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This is the landscape
from a distant planet?
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Or from the surface of the Moon?
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No. These are background images
from the largest freshwater bank in the world,
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the Great Lakes
from North America.
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Scientists have mapped
these majestic lakes.
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Now, for the first time,
we will combine data
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and specialized computerized images
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to drain the Great Lakes.
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We will find out
an extraordinary hidden world,
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of enormous cliffs,
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where they may have lived
the first men.
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Lost Valleys
and submerged waterfalls.
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A possible catastrophic impact.
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Maybe even a glimpse
our own history,
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never seen, until now,
by draining the Great Lakes.
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DRAIN THE GREAT LAKES
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The Great Lakes have been nicknamed
inland oceans,
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freshwater seas.
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Your name describes
its grand size.
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Along its banks
we can observe wonders of nature
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and man-made skyscrapers.
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It is home to 34 million people
who live near its waters.
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But no one ever looked
to its depths
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how we will do it.
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Only now can we reveal
your secrets.
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We begin our exploration
on Lake Superior,
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largest of the Great Lakes,
the vastest,
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deeper,
and the most mysterious.
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Along the south coast
from Lake Superior
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is the coast of Pictured Rocks National,
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name that should be given
to the colorful cliffs
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that rise from the bottom of the lake.
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It is one of the most spectacular locations
of the Great Lakes.
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But it's not the setting that makes it
this important location,
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is what lies on the shore, at the bottom of the water,
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never seen before.
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Draining water from Lake Superior,
a mere 40 km from Pictured Rocks,
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what will we find?
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We can reveal, for the first time,
the hidden landscape
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from the deepest part
from the Great Lakes basins.
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400 m deep,
the height of the Empire State Building.
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No one has ever been here.
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No light comes
at this depth.
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It's a landscape
truly alien.
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Most people have the idea
that a lake is just a bathtub.
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I like to think it's a record.
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Record not only what is happening now,
like what happened in the past.
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It's a fingerprint.
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A record of the past read by
Nigel Wattrus,
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who has studied this area
extensively.
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These valleys are very big.
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It's such a contrast
with other parts of the lake
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that makes us think about the processes
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who developed this topography.
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The processes that originated these valleys,
in the deepest part of the Superior,
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occurred
when ice dominated the landscape.
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Twenty thousand years ago,
if we looked from space,
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we would see a huge sheet of ice
covering this part of the planet
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where the Great Lakes exist now.
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The ice would have been more than 1.5 km long
thick, in certain parts.
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He would have towered over cities
like Chicago or Toronto.
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For thousands of years,
this huge sheet of ice exerts pressure,
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shaping the landscape
and carving holes.
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When the ice starts to melt,
disappearing,
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these deep depressions fill up
with cold glacial water.
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The result? The formation
of today's Great Lakes.
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Fast forward to the present.
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We can uncover the evidence of the effect
of the glaciers in the Superior bed,
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just because it was studied
in great detail.
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Modern technology allows us to see
through the water column.
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Nigel Wattrus and his team
Great Lakes Observatory in Duluth
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they use side scan sonars
and multibeams,
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to map parts of Lake Superior.
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How sound travels easily
in the water
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is capable of drilling into parts
deepest lake in Lake Superior
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revealing its shape and size
with surprising details.
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The data collected by the multibeam
allow us to recreate
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the deepest part of the Superior,
in a realistic way.
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400 m deep,
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we can see how it formed.
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Ice has a role,
but acts mainly as a cover
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and it's the water that runs underneath
who will dig the canals.
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Water created
these huge hidden valleys
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which stretch for kilometers,
in the deepest part of Lake Superior.
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The weight of the glacier pressurizes
melted water.
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Sand and pieces of rock
in high pressure jets
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sculpt the rock, shaping
these long, deep valleys.
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By removing water
from Lake Superior,
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another anomaly appears.
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We were very excited
for seeing the rings.
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It was the first set of data
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which documented the presence
of rings in the eastern part of the lake.
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These rings
these are unusual characteristics.
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Superior is the only one of the Great Lakes
where they were found.
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The easiest way to think of them
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is to imagine that Paul Bunyan
took a donut and pressed it
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in the soft sediments of the lake.
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This donut would have
some 200 to 300 meters wide.
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The print would be
5 meters deep
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and the diameter of the ring
it would be between 10 and 30 meters.
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Therefore,
It's a considerable feature.
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We think these rings
are the result of water,
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who was once imprisoned
in these very fine-grained sediments,
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and will have been released
as a result
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perhaps of a catastrophic descent
at the lake water level.
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These rings,
forged by changing water levels,
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they were preserved in the Superior's bed
for thousands of years.
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Draining the Lakes, reveals
not just hidden mysteries
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but it is a window into the past.
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Further south, we came across one
most impressive features
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created by man in lakes.
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A huge suspension bridge crosses
the Straits of Mackinac,
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between Lake Huron and Lake Michigan.
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With more than eight kilometers,
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it is the longest bridge
from the Western Hemisphere.
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Once a year, on Labor Day,
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the public can cross it on foot
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and admire this feat of engineering.
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The spans of the bridge
they are tall and wide enough
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to allow safe passage
to cargo ships.
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Thousands of people enjoy it
the opportunity to cross it on foot.
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But few, if any,
knows what lies beneath the surface.
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If we drain the Straits of Mackinac,
what will we discover?
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What people can't see
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and the challenge for the bridge builders,
many years ago
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it is a deep channel that meanders
through the Straits of Mackinac.
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It is a 40 km long gorge
1000 m wide,
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that passes, in secret,
underneath the center of the bridge.
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As we go
the long hidden channel,
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how did you end up here?
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It will be proof that the Great Lakes
Didn't they always look the way they do today?
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What happened to create it
this extraordinary feature?
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The answer may lie in expeditions,
further south,
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on Lake Huron.
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Expeditions you will find
incredible tastings
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of submerged waterfalls, so big
like today's Niagara Falls.
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With them, more revelations
about the past of the Great Lakes.
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When draining the water
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from the Straits of Mackinac,
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between Lake Huron and Lake Michigan,
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we discovered a huge canyon
hidden under the bridge.
