Colliding Continents | Naked Science
Summary
TLDRThis script explores Earth's geological future, predicting dramatic changes due to continental drift. It envisions a time when familiar continents merge into a supercontinent, causing extreme climate shifts and potential mass extinctions. The script delves into Earth's history, from its violent birth to the formation and destruction of supercontinents like Pangaea, driven by plate tectonics. It highlights natural disasters as a consequence of these movements and speculates on the future geological and climatic conditions that might challenge human survival.
Takeaways
- 🌏 The Earth's continents are in a constant state of motion and transformation due to tectonic forces, which will continue to shape the planet's surface for billions of years.
- 🌌 Intergalactic explorers in the distant future may find a vastly different Earth, possibly a single landmass with extreme climates and geological features, due to the ongoing process of continental collision and separation.
- 🏞️ Continents are formed and destroyed in cycles, with the current configuration of continents being just a snapshot in a long geological timeline.
- 🔥 The Earth was initially a molten mass, and over time, the cooling and solidification of its surface led to the formation of the first landmasses, including granite as a key component.
- 🌊 Water, possibly delivered by meteors and asteroids, played a crucial role in the formation of Earth's oceans, which are essential for the development of life and climate.
- 🌋 The theory of continental drift, proposed by Alfred Wegener, has been confirmed by evidence such as matching fossils on different continents, indicating that they were once joined.
- 🌈 Plate tectonics is driven by heat from the Earth's core, causing the movement of continents and the creation of geological features like mountains and ocean trenches.
- 🏞️ The formation of continents and their geological features, such as the Grand Canyon and the Alps, are the result of continental collisions and the immense forces involved.
- 🌍 The current configuration of continents has a significant impact on global climate and ecosystems, and changes in this configuration will affect the habitability of the planet.
- 🌪️ Natural disasters such as earthquakes, volcanic eruptions, and tsunamis are part of the Earth's natural cycle and are a consequence of the movement of tectonic plates.
- 🔮 Predicting the exact timing of geological events is impossible, but the locations of future volcanic activity and earthquakes can be anticipated based on plate boundaries and historical patterns.
Q & A
What is the premise of the video script discussing Earth's future?
-The video script discusses a future vision of Earth hundreds of millions of years from now, where intergalactic explorers return to find a drastically changed planet with a single giant landmass, massive geological features, and remnants of ancient civilizations.
How does the script describe the current continents of Earth?
-The script describes the current continents as distinct land masses separated by oceans, providing a stable environment with hospitable weather patterns suitable for civilization and city development.
What is the role of colliding continents in shaping Earth's geological features?
-Colliding continents are described as the mightiest force on Earth, responsible for the creation and destruction of geological features, including the formation of mountains, the disappearance of oceans, and the reshaping of landmasses in a cycle of death and rebirth.
How did the first land on Earth form?
-The first land on Earth formed as the heaviest elements like lead and nickel sank toward the center to form a molten core, while lighter elements including oxygen and silicon rose to the surface, erupting in volcanoes and slowly cooling to form patches of crust.
What is the significance of granite in the formation of the first continents?
-Granite is significant because it is less dense than other rocks in the mantle, allowing it to float on the surface and mix with other rocks to form the first continental nuclei, which are the seeds of the first continents.
How does the script explain the movement of continents?
-The script explains that continents are not fixed in place but are constantly moving due to powerful forces deep within the planet, which rip continents apart and then smash them together in an ever-changing cycle.
What evidence supports the theory of continental drift?
-Evidence for continental drift includes the discovery of identical fossils on different continents, which suggests that these continents were once closer together, and the observation of continents moving apart at the mid-Atlantic ridge.
How does the script describe the formation of the Atlantic Ocean?
-The script describes the formation of the Atlantic Ocean as a result of the collision and subsequent separation of the African and South American plates, which created a vast interconnected volcanic mountain range that extends through all the major oceans of the world.
What is the role of plate tectonics in the creation of natural disasters?
-Plate tectonics play a significant role in the creation of natural disasters such as volcanic eruptions, earthquakes, and tsunamis, as the movement and interaction of tectonic plates create stress points and instability at plate boundaries.
What does the script suggest about the future of Earth's continents?
-The script suggests that the continents will continue to move and change, potentially forming a new supercontinent called Pangaea Ultima, which could lead to extreme climate conditions and possibly trigger another mass extinction.
How does the script relate the geological history of Earth to the potential future of our planet?
-The script relates the geological history of Earth by highlighting the continuous cycle of continental movement and change, suggesting that the processes that have shaped Earth over billions of years will continue to do so in the future, potentially leading to the destruction and rebirth of continents and affecting the survival of life on Earth.
Outlines
🌍 Future Earth's Drastic Transformation
This paragraph envisions Earth in the distant future, where intergalactic explorers return to find a planet drastically altered from its current state. Continents have merged into a single landmass with immense mountain ranges and glaciers. The once-thriving metropolises are now mere remnants buried under tons of rock. The script introduces the concept of Earth's ever-changing landscape due to the power of colliding continents, which have been shaping and reshaping the planet in a cycle of creation and destruction for billions of years.
