed place

on the planet.

- So is this plane on the
seafloor a Nazi plane?

Or is it a British aircraft, whose
job was to defend against

Hitler's forces?

NARRATOR: The heavy marine growth is
obscuring any identifiable marks

on the plane.

The team has successfully taken
1000's of photos to build a

3D model of the wreck for
further analysis.

- Did you get footage?

- Good footage

- Very much a single seat aircraft.
It's absolutely beautiful condition.

Wow, wow, wow. "Bravo".

NARRATOR: The team has discovered a
WWII fighter plane.

Could their footage
unlock the secret of what kind

of plane it is, and will it reveal
how it ended up lost

for almost 80
years beneath the ocean waves?

Back in Valletta, Timmy and his
underwater cameraman

search for answers using a 3D model
built from footage taken during

their dive of the wreck.

- Oh wow. Yes. There,
there, there it is.

- Not bad, eh?
- Not bad at all. Wow.

To me, it looks Italian.

It looks like a Macchi 202, but
it's slightly squatter.

You know what, John?

It could actually be... Let me
look up on my database.

It's still an Italian plane, but
I think we may have a

Reggiane Re.2001.

Can you zoom in? Oh wow,
so yeah that's it.

This is an astonishing find.

- The Reggiane 2001 was a really
quite an advanced piece

of WWII machinery.

Actually, it was a formidable
fighter plane.

- Only about 250 were ever produced,
making it one of the rarest

planes on Earth.

- Because of its manoeuvrability and
speed, it was the pride of

the Regia Aeronautica —
the Italian Air Force.

- Since Italy was one of Hitler's
allies in WWII, it means that

this wreck they found is a
long-lost enemy plane.

- So the question remains,
how did it get here?

- For a fighter plane to go down
during the Battle of Malta,

only two real possibilities exist.

Either it was shot down during a dog
fight or it was blasted out

of the sky by anti-aircraft fire.

NARRATOR: During the battle of
Malta, the island's defenders

were armed with powerful
anti-aircraft weapons

called flak guns.

Flak guns worked in concert with
other batteries unleashing

sustained barrages at predetermined
angles and heights —

covering their own 'box' of the
sky with withering fire.

- It has a projectile that explodes
at high altitude and this sends

out these jagged metal fragments
that tear aircraft apart.

- It is not easy to distinguish
damage from anti-aircraft guns from

damage caused by other aircraft.

However, there are some
telltale signs.

I can see some damage.

NARRATOR: A closer inspection of the
wreck's 3D model

uncovers a vital clue.

- I'm noticing damage on the
starboard wing, which seems to be

coming from shots fired from
another aircraft that is actually

flying at the same level.

If I had to give a verdict, I'm
saying that the plane was

shot down by another plane
approaching head-on.

- Now the mystery becomes who shot
this plane down, and why?

- As a formidable fighter plane, the
Reggiane 2001 could dogfight

with the best of Allied planes.

As such, they had the
respect of RAF pilots.

NARRATOR: Except for maybe one:

George "Buzz" Beurling.

- As one of Canada's greatest ace
fighter pilots, Buzz Beurling

was so skilled at aerial dogfights
over the Mediterranean that

he was known as The Falcon of Malta.

NARRATOR: Buerling is credited with
shooting down 27

enemy aircraft over Malta in just 14
days, at least two of which

are recorded to be the ultra-rare
Reggiane RE.2001s.

- It's amazing to think this
particular aircraft is such a

rare specimen and possibly a
tangible relic of the

astonishing kill record of flying
Ace George Buzz Burling.

- This is a great example of the
mysteries that lie buried

under the world's deepest waters and
could only be uncovered with

technologies that peer
down from above.

- Any historical memory contributes
to ensure that the suffering

endured by our Maltese
ancestors is not forgotten.

Any artifact that can be connected
with this epic battle for

Malta is an object to be cherished.

NARRATOR: From a strange shape
uncovered deep below the waterline

to those spotted at the very
surface, a view from above tackles

yet another ocean mystery.

