Abstract:
This data product comprises 5 documents outlining biogeochemical data from three fjords along the West Antarctic Peninsula: Sheldon Cove (Adelaide Island), Borgen Bay (Anvers Island), and Marian Cove (King George Island). Data was collected in January 2020 on cruise JR19002 on the RRS James Clarke Ross. The project aimed at understanding the benthic release of dissolved silicon, a vital nutrient for phytoplankton in the Southern Ocean, in Antarctic fjords exposed to various degrees of glacier retreat. Data include elemental chemistry of porewater from inner and outer fjord in each bay, silicon isotopic composition of the porewater, dissolved inorganic nutrient concentrations in porewaters and the overlying seawater, and the diffusive benthic silica flux from the sediments.
LF is supported by the Natural Environmental Research Council GW4+ DTP (NE/S007504/1).
AA is supported by the Natural Environmental Research Council Fellowship Award (NE/P017630/1).
FSdF is supported by the Natural Environmental Research Council ChAOS project (NE/P005942/1, NE/P006108/1 and NE/P006493/1, at the University of Bristol).
KH is supported by the Natural Environmental Research Council SiCLING grant (NE/X014819/1) and the BIOPOLE National Capability Multicentre Round 2 funding (NE/W004933/1).
Keywords:
Southern Ocean, West Antarctic Peninsula , benthic flux, nutrients, silicon isotopes, trace metals
Friberg, L., Annett, A.L., Sales de Freitas, F., Woodward, E.M.S., & Hendry, K.R. (2026). Benthic silicon fluxes and sediment porewater chemistry in Sheldon Cove, Borgen Bay and Marian Cove, West Antarctic Peninsula, in January 2020 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/f8f72bf5-035b-4851-8a21-d278485081b1
| Access Constraints: | None. |
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| Use Constraints: | These data are governed by the NERC data policy http://www.nerc.ac.uk/research/sites/data/policy/ and supplied under Open Government Licence v.3 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/. |
| Creation Date: | 2026-04-10 |
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| Dataset Progress: | Complete |
| Dataset Language: | English |
| ISO Topic Categories: |
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| Parameters: |
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| Personnel: | |
| Name | UK Polar Data Centre |
| Role(s) | Metadata Author |
| Organisation | British Antarctic Survey |
| Name | Lisa Friberg |
| Role(s) | Investigator, Technical Contact |
| Organisation | University of Bristol |
| Name | Amber L Annett |
| Role(s) | Investigator |
| Organisation | University of Southampton |
| Name | Felipe Sales de Freitas |
| Role(s) | Investigator |
| Organisation | University of Bristol |
| Name | E. Malcolm S Woodward |
| Role(s) | Investigator |
| Organisation | Plymouth Marine Laboratory |
| Name | Katharine R Hendry |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Parent Dataset: | N/A |
| Reference: | Friberg, L., Grisby, C., Hendry, K.R., Sales de Freitas, F., Woodward, E.M.S, Annett, A., Jones, R.L., Meredith, M.P. (in review) Stable silicon isotopes uncover the influence of glacial processes on early sediment diagenesis on the West Antarctic Peninsula. Becker, S., Aoyama, M., Woodward, E.M.S., Bakker, K., Coverly, S., Mahaffey, C., and Tanhua, T. (2020) GO-SHIP Repeat Hydrography Nutrient Manual: The Precise and Accurate Determination of Dissolved Inorganic Nutrients in Seawater, Using Continuous Flow Analysis Methods. Front. Mar. Sci. 7:581790. https://doi.org/10.3389/fmars.2020.581790. Boudreau, B.P., 1996. The diffusive tortuosity of fine-grained unlithified sediments. Geochimica et Cosmochimica Acta 60, 3139-3142. https://doi.org/10.1016/0016-7037(96)00158-5. Cardinal, D., Alleman, L. Y., De Jong, J., Ziegler, K., & André, L. (2003). Isotopic composition of silicon measured by multicollector plasma source mass spectrometry in dry plasma mode. Journal of Analytical Atomic Spectrometry, 18(3), 213-218. https://doi.org/10.1039/b210109b. De Souza, G. F., Reynolds, B. C., Rickli, J., Frank, M., Saito, M. A., Gerringa, L. J., and Bourdon, B. (2012). Southern Ocean control of silicon stable isotope distribution in the deep Atlantic Ocean. Global Biogeochemical Cycles, 26(2):GB2035. https://doi.org/10.1029/2011GB004141. Georg, R. B., Reynolds, B. C., Frank, M., and