Sentences with phrase «oxygen isotopes contained»

Back at their Georgia Tech lab, they analyzed the stalagmites for the ratio of oxygen isotopes contained in samples of calcium carbonate, the material from which the stalagmites were formed.

Not exact matches

Moon rocks contain a tiny bit more of the rare isotope oxygen - 17 than do the rocks on Earth, say geochemists who measured oxygen using very precise methods.

Relative to oxygen - 16, which is the main (99.76 %) isotope of atmospheric oxygen, these nuclei contain two additional neutrons.

The abundance of bonds containing heavy isotopes of both oxygen and carbon are temperature - dependent, so they can give a reliable picture of the terrestrial climate.

Warmer air temperatures cause more water containing the heavier isotopes oxygen - 18 or deuterium to evaporate from the surrounding ocean.

Tripati and her team used a technique known as clumped isotope thermometry, which examines the calcium carbonate shells of marine plankton for subtle differences in the amounts of carbon - 13 and oxygen - 18 they contain.

Studies of meteorites indicate that comets contain a greater proportion of the heavy isotopes oxygen - 17 and oxygen - 18 than terrestrial rocks.

During big storms, water vapor containing the heavy isotope oxygen 18 condenses and falls first, rendering local precipitation deficient in that isotope for up to several weeks.

The most convincing evidence for this, says Jouzel, comes from isotope ratios; ice that has frozen in site has a higher proportion of water molecules containing the heavy form of oxygen, oxygen - 18, than that of ice that has been transported over long distances by weather systems.

The secret to Mars» climate lies in the fact that zircons (ZrSiO4) contain oxygen, an element with three isotopes.

Evidence for approximately contemporaneous global cooling in sediments that do contain YTT glass shards has been found in marine core oxygen isotope records from the South China Sea (3), as have terrestrial carbon isotope and pollen records from Northern India and Bengal (23).

Stott and his colleagues used the isotopes of oxygen contained within the remnants of microscopic surface and deep - sea creatures to establish temperatures; they then used a radioactive isotope of carbon to date their age.

Ancient sediments that once resided on a lake bed and the ocean floor show sulfur isotope ratios unlike those found in other samples from the same time, calling into question accepted ideas about when the Earth's atmosphere began to contain oxygen, according to researchers from the U.S., Canada and Japan.

Rainfall from cyclones contains relatively little heavy oxygen so analysing the oxygen isotope ratio of calcite in stalagmites can reveal the extent of cyclone activity.

Stable oxygen isotope ratios contained in the shell can be used to infer past water temperatures.

For example, ice cores taken in various locations around the world (Greenland and Antarctica, for example) are excellent proxies; gas bubbles containing CO2 trapped in ancient ice can be measured, and the age can be determined very accurately (by counting the seasonal ice layers, or measuring the isotope levels of oxygen).