Sentences with phrase «isotope records of»

The modulation potential used in the calculations is based on the composite of data determined from the cosmogenic isotope records of 10Be and a neutron monitor.

«The surface temperature changes for the last 4000 years in northern inland Iberia (an area particularly sensitive to climate change) are determined by a high resolution study of carbon stable isotope records of stalagmites from three caves (Kaite, Cueva del Cobre, and Cueva Mayor) separated several 10 s km away in N Spain.

Diatom and stable isotope records of late Holocene lake ontogeny at Indrepollen, Lofoten, N.W. Norway: a response to glacio - isostacy and Neoglacial cooling., The Holocene, 19, 261 - 271.

For the Holocene, the cosmogenic isotope records of 10Be from WAIS Divide and 14C for IntCal13 demonstrated that WD2014 was consistently accurate to better than 0.5 % of the age.

Their results overcome a basic problem of trying to discern the deep history of ice from bedrock: every time an ice sheet retreats and then grows back, it scours away the bedrock and the isotope record of its own past.

«Oxygen and Carbon Isotope Record of East Pacific Core V19 - 30: Implications for the Formation of Deep Water in the Late Pleistocene North Atlantic.»

We use the rich climate history of the Cenozoic era in the oxygen isotope record of ocean sediments to explore the relation of climate change with sea level and atmospheric CO2, inferring climate sensitivity empirically.

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.

In Greenland lead isotopes in ice cores reveal a record of lead pollution from Roman smelting in Spain some 2,000 years ago.

«Any potential [spike] would have both the radionuclide record as well as the SCP one — as well as a few invasive species, bits of microplastic and stable carbon isotopes,» explains geologist Jan Zalasiewicz of the University of Leicester in England and chairman of the working group that is evaluating whether or not to add the Anthropocene to the geologic timescale.

«A lot of this rests on the carbon isotope analysis,» Rothman says, which is exceptionally strong and clear in this part of the geological record.

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.

That could explain two other anomalies from the era's geologic record, Lenton says: the large amounts of organic - rich shale that were deposited as nearshore sediments and the unusually high proportion of carbon - 13 isotopes in the rocks.

They write, «The occurrence of humid periods previously identified in lacustrine or speleothem records highlights the complexity and heterogeneity of the Arabian paleoclimate, and suggests that interior migration pathways through the Arabian Peninsula may have been viable approximately every 23,000 years since at least marine isotope state (MIS) 6,» about 191 thousand years ago.

By carefully micro-sampling each shell along its direction of growth and analyzing for stable carbon and oxygen isotopes and trace elements, the team reconstructed a record of seasonal variation during the lifetimes of the organisms.

Brown researchers have compiled a detailed Indonesian climate record of the last 60,000 years, tracking telltale indicators in sedimentary cores: titanium levels (a marker for surface water runoff) and the carbon isotopes of leaf wax, a marker for plant varieties (grasses indicate dry conditions).

The researchers compared the lead isotopes in their sediment samples with those found in preserved Roman piping to create a historical record of lead pollution flowing from the Roman capital.

The extra mass of the exotic antiquark is enough to make this antihydrogen isotope heavier than the previous record - holder, antihelium.

Fisher, who studies the extinction of mastodons and mammoths, suggests some answers could lie in nitrogen isotopes in the Patagonian bones, which can record changes in an animal's diet and, thus, its environment.

For example, rock records of an isotope of strontium — 87Sr — seem to show an increase in so - called chemical weathering, or weathering that is not simply the result of rain or other natural but not life - related processes.

By studying the variations of uranium isotopes recorded in carbonates, the team was able to infer global anoxia occurring throughout the ocean using samples from a single outcrop.

In the past decade, paleoclimatologists have reconstructed a record of climate change over the last millennium by consulting historical documents and examining indicators of temperature change like tree rings, as well as oxygen isotopes in ice cores and coral skeletons.

Whenever they found large dips in the oxygen - 18 isotope, they found a corresponding historical record of a hurricane.

Eggshells contain carbon, which comes from the birds» diets, and because different plants have different ratios of carbon isotopes, the shells can be used as a rough record of what birds ate.

The difference between using DNA analysis and isotope tracking is a variation on the nature versus nurture debate: DNA records an organism's genetic inheritance, and isotopes reflect the composition of the environment in which it grows.

The oxygen and carbon isotopes present in the remains provided them with records of temperature and humidity levels during the period.

The paleoclimate data, which included mainly changes in the oxygen isotopes of the calcium carbonate deposits, were then compared to similar records from other caves, ice cores, and sediment records as well as model predictions for water availability in the Middle East and west central Asia today and into the future.

In both cases the climate records are based on oxygen isotope measurements on datable layers of ice or stalagmite cave deposition.

