On a dark September night in
1931, the British fishing boat Kinda was
dredging the bottom of the North Sea, 40
km
offshore. What they brought up with the
catch would transform our view of the
planet that we call home.
A lump of freshwater pete with a 20 cm
harpoon head stuck
inside carved from the antler of a red
deer. That's a strange thing to find in
the ocean. And strange things call for
further
investigation. Over time, other
prehistoric objects dating from the
Mesolithic period have been recovered
from those dark depths in fishing nets
and by marine archaeologists searching
the sea floor,
tools, weapons, and the remains of
animals such as mammoths, and even
lions. How did all these things get
there? Well, there's only one logical
explanation for this. that part of the
sea floor, now 40 m below the surface,
was once dry land, a place covered in
vegetation, and people lived there.
You've probably heard of Atlantis, the
mythical ancient land that disappeared
under the
sea. Well, thanks to recent advances in
mapping technology that can see deep
under the oceans and even under the
ocean floors, scientists really are
discovering lost lands. And not just
small islands like
Atlantis. They have found whole
continents that could be treasure troves
of minerals and fuels to power our
future. I'm James Stewart and you're
watching Astramm Earth. In this video,
we'll explore continents you may never
have heard of. Continents that have
disappeared under the water, have been
crushed into fragments, and have been
dragged down under the Earth's
crust. Lost continents that hold the
keys to understanding this planet in
which we
live. The vanished land where that
barbed spearhead was discovered has now
been mapped and is called Dogger Land
after the Dutch boats that fished this
part of the North Sea. But nearly a
century after that discovery was made,
we still know less about what lies
beneath our oceans than we do about the
surface of the moon. But geologists are
beginning to understand how the
continents that make up our planet are
changing over time. We like to think of
the land we stand on as something solid,
something permanent. But that is
actually not the
case. On the other side of the world
from where the Kinda was dredging the
sea floor lies Zeia, a continent twice
the size of India, 94% of which is
currently underwater.
Only the islands of New Zealand, which
are just the very highest parts of a
vast mountain range, poke out above the
surface. The rest of it has shrunk a
whole kilometer down beneath the
waves. We still don't know how much of
this lost continent was once dry land.
And until very recently, we didn't even
know that Zealandia existed at all.
The search for a large continent hidden
in these waters goes back a long time in
history. In 1642, the Dutch explorer
Abel Yanzun Tasman discovered New
Zealand, previously unknown to
Europeans. Even though Australia was
already known, they believed that there
must be another large continent on the
opposite side of the world. a large land
that would balance out the mass of
Europe and keep the world stable. And it
was this land that Tasine was sent to
discover. What he found was the South
Island of New Zealand, not the large
continent that he had been looking for.
Perhaps he was disappointed with his
discovery because he never set foot on
this new land. He did, however, give his
name to the Tasman Sea between New
Zealand and Australia.
It took 375 years until we came to
understand that Abel Tasman had in fact
discovered his large
continent. So how was it possible for
Zealandia to go unnoticed for so
long? The answer is in fact simple. It
is very difficult and very expensive to
explore what lies at the bottom of our
oceans. Oceans cover 71% of our planet.
Yet most of this enormous area remains
unexplored. The outline of Zealandia
only became visible once satellite
technology allowed mapping of small
variations in Earth's gravity. One other
thing that may have hindered discovering
lost continents is that until recently
we didn't have an agreed definition for
what a continent actually is. It's an
area or a kind of land mass, right? But
that's pretty vague. So to classify as a
continent you firstly have to be a large
continuous geological area with a high
elevation. Secondly you need a wide
variety of rocks and thirdly you need a
thick crust. This differentiates a
continent of varied rocks that is 20 to
40 km thick from more recently formed
sea flooror which tends to be entirely
ignous rock and much thinner typically
less than 10 km thick. Analysis of
satellite imagery and of rock samples
from the ocean floor allowed GNS
Science, a leading New Zealand research
institute, to confirm in 2017 that
Zeandia is a true continent separate
from
Australia. Very little is yet known
about it, but that's not entirely
surprising because it's a huge area to
explore, almost the size of Australia
and in very deep water.
You may be familiar with the movement of
the tectonic plates that make up Earth's
continents and how they've moved around
the surface with time, how they are
still moving. But the picture that is
now emerging appears much more complex.
As these continents slowly drift around,
they are pulled apart, opening new
oceans, and they're forced together,
creating vast mountain ranges. Mountains
such as the Alps and the Himalayas seem
astonishingly high to us. But in
reality, the surface of our planet is
almost completely smooth as it's
constantly pulled into shape by the
force of gravity.
