hydrothermal vents I - intro

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The
Strange
World
of
Hydrothermal Vents
Before you learn what they are,
take a look at what they are.
This is what a hydrothermal vent looks like.
(Click here 2:49)http://www.youtube.com/watch?v=J_jubgEzG9A
In 1977, Dr. Robert Ballard led an expedition in search of the first
hydrothermal vent to be discovered. He found them. But that is only the
beginning of this historic journey.
ALVIN
First deep sea submersible.
Built by WHOI (Woods Hole Oceanographic Institute).
Our Vineyard neighbors!
ALVIN was launched that day in 1977 near the Galapagos Islands, along
a mid-ocean ridge, where scientists predicted they might find
deep-sea hydrothermal activity.
And they found it.
Chimneys spewing out what looked like black smoke.
The scientists called them “black smokers.”
These were underwater geysers, fueled by hot magma
chambers just below the mid-ocean ridge.
In some places, there are so-called “white smokers”, where the plumes
contain different minerals.
Conditions at the vents:
 Extreme temperatures (35oF - 750oF)
[That’s almost freezing, to 4X hotter than
boiling water!]
 Extreme pressure (3500 lbs/ in2) [That’s
240x the pressure we feel on the surface.]
 Poison gases, heavy metals.
 Absolutely no light.
It was an amazing discovery.
But more amazing than these
remarkable vents…
The place was teeming with
life…
Strange life…
Organisms never before seen by
humans.
Especially obvious were countless giant tubeworms, with bright red
heads, larger than any tubeworms observed before.
And with the tubeworms were clams, mussels, crabs, shrimp, even a type
of fish and a type of octopus.
But what were these things doing down there?
And huge amounts of them!
Robotic arms on ALVIN allowed them to collect samples and bring them
up to the research vessel. What they discovered next is still harder to
believe. These were not normal clams and tubeworms at all…
And when they dissected them, they smelled horribly – of
rotten eggs, and looked nothing like anything they’d seen
before…for they had no mouths, stomachs, or intestines.
So…how did they eat? WHAT did they eat?
Ironically, there were no bioligists on that famous trip in 1977,
only geologists.
Why?
Because no one ever expected to find anything living at those
depths, under such extreme conditions.
Truly, these organisms were “extremophiles”.
It took two more years until the next trip to the vents, and much help from
biologists, including Dr. Fred Grassle, to unravel the mystery of these
bizarre vent creatures.
The answer?
Once again,
the smallest,
but most abundant
creatures on Earth…
BACTERIA.
But these are not normal bacteria.
These bacteria were living off the
energy of the Earth, not the
energy of the Sun.
Closer inspection revealed that these bacteria
could take the chemical energy locked within
the hydrogen sulfide (the rotten egg smell),
and convert it to sugar - glucose.
Much as green plants do with sunlight,
through photosynthesis.
But without LIGHT.
In TOTAL DARKNESS.
(No chlorophyll either!)
A process previously unknown to
all of science, which we now
call…
CHEMOSYNTHESIS
Look at some more video of these vents.
(Click for video 2:00)
Since 1977, dozens of other hydrothermal vents
have been discovered at mid-ocean ridges around
the globe.
The discovery of hydrothermal vents at mid-ocean
ridges is considered one of the most important
scientific discoveries of the century.
They have entirely changed the way we look at life
on Earth. And beyond.
We shall soon learn how.
(Click here for video 5:24)
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