Halliday, A. N. (2006). New sample preparation techniques for the determination of Si isotopic compositions using MC-ICPMS. Chemical Geology, 235(1-2):95-104. https://doi.org/10.1016/j.chemgeo.2006.06.006. Grasse, P., Brzezinski, M. A., Cardinal, D., De Souza, G. F., Andersson, P., Closset, I., Cao, Z., Dai, M., Ehlert, C., Estrade, N., Francois, R., Frank, M., Jiang, G., Jones, J. L., Kooijman, E., Liu, Q., Lu, D., Pahnke, K., Ponzevera, E., Schmitt, M., Sun, X., Sutton, J. N., Thil, F., Weis, D., Wetzel, F., Zhang, A., Zhang, J., and Zhang, Z. (2017). GEOTRACES inter-calibration of the stable silicon isotope composition of dissolved silicic acid in seawater. Journal of Analytical Atomic Spectrometry, 32(3):562-578. https://doi.org/10.1039/C6JA00302H. Hendry, K. R., and Robinson, L. F. (2012). The relationship between silicon isotope fractionation in sponges and silicic acid concentration: Modern and core-top studies of biogenic opal. Geochimica et Cosmochimica Acta, 81:1-12. https://doi.org/10.1016/j.gca.2011.12.010. Hughes, H. J., Delvigne, C., Korntheuer, M., De Jong, J., André, L., & Cardinal, D. (2011). Controlling the mass bias introduced by anionic and organic matrices in silicon isotopic measurements by MC-ICP-MS. Journal of Analytical Atomic Spectrometry, 26(9), 1892-1896. https://doi.org/10.1039/c1ja10110b. Karl, D. M., and Tien, G. (1992). MAGIC: A sensitive and precise method for measuring dissolved phosphorus in aquatic environments. Limnology and Oceanography, 37(1):105-116. https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1992.37.1.0105. Rebreanu, L., Vanderborght, J.-P., Chou, L., 2008. The diffusion coefficient of dissolved silica revisited. Marine Chemistry 112, 230-233. https://doi.org/10.1016/j.marchem.2008.08.004. Reynolds, B. C., Aggarwal, J., André, L., Baxter, D., Beucher, C., Brzezinski, M. A., ... & Cardinal, D. (2007). An inter-laboratory comparison of Si isotope reference materials. Journal of Analytical Atomic Spectrometry, 22(5), 561-568. https://doi.org/10.1039/b616755a. |
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| Lineage/Methodology: | All data were collected during the JR19002 cruise on the RRS James Clarke Ross. Porewater: Sediment cores were collected using an Oktopus multicorer (for specifics see cruise report), and porewaters were extracted by attaching Rhizon filters, attached to 30 mL syringes using spacers to create a vacuum, into pre-drilled coring to holes and collected into acid-clean HLPE bottles. Nutrient concentrations (NO2-, NO3-, DSi, PO43- and NH4+) were measured in thawed aliquots (previously frozen at -20°C) at the Plymouth Marine Institute by M. Woodward using a SEAL AutoAnalyzer 3 HR, following the GO-SHIP nutrient manual method (Becker et al. 2020), and using certified reference materials for seawater to define the accuracy (KANSO Ltd., Japan), which averaged 3% during the cruise. Major and trace elemental concentrations were measured in a clean setting in the Bristol Isotope Group (BIG) laboratory at the University of Bristol. Using the Element2 HR-ICP-MS, major (Ca, K, and Mg) and trace (Al, Fe and Mn) elemental concentrations were calculated using a multi-element calibration standard curve, and using an Indium (200ppm) solution to correct for potential instrumental mass drift. Repeat measurements of BIR-1 (Reykjavik Iceland Basalt) and reagent blanks (2% v/v HNO3) were used to determine accuracy and reproducibility, with an average error (1 RSD) of 6.2% (n=8). Silicon isotopic composition was determined on purified pretreated porewater samples at the BIG laboratory. Pre-treatment followed Karl and Tien (1992) and de Souza et al. (2012) by using a Mg-induced co-precipitation (MAGIC) method to reduce the cation and anion matrix and concentrate the Si. Preconcentrated porewater samples were then purified using cation exchange columns (Georg et al. 2006) filled with a Bio-Rad AG50W-X12 resin to remove the remaining cations. Sample solutions were then doped using H2SO4 (ROMIL-UpA) and 1 M HCl (in-house distilled) to counteract any potential anionic matrix effects (Hughes et al., 2011). Isotopic ratios were measured on a Finnigan Neptune Plus High Resolution MC-ICP-MS using the standard-sample bracketing method using NBS-28 as standard referencing material, while using a Mg-doping methods to correct for instrumental mass bias and matrix effects (Cardinal