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How and when it formed is a mystery
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that we can solve
as we venture south,
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to the center of the Great Lakes basin,
on the tip of the Bruce Peninsula.
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It is located here
the town of Tobermory, Ontario.
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This area contains many clues
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for geological history
of the Great Lakes.
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High up on the surrounding cliffs,
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there is evidence that is more than 10 thousand years old,
incredibly high water levels.
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These marks of the ancient coast
they are easy to see.
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What is not visible
we can find it on the coast,
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hidden below the surface of the lake.
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The Tobermory region is unique,
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because there are a large number here
of characteristics in the bed
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who tell us the story of the lake,
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the story
of changes in water levels.
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Is it possible to find
much of the story
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of how the Great Lakes
were drained,
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through bed studies
here in the Tobermory region.
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The idea that the water level
varied strongly,
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excited some
from leading researchers.
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Opens a window to the past and
can give clues about the future.
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We have preliminary maps
from the lake bed
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and we're looking for proof
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that the lakes drained 50
meters below the present elevation.
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Nobody ever thought that the level
of the water of the Great Lakes
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had gone so low,
but we have already discovered that it is true.
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It started about 10 thousand years ago.
The climate was more arid
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and the water level dropped
due to evaporation
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and ended up being very low,
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so much so that Georgian Bay
it was an isolated basin.
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It has been almost impossible to find evidence
lower water levels
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since, all traces
has been hidden,
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under hundreds of meters of water,
for more than six millennia.
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Now, modern technology provides
a kind of mirror.
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The Canadian Hydrographic Service Boat
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it is equipped with multibeam technology.
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The most exciting thing for a geologist
It's being able to see something in three dimensions.
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We can walk there,
see all sides of the canal,
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see where the water went
on top of the cliffs.
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And then I can see the pool,
in the background.
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Using this new data,
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what will we see when draining the water
from the Bruce Peninsula.
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If we were here 7,500 years ago,
the water would all be drained,
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the cliffs would be exposed
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and we would have the river flowing
from north to south.
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Actually turned east
at this location and ran east,
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over the cliffs to form
the Dunks Point Waterfall.
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More mapping reveals
more channels
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and waterfalls, some of them
bigger than those of Niagara,
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existed off the Bruce Peninsula,
8 thousand years ago.
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It's the key proof. Now we know
that climate change
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affect the water level of lakes.
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For example, a change
of one meter has an impact on the economy.
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We can look to the past
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and use it as a key to the future
to help us understand
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what nature and humanity
they will do it at lake level
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and we can determine what we have
to do in the future to adapt.
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The level of the lakes was low
throughout the Great Lakes system.
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The lakes are interconnected,
what affects one, affects all.
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About seven to eight thousand years ago,
we would see each lake as a separate basin
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with few or no rivers between them.
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The gorge beneath the bridge
from the Straits of Mackinac
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formed when lake levels
they were much inferior.
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At that time, it was a narrow river
which united Lakes Huron and Michigan.
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The low levels
stayed long enough
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to cut and carve the lakebed,
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leaving behind
evidence of an ancient river channel.
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The geology of the Great Lakes
it's so recent
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that these events
may have occurred
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when humans already lived
in North America.
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There will be some proof of its existence
during low water levels?
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The answer may be
80 km southwest of Tobermory,
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in the middle of Lake Huron.
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Another impressive feature emerges
from the lake bed,
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when we drain the second largest
of the Great Lakes.
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The Alpine-Amberley Ridge,
extends along the entire lake.
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Seven to eight thousand years ago
it was dry land.
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It is a massive limestone outcrop
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that withstood the sheets of ice
and that exists deep down
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like an amazing cliff of rock
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that on the northeast side
falls hundreds of meters.
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With the exhibition of this natural bridge
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during the times when the first
Paleo-Americans roamed the continent,
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did they live and hunt here?
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After all this time,
could something submerged,
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still show signs of its presence?
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From a historical point of view,
is important not only for the locations,
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but also because they represent
an opportunity we never had,
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since these places remained the same
way that the hunters left,
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like Pompeii submerged.
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Using an ROV,
a remotely operated vehicle,
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John O'Shea and his team
University of Michigan
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00:16:34,240 --> 00:16:37,200
have been looking for the lake bed
looking for something you can recommend
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the human presence on the dorsal.
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So far, what we have found is
a series of stone buildings
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very similar to those made
by modern caribou hunters
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00:16:55,760 --> 00:16:57,200
of the Canadian Arctic.
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Taking into account John's research
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00:17:00,120 --> 00:17:02,400
we can build an image
from the top of the dorsal.
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Only by draining the lake can we see
the line in its entirety.
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These will be caribou lines,
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the hunting technique
which depends on the animals' habits
244
00:17:13,560 --> 00:17:15,800
follow linear patterns in the landscape?
245
00:17:16,880 --> 00:17:20,080
These will be stone buildings
such devices
246
00:17:20,280 --> 00:17:22,920
to help guide caribou
for hunting areas?
247
00:17:23,680 --> 00:17:27,400
So far, John and his team
are limited to ROV research.
248
00:17:29,600 --> 00:17:34,880
To succeed and prove
that we have archaeological sites,
249
00:17:34,960 --> 00:17:37,200
prove that we have artifacts,
there is nothing to do
250
00:17:37,360 --> 00:17:40,520
in addition to placing divers
with in-bed archaeological training
251
00:17:40,840 --> 00:17:43,200
to do
this investigation methodically.
252
00:17:44,120 --> 00:17:45,680
John gets his wish.
253
00:17:49,680 --> 00:17:53,640
Divers descend into the water
of Lake Huron to explore its bed.
254
00:17:54,560 --> 00:17:58,160
They could be the first
on the Alpina-Amberley Ridge
255
00:17:58,400 --> 00:18:00,400
in more than seven thousand years?
256
00:18:06,080 --> 00:18:07,880
By draining Lake Huron,
257
00:18:08,040 --> 00:18:10,400
the extraordinary Alpina-Amberley ridge
258
00:18:10,560 --> 00:18:12,400
rises in the middle of the lake.
