Description: Das Projekt "A high-resolution study of Thorium isotopes in relation to the cycling of other trace elements in the Southern Ocean" wird vom Umweltbundesamt gefördert und von Stiftung Alfred-Wegener-Institut für Polar- und Meeresforschung e.V. in der Helmholtz-Gemeinschaft (AWI) durchgeführt. Natural radionuclides are powerful tracers to study particle dynamics and to estimate the rate of transport processes in the ocean. 231Pa (T1/2= 32760 y) and 230Th (T1/2=75380 y) are both produced by the constant decay of soluble and homogeneously distributed Uranium. They are very particle reactive, i.e they adsorb onto particles and sink to the bottom with the sinking particles. This substraction of radionuclides from the water column is known as 'scavenging'. This scavenging is 'reversible', i.e there is a constant exchange of the radionuclides between dissolved and particulate phases. They are therefore really efficient particle tracers and their distributions in the ocean are controlled by particle flux and boundary scavenging. 232Th, the most abundant isotope of thorium, has a lithogenic origin and is used to trace sediment-resuspension or terrigenous inputs. 231Pa and Th isotopes (230Th, 232Th and 234Th) were investigated in seawater and size-fractionated particulate samples along 3 transects (Figure 1): Zero-Meridian, Weddell Sea and Drake Passage during Polarstern ANTXXIV-3 (Feb-April 2008), as part of the IPY project GEOTRACES. These radionuclides, sampled in different environments (shelf, open-ocean, ice formation areas ), and for the first time in 3 different sizes of particles, give more insights into the particle dynamics in the water column.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Kontinentalschelf ? Meerwasser ? Thorium ? Tracer ? Uran ? Meereskunde ? Radionuklid ? Spurenelement ? Isotop ? Studie ? Wasserfläche ? Sediment ? Meeresgewässer ? Wasser ? Meeresforschung ? Partikel ? Stofftransport ? Südlicher Ozean ?
Region: Bremen
Bounding box: 8.83333° .. 8.83333° x 53.08333° .. 53.08333°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2007-07-01 - 2009-02-01
Webseite zum Förderprojekt
http://www.spp-antarktisforschung.de/ (Webseite)Accessed 1 times.