NARRAGANSETT, R.I. – March 11, 2013 — The Deep Carbon Observatory, a decade-long $500 million research project to discover the quantity, movement, origin, and forms of carbon deep inside the Earth, has released a landmark 700-page book, Carbon in Earth, which outlines questions that will guide the program through 2019 and beyond.
The research program, which includes URI scientists Steven D’Hondt, Katherine Kelley and Dawn Cardace, is investigating the movement of deep carbon in the slow convection of the mantle, the percolating fluids of the crust, and the violent emissions from volcanoes. It is searching for the ancient origin of deep carbon and the formation and transformation of its many forms, ranging from gas and oil to diamonds and deep microbes.
The Deep Carbon Observatory is also making a significant commitment to an international engagement and communications effort, led by Sara Hickox and Sunshine Menezes at URI’s Office of Marine Programs and funded through a grant to the Graduate School of Oceanography from the Alfred P. Sloan Foundation.
The new book, details of the Observatory program, and a new website (www.deepcarbon.net) were announced on March 4 at the U.S. National Academy of Sciences in Washington, D.C.
Ninety percent or more of Earth’s carbon is thought to be locked away or in motion deep underground—a hidden dimension of the planet as poorly understood as it is profoundly important to life on the surface, according to scientists.
D’Hondt, a URI professor of oceanography, co-authored a chapter in the new book and is a member of the Observatory’s Deep Life Directorate, which is discovering and describing the microbes and viruses that live in the deep ocean and beneath the ocean floor and how they interact with deep carbon cycles.
The variety of bacterial life at extreme high-pressure depths worldwide constitutes a subterranean “Galapagos,” he said, adding that such subsurface life comprises a large portion of Earth’s total biomass. DNA has unearthed a marvel of diversity among deep single-celled microorganisms. And deep fungi, organisms with complex cell structures in the marine subsurface, have been a scientific surprise.
“Given the extraordinarily low rates of respiration, subsurface microbes must reproduce very slowly, if at all,” said D’Hondt. “They take at least hundreds to thousands of years to reproduce and it’s conceivable that they live without dividing for millions to tens of millions of years.” Still to be determined, he noted, is the extent to which these organisms are “microbial zombies, incapable of being revived to a normal state.”
Cardace is also working with the Deep Life Directorate. She has established a series of serpentinite groundwater monitoring wells in northern California that enable her to characterize the rock, water, gases, and microbiological communities and monitor any changes taking place.
“In many ways, Earth’s deep subsurface habitats are similar to those of the early Earth when the first cells were assembled,” said Cardace, assistant professor of geosciences. “Studying modern life in blocks of Earth’s mantle can inform our understanding of how life arose.”
Kelley is a member of the Observatory’s Reservoirs and Fluxes Directorate and is investigating the dissolved carbon dioxide in the lavas that form the Earth’s crust at mid-ocean ridges. An associate professor of oceanography, her project aims to figure out how much carbon is held in the Earth’s mantle, beneath the oceanic crust, and assess how much escapes to the oceans and atmosphere during submarine volcanic processes at these ridges.
“We are measuring the dissolved CO2 contents of rapidly-quenched natural volcanic glasses from global mid-ocean ridges, with the ultimate goal of making these measurements on the complete collection of more than 10,000 submarine glass samples in the Smithsonian collection,” she said. “But CO2 is actually very insoluble in liquid magma, so it is usually partially lost to degassing very deep in the crust, long before volcanoes erupt at the sea floor. We are hoping to find examples of lavas that have not degassed their CO2, but such samples are rare.”
The Deep Carbon Observatory is expected to create a profound new understanding of this planet and others, shedding unprecedented light on Earth’s highly active subterranean environment, the globe’s oldest ecosystem. It hopes to answer such questions as: How much carbon is stored inside Earth, what are the reservoirs of that carbon, how does carbon move among reservoirs, how much rising carbon is recycled from the surface, and did deep organic chemistry play a role in life’s origins?
“Of the 88 naturally occurring, long-lived elements on Earth, carbon stands alone,” said Robert Hazen, executive director of the Observatory. “No other element contributes so centrally to the well-being and sustainability of life on Earth, including our human species.”