If smooth isn't the word that comes to
mind when talking about our planet
surface, let me compare it to a football
or a soccer ball. On that scale, our
highest peak, Mount Everest, would be
less than the size of a grain of sand.
The oceans that cover most of the
surface of our planet would be no
thicker than a layer of plastic food
wrap. It's all a matter of perspective.
Admittedly, though, things from our
point of view are more dramatic. As the
continents drift around the surface of
our planet and are pushed into each
other, this gravitational pull causes
parts of the crust to sink and in a
seessaw effect, other parts rise. In
addition to all this movement, climate
change causes ice ages that lasts for
tens of thousands of years, which means
that vast quantities of the planet's
water becomes locked in glacial ice.
The warming of our planet then causes
the ice to melt and flood into our
oceans again. Following a warming period
around 18,000 years ago, sea levels rose
by 120 m. All around the globe, huge
areas of land have gradually disappeared
under the
sea. There is more to this story than
just rising sea levels, though. As our
planet cools and warms, this affects the
stability of the Earth's crust and the
way it floats on the thick layer of
magma that makes up most of our planet.
If we go back to the North Sea, or
rather the sea floor, where our story
began, we can imagine what it would have
been like there on the day when a hunter
lost one of his most prized possessions,
his hunting harpoon. As he followed his
prey, the land beneath his feet was as
solid as the ground you or I set foot on
when we step outside our front doors,
unless you live on a houseboat, of
course. There were mammoths and deer to
be hunted, as well as cave lions that
roamed these lands. As the planet
warmed, the herds of animals moved north
to graze on new fertile pastures, and
the people who hunted those animals
moved north with them.
But when the hunter dropped his harpoon,
the land beneath his feet was far from
stable. It was moving and it keeps
moving even today. This part of the
earth's crust is still recovering from
the vast weight of ice that pressed it
down during what we call the last ice
age. Despite us still being in an ice
age that began about 3 million years
ago, and technically speaking, we are
merely experiencing a warmer
interglacial period. As the global
climate changes, cooling and then
warming again, the ice caps grow or
shrink, and the enormous weight of all
this ice affects the land
underneath. The north of Britain, for
example, continues to rise, while the
south is slowly sinking, a process known
as glacial isostatic adjustment. Since
London was established as a major city
by the Romans 2,000 years ago, it sunk
by more than a meter and is still
sinking. While Scotland, on the other
end of this slab of the Earth's crust,
continues to rise out of the sea. Far to
the north of our hunting man,
Scandinavia was rising out of the magma
upon which the thin surface crust of our
planet floats and it keeps on rising.
The port of Toro on the border of Sweden
and Finland has had to be moved down
river at least twice as the land rises
and the sea retreats. This is a
worldwide phenomenon. New York City is
slowly sinking while further north at
Batur Inlet in Canada, an amazing series
of raised beaches has been left behind
as the land continues to rise out of the
ocean. Around Antarctica, similar
effects are seen as land masses rise or
fall, recovering from the weight of the
vast amount of ice that 20,000 years ago
pressed this part of the Earth's crust
down into the mantle by as much as half
a
kilometer. New technologies such as high
precision GPS monitoring reveal that the
surface of the Earth recovers much more
quickly from the loss of melting ice in
Antarctica than it does in the Arctic. A
45 millimeter rise was recorded in just
one year. Now that may not sound a lot,
but over a century, that's almost the
height of a twostory house. The ground
beneath your feet is not just moving. It
moves at different rates depending on
where you
are. The main reason the hunting ground
once walked by our ancestors disappeared
beneath the North Sea is not because of
the moving Earth's crust. It's due to
the rise in sea levels since all that
ice melted and flooded the oceans.
Dogland is still there. It's just hidden
underwater. Unlike the former continent
known as Greater Adria, this is a
continent that has not simply vanished
beneath the waves. It has been entirely
obliterated and dragged down underneath
what is now southern Europe. New
geological methods are beginning to
reveal the story of a continent the size
of Greenland that has completely
disappeared. Parts of it are believed to
have sunk 1,500 km below the Earth's
surface. And all that remains are some
surface rocks that were scraped off as
it was consumed into the Earth's mantle.
So what happened to Greater Adria? How
can we just lose a continent? To
understand that, we have to remind
ourselves of where all our modern
continents came from. And the accepted
theory is that they formed from the
breaking up of a huge superc continent
we call
pangia. The name is from ancient Greek.
