Skip to comments.Life in deep Earth totals 15 to 23 billion tons of carbon—hundreds of times more than humans
Posted on 12/10/2018 11:43:51 AM PST by ETL
Barely living "zombie" bacteria and other forms of life constitute an immense amount of carbon deep within Earth's subsurface245 to 385 times greater than the carbon mass of all humans on the surface, according to scientists nearing the end of a 10-year international collaboration to reveal Earth's innermost secrets.
On the eve of the American Geophysical Union's annual meeting, scientists with the Deep Carbon Observatory today reported several transformational discoveries, including how much and what kinds of life exist in the deep subsurface under the greatest extremes of pressure, temperature, and low nutrient availability.
Drilling 2.5 kilometers into the seafloor, and sampling microbes from continental mines and boreholes more than 5 km deep, scientists have used the results to construct models of the ecosystem deep within the planet.
With insights from now hundreds of sites under the continents and seas, they have approximated the size of the deep biosphere2 to 2.3 billion cubic km (almost twice the volume of all oceans) - as well as the carbon mass of deep life: 15 to 23 billion tonnes (an average of at least 7.5 tonnes of carbon per cu km subsurface).
The work also helps determine types of extraterrestrial environments that could support life.
Among many key discoveries and insights:
Ever-increasing accuracy and the declining cost of DNA sequencing, coupled with breakthroughs in deep ocean drilling technologies (pioneered on the Japanese scientific vessel Chikyu, designed to ultimately drill far beneath the seabed in some of the planet's most seismically-active regions) made it possible for researchers to take their first detailed look at the composition of the deep biosphere.
There are comparable efforts to drill ever deeper beneath continental environments, using sampling devices that maintain pressure to preserve microbial life (none thought to pose any threat or benefit to human health).
To estimate the total mass of Earth's subcontinental deep life, for example, scientists compiled data on cell concentration and microbial diversity from locations around the globe.
Led by Cara Magnabosco of the Flatiron Institute Center for Computational Biology, New York, and an international team of researchers, subsurface scientists factored in a suite of considerations, including global heat flow, surface temperature, depth and lithologythe physical characteristics of rocks in each locationto estimate that the continental subsurface hosts 2 to 6 × 10^29 cells.
Combined with estimates of subsurface life under the oceans, total global Deep Earth biomass is approximately 15 to 23 petagrams (15 to 23 billion tonnes) of carbon.
Says Mitch Sogin of the Marine Biological Laboratory Woods Hole, USA, co-chair of DCO's Deep Life community of more than 300 researchers in 34 countries: "Exploring the deep subsurface is akin to exploring the Amazon rainforest. There is life everywhere, and everywhere there's an awe-inspiring abundance of unexpected and unusual organisms.
"Molecular studies raise the likelihood that microbial dark matter is much more diverse than what we currently know it to be, and the deepest branching lineages challenge the three-domain concept introduced by Carl Woese in 1977. Perhaps we are approaching a nexus where the earliest possible branching patterns might be accessible through deep life investigation.
"Ten years ago, we knew far less about the physiologies of the bacteria and microbes that dominate the subsurface biosphere," says Karen Lloyd, University of Tennessee at Knoxville, USA. "Today, we know that, in many places, they invest most of their energy to simply maintaining their existence and little into growth, which is a fascinating way to live.
"Today too, we know that subsurface life is common. Ten years ago, we had sampled only a few sitesthe kinds of places we'd expect to find life. Now, thanks to ultra-deep sampling, we know we can find them pretty much everywhere, albeit the sampling has obviously reached only an infinitesimally tiny part of the deep biosphere."
"Our studies of deep biosphere microbes have produced much new knowledge, but also a realization and far greater appreciation of how much we have yet to learn about subsurface life," says Rick Colwell, Oregon State University, USA. "For example, scientists do not yet know all the ways in which deep subsurface life affects surface life and vice versa. And, for now, we can only marvel at the nature of the metabolisms that allow life to survive under the extremely impoverished and forbidding conditions for life in deep Earth."
Among the many remaining enigmas of deep life on Earth:
Movement: How does deep life spreadlaterally through cracks in rocks? Up, down? How can deep life be so similar in South Africa and Seattle, Washington? Did they have similar origins and were separated by plate tectonics, for example? Or do the communities themselves move? What roles do big geological events (such as plate tectonics, earthquakes; creation of large igneous provinces; meteoritic bombardments) play in deep life movements?
Origins: Did life start deep in Earth (either within the crust, near hydrothermal vents, or in subduction zones) then migrate up, toward the sun? Or did life start in a warm little surface pond and migrate down? How do subsurface microbial zombies reproduce, or live without dividing for millions to tens of millions of years?
Energy: Is methane, hydrogen, or natural radiation (from uranium and other elements) the most important energy source for deep life? Which sources of deep energy are most important in different settings? How do the absence of nutrients, and extreme temperatures and pressure, impact microbial distribution and diversity in the subsurface?
"Discoveries regarding the nature and extent of the deep microbial biosphere are among the crowning achievements of the Deep Carbon Observatory. Deep life researchers have opened our eyes to remarkable vistasemerging views of life that we never knew existed."says Robert Hazen, senior staff scientist, Geophysical Laboratory, Carnegie Institution for Science, and DCO Executive Director.
