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Use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern Marguerite Bay, Antarctic Peninsula

Part of: Antarctic Science International Bursary collection: Geosciences

Published online by Cambridge University Press:  29 October 2012

Amber L. Annett ,
Sian F. Henley ,
Pieter Van Beek ,
Marc Souhaut ,
Raja Ganeshram ,
Hugh J. Venables ,
Michael P. Meredith  and
Walter Geibert
Amber L. Annett*
Affiliation:
School of GeoSciences, University of Edinburgh, EdinburghEH9 3JW, UK
Sian F. Henley
Affiliation:
School of GeoSciences, University of Edinburgh, EdinburghEH9 3JW, UK
Pieter Van Beek
Affiliation:
Laboratoire d'Etudes en Geophysique et Oceanographie Spatiales (CNRS/UPS/IRD/CNES), Observatoire Midi Pyrénées, Toulouse, France
Marc Souhaut
Affiliation:
Laboratoire d'Etudes en Geophysique et Oceanographie Spatiales (CNRS/UPS/IRD/CNES), Observatoire Midi Pyrénées, Toulouse, France
Raja Ganeshram
Affiliation:
School of GeoSciences, University of Edinburgh, EdinburghEH9 3JW, UK
Hugh J. Venables
Affiliation:
British Antarctic Survey, NERC, High Cross, Madingley Road, Cambridge CB3 0ET, UK
Michael P. Meredith
Affiliation:
British Antarctic Survey, NERC, High Cross, Madingley Road, Cambridge CB3 0ET, UK
Walter Geibert
Affiliation:
School of GeoSciences, University of Edinburgh, EdinburghEH9 3JW, UK Scottish Association for Marine Science (SAMS), Scottish Marine Institute, Oban, UK
*
[email protected]
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Abstract

In the western Antarctic Peninsula region, micronutrient injection facilitates strong plankton blooms that support productive food webs, unlike large areas of the low-productivity Southern Ocean. We use naturally occurring radioisotopes of radium to constrain rates of chemical fluxes into Ryder Bay (a small coastal embayment in northern Marguerite Bay), and hence to evaluate possible sources of sediment-derived micronutrients and estimate sediment-ocean mixing rates. We present the first coupled, short-lived radium isotope (223Ra and 224Ra) measurements from Antarctic waters, both present at very low activities (mean 0.155 and 3.21 dpm m-3, respectively), indicating much lower radium inputs than in other coastal environments. Longer-lived 228Ra activity was also lower than existing nearshore values, but higher than open ocean waters, indicating some degree of coastal radium input on timescales exceeding the week-to-month range reflected by 223Ra and 224Ra. Using a simple diffusion model along a shore to mid-bay transect, effective horizontal eddy diffusivity estimates ranged from 0.22–0.83 m2 s-1 from 223Ra and 224Ra, respectively, much lower than already-low mixing estimates for the Southern Ocean. Significant radium enrichment and much faster mixing (18 m2 s-1) was found near a marine-terminating glacier and consequently any sediment-derived micronutrient inputs in this location are more probably dominated by glacial processes than groundwater, land runoff, or marine sediment sources.

Keywords

actinium-227glacial inputshorizontal eddy diffusivityland-ocean interfaceRadium Delayed Coincidence Counter (RaDeCC)Ryder Bay
Type
Physical Sciences
Information
Antarctic Science , Volume 25 , Issue 3 , June 2013 , pp. 445 - 456
Copyright
Copyright © Antarctic Science Ltd 2012 

