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) 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)

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 (35 o F o F) [That’s almost freezing, to 4X hotter than boiling water!]  Extreme pressure (3500 lbs/ in 2 ) [That’s 240x the pressure we feel on the surface.]  Poison gases, heavy metals.  Absolutely no light.  Extreme temperatures (35 o F o F) [That’s almost freezing, to 4X hotter than boiling water!]  Extreme pressure (3500 lbs/ in 2 ) [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) 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) (Click here for video 5:24) 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) (Click here for video 5:24)