Sentences with phrase «because isotopic»

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.

Nonetheless, the findings are valuable because isotopic nitrous oxide data from the Arctic and sub-Arctic are extremely rare.

«There could be unique biochemistry, because the isotopic signature of the biomass of microorganisms oxidizing methane in freshwater wetlands is different from their marine counterparts.

Because the isotopic ratios of carbon and hydrogen display geographic variation, the composition of a feather can reveal where the bird was when the feather grew.

The Temagami Banded Iron Formation, which was formed 2.7 billion years ago during the Neoarchean period, can be used as an archive because the isotopic composition of many chemical elements such as Hafnium and Neodymium directly mirrors the composition of Neoarchean seawater.

Because the isotopic makeup of those elements varies from place to place, Diprotodon's steadily growing teeth became, in essence, a chronicle of its movements, in layers akin to tree rings.

Not exact matches

So because there isn't a single reliable Radioactive Isotopic Dating Method (and dismissing that using many methods together is what we do), you have determined that the earth is 10,000 years old or less.

«As an industrial civilization, we're driving changes in the isotopic abundances because we're burning carbon,» Frank says.

That helped narrow down the sources, Schaefer says, because different types of wetlands have different isotopic signatures.

Their physical bodies are data, you can track where they've been because of the discrete isotopic characteristics of different parts of the ocean.

This is a particularly useful region because the oxygen isotopic composition of the seawater is largely determined by the flow of water through the Strait of Gibraltar, which in turn is sensitive to changes in global sea level — in a way like the pinching of a hosepipe.

Because life prefers lighter carbon, the isotopes suggest to some scientists that the atmospheric rise must be due to extra microbial production, and not a boost due to leaked gas from fracking operations, which has a heavier isotopic signature.

Because the tiny zircon crystals retain their isotopic signatures despite episodes of remelting, the researchers could date their cores at 0.8 million to 2.1 million years old.

Referred to as the «lunar isotopic crisis,» this was a problem for the main theory of lunar formation, because it's highly unlikely the isotopes would be exactly the same for two random objects in the solar system.

When I analyzed their isotopic composition, the numbers seemed weird at first because they indicated an essentially freshwater environment.»

Because of these precise measurements, said Humayun, «we now have an isotopic record of how the atmosphere changed, with dates on it.»

We also know the atmospheric increase is from burning fossil fuels because of the isotopic signature of the carbon in the atmosphere.

«Because we extracted high - resolution stable isotopic profiles from these shells, we were able to match them to active spells and breaks in the monsoon,» Thirumalai said.

It is possible to reconstruct past precipitation changes by measuring the stable hydrogen isotopic composition in terrestrial plant waxes because rainfall is the primary source of hydrogen stored in plant material.

[Response: Methane is the «usual suspect» for those events, such as the Paleocene Eocene thermal maximum, because it is easier to explain the carbon isotopic spikes if the source is strongly isotopically labeled.

Because carbon cycle processes such as photosynthesis fractionate the heavy isotope 13C from the lighter 12C, isotopic analysis can usually be used to «trace» sources and sinks of carbon.

However they were all the more remarkable because the guys were able to carry out isotopic analysis on the air samples.

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.

«As an industrial civilization, we're driving changes in the isotopic abundances because we're burning carbon,» Frank says.

We also know the atmospheric increase is from burning fossil fuels because of the isotopic signature of the carbon in the atmosphere.

The statement that only 55 % of human CO2 emissions have been removed by the biosphere / biosphere is something you'll have to prove, which is hard because as far as I'm aware human CO2 does not posses an isotopic signature that can be easily differentiated from natural sources — the arguments you often hear on Skeptical Science are measurements in changes of the C12 / C13 / C14 atmospheric mass, not individual CO2 molecules, which can be misleading.

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.

«As an industrial civilisation, we're driving changes in the isotopic abundances because we're burning carbon,» said Professor Frank.

«Because we extracted high - resolution stable isotopic profiles from these shells, we were able to match them to active spells and breaks in the monsoon,» Thirumalai said.

Because of these confounding factors, palaeoreconstructions based on the isotopic composition of organic carbon (δ13C) will almost certainly have to be based on the isotopic signatures of organic compounds that can be associated with a single species, or group of physiologically similar species

By looking at the distinct isotopic signatures, the researchers could differentiate between methane produced from fracking, for instance, and methane produced from agriculture, because they each have different signatures.

Because the different isotope ratios for the two kinds of plants propagate through the food chain, it is possible determine if the principal diet of a human or other animal consists primarily of C3 plants or C4 plants by measuring the isotopic signature of their collagen and other tissues.