Determination of thorium isotopes in seawater by nondestructive and radiochemical procedures

Evaluation of two cross-flow ultrafiltration membranes for isolating marine organic colloids

“…Source sea water without any spikes was used for background substitution. Buesseler et al, 1992;Moran and Buesseler, . 1993 .…”

Investigating the carbon cycle in the Gulf of Maine using the natural tracer thorium 234

“…These data were fitted to the decay of 234Th and extrapolated back to the time of collection. Since the detector efficiency for an electroplated sample is known accurately and precisely (60 _+ 2%), a number of samples were radiochemically purified, electrodeposited on stainless steel discs, and counted on the beta detectors [Buesseler et al, 1992b]. Using the calculated activities from the plated samples, the beta detector efficiency for the QMA filter geometry was calculated to be 35 _+ 1.2%.…”

Distribution of low-level natural radioactivity in a populated marine region of the easternMediterranean Sea

“…234 Th shows high affinity for particles in the marine environment ( particle-reactive element). It is produced by the radioactive decay of the completely conservative 238 U and its radioactive disequilibrium in the marine environment has been used to trace processes occurring over short timescales (23,24) . The values observed here are of the same level as those observed in the Mediterranean Sea, although the variation of values is extremely wide.…”