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23 paź 2020 · Carbon isotopes are present in the atmosphere, ocean, and terrestrial biosphere in ratios of approximately 99% 12 C/C, 1% 13 C/C, and 1 × 10 −12 14 C/C. 12 C and 13 C are stable isotopes while 14 C is a radioactive isotope called radiocarbon. Radiocarbon is formed naturally in the upper atmosphere from cosmogenic radiation, which produces ...
28 wrz 2021 · Stable isotopes of hydrogen, carbon and oxygen are used to investigate numerous physical and chemical processes in the water and inorganic carbon cycles. Measuring and comparing natural...
1 paź 2019 · We discuss carbon isotope ratios as tracers in atmospheric carbon dioxide and methane, along with DIC, DOC, and methane in ocean and pore waters. We then address carbon isotope ratios of organic matter and foraminiferal carbonate in relationship to their ambient sea-water isotope composition and their utility as non-conservative proxies.
17 sty 2018 · Atmospheric effects must be taken into account when interpreting terrestrial stable carbon isotopes, with important implications for past environments and climates, and understanding plant ...
Introduction. Carbon isotopes are present in the atmosphere, ocean, and terrestrial biosphere in ratios of approximately 99% 12C/C, 1% 13C/C, and 1 × 10−1214C/C. 12C and 13C are stable isotopes while 14C is a radioactive isotope called radiocarbon.
Instrumentation for the continuous measurement of stable isotopes in atmospheric trace substances such as carbon dioxide (CO 2), methane (CH 4), and also water vapor (H 2 O), has grown tremendously in the last decade.
Carbon isotopes are preserved and expressed in the bulk composition of a wide variety of materials such as shells, speleothems, bones, leaves, peat, soils, sediments, wood, and food, and more recently in the composition of specific compounds or biomarkers contained therein.