Over 16,000 km away, the coast of
Australia's New South Wales

boasts some of the world's
most famous beaches.

- Visitors from all over the world
come here to soak-up the sun,

surf and sand and bask in its
natural beauty.

NARRATOR: Just off these golden
shores, something else beautiful yet

bizarre can be seen from above,
rising from the deep blue

waters of the Tasman Sea.

- In the distance there appears to
be something rising up out of

the water.

It looks like bubbles.

They're forming these beautiful and
brilliantly intricate patterns.

- This S-shape pattern looks like a
giant sea snake, like

something prehistoric.

- It's like a giant question mark,
begging you to answer its riddle.

- So what are these strange
patterns in the ocean?

NARRATOR: And who or what could be
causing them?

- When I see all these bubbles
coming up in such an orderly

fashion, I think of something
man-made like a machine.

- Ocean researchers are using this
new class of remotely-operated

underwater vehicles like AUVs and
ROVs that are known to cause

splashing when they come
up to the surface.

- So these small robots are being
used to collect data on

everything, including hunting for
new species that might exist.

- So could these small submersibles
be creating these weird circles

and spirals?

- When you look at how things are
being used by researchers,

it's actually an elaborate process.

You need a large boat and
a crew to run them.

But here, there's none of that.

- There's no sign of human activity
anywhere. So what's causing this?

Could a military submarine be
creating these designs when

they go underwater or come
back up to the surface?

- Are we seeing some kind of
Australian Navy exercise?

- But when submarines dive and
resurface, they do it in a

straight line, not in a circle or a
spiral like what we're seeing

here from above.

- What is going on underwater
to make this happen?

NARRATOR: Perhaps a clue could be
found some 8,000 kilometres away

in Japan's Naruto strait, where a
view from the air reveals

an extraordinary sight.

- This is an incredible and powerful
display of the forces of nature.

This is the Naruto Whirlpools.

NARRATOR: A mighty clash of fast and
slow flowing tides, producing one

the world's greatest tidal currents.

- These monster tides create
whirlpools that spin at

speeds of up to 20 km/h!

- You've got all this violent water
action creating these really

interesting spiral patterns.

Is that what's happening
back in Australia?

Are those designs the result of
natural whirlpools?

- The powerful tides of the
Naruto Strait do create interesting

patterns on the water, but they're
not quite like what we see

here from above off the
coast of New South Wales.

- The speed and shape of these
spiralling patterns is different.

It's considerably slower and the
circles and spirals aren't

whirling at all.

NARRATOR: So if it's not whirlpools,
could these patterns be made by

something else from the
natural world?

Below the water, a clue.

- When you drop down from the air
and go underwater, you can see

that these patterns are made up of
millions of foamy bubbles.

- The question is who or what is
creating these bubbles?

NARRATOR: Perhaps the answer lies
roughly a 600 metres off the coast

of New South Wales, with a view from
above of nearby Cook Island.

- This island is covered by what
looks like layers of lava.

- Clearly there's evidence of
previous volcanic activity here, and

it reminds us that to the east of
New South Wales lies the edge

of one of the most intense
volcanic regions on Earth.

- Is this strange pattern caused by
an underwater volcano releasing

vapours and gas through
vents in the sea floor?

NARRATOR: This region is outside the
most southern section

of the Ring of Fire.

A rim of seismic activity that
surrounds the pacific ocean.

Nearly 75% of all volcanoes occur
along this ring,

most erupting underwater.

Cracks in the seabed, known as
fissures, exposes molten

magma to the much cooler water.

Could these bubbles be the result of
this instantaneous blast of

steam and gas?

- But then why would they form
circular and spiral patterns?

I mean, this doesn't seem to add up.

NARRATOR: Perhaps a closer view from
above can reveal the mystery.

- There's something alive
down there. What is it?

And what the hell is it doing?!

- Whatever it is, there's definitely
more than one. Are these dolphins?

- So it certainly could be.

