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Posted on 01/03/2003 9:00:10 AM PST by RightWhale
Research Finds Life 1000 Feet Beneath Ocean Floor
CORVALLIS, Ore. A new study has discovered an abundance of microbial life deep beneath the ocean floor in ancient basalt that forms part of the Earth's crust, in research that once more expands the realm of seemingly hostile or remote environments in which living organisms can apparently thrive.
The research was done off the coast of Oregon near a sea-floor spreading center on the Juan de Fuca Ridge, by scientists from Oregon State University and several other institutions. It will be published Friday in the journal Science.
In 3.5 million-year-old crust almost 1,000 feet beneath the bottom of the ocean, researchers found moderately hot water moving through the heavily-fractured basalt. The water was depleted in sulfate and greatly enriched with ammonium, suggesting biological activity in a high-pressure, undersea location far from the types of carbon or energy sources upon which most life on Earth is based.It was one of the most precise biological samplings ever taken from deep under the ocean floor, scientists say.
"This is one of the best views we've ever had of this difficult-to-reach location in the Earth's crust and the life forms that live in it," said Michael Rappe, a research associate at OSU. "Until now we knew practically nothing about the biology of areas such as this, but we found about the same amount of bacteria in that water as you might find in surrounding seawater in the ocean. It was abundant."
According to Steve Giovannoni, an OSU professor of microbiology and one of the co-authors of the publication, the work represented a highly complicated "plumbing job," among other things. It took advantage of an existing hole and pipe casing that had been drilled previously in that area by the Ocean Drilling Program, through about 825 feet of sedimentary deposits on the ocean floor and another 175 feet of basalt, or hardened lava about 3.5 million years old.
Using the existing casing, scientists were able to fit an experimental seal and deliver to the seafloor, for testing and characterization, the crustal fluids from far below. "People have wondered for a long time what types of organisms might live within Earth's crust," Giovannoni said. "This has given us one of the best looks we've ever had at that environment."
The researchers found organisms growing without the need to consume organic molecules, as does most life on Earth. Instead, they processed carbon dioxide and inorganic molecules such as sulfide or hydrogen. DNA analysis of these microbes suggested they are closely related to known sulfate and nitrate "reducers" that are common in other environments. The level of biological activity was sufficiently high that ammonia levels in the subsurface samples were 142 times higher than those in nearby seawater.
"As more research such as this is done, we'll probably continue to be surprised at just how far down we can find life within the Earth, and the many different environments under which it's able to exist," Rappe said.
The deep ocean crust, the researchers said, is an immense biosphere in its own right that covers most of the Earth.
Necessary for what? Apparently not for the formation nor the continuence of life. A large central mass should aid formation of a dense dustcloud and the formation of planets, but it needn't be a sun. Imagine that earth cut loose from the sun right now and set out for interstellar space, total dark, total cold. Would life cease to exist on earth? Correct. Life would not cease to exist on earth. Those microbes inside the rock of the crust would happily continue to churn out ammonium and eat sulfates forever or at least a few billion more years.
The sun, great to have if you have one. Not necessary.
Hence proof of your theory I respectfully submit...
Washington DC
Indeed it does even this late in the life of the Milky Way. There is still a lot of unburned hydrogen out there, which means we are still youthful in terms of the life of the universe. We have a long way to go from here, our place of birth, and we could, if we wanted, do it the rest of the way without the sun.
Sure. Our very own sun is expected to take this route as well, become a red giant and expand to such size as to eat the earth as the sun runs short of hydrogen. It won't supernova, though since it lacks the mass to do so. We ought to be thinking about moving to a better neighborhood. Otherwise, the sun is not particularly relevant anymore.
Radioactive decay is already the energy source keeping the earth's interior hot. I'm not sure what more heat would contribute.
We live in optimistic times.
We don't actually have that much time. Burnout isn't our destiny. The sun will continue to warm, and earth will continue to warm. It's going to get hot down here and a planet of Algores can't stop it.
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Feet are pairs. Foot is one.
Interesting but it could also be surface microbes that found their way into fractures and pores.
This has been one of my favorite threads for several years.
Shoes salesman.
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