Pan meaning everything or all. Gia
meaning mother earth. This superc
continent was formed from all the other
continents coming together in a cycle
that seems to repeat itself about every
500 million
years. Continents have formed, reformed,
and disappeared ever since the outer
crust of our planet cooled and
solidified. Beneath the surface, our
planet is molten rock, which is far more
solid than the fiery red gloopy lava
that we see pouring out of volcanoes
when they erupt. but still moves like a
boiling liquid. The heat within the
Earth's core drives thermal currents
that flow beneath our feet and the
movement of this viscous mass drags the
surface crust along with it causing what
is known as continental drift. The same
process that brought all the earlier
continents together to form pangia then
started to break it up again. It was
ripped in two forming two superc
continents, Lorasia and Gonduana. These
were separated by a vast sea that no
longer exists called the Tethus ocean,
running east to west, unlike our present
Atlantic and Pacific oceans that divide
the continents north to south. This
difference in orientation will play into
our story later. Lorasia would later
break up to form North America, Europe,
Asia, and at least one more continent
that we will come to later. Gonduana,
much larger than Laorasia, drifted down
towards the South Pole and broke up to
form South America, Antarctica,
Australia, India, and Africa, and the
recently discovered Zeandia and Greater
Adria. As those land masses drifted
apart again, they were dragged to
different parts of the globe by the
powerful currents of magma flowing
underneath them. When something the size
of Africa begins to move, nothing is
going to stop it. And so the world was
about to witness the brutal murder of a
continent. It might have been a part of
our planet's geography for a long time
before it was pulled in with all the
other land masses to form pangia. But
when Gonduana and Lorasia broke apart
again to form the continents of today,
greater Adria was doomed. It became
stuck between the colliding continents
of Africa and Europe. Thanks to
groundbreaking work at Utrect University
in the Netherlands, we now know that
Greater Adria was first pushed into an
area roughly where the Mediterranean Sea
is now.
It was then spun round counterclockwise
as Africa bore down on it from the south
and it was trapped against Europe to the
north, shattering into pieces due to the
unstoppable forces of the two enormous
continents coming together like a small
speedboat getting squashed by a large
freighter on either side.
Subsequently, it began to sink as both
Europe and Africa were forced upwards
over the smaller land mass, driving it
down into the mantle. The ocean that
separated Africa from Europe was sliding
under the Eurasian tectonic plate, a
mechanism known as subduction, and it
looks like it simply took Great Adria
down with it. Now, Great Adria has
vanished completely underneath southern
Europe.
So little remains of this lost continent
that it's difficult to say what it was
like. Was it a single enormous island
covered in life or completely submerged
beneath our oceans? The team at the
Department of Earth Sciences at Utre
University have concluded that at least
part of it was underwater. Some of the
rocks that were left behind were
limestones deposited in a shallow sea,
but others are volcanic, suggesting
reefs or a chain of mountains. They
believe there were likely a string of
islands, but there could have been a
much larger landmass that we may never
know about. This enormous geological
pileup that created the Alps is ongoing.
Earthquakes and volcanic activity around
the northern Mediterranean remind us
that things we cannot see are happening
beneath our feet. As the African
continent continues its unstoppable
journey northwards, eventually the whole
Mediterranean Sea could disappear and
lands that we are familiar with today
could be sucked down into the mantle or
crushed and forced upwards to make the
Alpine mountain range even bigger.
Italy, Greece, and Turkey could be wiped
off the map.
There is another lost continent. One
that took scientists decades to find
using a combination of logic and
literally groundbreaking
science. Did you know that the force of
gravity is not always the same as you
move around our planet? It varies
according to several factors,
particularly the thickness and density
of the Earth's crust. Just such a
gravitational anomaly had been noticed
around the islands of Maitius. an island
country in the Indian Ocean, 2,000 km
off the southeastern coast of East
Africa. Here, the gravitational pull is
exceptionally strong, which suggests a
large mass somewhere between the
islands. This led geologists to start
looking into the rocks around Maitius,
particularly new volcanic rocks that can
reveal secrets about what lies deep
under the surface. In those rocks are
crystals called zirkons. They are
radioactive and can therefore be used to
measure the age of the rocks in which
they are found. They discovered that
rocks that were being thrown up to the
surface during volcanic eruptions were
billions of years old. But the rocks
that make up the overlying landmass are
only about 8 million years old. New
ocean floor crust is being created all
the time from magma as continents move
apart. But the zirkons that geologists
found in the volcanic rocks of Maitius
are older, much older than anything that
could have come from newly formed crust.
