Beryllium-7 concentrations in seawater during the MOSAiC expedition


Pumps were used to collect seawater within the upper 60 m of the ocean for Be-7analysis. Unfiltered seawater was drawn through a pvc hose to the surface where it was passed through iron-oxide impregnated acrylic fiber filters, which adsorb the Be-7. A flow meter attached in-line to the filter compartment recorded the amount of seawater passed through each filter. To maximize Be-7 collection, two or three fibers filtering approximately 600- 700 L of seawater apiece were collected from each depth and later combined. For the mixed layer samples, water was collected from the ship's seawater intake (~8m) into barrels from which the water was passed through the iron-oxide filters as described above. The fibers were dried and shipped to Florida International University. There, the fibers were ashed, placed in a Marinelli beaker and analyzed with a high purity germanium (HPGe) gamma detector. Be-7 has a readily identifiable gamma peak at 478 keV. The detector is calibrated by adding a commercially prepared mixed solution of known gamma activities to an ashed fiber and counting it in the Marinelli geometry.

Related Identifier
Metadata Access
Creator Stephens, Mark
Publisher PANGAEA
Publication Year 2022
Funding Reference Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, AFMOSAiC 1_00; Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, AWI_PS122_00; National Science Foundation, 1753423
Rights Creative Commons Attribution 4.0 International;
OpenAccess true
Language English
Resource Type Dataset
Format text/tab-separated-values
Size 75 data points
Discipline Earth System Research
Spatial Coverage (12.392W, 83.994S, 115.966E, 88.496N); Arctic Ocean
Temporal Coverage Begin 2019-12-21T12:00:00Z
Temporal Coverage End 2020-04-29T12:00:00Z