I mean, some scientists have
observed that when dolphins

mate, they do create these circular
patterns in the water's surface.

NARRATOR: But even from high up,
it's clear that whatever is stirring

in these strange patterns is
larger than dolphins.

So what kind of creature
could this be?

- The coast of New South Wales is
home to very large sharks, like

the great white.

- And sharks are certainly known to
move in circular patterns

when they're feeding in
large groups.

- Oh my God, are we looking at a
massive feeding frenzy?

- Is that what's causing
this bizarre pattern?

A bloodbath below the surface?

- But when you look at sharks
underwater, circling their

prey, they don't create any patterns
per se, just a lot of splashing.

- And that's because they feed
from below, right.

If these patterns are being caused
by a marine creature feeding,

then they're actually feeding
close to the surface.

NARRATOR: A closer look reveals that
these are much, much bigger than

even the biggest of great white
sharks.

- So we can tell by the distinctive
shape of their back when they

dive and these very long pectoral
fins that they are actually

humpback whales.

- Their long, white, flippers
are also a dead giveaway.

They're nearly one-third of
their body length.

- Which is saying a lot since they
can reach a length of more than

18 metres.

NARRATOR: So what we're seeing from
above is a rare super group

of humpback whales, animals that
typically travel in small groups

of two to a dozen.

- But why are they here?

And how or why are all these
humpback whales creating

millions of bubbles to make up
these strange patterns?

- I mean, these creatures are super
smart, but they wouldn't be

making these just to amaze
us with their beauty.

- So, what's its purpose? There has
to be a more practical reason.

What is it?

- Humpbacks, like other mammals,
breathe air, and so unlike

fish, they can't breathe underwater
because they don't have gills.

So what they'll do is they'll come
up to the surface of the

water, they'll inhale air through
their blow hole and then

they'll begin their dive.

NARRATOR: Underwater, the whales can
use that same blow hole to exhale

and blow bubbles.

- But why go through all that
trouble?

Why blow these bubbles that form
these intricate patterns?

NARRATOR: Perhaps a view from above
from over 15,000 kilometres away in

Canada's far north can shed a
light on the mystery.

- This looks a lot like what we're
seeing back in Australia.

- Except these aren't humpbacks.

These are narwhals, beluga-sized
whales that live in the North

and that are equipped with these
long and unicorn-like tusks.

NARRATOR: These narwhals are
actually hunting together

as a group, using
their tusks as a tool.

- Narwhals have learned to smack
their tusks on the water to stun

fish making it much
easier to eat them.

- Is that what the humpbacks
are doing in Australia?

Instead of using tusks, which they
obviously don't have, could

the whales be using bubbles to
make it easier to feed?

NARRATOR: This kind of behaviour
among marine animals

has been observed before.

It's a phenomena scientists call
bubble-net feeding.

- In bubble-net feeding, whales will
work together by blowing bubbles

that draw the fish or krill in an
increasingly tight circle or net.

So once their prey is nicely
bundled, the whales can come

up from underneath and
gobble them up.

- That's absolutely amazing.

So that's why you see this
nautilus shape from the sky.

- Think about how much coordination
and lung capacity is needed

to blow the bubbles in this
incredible pattern.

NARRATOR: But something about this
view from above isn't quite right.

- So humpback whales aren't known to
feed in this region which is

why when I see this bubble-net
feeding, I'm pretty surprised.

NARRATOR: Humpbacks typically feed
thousands of kilometres away, in the

colder waters of the south pole.

- In Antarctica, pods of humpback
whales will regularly

bubble-net feed and make these same
spectacular designs in the ocean.

- But Antarctica is several thousand
kilometres away from Australia.

- So humpbacks don't
usually feed here.

They normally use these waters to
migrate back and forth.

And during that migration,
they fast,

for weeks and sometimes months.

- So why are they suddenly
bubble-net feeding here?

NARRATOR: The answer might lie in
the water itself.