Because plants preferentially use the lighter isotope, its scarcity is a record of how much life the oceans supported.

«As an animal eats and drinks, the local strontium isotope composition of the water, plants and animals consumed is recorded in its skeletal tissues.»

New evidence of Holocene climate and atmospheric circulation variability, inferred from lacustrine stable isotope records from Gotland, southern Sweden Francesco Muschitiello, Dan Hammarlund, Barbara Wohlfarth

Wang, Lean, and Sheeley (2005) compared a flux transport model with geomagnetic activity and cosmogenic isotope records and to derive a reconstruction of TSI since 1713.

Biomineralisation influences on boron isotopes are then explored, addressing the apparently contradictory observations that foraminifera manipulate pH during chamber formation yet their δ11B appears to record the pH of ambient seawater.

Evidence from carbon isotope records from both soil carbonates [18]--[20] and biomarkers (n - alkanes) extracted from deep - sea sediments [21] provide clear evidence of a progressive vegetation shift from C3 (∼ trees and shrubs) to C4 (∼ tropical grasses) plants during the Plio - Pleistocene.

There are also a number of paleoclimatic recorders of oxygen isotopes, including lake / ocean records, speleothems (in caves), corals, ice cores, etc..

First, I do think that there is a lot of work to be done in the interpretation of oxygen / hydrogen isotope values obtained at a site, and there's still plenty of disagreement in the paleo - community on how to best connect the isotopic signal in a record with climate.

This absence is reflected in numerous proxies, particularly the record of mass - independent fractionation of sulfur isotopes.

According to the researchers, this isotope formed as a result of cosmic ray particles or protons hitting out atmosphere, emanating from a minor superflare, around 10 — 100 times larger than any solar flare in recorded history.

Based on the temperature minimum recorded from the early Late Oxfordian of Kachchh, it was suggested that the widening of the Trans - Gondwanan Seaway may have led to increased upwelling in the Malagasy Gulf and to a cooling recorded in the oxygen isotopes of belemnites and other marine invertebrates from Kachchh [38].

A fossil is the remains or traces of a once - living plant or animal that was preserved in rock or other material before the beginning of recorded history Carbon - 14, 14 C, or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.

Improved source apportionment of PAHs and Pb by integrating Pb stable isotopes and positive matrix factorization application (PAHs): A historical record DATING DOULTON BURSLEM.

For this rare Philadelphia appearance, he performs with the collective Digital Primitives featuring Israeli tenor saxophonist and bass clarinetist Assif Tsahar, known for his work with Cecil Taylor, Rashied Ali, Peter Kowald, William Parker and Hamid Drake; and drummer Chad Taylor, a member of the Chicago Underground Duo and Iron and Wine, and a major contributor to Chicago's post-rock scene where he has recorded or collaborated with Tortoise, Isotope 217, Stereolab, Sam Prekop and Jim O'Rourke.

As a starting point, we explore what the traces of the Anthropocene will be in millions of years — carbon isotope changes, global warming, increased sedimentation, spikes in heavy metal concentrations, plastics and more — and then look at previous examples of similar events in the geological record.

The afternoon sessions on water isotopes in precipitation was quite exciting because of the number of people looking at innovative proxy archives, including cave records of 18O in calcite, or deuterium in leaf waxes, which are extending the coverage (in time and space) of this variable.

We only have direct observations of total solar irradiance (TSI) since the beginning of the satellite era and substantial evidence for variations in the level of solar activity (from cosmogenic isotopes or sunspot records) in the past.

To replicate the observed isotopic offset, the model requires that enhanced levels of organic - carbon and pyrite burial continued a few hundred thousand years after peak organic - carbon burial, but that their isotope records responded differently due to dramatically different residence times for dissolved inorganic carbon and sulfate in seawater.

We analyzed stable carbon and oxygen isotopes (δ13C, δ18O) of decade - old California mussel shells (Mytilus californianus) in the context of an instrumental seawater record of the same length.

The record tells the story of the sudden release of an isotopically light source of carbon, triggering a fast warming in the deep sea of about 5 degrees C. Both the carbon isotope signal and the temperature (inferred from oxygen isotopes) then relaxed back toward their initial values in about 100,000 years.

Over even longer time scales (hundreds of years) there are a number of paleo - records that correlate with records of cosmogenic isotopes (particularly 10Be and 14C), however, these records are somewhat modulated by climate processes themselves (the carbon cycle in the case of 14C, aerosol deposition and transport processes for 10Be) and so don't offer an absolutely clean attribution.

[Response: The ice core evidence regards the magnitude of the eruption, not the climatic impact (though in principle, ice core isotopes in some locations would record the cooling signal).