منابع مشابه
Anthropogenic lead isotopes in Antarctica
We report the first measurements of Pb isotopes in Antarctic snow, which show that even recent snow containing 2.3 pg/g is highly polluted with anthropogenic Pb. This follows from a comparison of isotope abundances of Pb in surface snow and terrestrial dust extracted from ancient Antarctic ice (Dome C, depth 308 m, approximate age 7,500 a BP), the latter being distinctly more radiogenic. This r...
متن کاملAnthropogenic impacts on marine ecosystems in Antarctica.
Antarctica is the most isolated continent on Earth, but it has not escaped the negative impacts of human activity. The unique marine ecosystems of Antarctica and their endemic faunas are affected on local and regional scales by overharvesting, pollution, and the introduction of alien species. Global climate change is also having deleterious impacts: rising sea temperatures and ocean acidificati...
متن کاملLead Isotopes and Selected Metals in Ice from Law Dome, Antarctica
The isotopic composition of Pb and the concentrations of.Pb, Ba and Bi were measured in selected ice-core samples from Law Dome, East AntarctIca, to a depth of 1196 m. The range of concentrations found in decontaminated ice was 0.03\.5 pg g I for Pb, 0.96.1pggl for Ba and 0.417 fgg I for Bi , excluding the deepest sample which contained rv I p:}6m of rock dust. The abundances of all four stable...
متن کاملPreliminary Interpretations of Lead Isotopes
Large stratiform, syngenetic deposits commonly yield galena-lead isotope 'model' ages that agree closely with the stratigraphic ages of their host rocks. However, analyses in Table 1 from stratiform,shale-hosted deposits (located on Fig. 701 of Cambrian to Devono-Mississippian age in or adjacent to the Selwyn Bar,in in British Columbia and Yukon Territory do not give reasonable ages if the mode...
متن کاملStable nitrogen isotopes in coastal macroalgae: geographic and anthropogenic variability.
Growing human population adds to the natural nitrogen loads to coastal waters. Both anthropogenic and natural nitrogen is readily incorporated in new biomass, and these different nitrogen sources may be traced by the measurement of the ratio of stable nitrogen isotopes (δ(15)N). In this study δ(15)N was determined in two species of macroalgae (Ascophyllum nodosum and Fucus vesiculosus), and in ...
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ژورنال
عنوان ژورنال: Geophysical Research Letters
سال: 1994
ISSN: 0094-8276
DOI: 10.1029/94gl02603