🏔 The Birth and Evolution of Continents
The script delves into the geological history of Earth, starting from its formation 4.5 billion years ago. It describes the initial creation of the planet from debris, the formation of the Moon, and the intense heat that characterized the early Earth. The process of land formation is detailed, with heavy elements sinking to form the core and lighter elements like oxygen and silicon rising to create the first patches of crust. The challenges faced by the early crust due to asteroid bombardments are highlighted, and the eventual stabilization leading to the formation of the first continents is discussed.
📅 Geological Time and the Formation of Granite
This paragraph focuses on the role of granite in the formation of the first continents. It discusses the importance of zircon crystals in dating rocks and the process of how these crystals form a natural clock to measure geological time. The granite in South Africa's cup Val region is presented as an ancient remnant of the first continental nuclei. The paragraph also explores the theory that life, specifically photosynthetic organisms, may have contributed to the formation of granite and the growth of the continents.
🌏 The Dynamics of Continental Drift
The concept of continental drift is introduced, with the explanation of tectonic plates and their movement powered by heat from the Earth's core. The paragraph discusses the evidence for continental drift, such as identical fossils found on different continents, and the process of plate tectonics that leads to the creation of new land and the destruction of existing land masses. The formation of the Atlantic Ocean and the mid-Atlantic ridge is highlighted as an example of continents being pushed apart.
🌋 The Creation and Destruction of Supercontinents
The script discusses the cyclical nature of continental movement, leading to the formation and breakup of supercontinents. It describes the process of how continents drift apart and then collide again to form new landmasses. The history of the supercontinent Val Barra and its eventual destruction by the heat buildup beneath it is detailed. The paragraph also touches on the formation of the next known supercontinent, Rodinia, and the continuous cycle of continental dispersion and collision.
🛑 Mass Extinctions and the Formation of Pangaea
This paragraph discusses the formation of the supercontinent Pangaea and its impact on Earth's climate and life. It describes how the formation of Pangaea led to drastic climate changes and may have contributed to one of the largest mass extinctions in Earth's history. The script also details the breakup of Pangaea and the gradual formation of the continents we recognize today, including the separation of South America from Africa and the movement of other landmasses.
🏞️ The Geological Features Formed by Colliding Continents
The script explores the geological features created by continental collisions, such as the formation of the Alps and the Himalayas. It explains the process of mountain building as a result of the collision between the African and Eurasian plates, and the formation of the Grand Canyon due to the uplift of the seabed following a plate collision. The paragraph also discusses the impact of these geological events on the planet's climate and ecosystems.
🌊 The Isthmus of Panama and Global Climate Change
This paragraph discusses the formation of the Isthmus of Panama and its effects on global ocean currents and climate. The joining of North and South America led to a change in the flow of water between the Pacific and Atlantic oceans, potentially triggering an ice age and causing mass extinctions. The script highlights the interconnectedness of continental movements and global climate patterns.
🌐 The Future of Earth's Continents and Natural Disasters
The script envisions the future of Earth's continents, predicting the widening of the Atlantic Ocean and the formation of new mountain ranges. It discusses the inevitability of natural disasters such as earthquakes and volcanic eruptions due to plate tectonics. The paragraph also contemplates the potential for future mass extinctions and the resilience of the human species in the face of these geological changes.
🌑 The Ultimate Fate of Earth: Pangaea Ultima
In this final paragraph, the script speculates on the far future of Earth, predicting the formation of a new supercontinent called Pangaea Ultima. It describes the potential climate extremes and the geological changes that will reshape the planet's surface. The paragraph concludes with a reflection on the resilience of life and the possibility that humanity may have to leave Earth in search of a new home due to these drastic changes.
Mindmap
Keywords
💡Continents
💡Tectonic Plates
💡Continental Drift
💡Supercontinent
💡Subduction Zone
💡Mountain Ranges
💡Fossil Record
💡Geological Time Scale
💡Mantle
💡Mass Extinctions
💡Natural Disasters
Highlights
Intergalactic explorers in the distant future find Earth drastically changed, with a single giant landmass and signs of ancient civilizations nearly erased.
The Earth's continents are not fixed but constantly moving due to powerful forces within the planet.
The geological future of New York is predicted to be traumatic, with continents like Africa and Europe colliding.
The Earth's current continents are formed through a natural cycle of construction and destruction over billions of years.
The first land masses were small 'rafts' of rock floating on the mantle, which later grew into continents.
Granite, a buoyant rock, played a crucial role in the formation of the first continents.
Zircon crystals within rocks provide a natural clock to date the Earth's earliest geological events.
Early life forms may have contributed to the formation of granite, which in turn created the first continents.