259
00:18:12,760 --> 00:18:17,360
Seven to eight thousand years ago
this imposing cliff was dry land.
260
00:18:17,960 --> 00:18:20,960
An archaeological team believes
have discovered
261
00:18:21,160 --> 00:18:24,520
evidence of early humans
living and hunting in this mountain range.
262
00:18:25,280 --> 00:18:28,680
Draining the water,
we see rock formations
263
00:18:28,840 --> 00:18:32,040
which may have been placed by man
to hunt caribou.
264
00:18:34,480 --> 00:18:37,480
A new expedition hopes to clarify
the situation.
265
00:18:37,640 --> 00:18:41,400
This is the first day we go
do research diving
266
00:18:41,560 --> 00:18:43,040
on these caribou dive routes.
267
00:18:43,320 --> 00:18:48,520
It's exciting for us,
because everything we see today,
268
00:18:48,680 --> 00:18:50,680
even on the first dive,
it will be new.
269
00:18:54,360 --> 00:18:58,360
To be honest, the Holy Grail
is the simplest splinter,
270
00:18:58,520 --> 00:19:00,920
the simplest piece
of broken rock,
271
00:19:01,080 --> 00:19:04,920
that confirms with certainty that
this site has been occupied by humans.
272
00:19:11,600 --> 00:19:14,560
Fifty miles in the middle of Lake Huron,
273
00:19:15,000 --> 00:19:18,440
divers descend for the first time
in this part of the dorsal.
274
00:19:19,000 --> 00:19:22,720
They could be the first humans here
in more than seven thousand years.
275
00:19:34,640 --> 00:19:36,920
Divers begin
documenting and studying
276
00:19:37,080 --> 00:19:38,800
this unique underwater landscape.
277
00:19:47,200 --> 00:19:51,680
Any handful that withdraw
may have essential material.
278
00:19:51,840 --> 00:19:54,680
All of this is full of potential.
279
00:19:55,360 --> 00:19:59,760
We see it here from the video
and we say, "I want to see that!"
280
00:20:04,760 --> 00:20:07,560
Divers have access
45 minutes deep
281
00:20:07,720 --> 00:20:10,480
to gather as much evidence as possible.
282
00:20:11,000 --> 00:20:12,440
Here comes the basket.
283
00:20:13,520 --> 00:20:15,480
The expedition proves fruitful.
284
00:20:15,800 --> 00:20:19,080
There are countless samples
for the team to analyze.
285
00:20:21,040 --> 00:20:24,720
A small uncut stone,
offers immediate hope.
286
00:20:25,080 --> 00:20:26,960
It definitely looks like a bulb.
287
00:20:27,480 --> 00:20:30,400
This could be a splinter.
288
00:20:30,560 --> 00:20:34,200
This size
could be a splinter from a biface,
289
00:20:34,360 --> 00:20:37,800
a tertiary splinter
in which the edges change,
290
00:20:37,960 --> 00:20:40,120
what is smoothed and what can be done
291
00:20:40,280 --> 00:20:42,280
when changing
a tool.
292
00:20:42,440 --> 00:20:46,320
And that's why it's so small.
293
00:20:47,480 --> 00:20:50,200
Remember what I said in the piece
smaller and simpler?
294
00:20:51,080 --> 00:20:55,080
This may be the smallest piece
and simpler, but we'll take it.
295
00:20:56,320 --> 00:20:58,480
Maybe necessary
many more expeditions
296
00:20:58,640 --> 00:21:01,280
and detailed explorations
from the dorsal surface
297
00:21:01,440 --> 00:21:04,560
before the truth about
human presence can be confirmed.
298
00:21:05,200 --> 00:21:07,480
But the lake bed
is giving up some secrets.
299
00:21:07,920 --> 00:21:11,640
Evidence of low water levels
thousands of years ago
300
00:21:12,000 --> 00:21:15,040
are being revealed,
as we drain the lakes.
301
00:21:20,760 --> 00:21:25,280
Farther south, water flows from the Huron
to the shallowest of the great lakes,
302
00:21:25,560 --> 00:21:26,840
Lake Erie.
303
00:21:27,320 --> 00:21:31,280
On the north bank,
we see a geological wonder.
304
00:21:32,280 --> 00:21:37,120
A land formation that stretches
more than 40 km into the lake.
305
00:21:37,920 --> 00:21:40,360
It is made exclusively of sand.
306
00:21:40,800 --> 00:21:44,680
A secondary product of erosion
from glacial ice on rock.
307
00:21:45,280 --> 00:21:48,760
This is Long Point.
308
00:21:49,720 --> 00:21:54,640
In the context of the Great Lakes,
Long Point is almost unique.
309
00:21:54,920 --> 00:21:58,280
It is not unique in the processes
who formed it,
310
00:21:58,480 --> 00:22:02,920
it is unique in size
and the dimension of what is happening.
311
00:22:04,480 --> 00:22:05,840
What's going on?
312
00:22:06,120 --> 00:22:08,760
Simply put,
this colossal sand structure
313
00:22:09,040 --> 00:22:13,640
is being created in Lake Erie
at high geological speed.
314
00:22:14,840 --> 00:22:19,040
5 thousand years ago, probably
we were on top of the water,
315
00:22:19,200 --> 00:22:21,920
Why Long Point
did not exist at the time.
316
00:22:23,640 --> 00:22:27,160
Long Point formed
in the deepest basin of Lake Erie
317
00:22:27,320 --> 00:22:29,400
at a depth of 65 meters.
318
00:22:31,040 --> 00:22:34,280
Therefore, it took a quantity
huge amount of sand to form it
319
00:22:34,440 --> 00:22:35,800
up to the surface.
320
00:22:36,120 --> 00:22:38,040
Troy Holcombe led the team
321
00:22:38,240 --> 00:22:40,840
who created the first bathymetric map
detailed,
322
00:22:41,000 --> 00:22:43,320
representing the depth of the water
from Lake Erie,
323
00:22:43,480 --> 00:22:44,840
when you worked with JOAN,
324
00:22:45,000 --> 00:22:47,840
the Oceanic Administration
and National Atmospheric.
