Preliminary assessments by scientists from Russia, the University of Florida, and the University of Alaska Fairbanks indicate that loess permafrost, which covers more than a million square kilometers in Siberia and Alaska, is a large carbon reservoir with the potential to be a significant contributor of atmospheric carbon, yet it is seldom incorporated into analyses of changes in global carbon reservoirs.
“The unique aspect of the Siberian loess permafrost is that it is quite deep – 20 to 40 meters - and has a surprisingly high carbon concentration at depth for a mineral soil,” said Terry Chapin, co-author from the Institute of Arctic Biology at UAF. “This paper explains the processes that led to the accumulation of large amounts of soil carbon and the processes that could lead to its return to the atmosphere.”
The largest carbon reservoir on Earth is the ocean, which scientists estimate holds about 40,000 gigatons; soils contain about 2,500 Gt and vegetation about 650 Gt. According to the authors, about 500 Gt of carbon are contained in the thaw-threatened loess, also called yedoma, of Siberia and Alaska.
“I was surprised, because it is unusual to find major new large carbon stocks,” Chapin said. “We have spent more than five years discussing among ourselves all the details of the calculations, because initially I did not believe that the pool could be both so large and so decomposible (once thawed).”
Permafrost has been seldom incorporated into global carbon budgets in part because the “... size of the carbon pool was so poorly quantified ... and in part because global data bases for soils have been standardized to provide data only for the top meter of soil,” Chapin said. “People know about carbon in permafrost - it’s not a trivial amount,” said Ted Schuur, co-author from the University of Florida. “Normally, scientists look for carbon in the upper layers of permafrost where organic matter decomposes.”
Laboratory and field experiments by the scientists demonstrate that the organic matter in yedoma decomposes quickly when it is thawed and produces rates of carbon release similar to those of productive northern grassland soils. “If these rates continue as field observations suggest, most carbon in recently thawed yedoma will be released within a century - a striking contrast to the preservation of carbon for tens of thousands of years when frozen in permafrost,” state the authors.
The National Science Foundation provided financial support for this research.
Marie Gilbert | EurekAlert!
Predicting unpredictability: Information theory offers new way to read ice cores
07.12.2016 | Santa Fe Institute
Sea ice hit record lows in November
07.12.2016 | University of Colorado at Boulder
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine