Sentences with phrase «oxygen isotope ratios from»

Paleo temperatures from oxygen isotope ratios from the greenland ice cores show that a temperature increase of 0.7 °C will not bring the current temperature up to the level of the Medieval Warm Period let alone the Roman optimum and the MInoan Warm period which were both warmer than the medieval warm period.

A study by Thomas, Dennis et al 2009 [8] derived a high resolution temperature proxy record from oxygen isotope ratios from the ice core.

Like the data used right through 0.02 to 66 My, the Freidrich et al collection comprises stable oxygen isotope ratios from the shells of tiny bottom - dwelling, deep - water marine organisms (benthic foraminifera).

That seems a way more satisfactory approach than the crude estimate in Hansen et al (2013) that I've been using, which relies on an interpretive leap from a deep water temperature proxy (oxygen isotope ratios from the microscopic shells of bottom - dwelling marine critters).

When the jet stream got loopy In order to track the jet stream's behavior thousands of years ago, Bowen and his fellow researchers looked at oxygen isotope ratios from lake cores and cave formations in the eastern and western United States.

Not exact matches

The team used records of oxygen isotope ratios (which provide a record of ancient water temperature) from microscopic plankton fossils recovered from the Mediterranean Sea, spanning the last 5.3 million years.

The researchers determined from the isotope ratio that the Taylor Glacier samples were 120,000 years old, and validated the estimate by comparing the results to well - dated ice core measurements of atmospheric methane and oxygen from that same period.

It is measurable in terms of oxygen and carbon isotope ratios and was compared to «environmental archive» data from other parts of the earth.

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.

Nevertheless, some scientists claim that ratios of oxygen isotopes in marine fossils from the east coast of the US indicate that the Antarctic ice sheet melted at least partially during the Pliocene.

David Hodell, Jason Curtis and Mark Brenner from the University of Florida obtained their evidence from the ratio of calcium carbonate to calcium sulphate in sediments from Lake Chichancanab, in Yucátan, Mexico, and from the proportion of heavy to light isotopes of oxygen in buried shells.

To better understand the cycle of magma production, the researchers analyzed oxygen isotope ratios in quartz and zircon, water - and heat - resistant minerals, from volcanic rocks in the Yellowstone caldera.

The Earth's water must have come from its interior, according to a scientist who has studied the ratios of oxygen isotopes in rocks.

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.

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.

Dust from our own solar system has a characteristic ratio of heavy to light oxygen isotopes.

The information about oxygen concentration comes from the isotopic composition of carbon or rather from the ratio between the stable carbon isotopes 12C and 13C.

To date, we have a full complement of analyses for about three years of growth for one tusk from the Taimir Peninsula of Siberia (the Jarkov mammoth; ca. 20,300 rybp) and growth increment and tusk apatite carbon and oxygen isotope ratios for two to three years of growth from two tusks from Wrangel Island (4,400 and 4,120 year bp).

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.

u «The moon rocks, however, showed [oxygen isotope] ratios markedly similar to those of rocks from Earth.

Then the team restricted evidence to just three measurements that can be obtained from shell samples in sediment cores: cadmium concentration and carbon and oxygen isotope ratios in the calcium carbonate shells.

To date, we have a full complement of analyses for about three years of growth for one tusk from the Taimir Peninsula of Siberia (the Jarkov mammoth; ca. 20,300 rybp) and growth increment and tusk apatite carbon and oxygen isotope ratios for two to three years of growth from two tusks from Wrangel Island (4,400 and 4,120 year bp).

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.

The team then compared the oxygen isotope ratio for each year's wet season from 1990 to 2010 with a cyclone activity index of the average accumulated energy expended, based on factors such as number of cyclones, cyclone strength, size and time on storm track.

Stable isotope ratios of oxygen reflect water temperatures, with higher δ18O values indicating colder water [6], [9], [12], such as water upwelled from lower depths.

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

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.