Continental drift was proposed by Alfred Wegener in 1912, based on the discovery of identical fossils across oceans.
Plate tectonics is driven by the Earth's core heat, creating convection currents in the mantle.
The mid-Atlantic ridge is a place where continents are currently being pushed apart, forming new ocean crust.
The formation of supercontinents like Pangaea has significant effects on global climate and can lead to mass extinctions.
The breakup of Pangaea led to the formation of the continents and climate patterns we recognize today.
The collision of continents creates mountain ranges like the Alps and the Himalayas.
The Grand Canyon was formed by the uplift of the land due to continental collision and subsequent erosion by the Colorado River.
The Isthmus of Panama's formation changed global ocean currents and may have contributed to an ice age.
Continents will continue to move, potentially leading to another supercontinent and altering Earth's climate and ecosystems.
In the far future, Earth may become a single landmass again, known as Pangaea Ultima, with extreme climate conditions.
The movement of continents is responsible for many natural disasters, such as earthquakes and tsunamis.
Despite the inevitability of these geological processes, humanity may need to adapt or seek new habitats in the distant future.
Transcripts
planet Earth hundreds of millions of
years in the future
intergalactic explorers return to their
home planet in search of signs of
ancient civilizations they find a planet
that has changed beyond recognition
all other familiar continents that we
know today instead may find a giant
landmass with huge mountain ranges
massive frozen snow fields and glaciers
the once thriving metropolis they seek
has disappeared a few broken remnants
are all that remain crushed and buried
beneath tons of rock
could this be a future vision of Earth
naked science asks what forces could
create such a bleak and barren world and
investigates how the awesome power of
colliding continents shapes and reshapes
our planet in an endless cycle of
construction and destruction
[Music]
[Music]
our world's fierce
from space it's easy to see the
distinctive pattern of land that makes
up the continents North America South
America Africa Antarctica Europe Asia
and Australia giant land masses
separated by oceans that stabilise the
environment with hospitable weather
patterns suitable for civilization and
cities to evolve and prosper
[Music]
now imagine our planet ravaged by storm
force winds subjected to extremes of
temperature giant freezes heat waves and
droughts a world where cities are
crushed and destroyed where Africa
tramples New York underfoot and London
freezes at the North Pole
the geological future of New York is
going to be rather traumatic North
America and Europe are going to collide
with one another the world as we know it
will be unrecognizable this is not a
portrait of the earth after a
devastating global disaster
this is how nature will shape our planet
many millions of years in the future
this incredible remodeling is just part
of a natural cycle that has shaped the
earth for the last 4 billion years and
will continue to do so until the Sun
finally destroys its surface once and
for all
today our continents may seem solid safe
and forever fixed in place but they are
none of those things these great land
masses are constantly on the move speed
up the last few billion years and one
can see the continents sailing across
the globe powerful forces deep within
the planet rip the continents apart and
then smash them together in an
ever-changing cycle of death and rebirth
oceans disappear mountains crumble and
rise again land masses form and reform
colliding continents are the mightiest
force on earth when we look at the
history of planet Earth we see that it
is full of change changes as part of
nature and this change continues today
and will continue into the future
to understand how the continents shape
our world we must first travel back in
time to the very birth of the earth four
and a half billion years ago the earth
is created from the debris leftover from
the formation of the Sun dust and debris
collide and clumped together once these
clumps grow into objects about half a
mile in diameter they create enough
gravity to attract more material
slowly these clumps grow into as many as
20 planets as these new planets orbit
the Sun they begin to collide one
collision with the planet theá--
which creates the moon obliterates the
surface of the earth
the energy from the collision makes the
earth incredibly hot at around 11,000
degrees Fahrenheit it's more than seven
times hotter than the inside of a
cremation furnace earth is a massive
molten ball of boiling lava
this is primeval hell with thousands of
asteroids and comets bombard our world
but deep within the planet a process
starts that will lead to the first land
the heaviest elements LED and nickel
synched down toward the center of the
earth to form a molten core the lighter
elements including oxygen and silicon
rise toward the surface where they erupt
in volcanoes of molten rock slowly the
Earth's surface cools molten lava
solidifies to form patches of crust the
seeds of the first continents
but even as the first land is born it
faces a battle to survive
we were being bombarded by a large
number of asteroids very early in the
history of the planet so there's a lot
of dynamic change from being walloped by
giant impacts disturbing things geology
professor Sam bowring is an expert in
early Earth and the genesis of the
continents when we had a early crust as
is an interesting question I suspect
we've had and we had an early crust from
day one the question is how long was
that preserved when the earth was being
bombarded constantly by asteroids the
chance of preserving any small chunk of
that crust was very low the relentless
bombardment destroys the new planet's
crust almost as soon as it forms this
recycling of the surface continues for
many millions of years but as the flux
of asteroids began to wane and as the
earth matured a little bit I suspect the
early crust lasted a little bit longer
eventually the barrage from asteroid