325
00:22:49,120 --> 00:22:52,280
This is the data used
to drain Lake Erie.
326
00:23:04,880 --> 00:23:09,120
As the water level drops,
we see two huge sand ridges
327
00:23:09,480 --> 00:23:12,720
the Long Point Escarpment
and the Clear Creek Range,
328
00:23:12,880 --> 00:23:14,920
hidden from view,
until now.
329
00:23:15,400 --> 00:23:19,080
Both sand ridges cross,
almost completely, the lake.
330
00:23:21,880 --> 00:23:25,920
Just 20 km west of Long Point,
are these sand canyons,
331
00:23:26,080 --> 00:23:29,400
deposited by receding waters
after the glaciers melt.
332
00:23:29,960 --> 00:23:32,240
These cliffs feed into Long Point
333
00:23:32,400 --> 00:23:35,160
and probably
helped build the mountain ranges.
334
00:23:35,440 --> 00:23:37,640
A sand redistribution process
335
00:23:37,840 --> 00:23:40,640
which has been unfolding since
the glaciers have disappeared,
336
00:23:40,840 --> 00:23:42,840
and continues to this day.
337
00:23:43,160 --> 00:23:47,880
Today we saw geological processes
in operation moving the sands,
338
00:23:48,080 --> 00:23:49,840
just as if we were there.
339
00:23:53,480 --> 00:23:56,040
This area is eroding
very quickly.
340
00:23:56,640 --> 00:23:59,240
We can see the mud, the sand in the water.
341
00:24:01,520 --> 00:24:05,000
The wind comes from the southwest, therefore,
the coast is carried by the wind,
342
00:24:05,200 --> 00:24:07,520
the sand will stay towards this one.
343
00:24:07,720 --> 00:24:12,040
Finally, it will arrive
at the tip of Long Point.
344
00:24:14,240 --> 00:24:18,400
Here we see the dynamics
of all sedimentation that occurs.
345
00:24:18,560 --> 00:24:20,760
And it's happening now, and fast.
346
00:24:25,960 --> 00:24:28,920
Downstream of Lake Erie,
there's a place
347
00:24:29,120 --> 00:24:31,760
where would it have happened
the most dramatic change of all,
348
00:24:31,920 --> 00:24:36,080
probably the largest land landmark
in the Great Lakes system.
349
00:24:48,000 --> 00:24:49,640
Niagara Falls.
350
00:24:50,200 --> 00:24:51,800
In a single minute,
351
00:24:52,320 --> 00:24:57,040
more than 135 million liters of water
352
00:24:57,200 --> 00:25:01,040
flow over the Niagara Gorge.
353
00:25:02,680 --> 00:25:04,960
All the water in the Great Lakes basin
354
00:25:05,120 --> 00:25:07,520
go through this narrow corridor.
355
00:25:10,760 --> 00:25:15,680
The strength of the water continually reduces
the canyon.
356
00:25:19,080 --> 00:25:23,240
Since the retreat of the glaciers,
the falls have advanced up the river,
357
00:25:23,440 --> 00:25:28,720
from Lake Ontario, closer
from Lake Erie, approximately 11.5 km,
358
00:25:29,240 --> 00:25:32,240
as the constant flow of water,
wears out
359
00:25:32,520 --> 00:25:34,800
carves and shapes the canyon.
360
00:25:37,680 --> 00:25:41,000
But during the times when men
they could have walked in the Alpine mountain range,
361
00:25:41,440 --> 00:25:44,440
and the falls existed
in the Tobermory area,
362
00:25:45,280 --> 00:25:47,960
Niagara's roar fell silent.
363
00:25:53,280 --> 00:25:58,240
Draining Niagara Falls just like
they were about 10 to 5 thousand years ago,
364
00:25:58,960 --> 00:26:00,600
this is what we would see.
365
00:26:02,880 --> 00:26:05,920
The raging Niagara River becomes
a trickle of water,
366
00:26:06,360 --> 00:26:08,760
and for several thousand years,
367
00:26:09,120 --> 00:26:10,920
the waterfalls dry up.
368
00:26:11,200 --> 00:26:13,920
With the lakes upstream transformed
in separate basins
369
00:26:14,120 --> 00:26:17,160
little water flows between Ontario and Erie.
370
00:26:18,040 --> 00:26:21,240
Niagara was not that powerful.
371
00:26:26,600 --> 00:26:29,520
Downstream of the falls
is Lake Ontario.
372
00:26:29,960 --> 00:26:33,080
Drain this lake,
reveals impressive clues
373
00:26:33,240 --> 00:26:36,640
from a turbulent past
and an uncertain future.
374
00:26:41,560 --> 00:26:46,720
Five thousand years ago,
water begins to rise in the Great Lakes.
375
00:26:47,200 --> 00:26:50,680
A tropical air mass settles in
over the Great Lakes basin
376
00:26:51,000 --> 00:26:54,400
and precipitation fills the lakes
up to current levels.
377
00:26:54,560 --> 00:26:58,480
Niagara begins to flow.
Long Point begins to form.
378
00:26:59,000 --> 00:27:03,640
And on Lake Ontario, something out of the ordinary
it's happening on the lake bed.
379
00:27:07,000 --> 00:27:10,440
Toronto is the largest Canadian city
in the Great Lakes.
380
00:27:10,800 --> 00:27:12,880
Two and a half million people live
and work
381
00:27:13,040 --> 00:27:14,800
near the shores of Lake Ontario.
382
00:27:15,360 --> 00:27:18,440
It's a well-known city
due to its geological stability.
383
00:27:21,400 --> 00:27:24,160
But not too far
the imposing silhouette of the city,
384
00:27:24,840 --> 00:27:27,320
something dramatic is happening.
385
00:27:34,200 --> 00:27:38,960
Long gorges full of fractures
crisscross the bottom of the lake.
386
00:27:44,640 --> 00:27:48,960
What happened is that
North America is under pressure.
387
00:27:49,400 --> 00:27:52,360
They believe that the northeastern area,
like Greenland,
388
00:27:52,520 --> 00:27:54,000
is moving southwest,
389
00:27:54,160 --> 00:27:57,480
and the California area
to the northeast?
