Sentences with phrase «measuring oxygen isotopes»

An ice drilling pioneer, Oeschger was now measuring oxygen isotopes in glacial - era lake deposits near his home in Bern, Switzerland.

By measuring the oxygen isotopes in the sea ice, the scientists were able to deduce where and when the ice was formed.

For the new study, the researchers used an extremely precise laser - based method to measure oxygen isotopes in a range of Earth rocks, meteorites and three lunar samples gathered by the Apollo astronauts.

They then measured the oxygen isotope content of 1200 other samples of rock.

He is encouraged that the wafers designed to measure oxygen isotopes (atomic variants that have slightly different masses) in the early solar system are 85 percent intact.

In addition, Valley and his group measured oxygen isotope ratios, which give evidence of early homogenization and later cooling of the Earth.

For decades, scientists studying climate change have measured the oxygen isotope ratio in tree - ring cellulose to determine the ambient temperature and relative humidity of past climates.

Not exact matches

They then compared the oxygen isotope ratio in Yonderup dripwater with that predicted by a model (which simulated the dripwater δ18O based on measurements of rainwater δ18O), as well as that measured at a different cave in the region.

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.

Barrick and Showers measured the relative ratios of the isotopes oxygen - 16 and oxygen - 18 in the phosphate from 54 samples of a near - complete T. rex skeleton.

By applying uranium - thorium dating to the corals and measuring ratios of oxygen isotopes in their skeletons, her lab reconstructed ocean temperatures for much of the last 7000 years.

But if most of Earth's water was delivered via later meteorites, this would have shown up as a greater isotopic difference than what the researchers measured — as water - bearing meteorites have unusual mixtures of oxygen isotopes.

Karlos Muehlenbachs of the University of Alberta measured the ratio of oxygen isotopes in the oldest rocks known on Earth, which formed 3.96 billion years ago.

Environmental scientist Suzanna Richter and plant physiological ecologist Brent Helliker, both at the University of Pennsylvania, measured the ratio of two isotopes of oxygen — rarer oxygen - 18 and more common oxygen - 16 — in samples of wood.

By measuring the content of the special oxygen isotope O18 in the ice cores, you can get information about the temperature in the past climate, year by year.

They next measured overall energy expenditure by giving volunteers water laced with hydrogen and oxygen isotopes and measuring how much was excreted in urine.

In order to measure the proportions of the oxygen isotopes in the zircons, the team, led by scientist Alexander Nemchin, used a device called an ion microprobe.

By measuring the isotopes in multiple ways, the chemists found carbonates depleted in carbon - 13 and enriched in oxygen - 18.

Once the layers are dated, they drill every millimeter to measure the oxygen and carbon isotopes, which allow them to calculate temperature and moisture histories.

Curiosity measured the same pattern in isotopes of hydrogen, as well as carbon and oxygen, consistent with a loss of a substantial fraction of Mars» original atmosphere.

Temperature is often the easiest thing to measure, thanks to the oxygen isotope ratio correlating with air temperature, but it is not necessarily the most relevant.

The group highlighted the added value of measuring paired coral strontium / calcium ratios (Sr / Ca) and oxygen isotope ratios (δ18O), two key proxies for sea surface temperature that are often referred to as paleothermometers (δ18O also reflects sea surface salinity).

The temperature is measured by the the oxygen isotope ratio, which we recently learned is the temperature of the leaves, and the leaves tend to keep a constant temperature.

What about measuring variations in nutrients, oxygen isotopes... hey, mass spec each ring — maybe we can determine if the plant has been engulfed in volcanic smoke, forest fire smoke, been bombarded variably by cosmic rays, ultraviolet, cosmic microwave background... lets get this 19th Century botanists pursuit up to speed!

They measure the hydrogen and oxygen isotopes to infer air temperatures at the time the snow fell, and the dust particles give a nice indication of the dusty periods (much of the dust was kicked up far away, in the Gobi Desert, rather than from sources closer to Greenland).

I understand what you're saying is being said in this Earth Observatory article regarding the measuring of oxygen isotopes.

Phytoplankton prefer to consume nitrate with lighter oxygen and nitrogen isotopes, so they leave behind heavier isotopes; measuring these can reveal microbial activity in the environment.

However, when measuring the isotopes in nitrate alone, the team found an unexpected imbalance in the ratio of heavy nitrogen and oxygen.

The scientists collected seawater from various depths and measured the ratios of certain oxygen and nitrogen isotopes in the samples.

As shown in the graph below, cosmic - ray intensity (as measured by the radioactive carbon isotope C - 14) and terrestrial climate (as measured by the oxygen isotope O - 18) correlate in amazing detail over an interval of at least 3000 years (see graph below; the bottom graph is the central section, blown up to reveal detail)

For a few years they held their ground, for it turned out that Emiliani's data on oxygen isotopes taken up in plankton shells did not directly measure ocean temperatures after all.

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).

Measured decreases in the fraction of other forms of carbon (the isotopes 14C and 13C) and a small decrease in atmospheric oxygen concentration (observations of which have been available since 1990) show that the rise in CO2 is largely from combustion of fossil fuels (which have low 13C fractions and no 14C).