impact slows down the surface of the
earth continues to cool but the earth is
missing one vital ingredient oceans
we're earth goddess water has been a
controversial topic over the years I
think most people now think that many
meteoritic bodies actually contain quite
a lot of water water carried by meteors
and asteroids may form the oceans that
surround the first continents
the earth 4.4 billion years ago our
planet is now 150 million years old and
the first primitive land masses have
formed they are not like the seven
instantly recognizable continents of
today they are just small rafts of rock
floating on the mantle but now a type of
rock appears on the Earth's surface that
will form the nucleus of future
continents a rock buoyant enough not to
sink into the bowels of the earth
granite in South Africa in the cup vowel
region southwest of Johannesburg
geologists examine ancient granite that
has survived the ravages of time these
are the ancient remains of what some
people consider to be the first true
continent we're looking at the relics
the remnants of the first continental
nuclei this is one of the oldest but
certainly the best preserved continental
nucleus in the world geologist Alex
kissters studies how granite formed the
first continents the rocks here are so
important because they are remarkably
well-preserved much better than any way
on on earth and that allows us actually
to study processes that were involved in
the formation while these early crustal
rocks
kissters is collecting samples to date
the age of the granite we're joining
these little rock horse taking them out
and then sending off their light onto
the lap to potatoes dating rocks is a
complex process because over long
periods of time the minerals can break
down and reform into new rocks
scientists look for an ingredient of
rock that is tough enough to withstand
the test of time
the answer is zircon a crystal that is
made inside molten rock as it solidifies
even if the rock is destroyed the
zircons are durable enough to survive
zircon is an incredibly interesting
mineral and it incorporates uranium and
excludes lead and that sets us up to
have basically nature's time capsule to
illustrate this process imagine that
this hourglass is a newly formed circle
crystal sand in the top represents
uranium the sand in the bottom
represents lead over millions of years
the uranium in the zircon turns into
lead measuring the relative proportions
of sand in the top and bottom of the
glass reveals how much time has passed
uranium's relentless decay into lead
gives us a natural clock using this
technique geologists date this granite
at three and a half billion years old
this makes it some of the oldest rock on
the planet these rocks make up a major
part of what is known as the cup Val
Creighton a Creighton is an ancient raft
of rock light enough to float on the
mantle and around which a continent will
grow ancient cratons have also been
found in the heart of the Australian and
North American continents the Creighton
here in cap Val in South Africa
stretches for four hundred and
sixty-three thousand square miles it's
almost twice the size of Texas without
granite the Creighton and modern
continental crust wouldn't exist
granite forms when minerals in the crust
melt then react with water cool and
crystallize because it is made of
lighter minerals granite is less dense
than other rock in the mantle so it
floats on the surface and mixes with
other rocks to form rafts of land the
cup Val Creighton is not totally built
from granite the oldest rocks here are
these amazing pillow lavas exposed along
the kamati River three and a half
billion years ago they form under the
sea as lava emerges from an underwater
volcanic vent upon contact with water
the lava immediately gains a solid crust
which then cracks and oozes additional
large blobs called pillows these rocks
are amongst the oldest that we know it
is basically identical to Pillar laws
that we see on a recent ocean floor when
settings like a wide the kamati pillow
lavas begin their life on the ocean
floor but are pushed up out of the sea
to form part of a continent
but where did the granite come from to
create it you need the right mix of
minerals a new theory suggests that life
itself may have provided the missing
ingredients it may sound like an
outlandish idea but there's some
evidence that living organisms that use
photosynthesis appeared around the same
time that the continents began to grow
3.8 billion years ago scientist suggests
that early organisms microbes help speed
up the breakdown of rock emerging at the
Earth's crust over hundreds of thousands
of years this rock breaks down into new
minerals which sink back into the mantle
deep below the surface they heat up and
form granitic magma the magma rises into
the proto continent freezes and forms
huge solid rafts of granite
now stabilized the Creighton begins to
grow forming new baby continents but
crayons are not the only factors at work
more powerful forces are building up
deep within the planet forces that have
the power to rip apart land masses and
smash them together changing the face of
the planet forever four and a half
billion years ago the earth forms for
many years it is bombarded by asteroids
and meteors
[Music]
slowly the molten planet cools and small
land masses form around crayons of
granite rock massive forces from deep
within the planet rip apart and smash
these small proto continents together as
they grow into the large land masses we
see today the surface of the earth the
crust is made up of a giant jigsaw of
interlocking pieces called tectonic
plates the separate plates themselves
sit on the mantle the layer between the
crust and the Earth's core
although the mantle is made of rock the
heat and pressure deep down mean it's
flexible enough to allow the plates
above to move up to several inches a
year evidence for the theory of
continental drift was first proposed in
1912 by German scientist Alfred Wegener
he noticed that identical fossils were
discovered oceans away from each other
paleontologist professor Mark McManaman
of Mount Holyoke College in
Massachusetts is an expert in fossil