390
00:27:57,720 --> 00:28:00,480
So this puts the region
of the Great Lakes under pressure.
391
00:28:01,520 --> 00:28:05,520
And what happens with this pressure?
is that the earth rises.
392
00:28:06,520 --> 00:28:09,880
These elevations have a simple name,
pop-ups.
393
00:28:10,720 --> 00:28:14,400
The elevations are the demonstration
of the fact that earthquakes
394
00:28:14,560 --> 00:28:17,520
occur in this region
and will continue to occur.
395
00:28:18,880 --> 00:28:22,320
Normally, we do not associate the region
from Great Lakes to earthquakes.
396
00:28:22,680 --> 00:28:25,680
But the lake bed shows signs
that seismic activity
397
00:28:25,840 --> 00:28:27,840
maybe more frequent
than we think.
398
00:28:28,640 --> 00:28:30,920
It was just
with the appearance of the multibeam
399
00:28:31,120 --> 00:28:36,520
that we can understand
this network of fissures and fractures
400
00:28:36,800 --> 00:28:39,560
that have appeared
in the depths of the bedrock.
401
00:28:41,680 --> 00:28:44,640
Those big tergos
that look like characteristics
402
00:28:44,800 --> 00:28:46,720
are tectonic elevations.
403
00:28:47,600 --> 00:28:50,480
These are compression fractures
on the rock.
404
00:28:51,120 --> 00:28:55,040
Like this sheet.
The limestone compressed.
405
00:28:55,440 --> 00:28:59,040
We started pushing her
in both directions
406
00:28:59,200 --> 00:29:01,840
and folds in the middle.
407
00:29:02,000 --> 00:29:04,680
This is how a rise is formed.
408
00:29:05,320 --> 00:29:10,720
It shows us that the bed is not stable
geologically as we thought.
409
00:29:12,520 --> 00:29:14,800
With detailed data
of the multibeam,
410
00:29:14,960 --> 00:29:17,920
let's drain Lake Ontario
near Toronto Harbor
411
00:29:18,680 --> 00:29:21,640
and see, ourselves,
what lies on the lake bed.
412
00:29:31,640 --> 00:29:34,880
The number of linked pop-ups
it's surprising.
413
00:29:35,520 --> 00:29:40,240
They are one to three meters tall,
a width of five to ten meters,
414
00:29:40,600 --> 00:29:43,480
and extend for several kilometers.
415
00:29:44,080 --> 00:29:46,800
Nobody knows for sure
your age.
416
00:29:47,920 --> 00:29:50,560
But with this evidence of seismic activity,
417
00:29:50,920 --> 00:29:54,120
what the future holds
to this part of the Great Lakes.
418
00:29:54,520 --> 00:29:58,000
In the history of southern Ontario we have
low intensity earthquakes.
419
00:29:58,160 --> 00:30:00,200
We have a lot of small earthquakes.
420
00:30:00,520 --> 00:30:05,920
If there will be a big one in the future
What do we have to take into account?
421
00:30:06,280 --> 00:30:09,120
We don't think so,
but this research is accurate
422
00:30:09,280 --> 00:30:12,200
to ensure we build
strong structures to withstand
423
00:30:12,360 --> 00:30:15,520
the biggest earthquake
424
00:30:15,680 --> 00:30:18,320
or the greatest strength
that these structures will feel.
425
00:30:19,360 --> 00:30:22,760
Draining Lake Ontario doesn't just reveal
a possible future,
426
00:30:23,280 --> 00:30:25,880
also gives us a glimpse
from a turbulent past.
427
00:30:26,560 --> 00:30:30,200
In the easternmost part of the lake,
near the exit to the St. Lawrence River,
428
00:30:30,560 --> 00:30:34,280
a strange and mysterious formation lies
below the surface.
429
00:30:37,600 --> 00:30:41,480
This is Charity Shoal,
about 20 km from the coast,
430
00:30:41,720 --> 00:30:43,920
right on the border
between the USA and Canada.
431
00:30:46,920 --> 00:30:50,280
It's a shallow elevation,
with a lighthouse to keep ships away
432
00:30:50,440 --> 00:30:52,120
from its dangerous shallows.
433
00:30:53,640 --> 00:30:56,440
Recent depth surveys
reveal a circular anomaly.
434
00:30:56,800 --> 00:30:58,440
Its origin is a mystery.
435
00:31:00,760 --> 00:31:05,080
Today, Charity Shoal will be analyzed
with a multibeam, for the first time.
436
00:31:07,200 --> 00:31:09,840
As the boat moves
437
00:31:10,040 --> 00:31:12,040
the formation begins to reveal itself.
438
00:31:13,800 --> 00:31:16,000
Something like a crater
is revealed.
439
00:31:17,840 --> 00:31:20,920
But what is a crater doing
in the Great Lakes?
440
00:31:23,240 --> 00:31:26,120
Troy Holcombe, University of Texas,
441
00:31:26,280 --> 00:31:28,520
has been interested in this training
for years.
442
00:31:28,920 --> 00:31:32,200
Now he wants to solve the mystery
from Charity Shoal.
443
00:31:35,680 --> 00:31:40,200
From what we saw, Charity Shoal
It's a very old feature
444
00:31:40,360 --> 00:31:43,480
which was excavated again
by glacial erosion.
445
00:31:44,720 --> 00:31:49,280
It's still possible
that it is an impact crater,
446
00:31:49,720 --> 00:31:54,960
an extraterrestrial impact,
but still awaiting confirmation.
447
00:31:59,280 --> 00:32:01,600
It's absolutely incredible.
448
00:32:03,280 --> 00:32:05,800
We were able to gain insight
your size.
449
00:32:11,040 --> 00:32:14,320
The Barringer Crater
seems to be frozen in time
450
00:32:14,480 --> 00:32:17,040
looks the same
50 thousand years ago,
451
00:32:17,280 --> 00:32:21,520
when a meteorite, traveling
more than 40 thousand km per hour,
452
00:32:21,680 --> 00:32:23,160
hit the Earth.