- So in our oceans, we're seeing
changes to currents, changes

to sea temperature, and these
changes are likely to impact

where and when certain species feed
and also what feeds on them.

- What this view from above shows us
is how nature in response to

climate challenges is learning how
to survive in a changing world.

- This behaviour is not
instinctual, it's learned.

So some populations of humpback
whales don't do this because

they've never been taught.

So we're not just seeing feeding,
we're seeing learning.

We're seeing a cultural event.

- And that's mind-blowing to see
it with your own eyes.

Whales are absolutely
magnificent creatures.

NARRATOR: But, at the same time,
this rare view from above is also a

stark warning.

- The emergence of these new feeding
patterns could significantly

impact other microorganisms like
plankton which feed off the

waste that whales produce.

- The use of drones has definitely
revolutionized the way in

which we learn about species,
like humpback whales.

- Seeing nature like this from above
is definitely a game changer.

It allows scientists to document
behaviours not necessarily

seen before.

- And in the process give us insight
into the future of marine

ecosystems.

NARRATOR: The danger with scanning
the world's ocean from above is that

sometimes you come face
to face with a ghost.

Just off the southern coast of
Japan, an ominous form rises

from the waves.

- What you've got here is this
massive, grey structure and

its standing all by
itself in the waters.

- From the air, with its elongated
shape, it looks like a battleship.

NARRATOR: Clocking in at 480 metres
in length and 150 metres in width,

this maritime monolith towers over
the surrounding sea.

- It appears to be some kind of
enormous, floating city of

concrete, but where are
all the people?

- It has this really eerie
atmosphere of abandonment.

I mean, I've never seen
anything quite like it.

- What is this place?

NARRATOR: A seemingly lonely
concrete bastion in a vast ocean.

A view from higher up
reveals a clue.

- When you take a step back, the
first thing you notice is how close

this place is to the Japanese
port city of Nagasaki.

- Nagasaki has been a major
manufacturing centre and ship

building hub for centuries.

And at no more critical time than
during the Second World War.

- Nagasaki was vital to the
Japanese war effort.

It's where their heaviest and most
powerful warships were made,

including the pride of the imperial
fleet — the Yamato class Battleship.

- For control of the South Pacific,
it was all about sea power.

- So it stands to reason that the
Japanese would go to great

lengths to defend this
key port city.

- Is that what we're looking at
here?

Could this be a remnant of some sort
of WWII-era maritime fortress?

- When you take a closer look, you
can see this place is entirely

made of concrete.

And when I see this much
concrete, I think fortifications.

- Concrete was crucial for the
construction of bases,

defensive lines, bunkers and
gun emplacements.

- During the war, the world went
concrete crazy, and its

construction applications
reached a whole new level.

NARRATOR: Examples of these wartime
innovations lie a world away

in America, at the unique
ship graveyard in

Kiptopeke State Park, Virginia.

- This is so bizarre, so
creepy. What are these?

- By 1942, there was a global
shortage of steel

to produce warships, but there was
plenty of sand, gravel, water,

and crushed stone.

- Which are the perfect ingredients
to make concrete, and so that's

what the military started
using to build its ships.

- When we say concrete, we mean
ferrocement, which is

essentially reinforced
mortar or plaster.

And that is applied over metal
frames to make a ship's hull.

- The Concrete Fleet, here in
Virginia, has 9 of the

original 24 concrete ships that
the US Navy built for WWII.

They were permanently anchored here
in 1948 to protect the nearby

shoreline from severe weather.

NARRATOR: But this ghostly form in
the East China Sea

is very different.

- This is no mortar or plaster
construction.

This whole thing is made of solid
concrete. This could never float.

- This place is clearly not a ship.

It could be some kind of coastal
defence, but then why is it

out here in the middle of the water?

- As the name implies, coastal
fortifications are, well, on

the coast.
Sea forts, however, are not.

Instead, they are structures usually
built on artificial islands

away from the mainland.

- Sea Forts have existed in one
shape or another for centuries and

this really reminds me of the Bull
Sand Fort

off the east coast of England.