records begginer noted that a freshwater
organism cannot cross a salty sea and so
if you find the fossils of a freshwater
organism or a land creature on two
continents that are now greatly
separated by distance they must once
have been closer together by identifying
like fossils on different continents
scientists can map which continents were
joined in the past the fossil
distributions will tell us where fossils
occur and how the continents must have
been juxtaposed fossils that are
identical but occurring in very
different parts of the world imply that
the continents have drifted when he
first proposed his theory of continental
drift begginer was laughed at the idea
that continents could actually move was
considered preposterous the problem was
he didn't know how the continents moved
the missing mechanism wasn't discovered
until the 1960s plate tectonics is
powered by heat plate echinus is being
largely driven by the fact that the
interior of the earth is much hotter
than the surface the temperature at the
center of the core is 10,000 degrees
Fahrenheit it's as hot as the outer
parts of the Sun much of the heat is
left over from the collisions and
massive bombardment during the early
days of the earth the rest comes from
radioactive decay of heavy elements in
the core heat escaping from the core
creates convection currents in the next
layer of the earth the mantle the
process is like a lava lamp where heat
from the bulb at the bottom creates
convection currents in the oil pushing
the synthetic lava upward the heat melts
part of the mantle and sends plumes of
magma molten rock rising to the surface
it rises between cracks in the plates
creating new rock that pushes the plates
apart I think that plate tectonics is
virtually inescapable on this planet
it's an exceedingly efficient way to
cool the interior of the earth this
formation of new rocks splits apart and
separates the plates and the continents
sitting on them today the majority of
this new rock forms under the sea
creating vast interconnected volcanic
mountain ranges that extend through all
the major oceans of the world
one range can clearly be seen at the
bottom of the Atlantic Ocean along the
mid-atlantic ridge it stretches more
than 12,000 miles from a sub-antarctic
to the Arctic it comes to the surface in
a few places Iceland was created from
volcanic lava bubbling up at the
junction between the North American and
Eurasian plates it's one of the few
places on earth that one can actually
see continents being pushed apart we are
watching here geological structures that
you cannot really watch anywhere else
it's like a big textbook of geology this
is where the Earth's crust is being made
pal I nursin professor of geophysics at
the University of Iceland monitors the
mid-ocean ridge where the continental
plates are splitting apart the ridge in
Iceland is almost three miles wide on
one side is the North American plate on
the other side the eurasian plate the
rift here grows as new rock forms at its
center
pushing North America and Europe away
from each other the Atlantic Ocean
widens and the two continents drift
apart eventually the Atlantic could
become as big as the Pacific to measure
how fast they're splitting a nursin
takes Global Positioning System readings
at specific points along the plate
margin to put the antenna right on top
of the point and then we can calculate
the exact position of this point in the
world respect to the central earth
although the ridge appears calm and
there's no magma rising to the surface
ina syns measurements show that the two
continents are drifting apart by around
an inch a year so by the end of the
century Europe and America will be
almost eight feet further apart
the movement in Iceland is typical of
the processes shaping the continents
since their birth 4.4 billion years ago
it's part of the great cycle of the
Earth's continents the new crust created
at the mid-ocean ridge moves away cools
and eventually sinks back into the earth
when the first proto continents formed
there were several interconnecting
tectonic plates constantly bumping and
grinding against each other pushing the
new land over the planet today the earth
has over a dozen plates some colliding
together some moving apart they are
powerful enough to move a continent the
size of North America over 3,000 miles
in 200 million years that's 15 miles
every million years the earth 3.4
billion years ago and plate tectonics
pushes the proto continents together
they combine to form ever larger tracts
of land
scientist suggests that cratons combined
with other crayons to form a
supercontinent a huge continuous stretch
of land
it's called Val Barra scientists are
unsure of its exact shape or size as
only a few pieces like the crayon in
South Africa still remain but Val Boras
days are numbered
a rising plume of heat is growing
beneath it it's about to rip the world's
first supercontinent into pieces 2.7
billion years ago val barra the world's
first supercontinent still dominates the
planet but plate tectonics powered by
heat from the Earth's core is about to
split it apart rock is a good insulator
when a continent gets very large the
rock traps heat beneath it
as it gets hotter and hotter a plume of
superheated magma builds up beneath the
giant continental mass the temperature
continues to rise and pressure in the
mantle increases eventually the crust
can no longer contain the pressure and
the hot lava breaks through ripping the
land apart
you can see this process happening today
in Africa heat from the Earth's core is
ripping the continent apart a giant Rift
Valley runs from the Red Sea down to
Mozambique giant cracks are opening up
in the land volcanoes like Kilimanjaro
marked spots where molten rock have
risen to the surface in the past
in ten million years the eastern half of
the continent will have split away
the molten lava trapped beneath the
giant supercontinent of all bara
eventually smashes through the surface
Rock the continent ruptures into several
smaller pieces these bits of land sail
across the earth but nobody knows what
happens to them or what the planet looks
like at this time the earth is entering