In geological terms, Maitius is a recent
formation, and it must be sitting on top
of something very old, meaning it can
only be above ancient continental rock.
They had found another lost continent.
The history of Maitius is only now being
pieced together. And again, it's a story
of violence and destruction. Fossil
evidence tells us that after Gondana
split up, a land bridge allowed animals
to walk between Madagascar and India.
But Madagascar can now be found off the
southeast coast of Africa. While India
has moved 5,000 km northeast, where it
crashed into the Eurasian continental
mass, an impact that is still creating
the Himalayas. At some point, and for
reasons we do not yet understand, that
land bridge that we now call Maitia was
torn apart and was dragged down beneath
the ocean floor. It's now disappeared
completely, but fragments of its
compressed and heated rocks are brought
back to the surface during volcanic
eruptions. How large Maitius was and how
much of it is spread out beneath the
floor of the Indian Ocean is still a
mystery.
[Music]
10,000 km away on the edge of the Arctic
Circle, a geological treasure trove
could lie beneath the waves, believed to
be yet another lost continent. Very much
like Zealandia, it is a large
continental mass with only the islands
of Iceland visible above the surface. So
yeah, you've guessed it. That continent
is called
Icelandia. Although it could tell us a
lot about the world that exists beneath
our oceans that we know so little about,
the discovery has already become
controversial. For a long time, we
assumed Iceland to be no more than a
volcanic rock formation that has erupted
out of the seafloor. Geological data,
however, has never fitted well with that
theory. For example, the crust
underneath Iceland is 40 km thick, which
is what you'd expect from a slab of a
continent, not from recently formed
ocean floor, which is more typically
only around 6 km thick. This and other
geological anomalies arouse the
curiosity of scientists. A team led by
Jillian Folar, professor of geoysics at
Durham University in the UK, now
believes that Iceland sits above an
enormous tectonic plate of continental
crust that stretches from Greenland to
Europe. If this turns out to be correct,
then the way in which the former superc
continent of Pangia is believed to have
broken apart will have to be
reconsidered. But that's not what's so
controversial about this theory. The
discovery of Icelandia is hugely
political and is being discussed in
corridors of power across the globe. If
it can be proved that Iceland sits on an
enormous seabed that's an extension of
their continental land mass, the country
could be granted exclusive rights by the
United Nations to the mineral resources
contained in that area. Continental
crust is where all our minerals are
found. Just as Thogand or what is now
part of the North Sea was once dry land,
Icelandia could once have been dry land
too, rich with forests and swamps. The
conditions in which fossil fuels such as
oil and coal are formed. New ocean crust
does not contain these sources of
hydrocarbons. But if areas of the ocean
floor are found to be former continental
land mass, well, that changes our view
of what might be hidden down there. Many
of the recent discoveries about
Doggerand were made during surveys for
offshore wind farms, driven by our
understanding of the need to move away
from burning fossil fuels. As we place
ever greater demands on what our planet
can provide and even greater demands on
what our planet can absorb, the
discovery of a previously unknown
continent that has sunk beneath the
Atlantic Ocean could lead to exploration
for new sources of fossil fuels and the
temptation to make use of them will be
completely at odds with our need to
pursue sustainable sources for the
increasing amount of energy we need.
There is a real risk that rapid
exploration of our ocean floors will
begin for the purpose of nations
claiming territories to be their own.
Why does this matter? Well, if the
oceans remain as international waters,
there are strict controls about the use
of their resources. This helps to
preserve vast areas of our planet. If
nations claim areas of this underwater
wilderness and call it their own,
they'll be legally free to exploit it,
adding to the already overstretched
burden that we place on the floating
greenhouse in space that we call Earth.
If recently discovered continents like
Icelandia and Zealandia prove to be
enormous sections of what used to be
pangia, it will suggest that there are
other lost continents to be discovered
and they too could be exploited for
valuable resources. Our ocean floors
would become political
battlegrounds. Deep ocean mining is
currently banned in international waters
because the environmental impacts of
this emerging industry are not yet fully
known. But it could make nations rich.
And we know from experience how hard it
can be to prevent such exploitation. Our
constant hunger for Earth's natural
resources could start to destroy the
ecosystems that depend upon our ocean
floors before we even have any proper
understanding of
them. There is one last continent we
want to talk about today. One with a
huge land mass bigger than Australia
that has been lost underwater, but one
that you've definitely heard of. hidden
underwater that is cold and solid.
Antarctica. Surprisingly, we know as
little about the continent under those
frozen plateaus and glaciers as we do
about the other lost continents that
we've looked at. Indeed, we know more
about the surface of Mars than we do
about the land under the Antarctic ice.
