Tag Archives: isotopic composition

Isotope Fingerprints

Jaisi laboratory tracks chemicals in water, farmland throughout Mid-Atlantic

University of Delaware researcher Deb Jaisi is using his newly established stable isotope facility in the Environmental Biogeochemistry Laboratory (EBL) to find the fingerprints of isotopes in chemical elements — specifically phosphorus — in order to track sources of nutrients in the environmentally-sensitive Chesapeake Bay, other bodies of water and farmland throughout the Mid-Atlantic.

Jaisi, assistant professor in the Department of Plant and Soil Sciences in the College of Agriculture and Natural Resources, explained that he and his research team are currently working on many projects in the EBL, including two that are funded through seed grants, one focusing on terrestrial phosphorus sources and the other on marine phosphorus sources in the Chesapeake. One of those grants is from the UD Research Foundation (UDRF) and is titled “Role of Non-terrestrial Phosphorus Sources in Eutrophication in the Chesapeake Bay.” (more…)

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UMD Finding May Hold Key to Gaia Theory of Earth as Living Organism

Discovery ultimately could lead to better climate understanding and prediction

COLLEGE PARK, Md. Is Earth really a sort of giant living organism as the Gaia hypothesis predicts? A new discovery made at the University of Maryland may provide a key to answering this question. This key of sulfur could allow scientists to unlock heretofore hidden interactions between ocean organisms, atmosphere, and land — interactions that might provide evidence supporting this famous theory.

The Gaia hypothesis — first articulated by James Lovelock and Lynn Margulis in the 1970s — holds that Earth’s physical and biological processes are inextricably connected to form a self-regulating, essentially sentient, system.

One of the early predictions of this hypothesis was that there should be a sulfur compound made by organisms in the oceans that was stable enough against oxidation in water to allow its transfer to the air. Either the sulfur compound itself, or its atmospheric oxidation product, would have to return sulfur from the sea to the land surfaces. The most likely candidate for this role was deemed to be dimethylsulfide. (more…)

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Titanium Paternity Test Fingers Earth as Moon’s Sole Parent

A new chemical analysis of lunar material collected by Apollo astronauts in the 1970s conflicts with the widely held theory that a giant collision between Earth and a Mars-sized object gave birth to the moon 4.5 billion years ago.

In the giant-collision scenario, computer simulations suggest that the moon had two parents: Earth and a hypothetical planetary body that scientists call “Theia.” But a comparative analysis of titanium from the moon, Earth and meteorites, published by Junjun Zhang, graduate student in geophysical sciences at the University of Chicago, and four co-authors indicates the moon’s material came from Earth alone. (more…)

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Ice Cores Yield Rich History of Climate Change

*Research project completes drilling for the year, reaching two miles below West Antarctic Ice Sheet* 

On Friday, Jan. 28 in Antarctica, a research team investigating the last 100,000 years of Earth’s climate history reached an important milestone completing the main ice core to a depth of 3,331 meters (10,928 feet) at West Antarctic Ice Sheet Divide (WAIS). The project will be completed over the next two years with some additional coring and borehole logging to obtain additional information and samples of the ice for the study of the climate record contained in the core.

As part of the project, begun six years ago, the team, funded by the National Science Foundation (NSF), has been drilling deep into the ice at the WAIS Divide site and recovering and analyzing ice cores for clues about how changes in the concentration of greenhouse gases in the atmosphere have influenced the Earth’s climate over time. (more…)

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