the dark ages it is over two and a half
billion years since it was formed it
will be over a billion years before
another supercontinent forms
the earth is entering a deadly cycle of
destruction and rebirth the theory of
continental drift suggests that we go
through cyclic phases of continental
dispersion and then continental
collision and the continents then seem
to move apart from one another and then
collide with one another over a maybe a
hundred million year or more timescale
when a large continent splits apart the
separate pieces travel away from each
other
pushed by the creation of new land at
the ridge between plates because the
earth has a constant surface area the
same amount of land created must be
absorbed into the earth this process
happens at subduction zones at the
junctions of plates at a subduction zone
crust dives down into the mantle to be
melted to form new rock when the plate
subducts into the earth it brings two
pieces of land together when they
collide a new supercontinent starts to
form
it is now 1.1 billion years ago on our
timeline and the next known
supercontinent has formed its name is
rodinia and it holds almost all of the
continental rock on the surface of the
earth still no one knows exactly what it
looked like but at its heart is an area
that will eventually become North
America 350 million years later the
cycle of annihilation and creation
starts again as the buildup of heat
beneath the surface of the earth tears
Rodinia apart when Rodinia splits it
forms several smaller continents that
for millions of years drift apart and
then drift back together again to form
Gondwana a supercontinent in the
southern hemisphere eventually after
several hundred million years Gondwana
slowly splits apart
plate tectonics pushed the land back
together to create the world's last
supercontinent it's a huge landmass
known as Pangaea
all the continents we know today are
here join together geologists are able
to plot the continents relative
positions because 350 million years ago
there are numerous species on earth each
living in distinct regions this specimen
that I have right here is the first
trial of light that was ever described
from what is now the United States it is
exactly the same type of trilobite that
occurs on the other side of the Atlantic
Ocean in North Africa so we know then
that the trello bites in the old and new
worlds must have been close together
because they're so closely related the
fossil records show that North America
and Europe rests next to one another the
land where New York now sits is next to
Morocco in North Africa the Atlantic
Ocean does not exist the east coast of
South America Nestle's against the
western coast of Africa while Australia
India and Antarctica are joined to the
southeast of Africa if we want to look
at a picture of the world 250 million
years ago we're gonna look at a world in
which a four-footed creature could walk
from one end of this landmass to the
other Pangaea is one giant continuous
landmass
it not only makes the world look very
different it also has a dramatic effect
on climate because much of the land is
located far from the sea the climate of
the interior changes radically from
season to season it gets very hot in the
summertime and extremely cold in the
winter you don't have the moderating
influence of the ocean that we have
today so it's a very different world and
it's a world that in some ways is is
harsher and less hospitable at least to
life on land it's thought that the
climate change caused by pangaea's
formation may have played a role in one
of the largest mass extinctions on earth
this event known as the per mo Triassic
mass extinction wipes out about 90% of
all life on Earth
it's been called the mother of all mass
extinctions I would consider that the
formation of Pangaea with its climate
worsening effects to be a contributing
factor however and not the sole cause of
the mass extinction 250 million years
ago and the supercontinent of pangaea is
breaking up the continents we know and
recognize today begin to take shape over
the next tens of millions of years South
America drifts away from Africa North
America away from Europe
Australia splits off from Antarctica and
heads north to warmer climes the
positions of our continents are becoming
familiar although they're
distinguishable features are not the
world's vast mountain ranges the Alps
and Himalayas and it's great valleys
like the Grand Canyon are yet to form
they will emerge out of one of the
biggest battles in nature the battle
between colliding continents
[Music]
earth 100 million years ago the
continental map of the modern world is
gradually becoming recognizable but a
battle is still raging between the
continents that will change the face of
our world forever and create some of the
most extraordinary geological features
on the planet as the continents move
slowly across the earth crust and rock
is dragged back down into the earth at
subduction zones between the tectonic
plates but when continents collide at
the plate junctions sometimes there is a
battle for supremacy if neither plate
will submit and drop down to be consumed
by the mantle then both the continents
slowly smash and grind into each other
these pinch points of continental
collision build mountains
[Music]
the Alps are the largest mountain range
in Europe higher than the Rockies the
Alps stretch from France in the West
through Italy Switzerland and Austria to
Slovenia in the east their formation is
a direct result of a continental
collision between Africa and Europe the
story of the Alps begins when the
African plate breaks away from the South
American plate it starts moving toward
Europe without the plate movement there
wouldn't be any mountain on this planet
professor Gerard Stanley of Lausanne
University in Switzerland studies the
processes that built the Alps
the African and Eurasian plates start to
move toward each other trapping a third
smaller Iberian plate between them the
three plates collide the Eurasian Plate
is pushed downward into the mantle
chopping off the Iberian plate but ëthis
si begins to close as the eurasian plate
grinds underneath the African plate it
pushes the tether part of the iberian