NARRATOR: Built for the first world
war, but only used in the second,

this stand-alone fortress resembles
what we see here in Japan but is

much smaller and compact.

- The Japanese are renowned for
taking good ideas and making them

bigger and better.

- And despite being shaped like a
gigantic battleship, we don't

see any evidence of gun
emplacements or battlements.

Instead, we see signs of a
long-lost community.

- So if this place isn't a
fort, what is it?

NARRATOR: A closer look from above
reveals another important clue.

- You can see buildings and other
clear signs that people lived here.

- Was this some kind of
island settlement?

But if so there's nothing around?

I mean, why would anyone want
to live out here?

NARRATOR: This is Japan's mysterious
Hashima Island.

Because of its unusual shape, its
nickname is Gunkanjima,

meaning battleship island.

- You've got what look like
apartment buildings.

Clearly, this used to be
home to someone.

Is there anyone still living there?

- Whatever this used to be, it's now
a mere shadow of its former self.

But why are there no signs of life?

- It looks like it was hit by a bomb
or something equally devastating.

What was it?

- There's some pretty big
questions here.

I mean, how and why did this
island become a ghost town?

I mean, what happened here on
Hashima Island?

NARRATOR: From above, various clues
litter the island.

Objects that don't belong in most
residential settlements.

- What you can see all this really
heavy-duty industrial

equipment and it's just
rusting away.

- Some of it looks like it dates
back as far as the early 1900s.

What was it used for?

- If this island had an industrial
purpose, what was it?

What were they making here?

- Why would you build a factory in a
place that's so difficult to get to?

NARRATOR: The answer might be found
nearly a kilometre below the sea,

where, in 1810, an extremely
valuable discovery was made.

- If you know what you're looking
for, the ocean floor is a vast

treasure trove.

There are all kinds of valuable
minerals and precious metals

down there, like silver and gold.

- It's estimated that there could be
as much as $700 trillion

worth of gold under our oceans.

NARRATOR: So was Hashima Island once
a booming gold town that went bust?

- That certainly would explain
why it was abandoned.

The gold mining could simply
have just dried out.

- There are certainly many examples
of this type of abandoned

settlement around the world.

For example, Ruby, Arizona, a gold
town founded in the late

1800s, shut down in 1940.

- For 70 years, Ruby produced not
only gold but silver, lead, zinc,

and copper.

- Is that the mystery
behind this island?

Is Hashima a gold town that's now
become a well-preserved ghost town?

NARRATOR: The answer lies in
not what is above the island

but what is below...

And that's coal.

- That discovery would have been
huge news for Japan, because in

the Second World War, Japan was
desperately looking for ways to

fuel their ships and coal would have
been almost as valuable as gold.

NARRATOR: To extract the coal,
engineers created

vertical mine shafts below the
island, leading to kilometres

of underwater tunnels that increased
coal production.

- By 1950, the coal mine was
extremely productive, yielding a

monthly average of
14,000 tonnes of coal.

- This island is six hectares in
size, roughly two-thirds as big as

Alcatraz Island.

So this coal mine operation
was massive.

NARRATOR: Because of its isolated
location, the mine was designed and

built with a permanent home for its
workers and their families.

- They used all this concrete and
steel to build apartment buildings,

a rooftop garden, a religious
shrine, even a public bathhouse.

NARRATOR: By 1959, with over 5,000
inhabitants on just six hectares

of land, Hashima Island becomes the
most densely populated

area on earth.

- That is simply incredible.

Because of a rock they find at the
bottom of the sea, this

island is transformed into a densely
populated concrete city with

residential buildings and amenities.

- But all that's left now are these
crumbling, ghostly buildings

and ruins.

- This was such a vital community,
but where did everybody go?

- Something made these people leave
and never come back. What was it?

- What happened here on
Hashima Island?

- According to official records, the
working conditions for the

miners were brutal, often reaching
temperatures as high as

38-degress Celsius.

Miners collapsed on a daily basis.

NARRATOR: As many as five workers
died every month,

victims of industrial accidents.

- Back then, modern concepts of
safety were non-existent.

The corpses were cremated on
a nearby island.

- Is that what turned Hashima
into a ghost town?

Did the labour force
just quit and leave?

NARRATOR: The island's decline was
not caused by a dwindling workforce

but instead by the cheaper abundance
of oil and gas and the meteoric

rise of the automobile.

- With the worldwide popularity of
cars, petroleum was gaining

popularity in Japan as an
alternate source for coal.

So, by the 1960s, you started to
see coal mines shutting down

pretty much across the country.

NARRATOR: By January 1974, Hashima's
coal mine was formerly closed.

Three months later, everyone now
out of work, island residents

were forced to leave their
beloved homes behind...

forever.

- But with living space at a premium
in Japan, why hasn't anyone

returned or developed the
island for residential use?

- From above, you can see how the
ongoing action of the waves

and the weather have reduced the
concrete to rubble and

corroded the steel structures.

So that would pose a threat to
anyone that would try to live here.

- Every year, more and more of the
island's crumbled concrete

gets taken into the East China Sea.

NARRATOR: At its current rate of
decay, Hashima Island, and its

unique place in history, is destined
to be swallowed beneath the waves.

- It's incredible to me that in the
middle of all this water you

come across what was once the most
densely populated area on Earth.

- All this history captured on
this one little island.

- This is a story that can only be
fully appreciated and

actually discovered from the air.

NARRATOR: From a mystery discovered
on the surface of a sea to one

hiding in the ocean's depths, a view
from above uncovers a secret

never before seen by human eyes.

In the Mid-Atlantic ocean, 480
kilometres east of Portugal's Azores

islands, marine researchers

for NOAA, the National Oceanic and
Atmospheric Administration,

deploy their research vessel to
get a unique view from above,

below the ocean's surface.

- As this camera's moving farther
down, it's getting closer to

the centre of the Earth. It's got
more and more water on top of it.

You can just feel the pressure
getting more and more intense.

- Because of the pressure, no
human can dive this deep.

- That's why they're using these
remotely operated vehicles or ROVs.

- This view from above is really the
only way to get a glimpse at

this dark abyss.

- Roughly 75% of the ocean's floor
is unmapped, so you're never sure

what species you're going to
come face to face with.

NARRATOR: This strange, dark world
is home to an untold number

of unique organisms, many of whom
remain unknown.

With little oxygen, no light,
frigid temperatures, and extreme

pressure, it's a wonder there's life
in this part of the world.

- This is very freaky stuff.

NARRATOR: Remarkably, of all the
wondrous things the team from NOAA

have seen here in the deep ocean,
nothing is more inexplicable

and mysterious as what
they see next.

- There we go. They're
elongated holes.

It is peculiar to have the holes
in such a straight line.

- And the regularity of the spacing.

- And a whole chain of them.

NARRATOR: What can this series of
seemingly random trails of evenly

spaced holes on the ocean
floor tell researchers?

- It's a little bit eerie.

There's nothing else around them,
just these little tracks in

the sand.

- They're so perfectly spaced.

I mean, why would it
always be that spacing?

- No, that's really,
that's really odd.

- It seems really symmetrical.

As if Poseidon had come along and
started jabbing his trident

into the bottom of the sea.

- What are these mysterious holes?
Where did they come from?

- And who or what created them?

NARRATOR: Maybe the view from above
can reveal a possible clue?

This is the Mid-Atlantic Ridge, a
mountain range that runs for over

16,000 kilometres along the
length of the ocean floor.

- It's part of the longest
mountain range in the world.

- In terms of geology, that ridge
is hugely significant.

In the North Atlantic, it separates
the North American, Eurasian,

and African Tectonic Plates.

And in the South Atlantic, it
separates the South American

and African Plates.

- And where there's the meeting of
tectonic plates, there's volcanoes.

