Now showing items 51-60 of 866
Examination of precipitation chemistry and improvements in precision using the Mg(OH)2 preconcentration inductively coupled plasma mass spectrometry (ICP-MS) method for high-throughput analysis of open-ocean Fe and Mn in seawater
The chemistry of magnesium precipitation preconcentration of Fe, Mn and Co from seawater was investigated, and this analytical technique was adapted for use with the Element-2 inductively coupled plasma mass spectrometer ...
217 000-year-old DNA sequences of green sulfur bacteria in Mediterranean sapropels and their implications for the reconstruction of the paleoenvironment
Deep-sea sediments of the eastern Mediterranean harbor a series of dark, organic carbon-rich layers, so-called sapropels. Within these layers, the carotenoid isorenieratene was detected. Since it is specific for the ...
Geochemistry of low-molecular weight hydrocarbons in hydrothermal fluids from Middle Valley, northern Juan de Fuca Ridge
Hydrothermal vent fluids from Middle Valley, a sediment-covered mid-ocean ridge on the northern Juan de Fuca Ridge, were sampled in July, 2000. Eight different vents with exit temperatures of 186 to 281°C were sampled from ...
Methylmercury cycling in sediments on the continental shelf of southern New England
Exposure of humans to monomethylmercury (MMHg) occurs primarily through consumption of marine fish, yet there is limited understanding concerning the bioaccumulation and biogeochemistry of MMHg in the biologically productive ...
Lateral organic carbon supply to the deep Canada Basin
(American Geophysical Union, 2008-06-12)
Understanding the processes driving the carbon cycle in the Arctic Ocean is important for assessing the impacts of the predicted rapid and amplified climate change in this region. We analyzed settling particle samples ...
Seasonally resolved stable isotope chronologies from northern Thailand deciduous trees
Despite the existence of a number of climate proxies, the terrestrial expression of tropical climate variability over the past few centuries remains poorly resolved. We explore the applicability of stable isotope ...
Aqueous phase methylation as a potential source of methylmercury in wet deposition
The source of monomethylmercury (MMHg) in wet deposition is unknown. Volatilization of gaseous MMHg, evasion and demethylation of dimethylmercury, and methylation of Hg0 have been either proposed or tested unsuccessfully ...
Tracing river chemistry in space and time : dissolved inorganic constituents of the Fraser River, Canada
The Fraser River basin in southwestern Canada bears unique geologic and climatic features which make it an ideal setting for investigating the origins, transformations and delivery to the coast of dissolved riverine loads ...
Variable morphologic expression of volcanic, tectonic, and hydrothermal processes at six hydrothermal vent fields in the Lau back-arc basin
(American Geophysical Union, 2008-07-26)
Ultrahigh-resolution bathymetric maps (25 cm grid) are used to quantify the physical dimensions of and spatial relationships between tectonic, volcanic, and hydrothermal features at six hydrothermal vent fields in the Lau ...
Revisiting carbon flux through the ocean's twilight zone
(American Association for the Advancement of Science, 2007-04-27)