plate 600 miles north and many thousands
of feet into the air rocks that started
life on the bottom of the ocean end up
at the top of the alps what's
fascinating to imagine that if you are
on top of the Matterhorn you actually is
staying on top of africa for geologists
africa stops in the alps over the next
100 million years the continents
continue to smash together new mountain
ranges start forming around the globe
the largest the Himalayas form as the
Indian plate charges northward toward
the Eurasian Plate it moves at two
inches per year lining up a head-on
collision the movement of the Indian
plate leads to a clash between two giant
continents and creates some of the
highest structures ever to exist on
earth the incredible power of
continental drift not only builds
mountains
it also sculpts one of the world's most
recognizable landmarks the Grand Canyon
in Arizona
the Grand Canyon is a great scar in the
surface of the earth geologist Ron
Blakey
has been studying the canyon for over 30
years it's just a wonderful place to
come face to face with planet earth the
Grand Canyon is 277 miles long and up to
18 miles wide at its deepest it
stretches down for over a mile
the gorge exposes the interior of the
North American continent it's like
looking through the pages of a book each
layer tells a story about the past
[Music]
whatever really neat things about Grand
Canyon is this we go up the walls of the
Grand Canyon since it's like going
through a time machine layer upon layer
of rock reveal the geological history of
North America from present day to two
billion years ago the deeper you go the
older the rocks by studying the layers
Blakey can piece together the history of
the canyon he finds some of the most
interesting evidence at the very top
fossils of ocean creatures Wow this beds
the jackpot here what we have is a
extraordinary example of a Permian sea
floor the most important thing it tells
us with respect to the Grand Canyon is
that this area had to be near sea level
when these rocks formed now it's 7,000
feet above sea level in the room of the
Grand Canyon so something had to happen
either the sea had a fall 7,000 feet and
we're pretty sure that didn't happen or
this landscape had to be uplifted 7,000
feet we're pretty sure that happened 250
million years ago the canyon starts to
form as a result of a collision between
the Pacific and North American plates
they collide with such force the North
American plate thrusts more than two
miles upward what was once seabed rises
over a period of 15 million years to
form a vast plateau far above sea level
it stays that way for millions of years
until it is transformed by water erosion
[Music]
six million years ago several hundred
miles south of the canyon plate
movements open up the Gulf of California
to the sea for the first time small
streams in the Rocky Mountains could
empty into the ocean so if we're
starting a stream at 14,000 feet in the
Rocky Mountains and carving down the sea
level and the Grand Canyon just happens
to be in the way the Grand Canyon is
going to get cut out these streams
merged to form what is now called the
Colorado River it cuts down through the
land heading to the Gulf of California
it took a river to carve the canyon the
water has carved down through the rocks
layer by layer by layer removing
material out of the canyon and leaving
the great void that sits behind me the
Grand Canyon is a testament to the
awesome power of the continents in
shaping our world back on our journey
tracing the birth and death of the
continents it is now 20 million years
ago two and a half thousand miles south
of the Grand Canyon another plate
collision is about to take place the map
of the modern world is almost complete
at this time water flowing freely
between the Pacific and Atlantic oceans
still separates North and South America
over many millions of years the Pacific
plate begins sliding under the Caribbean
plate the pressure causes underwater
volcanoes to erupt some explode with
such ferocity that they create a range
of small islands between North and South
America
over the next 17 million years ocean
currents deposit sediment and gaps
between these new islands
gradually the sediment builds up and
compresses to form land bridges between
the islands three million years ago the
Isthmus of Panama a narrow strip of land
finally joins North and South America it
separates the Pacific and Atlantic
oceans the flow of water between the two
stops and ocean currents must take new
routes
this causes yet another change in the
climate of our planet
it changes the movement of warm seas
around the globe disrupting weather
patterns possibly pushing the planet
into an ice age many species are wiped
out the continents as we know them today
are formed creating the nice hospitable
environment for human civilization to
evolve and thrive on planet Earth
but how long will it last the forces
that power plate tectonics are still
active and will tear our continents
apart once again they will build a new
world one that may trigger another mass
extinction and push humanity to the
brink of annihilation
[Music]
a view from space reveals Earth's
continents as we know them today there
are seven in total but some are
separated by a political divide rather
than a geographical one Africa Eurasia
is a super continent comprising of
Africa Europe and Asia it stretches from
the Siberian plateau in Russia to the
Cape of Good Hope in South Africa a
spectacular route across three
continents incorporating dramatic
climate change vivid scenery and diverse
cultures however Africa Eurasia isn't
the only super continent on the planet
because the Panama isthmus links North
and South America together they too can
be thought of as one vast landmass and
if the Bering Strait between Russia and
Alaska were to freeze over it would be
possible to walk from Cape Horn in South
America to the Cape of Good Hope in
South Africa a journey of around 25,000
miles but this won't always be possible
for powerful forces deep below the
surface continue to send the continents
hurdling across the globe a process that
started at their birth 4.4 billion years