- The Mid-Atlantic Ridge system is
actually a continuous range

of underwater volcanoes,
wrapped around the globe.

- Is that what's causing these
holes?

It's the beginning of an
underwater eruption?

Is the whole sea floor
about to blow wide open?

- But when an underwater volcano is
active, there's also a

significant number of bubbles
because it's seeping gas.

I don't see any of that here.

- Ongoing volcanic activity also
tends to leave behind these yellow

sulphur deposits.

You don't see any of that
yellow stuff here.

- So how were these holes created?

- I mean, it looks like it must
have been a machine.

- I mean, that, that's...
- It does look like sprockets.

- Yeah, that looks rectangular to
me.

NARRATOR: Even the experts marvel at
the uniformity of these strange

deep water cavities.

- They're almost, um, blade-like.

- I mean, it looks like somebody had
a bicycle with spiky wheels and

they rode it along the
bottom of the ocean.

NARRATOR: The pattern is similar to
farming techniques used on land to

produce evenly spaced out
holes for seedlings.

- Who could possibly be toiling away
here three kilometres down in

the darkest, deepest
corners of the Earth?

- As far we know, this is the first
time humans have ever laid

eyes on this part of the ocean, so
it seems highly unlikely any machine

has ever reached this part of our
planet, never mind worked its soil.

So what could it be?

- Is there something underneath?

Are these holes just a little
window into something even more

mysterious that's under
the sea surface?

Who knows what's down there?

NARRATOR: Perhaps what lies
underneath is something

that doesn't want
to be found

- When you look closer at these
holes, you see that around each of

them there's these small
mounds of sediment.

NARRATOR: Could this be an
indication that some small creature

is burrowing under the sandy
surface?

- There are several marine species
that are known to burrow into

the ocean floor, like box crabs.

- Probably the most dramatic of
these is the male puffer fish who

creates these incredible, underwater
geometric crop circles to

attract a mate.

- They do that with the continuous
flapping of their fins as

they swim along the seafloor.

- But these puffer fish crop circles
are way too big and don't

look anything like our
deep sea holes.

- There are other animals like sea
worms and garden eels that

create holes similar to the ones
we're seeing here on the

Mid-Atlantic Ridge.

NARRATOR: Creatures whose burrowing
behaviour are well documented.

So why don't scientists just wait to
see what pops up from these

newly discovered holes?

- Because it's possible that
whatever made these holes

is long gone.
As in long dead.

- If that's the case, these could be
what's called ichnofossils.

- Whereas traditional fossils are
the preserved impression of

something that was once living,
ichnofossils are the preserved

impression of an activity that this
once-living thing left behind.

Like a dinosaur footprint.

NARRATOR: Or, in this case,
perfectly spaced rectangular holes

dug into the sea floor
for whatever reason.

- The truth is our oceans are filled
with bizarre and wonderful

creatures both big and small that
we've never seen before.

So we're discovering these
animals for the first time.

- So with these holes, we might not
understand what creature made

them or why, for the simple
reason that we just haven't

discovered that creature yet.

- We've got no idea what
makes these things.

We don't even know if they're made
by something underneath the

surface or made by something
walking along the surface.

It's a mystery, basically.

NARRATOR: Perhaps the ultimate
origin and purpose of these strange

deep sea holes will forever
remain a mystery.

- Our oceans make up 71% of our
planet and yet there's so much about

that world that we
simply don't know.

- A lot of it hasn't been explored
by humans yet because you need

such specialized equipment to even
get anywhere close to get that deep.

- But what we do have is this
amazing technology that allows us to

scan these hidden worlds from above
and start to explore their

deep sea mysteries.

NARRATOR: From a rare war relic
discovered at the bottom of the

Mediterranean, to bizarre bubble
patterns in a sea down under,

to a ghostly island off the coast of
Japan, and curious deep sea holes

dotting the world's longest mountain
range, the view from above allows

us to investigate the mysteries of
our planet's ocean depths.

Subtitles by Sky Access Services