Details of VECTOR-TRANSMED-07 IV leg. Vertical profiles of 210Pb, 137cs and 226Ra in sediment cores.

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Dataset identification

Title of datasetVECTOR-TRANSMED-07 IV leg. Vertical profiles of 210Pb, 137cs and 226Ra in sediment cores.
Narrative summary of datasetThis dataset was acquired in the framwork of Project V.E.C.T.O.R. (VulnErability of the Italian coastal area and marine Ecosystems to Climatic changes and Their rOle in the Mediterranean caRbon cycles).The project studies the most significant impacts of climate change on the Mediterranean marine environment and the role of this basin on the planetary CO2 cycle.
Summary of processing methodologyAll sediment cores were sampled using a cylindrical (ID, 32 cm; height 52 cm) box corer equipped with top valve which ensures the recovery of surface sediment with minimal disturbance. Subsamples were collected by PVC tubes (10 cm diameter) onboard and sliced with a precision extruder at 0.5 cm intervals in the top 2 cm, and at 1 cm resolution thereafter down to the core bottom. Once in the laboratory, sediment samples were weighed wet, then dried at 50 °C to constant weight, in order to determine wet and dry bulk density. 210Pb, 226Ra and 137Cs were measured on 10 g aliquots of dried sediment samples in a standard geometry by gamma spectrometry. Samples were sealed and sample counting took place 20 days after, a time interval sufficient to re-establish radioactive equilibrium between 226Ra and 222Rn. Three ORTEC HPGe gamma detectors were used to perform analyses; the detectors have an efficiency of 30–60% and a nominal resolution from 1.9 to 2.5 keV at the 1.33 MeV 60Co gamma emission. Sediment samples were counted for 2–3×105 s and 210Pb activities were corrected for self-adsorption effects for the detection of low-energy gamma rays, such as the 46.5 keV ray of 210Pb (Cutshall et al., 1983). Excess 210Pb (210Pbxs) activity was determined as the difference between total 210Pb and supported 210Pb (in equilibrium with the parent radionuclide 226Ra). Dataset variables decoding: PORO: Porosity MSDP: Mass depth Bot. Depth [m]: length of sediment core Depth [m]: sediment core layer PB0S: 210Pb excess activity (sediment) EPBS: 210Pb excess activity error (sediment) RA6S: 226Ra activity (sediment) ERAS: 226Ra activity error (sediment)
Supporting documentationBarsanti, Mattia et al. 2011, "Sediment reworking rates in deep sediments of the Mediterranean Sea", Science of the Total Environment, (409):2959-2970, doi:10.1016/j.scitotenv.2011.04.025
Project/programmeVECTOR-Vulnerability of coasts and marine ecosystems to the climatic changes and their role on Mediterranean C cycle
Start date2007-07-02
End date2007-07-10
Frequency of observationsinapplicable

Responsible organisations

CountryItaly
Organisation nameENEA Centro Ricerche Ambiente Marino (La Spezia)
Role of organisationOriginator of Dataset

Dataset availability

Original dataset download linkhttps://cloud.emodnet-ingestion.eu/index.php/s/gfpeDPQKC9zm1TJ
Date of original dataset publication2018-03-09
Dataset formatText or Plaintext
Public accessNo limitations
License for useCC BY-SA 4.0
TypeDataset
DOIhttps://doi.org/10.1016/j.scitotenv.2011.04.025

Locations

Map
Latitude north boundary38
Longitude east boundary29
Latitude south boundary32
Longitude west boundary18
Coordinate reference systemWorld Geodetic System 84
Sea areaMediterranean Sea, Eastern Basin

Data types, collection and processing

Observation typeIsotopes
ParameterGeological sample radioactivity
Instrument typegamma-ray spectrometers
Instrument nameGEOTEK Multi-Sensor Core Logger XYZ {MSCL-XYZ} core analyser
Platform typeresearch vessel
Platform nameUrania
Data quality processing informationThe ORTEC HPGe gamma detectors have an efficiency 30–60% and a resolution from 1.9 to 2.5 keV at the 1.33 MeV 60Co gamma emission. Each detector is accurately calibrated as follows: for 210Pb, the CANMET (CANada centre for Mineral and Energy Technology) reference standard DL1a is used; calibration for 137Cs and 7Be is performed using the multi-elemental Amersham reference standard solution QCY48. The accuracy of the results is verified through quality controls routinely realized by analyzing standard reference materials of the International Atomic Energy Agency (IAEA-300, IAEA-315 and IAEA-385). Detector blanks are monthly determined from measurements performed on empty sample containers over a few days. Sediment samples were counted for 2-3 days and the gamma-ray spectra were analysed for the selected radionuclides at the following photopeaks: 210Pb at 46.5 keV, 226Ra (as an estimate of supported 210Pb), via 214Pb at 352 keV and 214Bi peaks at 609 keV, 7Be at 477.7 keV, 137Cs at 662 keV. 210Pb activities were corrected for self-absorption effects for the detection of low-energy gamma rays, accordingly to Cutshall et al. (1983). Excess 210Pb (210Pbxs) activity is the difference between total 210Pb and supported 210Pb (in equilibrium with the parent radionuclide 226Ra).

Process information

Submitting organisationENEA Centro Ricerche Ambiente Marino (La Spezia)
Submission identifier (UUID)aa3559be-8e4c-46a3-842a-0382ab0284dc
Date of dataset creation2009-01-01
Date of dataset revision2009-01-01
Date of metadata creation2017-11-22
Date of metadata latest revision2018-02-27
Date of publishing2018-02-26
Processing data centreENEA Centro Ricerche Ambiente Marino (La Spezia)
Summary record-ID74