ago and one which will continue long
into their future what we observing at
the moment is only a snapshot of the
Earth's global cycle that has been
undergoing for last four and a half
billion years probably and will be
undergoing even if you're not around any
the global continental cycle has another
impact on our world it causes many
natural disasters plate movement creates
stress points which lead to volcanic
eruptions as continents split apart
instability at the plate junctions
causes earthquakes that rip apart whole
communities this one on October 8th 2005
in Pakistan ruled Kashmir killed nearly
75 thousand people and left up to 3
million homeless and when plates abduct
into the earth their death throes
produced devastating waves the 2004
Indonesian tsunami is just one
demonstration of the terrifying power
unleashed when plates move
such natural disasters are part of the
continental cycle and they're not going
to stop
plates moving is something we have to
live with there's nothing we can do
about it it's going to happen they're
going to be big earthquakes in
California there's going to be a lot of
damage there's going to be loss of life
in recent years it seems as though
natural disasters powered by the
movement of the continents have been on
the rise but what we are witnessing is
an increase in awareness rather than an
increase in the number or severity of
natural disasters I think what we're
really seeing here is a very raised
consciousness of the public with instant
communication abilities much more
publicity is given to volcanic eruptions
and earthquakes we are observers to only
a very short period of the life of the
earth if we could monitor earthquakes
and volcanic activity caused by plate
movements over millions of years we
would see a very different picture when
you look at something over 10 years you
might have 10 major earthquakes the next
10 years you might not have any but
that's not significant it just is
related to the short period of time that
you're making the observation at when
you start looking at hundreds thousands
and millions of years all that averages
out it's impossible to predict exactly
when the next disaster will occur but it
is possible to predict where it will
happen the plate boundaries
map the location of earthquakes and
volcanoes and they line up with the
cracks between plates plot where these
plates will move over the next tens of
millions of years and the future looks
bleak for many of the world's cities
[Music]
so what will our world look like in the
future 50 million years from now the
Atlantic Ocean will widen pushing New
York further away from North Africa
meanwhile in the southern hemisphere
Australia will be on a collision course
with Southeast Asia and in Europe Africa
will head north closing the
Mediterranean Sea a new mountain range
will form where Italy and Greece once
stood known as the Mediterranean
Mountains they will be as big as the
Himalayas extending from Spain across
southern Europe through the Middle East
and into Asia 100 million years in the
future and the power of continental
movements will render the surface of the
earth unrecognizable the Atlantic Ocean
will continue to widen but a subduction
zone will form along its western
shoreline the first sign of it can be
seen today in the Caribbean the Puerto
Rico Trench this trench will grow north
and south along the east coast of North
and South America
this vast subduction zone will consume
the Atlantic Ocean drag in Europe and
Africa back toward the Americas
[Music]
250 million years in the future
intergalactic explorers returning to
their home planet will find a world very
different to the one in their records
there will no longer be seven continents
but one gigantic landmass containing
most of the land on earth they could
find it a barren frozen world the
explorers search for the remains of our
cities but when Europe and America
collide any cities along the coastlines
will be gradually destroyed the
geological future of New York is going
to be rather traumatic in the long term
a New York is going to be at the site of
a continental collision North America
and Europe are going to collide with one
another and produce a distinctive suite
of rocks which will eventually be
crumpled between the two continents as
they collide New York and its neighbors
will be crushed and buried beneath the
surface leaving no more than a few
remains in the future geologists will be
able to find remains of New York City
trapped in the rocks themselves either
buildings or plastic bottles or old
autos and their parts all of these
things will be incorporated into the
fossil record and will be recognizable
to a future geologist who knows what she
or he is looking for
because of its similarities to pass
supercontinents this future land mass is
called Pangaea Ultima the final Pangaea
nearly all the land masses in the world
will be joined together an Gaea Ultima
will probably experience climate
extremes freezing winters and scorching
summers this deadly weather could have
devastating effects on all life on Earth
the implications for the human race are
interesting to speculate about certainly
the disposition of the continents over
time will affect Earth's climate and
that will in turn have an influence on
which organisms survive which go extinct
and could be a factor in future mass
extinctions
the world we know is inching slowly
toward its own destruction the processes
that shape the surface of the earth are
never going to change we're going to
have earthquakes we're going to have
volcanoes we're going to have tsunamis
and hurricanes regardless of whether
humans inhabit the planet and so the
planet will always be here probably
plate tectonics will operate for the
foreseeable future or not but even
Pangaea Ultima might not be the end of
the story the forces that created it may
eventually rip it apart and start the
cycle of death and rebirth again but by
then the impact of colliding continents
could have been too much for our species
with our cities destroyed and the
climate severe we may have already left
our planet in search of a safer home
[Music]
you
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