et al., 2003). Repeat measurements of Si reference standards Diatomite and LMG-08 was used to assess long-term external reproducibility, which were in agreement with published literature (Grasse et al., 2017, Hendry and Robinson, 2012, Reynolds, 2007). All samples were measured in triplicate and errors were calculated using the standard deviation between all measurements (n=3). Seawater: Dissolved inorganic nutrients (NO2-, NO3-, DSi, and PO43-) were measured in seawater samples collected directly from the CTD rosette. During collection, an AcroPak (0.8/0.45 µm) filter was attached directly onto the spigot of the Niskin bottles using plastic tubing and seawater samples were collected into acid-rinsed bottles that were rinsed three times with the respective seawater. Samples were then frozen at -20°C and transported back frozen to PML for further analysis using the SEAL AA3 HR as above to quantify dissolved inorganic nutrient concentrations. Oxygen_Concentrations: Oxygen concentrations were estimated in sediment porewaters using a Pyro Science FireSting O2-Mini sensor. Prior to analysis, the probe was calibrated with the "one-point calibration - air saturated water" mode within the Oxygen Logger software, using a bottle containing Milli-Q water saturated with air (vigorously shaken before calibration). After the calibration, the sensor was kept in Milli-Q water until analysis. At each sampling location, two sediment cores with no disturbance in the overlying water or surface sediments were selected. The cores were transferred to a room at constant temperature (4°C) and the probe was attached to the core tube, measuring 5-10 consecutive points at every cm in the bottom water, and 10-20 consecutive points every 0.5cm in the sediment until 3cm below the seafloor. The data from the two cores were averaged and presented in this file. Benthic_Si_Flux: The diffusive benthic DSi flux was calculated using Fick's first law of diffusion. Porosity was measured in surface sediments by drying and weighing it to determine water content. The diffusion coefficient in the sediment is corrected for tortuosity (Boudreau 1996), using diffusion coefficient of DSi in seawater (Dsw ) 4.7 * 10-11 m-2 s-1 for T=2°C, 36 PSU (Rebreanu et al., 2008). |
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| Temporal Coverage: | |
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| Start Date | 2020-01-01 |
| End Date | 2020-01-18 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | -67.59 |
| Northernmost | -62.2 |
| Longitude | |
| Westernmost | -68.28 |
| Easternmost | -58.72 |
| Altitude | |
| Min Altitude | N/A |
| Max Altitude | N/A |
| Depth | |
| Min Depth | 0 m |
| Max Depth | 300 m |
| Location: | |
| Location | Antarctica |
| Detailed Location | Marian Cove, Maxwell Bay, King George Island |
| Location | Antarctica |
| Detailed Location | Borgen Bay, Anvers Island |
| Location | Antarctica |
| Detailed Location | Sheldon Cove, Ryder Bay, Adelaide Island |
| Data Collection: | Oktopus 12-core multicorer Element2 High Resolution MC-ICP-MS, University of Bristol SEAL AA3 HR, Plymouth Marine Lab Pyro Science FireSting O2-mini sensor Finnigan Neptune Plus High Resolution MC-ICP-MS by Thermo Fisher Scientific, University of Bristol |
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| Data Storage: | 5 x csv files (total 76 KB) containing porewater elemental concentrations, seawater nutrient concentrations, station coordinates, porewater oxygen concentrations and benthic silica flux magnitudes, respectively. Benthic Si Flux: these are all parameters used to calculate the diffusive Si flux from the sediments (Jdiff), and the equation is within the metadata guidance form. Dsw = Diffusion coefficient in seawater Core-top [DSi] = the dissolved silicon concentration in seawater that sits just above the sediments, extracted when we extract sediment cores, hence "core-top". Surface porewater [DSi] = the dissolved silicon concentration in porewaters at 0.5cm within the sediment core. Dx = distance between core-top sample and porewater sample (0.5cm, used within Fick's law of diffusion equation) Jdiff = Benthic diffusive Si flux SE = Standard Error of Jdiff Porewater: d30Si = delta notation for stable isotope 30-silicon, it denotes the stable isotope ratio of 30Si/28Si. Its unit is permille. |
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