Sentences with phrase «isotopic ratios in»

The method used to determine the isotopic ratios in ice core gases is by sublimating all ice under vacuum over a cryogenic trap and subsequent sublimating all ingredients step by step.

PS — Five students deciphered the xenon data in a few weeks [O. Manuel, K. Windler, A. Nolte, L. Johannes, J. Zirbel and D. Ragland, «Strange xenon in Jupiter», Journal of Radioanalytical and Nuclear Chemistry 238, nos. 1 - 2, 119 - 121 (1998)-RSB-; «Isotopic ratios in Jupiter confirm intra-solar diffusion», Meteoritics and Planetary Science 33, A97, 5011 (1998).

The study of the rubidium / strontium isotopic ratios in a set of meteorite samples shows the general approach to

But she had to improve the sensitivity of the technique so that it could detect the isotopic ratio in DNA from the roughly 6 - gram sliver of neural tissue in the hippocampus thought to produce new neurons, the dentate gyrus.

Reference Lind K., Melendez J., Asplund M., Collet R. & Magic Z., The lithium isotopic ratio in very metal - poor stars, Astronomy & Astrophysics.

Not exact matches

The ratio of strontium to calcium in a given layer of coral reef — as well as the amount of a heavier isotope of oxygen in the carbonate itself — reflect the temperature in this historical record, but the isotopic information also reveals rainfall.

By comparing the isotopic ratios of nitrogen and carbon in the lions» remains with that of contemporary lions, humans and herbivore prey, Justin Yeakel of the University of California, Santa Cruz, estimates the lions ate around 35 people.

By comparing the isotopic ratios of nitrogen and carbon in the lions» remains with that of contemporary lions, humans and herbivore...

The discovery's telltale sign is found in the ratio of an isotopic form of hydrogen, called deuterium, to standard hydrogen.

Animals that live in the sea have ratios of carbon and nitrogen isotopes that differ from those found in terrestrial animals, and this isotopic signature is passed on to the people who eat them.

Using core samples of the seabed in three locations, the scientists measured the isotopic ratio of nitrogen - 15 to nitrogen - 14 in the organic matter therein; the ratio can be used to estimate the extent of anoxia in these OMZs.

Rainfall oxygen isotopic ratios are good indicators of the amount of rainfall occurring throughout the region, as determined by a modern - day calibration study recently published by another graduate student in Cobb's lab.

One of Mojzsis's former coauthors, geochemist Gustaf Arrhenius of the Scripps Institution of Oceanography, showed how the Isua carbon - isotopic ratio could arise by geologic activity alone, if certain iron minerals in the rock were melted and pressed together over time.

``... the 50Ti / 47Ti ratio of the Moon is identical to that of the Earth within about four parts per million, which is only 1/150 of the isotopic range documented in meteorites.»

Initial SAM results show an increase of 5 percent in heavier isotopes of carbon in the atmospheric carbon dioxide compared to estimates of the isotopic ratios present when Mars formed.

Isotopic Ratio of 13 - C: 12 - C in carbonate minerals.

Potassium - Argon Dating I Limitations of the If you read further in my second potassium - argon dating page: K - Ar - dating page 2 You will see that Ar dating method can overcome these limitations of conventional k - ar dating, and has the added advantage that potassium and argon are determined on the same sample and that only measurements of the isotopic ratios of argon are required.

Problems remain in the interpretation of the measured Pb isotopic ratios to transform them into ages.

But this juncture is where the GCMs fail catastrophically — thrice: (1) Manmade CO2 (ACO2) is irreversibly mixed with natural CO2 (nCO2) in the atmosphere to undergo processes according a distribution of isotopic mixing ratios.

Next, the methane in this air is combusted to produce carbon dioxide, which is analysed for its carbon isotopic composition — or carbon - 13 to carbon - 12 ratio.

The task is complicated, however, because nitrogen, when cycling through the atmosphere or deposited on land or in water, is subject to influences that can alter the isotopic ratios, thus masking the source.

Its isotopic signature is depleted in the carbon - 13 isotope, which explains why the atmospheric ratio of carbon - 12 to carbon - 13 has been going down as anthropogenic carbon dioxide goes up.

In other words, if all of the terrestrial carbon today (in forests, animals, soils, etc.) were converted to carbon dioxide and returned to the global inorganic carbon pool, the change in the global carbon isotopic ratio would only be a third as big as that observed during the PETIn other words, if all of the terrestrial carbon today (in forests, animals, soils, etc.) were converted to carbon dioxide and returned to the global inorganic carbon pool, the change in the global carbon isotopic ratio would only be a third as big as that observed during the PETin forests, animals, soils, etc.) were converted to carbon dioxide and returned to the global inorganic carbon pool, the change in the global carbon isotopic ratio would only be a third as big as that observed during the PETin the global carbon isotopic ratio would only be a third as big as that observed during the PETM!

Curiously, the PETM was accompanied by an exceptionally large change to the global carbon cycle as indicated by a large drop in the isotopic ratio of 13C to 12C in the ocean and on land.

In collaboration with the Institute for Arctic and Alpine Research (INSTAAR) of the University of Colorado, ESRL / GMD now routinely monitors carbon isotopic ratios of CO2 and CH4.

If he wanted to apply his scientific credentials to a scientific matter in climate, he might turn to what the isotopic ratio of carbon (13C / 12C) needs to be in atmospheric CO2 concentration to constitute a fingerprint of human origin.

he cites Semiletov / Shakhova but does not as these authors do not, tell you what the Ch4 isotopic ratio is.There is observation of aerobic methane production in the pacific region of the arctic waters.

Truth n ° 3 The amount of CO2 in the air from anthropic emissions is today no more than 6 % of the total CO2 in the air (as shown by the isotopic ratios 13C / 12C) instead of the 25 % to 30 % said by IPCC

We assumed only that due to the biological and physical effects the ratio fabsorbed (t) / (total CO2 content of then air) is more or less constant, hence a simple response pulse response exp -LRB-- t / lifetime) is applied to the anthropic time series of coal, gas, oil and cement which have different delta13C As the isotopic signature of (CO2 natural)(t) is slowly decreasing because plants living days or centuries ago are now rotting and degassing and as molecules entered in the ocean decades ago are now in the upwellings after a slow migration along the equal density surface from the high latitudes where those surface are surfacing at depth zero, there are common sense constraints or bounds on the possible evolution of the delta13C of the natural out - gassed CO2 molecules.

Within these archives, scientists can measure the isotopic ratios of oxygen and hydrogen to deduce changes over time in the isotopic composition of environmental waters, such as precipitation, seawater, and groundwater.

«Measurement of atmospheric mixing ratios, decline of O2 mixing ratios, pCO2 in the ocean, and the isotopic carbon composition and other stuff tells us about the source of CO2 increases.

Which is ludicrous in the context of CO2, since we can measure isotopic ratio changes (indicating the change in old carbon versus fresh carbon) and have good accounting for human inputs to the system versus sources and sinks.

Looking at the isotopic record from the PETM, scientists see both carbon and oxygen isotope ratios spiking in exactly the way we expect to see in the Anthropocene record.