Sentences with phrase «isotopic values»

An additional 9 small mussels (38.8 — 52.6 mm) were also collected to test whether younger mussels had similar isotopic values for a given year.

With regard to breeding status, solitary females had higher δ15N values and smaller variance in their stable isotopic values than females with cubs, suggesting that solitary females were more selective and prey on higher trophic level species (i.e. seals).

Depth horizons with functional genes indicative of methane - cycling and sulfate - reducing microorganisms are enriched in solid - phase sulfur and total organic carbon, host δ13C - and δ34S - isotopic values with a biological imprint, and show clear signs of microbial activity when incubated in the laboratory.

This time, the dominant carbon isotopic values in the new inputs were about -60 ‰, pointing to a microbially driven source rather than fossil fuel inputs.

As a result, methane emissions have distinct isotopic values: Methane emitted from any microbially driven source such as wetlands or agriculture have values of about -60 ‰ (signifying a relatively low ratio of carbon - 13 to carbon - 12); oil, gas, and coal emissions have an average carbon isotopic value of -37 ‰; and tree and crop burning averages about -22 ‰.

They found a sharp dip in methane concentrations after 1992; that dip corresponded with a decrease in a source with a carbon isotopic value of about -40 ‰.

Not exact matches

This enabled a direct measurement of the 12C / 13C isotopic ratio for the Orion hot core of 14 + / - 1 and an estimated maximum value of 21.

First, I do think that there is a lot of work to be done in the interpretation of oxygen / hydrogen isotope values obtained at a site, and there's still plenty of disagreement in the paleo - community on how to best connect the isotopic signal in a record with climate.

It took on the order of 100 kyr for the oxygen and carbon isotopic signals in the ocean to return to their original steady - state values after the PETM.

First, I do think that there is a lot of work to be done in the interpretation of oxygen / hydrogen isotope values obtained at a site, and there's still plenty of disagreement in the paleo - community on how to best connect the isotopic signal in a record with climate.

An isotopic mixing model estimation of diet proportions determined that bowhead whale comprised approximately 50 — 70 % of fall diet for bears with lower hair δ15N values.

Because the isotopic signatures measured in the study are lower than the values typically entered into global climate change models, the results of this study suggest the models may be underestimating the change to atmospheric carbon - 13 for each simulated emissions scenario.