453
00:32:24,040 --> 00:32:26,760
Will have Charity Shoal
have you ever looked like this?
454
00:32:32,520 --> 00:32:36,320
I think it's important to compare
with Charity Shoal crater,
455
00:32:36,520 --> 00:32:41,040
because craters formed in
stratified sedimentary rocks
456
00:32:42,560 --> 00:32:45,240
and both craters
are the same size.
457
00:32:47,880 --> 00:32:53,080
At Charity Shoal, we see tergos that
they look like the exposed tops of rocks
458
00:32:53,240 --> 00:32:58,400
on the surface, just like here,
but eroded, in the case of Charity Shoal.
459
00:32:59,160 --> 00:33:03,920
Both craters are almost
round and have a continuous edge.
460
00:33:04,840 --> 00:33:09,160
Both are 1.2 km in diameter.
461
00:33:09,320 --> 00:33:12,840
It is an important feature,
because it means that both,
462
00:33:13,000 --> 00:33:16,680
if that Charity Shoal
It's an impact crater,
463
00:33:16,840 --> 00:33:21,880
means that both
will have experienced the same projectile
464
00:33:22,040 --> 00:33:25,600
and an explosion of the same size.
465
00:33:27,280 --> 00:33:28,720
As in Barringer Crater,
466
00:33:28,880 --> 00:33:31,440
a meteorite 50 m in diameter,
467
00:33:31,760 --> 00:33:35,240
may have fallen into primordial Ontario.
468
00:33:35,560 --> 00:33:38,120
A 10 to 20 megaton explosion
469
00:33:38,360 --> 00:33:40,400
may have originated Charity Shoal.
470
00:33:44,000 --> 00:33:47,440
By draining Charity Shoal,
we see the similarities.
471
00:33:47,920 --> 00:33:50,520
But it passed, at least
through 4 glaciations,
472
00:33:50,840 --> 00:33:53,480
and was submerged
for thousands of years.
473
00:33:54,760 --> 00:33:56,840
It is a mere shadow of what it was.
474
00:34:00,000 --> 00:34:02,840
But perhaps, millions of years ago,
475
00:34:03,320 --> 00:34:05,760
positioned on the edge of Charity Shoal,
476
00:34:06,680 --> 00:34:08,400
looked like that.
477
00:34:13,480 --> 00:34:16,240
The impact of a meteorite
not the only dramatic event
478
00:34:16,400 --> 00:34:18,120
affecting the lake region.
479
00:34:18,520 --> 00:34:21,240
Violent storms
they shelter these inland seas,
480
00:34:21,560 --> 00:34:23,640
sending ships into the depths.
481
00:34:23,960 --> 00:34:27,520
We reveal some of the evidence
most dramatic of Nature's fury
482
00:34:28,120 --> 00:34:31,000
by draining the Great Lakes.
483
00:34:33,440 --> 00:34:35,240
By draining the Great Lakes,
484
00:34:35,400 --> 00:34:37,680
part of our own story
will be revealed,
485
00:34:37,840 --> 00:34:39,360
scattered at the bottom of the lakes.
486
00:34:40,640 --> 00:34:41,960
Ship wreckage
487
00:34:42,120 --> 00:34:46,000
about 6 thousand, spread out
across the five Great Lakes.
488
00:34:46,520 --> 00:34:49,680
Relics of metal and wood,
hidden below the surface of the water,
489
00:34:50,200 --> 00:34:53,000
that we can see now,
in all its glory.
490
00:34:53,640 --> 00:34:55,800
Some are still majestic and upright.
491
00:34:56,120 --> 00:34:58,560
Others, torn and twisted.
492
00:34:59,360 --> 00:35:02,320
The wreckage of the ships is from the visions
more impressive to behold,
493
00:35:02,640 --> 00:35:04,480
when we drained the Great Lakes.
494
00:35:06,480 --> 00:35:08,600
A large number of shipwrecks
in the Great Lakes
495
00:35:08,760 --> 00:35:11,640
shows the number of navigations
what was done.
496
00:35:12,600 --> 00:35:16,800
Therefore, for hundreds of
years, there was intense navigation
497
00:35:16,960 --> 00:35:21,000
in the Great Lakes, at the end of the century. XVIII,
19th and early 20th centuries,
498
00:35:21,160 --> 00:35:23,720
when this was the sea route
busiest on Earth.
499
00:35:25,600 --> 00:35:29,520
Russ Green works at the Marine Sanctuary
Thunder Bay National,
500
00:35:29,680 --> 00:35:31,320
on the shores of Lake Huron.
501
00:35:31,800 --> 00:35:34,000
Here, as in many other areas
of the Great Lakes,
502
00:35:34,160 --> 00:35:36,520
numerous wrecks populate
the bottom of the lakes.
503
00:35:40,520 --> 00:35:42,120
Lagos is a wrong name.
504
00:35:42,280 --> 00:35:44,720
It is the largest freshwater reservoir
on Earth.
505
00:35:44,960 --> 00:35:46,280
They're huge.
506
00:35:47,520 --> 00:35:51,360
They are treacherous and harsh places
to be on a 40 meter schooner
507
00:35:51,520 --> 00:35:54,960
in the 1870s in November,
with the constant rain,
508
00:35:55,120 --> 00:35:56,880
the ice covering the equipment.
509
00:35:57,160 --> 00:35:58,880
These are dangerous places to navigate.
510
00:35:59,720 --> 00:36:03,360
Fires, storms, fog,
shoals, human errors,
511
00:36:03,520 --> 00:36:07,840
no radars, no GPS,
Lots of collisions here in Thunder Bay.
512
00:36:10,120 --> 00:36:12,680
All these things contributed,
the quantity and dangers
513
00:36:12,840 --> 00:36:15,440
contributed
for the countless shipwrecks.
514
00:36:21,120 --> 00:36:24,720
The northeastern sector of Lake Michigan,
the Manitou Pass,
515
00:36:25,000 --> 00:36:27,200
it's a stunning area above the water,
516
00:36:27,520 --> 00:36:30,680
with the sand canyons
from the dunes of Sleeping Bear National,
517
00:36:30,840 --> 00:36:34,080
to rise above the passage that
It was once an important trade route.