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References

Charette, M.A., Buesseler, K.O.Andrews, J.E. 2001. Utility of radium isotopes for evaluating the input and transport groundwater-derived nitrogen to a Cape Cod estuary. Limnology and Oceanography, 46, 465–470.CrossRefGoogle Scholar
Charette, M.A., Gonneea, M.E., Morris, P.J., Statham, P., Fones, G., Planquette, H., Salter, I.Garabato, A.N. 2007. Radium isotopes as tracers of iron sources fuelling a Southern Ocean phytoplankton bloom. Deep-Sea Research II, 54, 1989–1998.CrossRefGoogle Scholar
Clarke, A., Meredith, M.P., Wallace, M.I., Brandon, M.A.Thomas, D.N. 2008. Seasonal and interannual variability in temperature, chlorophyll and macronutrients in northern Marguerite Bay, Antarctica. Deep-Sea Research II, 55, 1988–2006.CrossRefGoogle Scholar
Cochran, J.K.Krishnaswami, S. 1980. Radium, thorium, uranium and 210Pb in deep-sea sediments and sediment pore waters from the north equatorial Pacific. American Journal of Science, 280, 849–889.CrossRefGoogle Scholar
Cook, A.J., Fox, A.J., Vaughan, D.G.Ferrigno, J.G. 2005. Retreating glacier fronts on the Antarctic Peninsula over the past half-century. Science, 308, 541–544.CrossRefGoogle ScholarPubMed
Dimova, N., Dulaiova, H., Kim, G.Burnett, W.C. 2008. Uncertainties in the preparation of 224Ra Mn fiber standards. Marine Chemistry, 109, 220–225.CrossRefGoogle Scholar
Dulaiova, H., Ardelan, M.V., Henderson, P.B.Charette, M.A. 2009. Shelf-derived iron inputs drive biological productivity in the southern Drake Passage. Global Biogeochemical Cycles, 10.1029/2008GB003406.CrossRefGoogle Scholar
Garcia-Solsona, E., Garcia-Orellana, J., Masqué, P.Dulaiova, H. 2008. Uncertainties associated with 223Ra and 224Ra measurements in water via a Delayed Coincidence Counter (RaDeCC). Marine Chemistry, 109, 198–219.CrossRefGoogle Scholar
Geibert, W.Vöge, I. 2008. Progress in the determination of 227Ac in sea water. Marine Chemistry, 109, 238–249.CrossRefGoogle Scholar
Geibert, W., Rutgers van der Loeff, M.M., Hanfland, C.Dauelsberg, H.-J. 2002. Actinium-227 as a deep-sea tracer: sources, distribution and applications. Earth and Planetary Science Letters, 198, 147–165.CrossRefGoogle Scholar
Hanfland, C. 2002. Radium-226 and radium-228 in the Atlantic sector of the Southern Ocean. PhD thesis, University of Bremen, 135 pp.Google Scholar
Hoffmann, L.J., Peeken, I.Lochte, K. 2008. Iron, silicate, and light co-limitation of three Southern Ocean diatom species. Polar Biology, 31, 1067–1080.CrossRefGoogle Scholar
Howard, S.L., Hyatt, J.Padman, L. 2004. Mixing in the pycnocline over the western Antarctic Peninsula shelf during Southern Ocean GLOBEC. Deep-Sea Research II, 51, 1965–1979.CrossRefGoogle Scholar
Jeandel, C., Peucker-Ehrenbrink, B., Jones, M.T., Pearce, C.R., Oelkers, E.H., Godderis, Y., Lacan, F., Aumont, O.Arsouze, T. 2011. Ocean margins: the missing term in oceanic element budgets? Eos Transactions, 92, 217–224.CrossRefGoogle Scholar
Klinck, J. 1998. Heat and salt changes on the continental shelf west of the Antarctic Peninsula between January 1993 and January 1994. Journal of Geophysical Research, 103, 7617–7636.CrossRefGoogle Scholar
Martinson, D.G., Stammerjohn, S.E., Iannuzzi, R.A., Smith, R.C.Vernet, M. 2008. Western Antarctic Peninsula physical oceanography and spatio-temporal variability. Deep-Sea Research II, 55, 1964–1987.CrossRefGoogle Scholar
Meredith, M.P.King, J.C. 2005. Rapid climate change in the ocean west of the Antarctic Peninsula during the second half of the 20th century. Geophysical Research Letters, 10.1029/2005GL024042.Google Scholar
Meredith, M.P., Venables, H.J., Clarke, A., Ducklow, H.J., Erickson, M., Leng, M.J., Lenaerts, J.T.M.van den Broeke, M.R. In press. The freshwater system west of the Antarctic Peninsula: spatial and temporal changes. Journal of Climate.Google Scholar
Meredith, M.P., Wallace, M.I., Stammerjohn, S.E., Renfrew, I.A., Clarke, A., Venables, H.J., Shoosmith, D.R., Souster, T.Leng, M.J. 2010. Changes in the freshwater composition of the upper ocean west of the Antarctic Peninsula during the first decade of the 21st century. Progress in Oceanography, 87, 127–143.CrossRefGoogle Scholar
Moffat, C., Owens, B.Beardsley, R.C. 2009. On the characteristics of Circumpolar Deep Water intrusions to the west Antarctic Peninsula continental shelf. Journal of Geophysical Research, 10.1029/2008JC004955.CrossRefGoogle Scholar