Only very recently, researchers at the
University of Durham have been able to
analyze the results of satellite imagery
and ground penetrating radar to build up
a picture of what Antarctica, the
continent, is like. It's revealed a
landscape of mountains and valleys
formed by rivers now remodeled by the
ice that has covered the continent for
more than 30 million years. The
coastline of this hidden terrain is very
difficult to determine because while sea
levels would rise should all that ice
melt, the weight of the Antarctic ice
sheet is also pushing the land mass down
into the ocean. And nobody knows what it
might look like once all this geological
upheaval settles
down. 90% of the world's ice and an
astonishing 60% of all the world's fresh
water is currently locked away on
Antarctica.
This makes it very difficult to find out
what's hidden beneath this frozen
covering, which in places is nearly 5 km
thick. What we do know about Antarctica,
though, is how it's moved around the
surface of our planet over time. As
sediments are laid down on our
continents, and volcanic rocks cool and
become solid, they trap a record of the
Earth's magnetic field. By analyzing
this stored data from samples around our
continents, geologists have been able to
reconstruct a picture of where all the
land masses were in relation to the
magnetic poles over time. This
geological detective work has revealed
that Antarctica was once further north
in a warmer climate before taking up its
present location over the South Pole.
It's not always been frozen under ice as
it is today. Fossilized plant records
found on Alexander Island on the west
coast of the Antarctic Peninsula, show
that Antarctica was once covered in
forests, probably similar to the
temperate forests found in Patagonia
today. So why is it now this
cold? It's partly because the planet has
cooled, but mainly it's because
Antarctica's lonely isolation covering
the South Pole is responsible for its
own frozen existence. Let me explain. Do
you remember how pangia separated into
Gonduana and Durasia and the Tethus
ocean opened up between them? That ocean
ran east to west unlike our present
oceans that separate the continents from
the north to south. This is hugely
important in terms of our planet's
climates. The separation of the Atlantic
and Pacific oceans creates powerful
thermal currents that run north and
south and they distribute heat from the
equator around the planet. Ocean
currents that run from west to east have
the opposite effect. They actually
prevent the sun's heat from spreading
north and south from the equator. When
South America and Australia move north
away from Antarctica, they opened up the
Drake Passage and the Tasmanian Gateway,
allowing the ocean to flow freely around
Antarctica.
Strong winds driven by the corololis
effects, a force caused by the rotation
of our planet, circulate around
Antarctica. These strong winds cause the
cold water at the perimeter of
Antarctica to flow in a powerful and
endless stream called the Antarctic
circumpolar current. This prevents
warmer waters from further north from
reaching Antarctica, keeping the
freezing cold waters trapped around it
and imprisoning it in ice.
The positions of all our continents and
the seas that flow between them have an
enormous impact on the wide range of
climates found on our planet. If
Icelandia and dogand had not sunk
beneath the oceans and had remained as
an extension of the European landmass,
the climate of the northern hemisphere
would be vastly different from how it is
today. The warming water cores that heat
up much of Europe would not be able to
flow through the Atlantic Ocean. Large
areas of Europe and North America would
be much colder. The Arctic could even
develop an enormous permanent ice cap
similar to that over
Antarctica. It seems such a small
difference whether these lost continents
remain above the oceans or not, but
their impact on the rest of the planet
would be immense. If greater Adri had
been pushed upwards over the European
continent instead of being subducted
underneath it, there would be no
Mediterranean Sea, possibly no sea there
at all. And the area now covered by much
of Europe could have been an arid desert
similar to the
Sahara. The very climates that we see on
our planet today are dependent on the
continents that have formed over
millions of years. If large land masses
like Zealandia and Icelandia had not
disappeared, the world would be a very
different
place. Discovering these lost continents
allows us to imagine all kinds of
different worlds that could exist if the
tectonic plates that move around our
planet's surface had behaved just a
little differently. But there's a
serious side to this, too. It raises
questions of politics and creates
arguments between nations over who has
the rights to newly discovered
resources. It would be incredibly sad to
begin destroying those hidden continents
as soon as we've discovered them and
before we even properly understand them.
So, we need to decide how to move
forward as an international community.
And we need to think about better ways
to obtain and make use of the minerals
that may be found under our oceans. Be
it sunken, crushed, or frozen over. It's
crazy to think how long these continents
went unnoticed. And it raises the
question of how many more are waiting to
be discovered.
Despite our species having inhabited our
planet for hundreds of thousands of
years, we clearly have so much more to
learn about it.