ZOMBIE-LIKE MICROBIAL LIFE LURKS BENEATH SEABED
TAMPA— Scientists have drilled 2.5 kilometers beneath the seabed and found vast underground forests of “deep life,” including microbes that persist for thousands, maybe millions of years, researchers said Monday.
Feeding on nothing but the energy from rocks, and existing in a slow-motion, even zombielike state, previously unknown forms of life are abundant beneath the Earth despite extreme temperatures and pressure.
About 70 percent of Earth’s bacteria and archaea—singlecell organisms with no nucleus—live underground, according to the latest findings of an international collaboration involving hundreds of experts, known as the Deep Carbon Observatory (DCO), released at the American Geophysical Union meeting in Washington.
This “deep life” amounts to between 15 and 23 billion tons of carbon, said the DCO, launched in 2009, as it nears the end of its 10-year mission to reveal Earth’s inner secrets.
“The deep biosphere of Earth is massive,” said Rick Colwell, who teaches astrobiology and oceanography at Oregon State University.
He described the team’s findings so far as a “very exciting, extreme ecosystem.”
Among them may be Earth’s hottest living creature, Geogemma barossii, a single-cell organism found in hydrothermal vents on the seafloor.
Its microscopic cells grow and replicate at 121ºC.
“There is genetic diversity of life below the surface that is at least equal to but perhaps exceeds that which is at the surface and we don’t know much about it,” Colwell said.
‘Distinct’ from surface life
Similar types of strange, deep life microbes might be found on the subsurface of other planets, like Mars.
“Most of deep life is very distinct from life on the surface,” said Fumio Inagaki of the Japan Agency for Marine-Earth Science and Technology.
Using the Japanese scientific vessel Chikyu, researchers drilled far beneath the seabed and removed cores that gave scientists a detailed look at deep life.
“The microbes are just sitting there and live for very, very long periods of time,” he said.