Moffat, C., Beardsley, R.C., Owens, B.van Lipzig, N. 2008. A first description of the Antarctic Peninsula coastal current. Deep-Sea Research II, 55, 277–293.CrossRefGoogle Scholar
Montes-Hugo, M., Doney, S.C., Ducklow, H.W., Fraser, W., Martinson, D., Stammerjohn, S.E.Schofield, O. 2009. Recent changes in phytoplankton communities associated with rapid regional climate change along the western Antarctic Peninsula. Science, 323, 1470–1473.CrossRefGoogle ScholarPubMed
Moore, W.S. 2000a. Determining coastal mixing rates using radium isotopes. Continental Shelf Research, 20, 1993–2007.CrossRefGoogle Scholar
Moore, W.S. 2000b. Ages of continental shelf waters determined from 223Ra and 224Ra. Journal of Geophysical Research, 105, 22 117–22 122.CrossRefGoogle Scholar
Moore, W.S. 2008. Fifteen years experience in measuring 224Ra and 223Ra by delayed-coincidence counting. Marine Chemistry, 109, 188–197.CrossRefGoogle Scholar
Moore, W.S.Arnold, R. 1996. Measurement of 223Ra and 224Ra in coastal waters using a delayed coincidence counter. Journal of Geophysical Research, 101, 1321–1329.CrossRefGoogle Scholar
Pritchard, H.D., Ligtenberg, S.R.M., Fricker, H.A., Vaughan, D.G., van den Broeke, M.R.Padman, L. 2012. Antarctic ice sheet loss driven by basal melting of ice shelves. Nature, 484, 502–505.CrossRefGoogle ScholarPubMed
Raiswell, R. 2011. Iceberg-hosted nanoparticulate Fe in the Southern Ocean mineralogy, origin, dissolution kinetics and source of bioavailable Fe. Deep-Sea Research II, 58, 1364–1375.CrossRefGoogle Scholar
Rutgers van der Loeff, M.M. 1994. 228Ra and 228Th in the Weddell Sea. In Johannessen, O.M., Muench, R.D. & Overland, J.E., eds. The polar oceans and their role in shaping the global environment. The Nansen centennial volume. Geophysical Monograph Series, 85, 177–186.Google Scholar
Scholten, J.C., Pham, M.K., Blinova, O., Charette, M.A., Dulaiova, H.Eriksson, M. 2010. Preparation of Mn-fiber standards for the efficiency calibration of the delayed coincidence counting system (RaDeCC). Marine Chemistry, 121, 206–214.CrossRefGoogle Scholar
Shaw, T.J.Moore, W.S. 2002. Analysis of 227Ac in seawater by delayed coincidence counting. Marine Chemistry, 78, 197–203.CrossRefGoogle Scholar
Shaw, T.J., Raiswell, R., Hexel, C.R., Vu, H.P., Moore, W.S., Dudgeon, R.Smith, K.L. 2011. Input, composition, and potential impact of terrigenous material from free-drifting icebergs in the Weddell Sea. Deep-Sea Research II, 58, 1376–1383.CrossRefGoogle Scholar
Smale, D.A., Barnes, D.K.A., Fraser, K.P.P.Peck, L.S. 2008. Benthic community response to iceberg scouring at an intensely disturbed shallow water site at Adelaide Island, Antarctica. Marine Ecology Progress Series, 355, 85–94.CrossRefGoogle Scholar
Stammerjohn, S.E., Martinson, D.G., Smith, R.C., Yuan, X.Rind, D. 2008. Trends in Antarctic annual sea ice retreat and advance and their relation to El Niño–Southern Oscillation and Southern Annular Mode variability. Journal of Geophysical Research, 10.1029/2007JC004269.CrossRefGoogle Scholar
Van Beek, P., Souhaut, M.Reyss, J.-L. 2010. Measuring the radium quartet (226Ra, 228Ra, 224Ra, 223Ra) in water samples using gamma spectrometry. Journal of Environmental Radioactivity, 101, 521–529.CrossRefGoogle ScholarPubMed
Van Beek, P., Bourquin, M., Reyss, J-.L., Souhaut, M., Charette, M.A.Jeandel, C. 2008. Radium isotopes to investigate the water mass pathways on the Kerguelen Plateau (Southern Ocean). Deep-Sea Research II, 55, 622–637.CrossRefGoogle Scholar
Van Beek, P., Souhaut, M., Lansard, B., Bourquin, M., Reyss, J-L., Jean, P.von Ballmoos, P. In press. LAFARA: A new underground laboratory in the French Pyrénées for ultra low-level gamma-ray spectrometry. Journal of Environmental Radioactivity.Google Scholar
Vaughan, D.G., Marshall, G.J., Connolley, W.M., Parkinson, C., Mulvaney, R., Hodgson, D.A., King, J.C., Pudsey, C.J.Turner, J. 2003. Recent rapid regional climate warming on the Antarctic Peninsula. Climatic Change, 60, 243–274.CrossRefGoogle Scholar
Venables, H.J., Clarke, A.Meredith, M.P. In press. Wintertime controls on summer stratification and productivity at the western Antarctic Peninsula. Limnology and Oceanography.Google Scholar
Wallace, M.I., Meredith, M.P., Brandon, M.A., Sherwin, T.J., Dale, A.Clarke, A. 2008. On the characteristics of internal tides and coastal upwelling behaviour in Marguerite Bay, west Antarctic Peninsula. Deep-Sea Research II, 55, 2023–2040.CrossRefGoogle Scholar