Depth profiles of selected radionuclides and grain size in marine sediments of the West Gironde Mud Patch (Bay of Biscay)

Date 2020-12
Temporal extent 2016-10-25 -2016-11-01
Author(s) Schmidt SabineORCID1
Affiliation(s) 1 : CNRS, UMR5805 EPOC
DOI 10.17882/77523
Publisher SEANOE
Keyword(s) West Gironde Mud Patch, Bay of Biscay, continental shelf, 210Pb, 226Ra, 228Th, 137Cs, K, grain size, dry bulk density, sediment
Abstract

The West Gironde Mud Patch (WGMP) is a 420-km2 mud belt in the Bay of Biscay, located 25 km off the mouth of the Gironde estuary. This clay-silt feature of 4 m in thickness extends between 30 and 75m water depth, surrounded by the sands and gravels that cover the North Aquitaine continental shelf. Interface cores were collected during JERICOBent-1 cruise (October 2016; Deflandre (2016) doi.org/10.17600/16010400) along two cross-shelf transects for a total of 9 sites. Each sediment core was carefully extruded every 0.5 cm from the top core to 4 cm and every 1 cm below until the core bottom. The sediment layers were used to determine dry bulk density, grain size and selected radioisotope activities (210Pb, 226Ra, 137Cs, 228Th, K).

Licence CC-BY-NC
Acknowledgments This work was supported by: (1) the JERICO-NEXT project (European Union's Horizon 2020 Research and Innovation program under grant agreement no. 654410), (2) the VOG project (LEFE-CYBE R and EC2CO-PNEC), We are thankful to the French Nouvelle Aquitaine Research Council (E3A Project) for the co-funding of the low‐background gamma detector.
Sensor metadata

Dry bulk density (DBD) determination: water content was determined by weighing each sediment samples before and after drying at 60°C, and dry bulk density was subsequently calculated, assuming a mineral density of 2.65 g/cm.

Sediment grain size was measured using a Malvern Mastersizer 2000 laser diffraction particle size analyzer.

Radionuclide activities were measured using a high-efficiency, broad energy gamma detector equipped with a Cryo-Cycle II (Mirion). The gamma detector is calibrated using IAEA certified materials (RGU-1). Errors on activities are based on standard deviation counting statistics

 

Data
File Size Format Processing Access
Profiles of selected radionuclides, grain size and dry bulk density in marine sediment of the West Gironde Mud Patch (Bay of Biscay) 142 KB XLS, XLSX Quality controlled data Open access
Top of the page

How to cite 

Schmidt Sabine (2020). Depth profiles of selected radionuclides and grain size in marine sediments of the West Gironde Mud Patch (Bay of Biscay). SEANOE. https://doi.org/10.17882/77523