518
00:36:38,920 --> 00:36:41,920
But underwater,
things are changing quickly
519
00:36:42,080 --> 00:36:43,880
with the massacre of bivalve molluscs.
520
00:36:47,800 --> 00:36:49,640
Divers prepare
to dive the wreck
521
00:36:49,840 --> 00:36:51,800
off the coast
from South Manitou Island.
522
00:36:52,600 --> 00:36:54,560
The wreckage is calledThe Three Brothers
523
00:36:54,920 --> 00:36:58,640
famous for being buried in sand,
for most of the last century,
524
00:36:59,080 --> 00:37:03,560
until a decade ago, when the sands
in movement they revealed it again.
525
00:37:04,200 --> 00:37:07,080
Unfortunately, the ship is now
a shocking example
526
00:37:07,480 --> 00:37:09,360
the real impact of shellfish.
527
00:37:14,200 --> 00:37:17,040
A species of algae,
known as Cladophora,
528
00:37:17,200 --> 00:37:19,200
is growing at a phenomenal rate.
529
00:37:19,560 --> 00:37:21,640
Tailor-made
that molluscs clarify the water,
530
00:37:21,800 --> 00:37:24,440
sunlight penetrates,
deeper and deeper into the lake
531
00:37:24,760 --> 00:37:27,240
resulting in explosive growth
from algae.
532
00:37:28,040 --> 00:37:29,680
This Cladophora is dying
533
00:37:29,840 --> 00:37:32,760
and to pile up into a thick mass,
decomposing, near the wreckage.
534
00:37:33,400 --> 00:37:37,800
Dead algae release deadly toxins
for the fish and birds.
535
00:37:41,560 --> 00:37:46,320
Here, at Manitou Pass,
an environmental disaster is on the way.
536
00:37:47,840 --> 00:37:52,440
It looks like there is a thick layer
of mussel shells
537
00:37:52,600 --> 00:37:54,080
around the hull.
538
00:37:54,240 --> 00:37:57,920
And here is the dead cladophora
and rotten.
539
00:37:59,120 --> 00:38:00,280
AND...
540
00:38:01,640 --> 00:38:03,280
Damn! What a huge amount!
541
00:38:03,680 --> 00:38:08,680
I think cladophora
It's dead deep inside.
542
00:38:08,840 --> 00:38:12,120
The existing quantity is enormous
543
00:38:12,280 --> 00:38:16,720
and see how he got involved in the ship.
544
00:38:16,880 --> 00:38:21,120
It took the help of the waves, but
as there are recently dead fish,
545
00:38:21,280 --> 00:38:24,440
means it has to be active
in decomposition
546
00:38:24,600 --> 00:38:26,840
and in production
of botulism toxin.
547
00:38:29,480 --> 00:38:32,120
The first thing I think about is where
is that more of this will be happening.
548
00:38:32,280 --> 00:38:35,000
As far as I know,
I don't know other places on the lakes,
549
00:38:35,160 --> 00:38:39,560
but I suppose if it happens here,
it has to happen elsewhere.
550
00:38:42,760 --> 00:38:46,000
A mapping campaign
initiated by the National Park Service,
551
00:38:46,160 --> 00:38:50,240
at Sleeping Bear Dunes, and the program
Great Lakes Water Study
552
00:38:50,440 --> 00:38:53,840
from Northwest Michigan University,
is using multibeam,
553
00:38:54,000 --> 00:38:57,120
to help you understand better
this ecological problem
554
00:38:57,320 --> 00:38:59,320
that is affecting
this part of Lake Michigan.
555
00:39:00,200 --> 00:39:02,880
We hope to find these zones
of large cliffs and sites
556
00:39:03,040 --> 00:39:07,000
where the bathymetry
changes very quickly
557
00:39:07,200 --> 00:39:10,600
and we hope to find these zones
of depression near the coast
558
00:39:10,840 --> 00:39:13,480
where we suspect
that algae is accumulating.
559
00:39:16,000 --> 00:39:17,600
We are advancing the system
560
00:39:17,800 --> 00:39:19,800
to the Cladophora cemetery,
as we call it.
561
00:39:20,720 --> 00:39:22,320
The Cladophora Cemetery,
562
00:39:22,800 --> 00:39:25,600
the name given to the zone
around the Three Brothers.
563
00:39:26,600 --> 00:39:30,440
They hope the multibeam can provide clues
let them explain why it's happening.
564
00:39:31,520 --> 00:39:33,680
There it is!
565
00:39:43,040 --> 00:39:46,040
After several passes,
the multibeam clearly shows
566
00:39:46,200 --> 00:39:48,960
and the great depression that is at its origin
this ecological problem.
567
00:39:49,600 --> 00:39:52,360
The wreckage of the ship is lying
on top of this sand depression.
568
00:39:52,880 --> 00:39:54,880
Due to this geological characteristic,
569
00:39:55,080 --> 00:39:58,120
algae are captured
and decomposes in this zone.
570
00:40:01,640 --> 00:40:03,800
Draining the Manitou Pass,
571
00:40:04,200 --> 00:40:07,000
how many more areas are like this
on Lake Michigan
572
00:40:07,320 --> 00:40:08,840
and the other Great Lakes?
573
00:40:09,560 --> 00:40:13,440
This will be the first stage of the end
of the Great Lakes as we know them?
574
00:40:14,680 --> 00:40:16,960
I think our lakes
they will never disappear.
575
00:40:17,120 --> 00:40:21,880
We have existed for thousands of years
and many thousands more will come.
576
00:40:22,040 --> 00:40:24,320
Our ecosystem
is going through a great challenge.
577
00:40:25,200 --> 00:40:28,640
The changes that occurred in the
The last 20, 30 years have been dramatic.
578
00:40:29,120 --> 00:40:30,720
The lakes are strong enough.
579
00:40:30,880 --> 00:40:32,480
But what is the new ecosystem like?
580
00:40:32,640 --> 00:40:36,040
How will it evolve and what is it like?
How are we going to interact with him?