"They are not Christmas ornaments, but the tiny balls and tinsel of deep life look they could decorate a tree as well as Swarovski glass. Why would nature make deep life beautiful when there is no light, no mirrors?" says Jesse Ausubel of the Rockefeller University, a founder of the DCO.
Explore further: Microorganisms in the subsurface seabed on evolutionary standby
Provided by: Deep Carbon Observatory
Based upon what??? bacteria suddenly exposed to a relatively limitless supply of energy? They could be voracious little things.
Leftists look at that and think imagine the carbon taxes on that!
Makes me wonder if we should be drilling on asteroids and comets anytime soon.
There are clouds of methane in space, the atmospheres of the gas giants are primarily methane.
If they can live in such harsh environments the surface world could be a bonanza for them and a disaster for us.
Just the bacteria on the drill casings will be freed to the surface by the billions and we're unlikely to have any resistance to these new critters. Where's my tin foil hat dammit!
“DEEP HOT BIOSPHERE: The Myth of Fossil Fuel” By Thomas Gold... or not (he also suggested a “garbage theory” for the origin of life which was an accidental panspermia; the theory says that life on Earth might have spread from a pile of waste products accidentally dumped on Earth long ago by extraterrestrials.)
Deep microbes are often very different from their surface cousins, with life cycles on near-geologic timescales, dining in some cases on nothing more than energy from rocks
I remember Pat Boone was on an expedition to explore carbon residual or something deep inside the earth. I’m really hazy on the details of that adventure.
Petroleum oil and gas is absolutely NOT all derived from fossilized forests and dinosaurs.
Read Deep Hot Biosphere to learn why we are not running out of oil.
RE: “DEEP HOT BIOSPHERE: The Myth of Fossil Fuel By Thomas Gold”
Thanks for another fascinating post!
BTW, were you already familar with Cornell Dr. Thomas Gold book:
Deep Hot Biosphere?
He took so much harrassent from science community peers over his contention that oil & natural gas result from petro-hydrocarbons produced from deep subterrain microbes, and Not originating from ancient composed forests and animals.
Russian and Swede petro-geologists had long observed oil & nat gas deposits deep within massive solid granite domes that could have never hosted prehistoric forests and animal life.
Back in college several of the professors would comment on their belief (and science) that there were deep oil microbe sources, but they were on the fringes. IIRC they said it didn’t matter a whole lot with regard to exploration (that’s what my school taught) as it still needed to get trapped so we could get to it.
I recall a professional talk years after college where some guy proposed that these deep sources were on some sort of regular pattern across the globe - something like the dimples in a golf ball. Something to do with stresses and magnetic fields??? That seemed more like a quack theory, but who knows?
I worked for a company that was involved with drilling deep next to volcanic zones looking to extract deep oil-eating microbes for research into cleaning up oil spills and groundwater contamination.
While pretty cool stuff, I had visions of them growing these microbes, it getting out of control, and they end up eating all hydrocarbon materials (rubber hoses, etc.) I think the Andromeda Strain did that!?
The entire earth will need to be sequestered on Mars. But if that’s what it takes.....
Hmmm, sounds like the black oil from X-files.
If this time period was substantial, then there might have been an era in our universe's past where huge amounts of organic material spanned vast spaces between the planets.
As meteors and asteroids plummeted through this goo, then the goo would have gotten smeared on their surfaces and then ended up in planets as the rocks coalesced.
This is one version of the panspermia hypothesis. I think it is plausible. It also might make for a good premise for a SF novel if one could imagine intelligent beings alive during such an epoch.
He ultimately failed, but his failure did not prove there was no such oil. It might just have been somewhere else or deeper.
Even with this exploration we are barely scratching the surface.
Thank you for sharing and congratulations on that fascinating part of your career.
Doctor Thomas Gold hypothesized this 20 years ago...
The Deep Hot Biosphere: The Myth of Fossil Fuels
Thomas Gold, Author, F. Dyson, Foreword by Copernicus Books
The Deep Hot Biosphere: The Myth of Fossil Fuels
When scientists discovered thermophiles—primitive microorganisms that live in deep seafloor vents and eat hydrocarbons (chemicals like gasoline)—experts assumed the mysterious bugs had little to tell us about ourselves or about the earth’s core. Cornell University Professor Emeritus Gold, however, who for 20 years directed the Cornell Center for Radiophysics and Space Research, here proposes the striking theory that “”a full functioning... biosphere, feeding on hydrocarbons, exists deep within the earth, and that a primordial source of hydrocarbons lies even deeper.”” Most scientists think the oil we drill for comes from decomposed prehistoric plants. Gold believes it has been there since the earth’s formation, that it supports its own ecosystem far underground and that life there preceded life on the earth’s surface. The “”deep hot biosphere”” hypothesis would explain the thermophiles, the minerals and the oil Swedish drillers found in 1990 under rock where no one expected them. The hot goo and massed gas far under our feet would also explain some mysterious historical earthquakes (notably the New Madrid, Mo., shocker of 1811), and it would tell puzzled geologists why so many oil reserves just happen to sit underneath coal fields. As later chapters explain, if Gold is right, the planet’s oil reserves are far larger than policymakers expect, and earthquake-prediction procedures require a shakeup; moreover, astronomers hoping for extraterrestrial contacts might want to stop seeking life on other planets and inquire about life in them.
Reviewed on: 11/02/1998
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