Now showing items 1-10 of 54
Sinking phytoplankton associated with carbon flux in the Atlantic Ocean
(John Wiley & Sons, 2016-05-04)
The composition of sinking particles and the mechanisms leading to their transport ultimately control how much carbon is naturally sequestered in the deep ocean by the “biological pump.” While detrital particles often ...
Plutonium isotopes in the North Atlantic
(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1986-09)
The artificial radionuclide Plutonium (Pu) has been introduced into the environment primarily as fallout from atmospheric nuclear weapons testing during the 1950's and 1960's. Earlier studies of Pu geochemistry are ...
An assessment of particulate organic carbon to thorium-234 ratios in the ocean and their impact on the application of 234Th as a POC flux proxy
Thorium-234 is increasingly used as a tracer of ocean particle flux, primarily as a means to estimate particulate organic carbon export from the surface ocean. This requires determination of both the 234Th activity ...
Revisiting carbon flux through the ocean's twilight zone
(American Association for the Advancement of Science, 2007-04-27)
Th-234 sorption and export models in the water column : a review
Over the past few decades, the radioisotope pair of 238U/234Th has been widely and increasingly used to describe particle dynamics and particle export fluxes in a variety of aquatic systems. The present paper is one of ...
An inverse relationship between production and export efficiency in the Southern Ocean
(John Wiley & Sons, 2013-04-23)
In the past two decades, a number of studies have been carried out in the Southern Ocean to look at export production using drifting sediment traps and thorium-234 based measurements, which allows us to reexamine the ...
Sr-90 and Sr-89 in seawater off Japan as a consequence of the Fukushima Dai-ichi nuclear accident
(Copernicus Publications on behalf of the European Geosciences Union, 2013-06-03)
The impact of the earthquake and tsunami on the east coast of Japan on 11 March 2011 caused a loss of power at the Fukushima Dai-ichi nuclear power plant (NPP) that resulted in one of the most important releases of artificial ...
Beryllium-7 analyses in seawater by low background gamma-spectroscopy
7Be is a cosmogenic isotope produced in the stratosphere and troposphere. 7Be has a half-life of 53.4 days and decays to 7Li emitting a 477 keV gamma line with a branching ratio of 0.104. It is predominantly washed out of ...
Adsorbers for in-situ collection and at-sea gamma analysis of dissolved Thorium-234 in seawater
(Woods Hole Oceanographic Institution, 1994-07)
Two polypropylene cartridge types (Beta Pure and Hytrex II) were tested in the laboratory as adsorbers for in-situ collection of dissolved Thorium-234 (234TH) in seawater. Using a uranyl nitrate tracer, we determined that ...
High particle export over the continental shelf of the west Antarctic Peninsula
(American Geophysical Union, 2010-11-24)
Drifting cylindrical traps and the flux proxy 234Th indicate more than an order of magnitude higher sinking fluxes of particulate carbon and 234Th in January 2009 than measured by a time-series conical trap used regularly ...