581
00:40:38,160 --> 00:40:40,480
There are many legendary stories
over the Great Lakes,
582
00:40:41,400 --> 00:40:44,760
but none so captivating
as the most iconic of them all,
583
00:40:45,240 --> 00:40:47,600
the sinking of the Edmund Fitzgerald.
584
00:40:52,400 --> 00:40:54,200
When we drained the Great Lakes,
585
00:40:54,480 --> 00:40:58,400
we discovered dramatic evidence
from a rich and diverse past.
586
00:40:58,560 --> 00:41:00,560
Both of natural origin
as a human.
587
00:41:06,080 --> 00:41:08,640
Geological mysteries hidden from view.
588
00:41:10,400 --> 00:41:13,280
These inland seas
they were the highway to the continent.
589
00:41:13,520 --> 00:41:16,960
The trail of debris, proof that
the lakes have always had control.
590
00:41:18,120 --> 00:41:21,720
In the biggest of them all, Lake Superior,
more than anywhere else.
591
00:41:21,960 --> 00:41:24,560
With the deepest waters
and the most powerful storms,
592
00:41:24,840 --> 00:41:27,200
it is a test of the most modern of ships.
593
00:41:28,680 --> 00:41:30,680
On the south shore, Whitefish Point
594
00:41:30,840 --> 00:41:33,200
is known
like the ship graveyard.
595
00:41:33,560 --> 00:41:38,760
One in particular, 27 km from the coast,
became a legend.
596
00:41:39,200 --> 00:41:42,280
Without a doubt
than the most iconic shipwreck
597
00:41:42,560 --> 00:41:44,880
of the 6 thousand that were in the lakes
598
00:41:45,080 --> 00:41:49,040
is the loss of Edmund Fitzgerald,
in 1975.
599
00:41:50,880 --> 00:41:55,960
The Edmund Fitzgerald, the largest ship
sunk in the Great Lakes.
600
00:41:57,000 --> 00:41:59,560
Draining water from Lake Superior,
601
00:41:59,960 --> 00:42:03,640
we can see this powerful ship
like it's never been seen before.
602
00:42:07,360 --> 00:42:09,840
It was the worst storm
in three decades
603
00:42:10,000 --> 00:42:11,520
that sank the Edmund Fitzgerald.
604
00:42:16,640 --> 00:42:20,720
It sank in 160 meters of water,
without a single request for help
605
00:42:21,360 --> 00:42:26,480
and took 29 men to the bottom
which continue on the ship to this day.
606
00:42:26,880 --> 00:42:30,440
Tom Farnquist knows the wreck well
by Edmund Fitzgerald.
607
00:42:31,040 --> 00:42:33,960
Leaded three expeditions
to the watery grave.
608
00:42:34,400 --> 00:42:37,520
You are one of the few people
who saw him.
609
00:42:42,960 --> 00:42:47,120
The exploration of Edmund Fitzgerald
revealed a very damaged ship,
610
00:42:47,280 --> 00:42:51,240
party to the may, the front section,
which is about 60 m long,
611
00:42:51,560 --> 00:42:54,000
It's almost out of balance.
612
00:42:54,600 --> 00:42:56,840
The stern was torn off
and fell backwards.
613
00:42:58,720 --> 00:43:00,920
Based on sonar data
side-scan
614
00:43:01,080 --> 00:43:04,560
these images show how
Edmund Fitzgerald lies,
615
00:43:04,760 --> 00:43:06,960
163 meters deep.
616
00:43:07,520 --> 00:43:09,920
The images reveal
the intensity of the storm
617
00:43:10,120 --> 00:43:11,760
and how fast it sank.
618
00:43:13,640 --> 00:43:16,880
If we drain Lake Superior,
we see the damage in the background
619
00:43:17,040 --> 00:43:18,560
caused by the impact of the ship.
620
00:43:20,440 --> 00:43:22,600
The rest of the lake bottom
looks like the lunar landscape,
621
00:43:22,760 --> 00:43:24,760
very smooth,
with a few holes here and there.
622
00:43:24,920 --> 00:43:26,280
But next to Edmund Fitzgerald,
623
00:43:26,440 --> 00:43:28,800
it almost seems
that a snowplow passed there
624
00:43:28,960 --> 00:43:33,080
and pushed the slime aside
of the Fitzgerald and trimmed the bottom.
625
00:43:34,520 --> 00:43:37,040
Maritime experts, naval architects
626
00:43:37,440 --> 00:43:40,960
suggest that Fitzgerald
It hit the bottom at 56 km/h.
627
00:43:41,760 --> 00:43:45,400
Eight meters below the silt, he hit
on the bed and began to fall apart.
628
00:43:47,360 --> 00:43:50,040
This mountain of steel
is in good condition
629
00:43:50,200 --> 00:43:53,720
and in some cases it even has paint,
It is visible and you can read the name.
630
00:43:54,680 --> 00:43:56,720
Therefore, this moment in the past,
is still well preserved
631
00:43:56,880 --> 00:43:58,400
by the cold water of Lake Superior.
632
00:44:00,000 --> 00:44:03,360
A few decades ago
that I see several shipwrecks,
633
00:44:03,520 --> 00:44:06,560
but there is nothing so overwhelming
and moving
634
00:44:06,720 --> 00:44:12,040
like Edmund Fitzgerald, for knowing
that 29 sailors sank.
635
00:44:13,720 --> 00:44:17,200
Remains the biggest
mystery of lake shipwrecks.
636
00:44:23,120 --> 00:44:25,200
Undisturbed and silent,
637
00:44:25,760 --> 00:44:30,120
Edmund Fitzgerald will haunt
Lake Superior for decades to come.
638
00:44:30,720 --> 00:44:33,160
A reminder of power
and grandeur
639
00:44:33,320 --> 00:44:35,920
the largest freshwater system on Earth.
640
00:44:36,960 --> 00:44:39,480
A system,
whose secret underwater world,
641
00:44:39,680 --> 00:44:44,720
is revealed for the first time,
by draining the Great Lakes.
642
00:44:59,520 --> 00:45:01,120
Translation and Subtitling
Rita Rocha