Dr Walter Geibert

Telephone: +44 (0) 131 651 7704
E-mail: walter.geibert@sams.ac.uk

Job Title: Senior Research Fellow in Ocean Circulation, Biogeochemical Cycles and Climate




Scientific interests
Quantification of marine biogeochemical fluxes using isotopes of the natural U/Th decay series, comprising:

• present and past particle fluxes to the sea floor
• interactions between the dissolved, colloidal and particulate pools of substances in the ocean
• biogeochemical cycling of trace elements in the ocean
• vertical mixing and deep upwelling in the ocean
• marine geochemistry of thorium, protactinium, uranium, actinium, and radium
• The Weddell Gyre
  

Current projects
Using radium and actinium isotopes as tracers of ocean dynamics A British-French co-operation with Dr Pieter van Beek, Toulouse, jointly funded by the British Council and Egide (ALLIANCE)

PI (1 of 2) in Physico-chemical modifications of marine dissolved organic matter A British-German co-operation with Prof Boris Koch, Bremerhaven, jointly funded by the British Council and DAAD (Academic Research Collaboration programme ARC

Participation in the "Antarctic Science Bursary" project of Amber Annett & Dr Raja Ganeshram (quantification of biogeochemical fluxes in an Antarctic coastal environment by means of short-lived radium isotopes)

Involved in the international GEOTRACES initiative

Primary production in the Eastern Weddell Gyre

Investigating the reasons for shallow remineralization in the Weddell Gyre

Investigating potential applications of sea water electrolysis
 

Teaching / supervising activities
WG has given introductury lectures in General an Inorganic Chemistry (University for Applied Sciences, Bremerhaven, Germany) from 2001-2007
He has supervised several Diploma/Master theses (Alfred Wegener Institute, Bremerhaven, Germany).
Currently, he is co-supervising one PhD student.
His most recent teaching activities (Edinburgh University) include lectures in Biogeochemistry and a one week field course in Environmental Geosciences.


Publications

Peer reviewed journals and book contributions

Martínez-Garcia, A., Rosell-Melé, A., Geibert, W., Gaspari, V., Masqué, P., Gersonde, R., and Barbante, C. (2009), Links between Fe supply, ocean productivity, sea surface temperature and CO₂ over the last 1.1 My: Paleoceanography 24, doi:10.1029/2008PA001657. external link to Paleoceanography

Bakker, D.C.E, Hoppema, M. Schröder, M., Geibert, W. and de Baar, H.J.W. (2008) A rapid transition from ice covered CO₂-rich waters to a biologically mediated CO₂ sink in the eastern Weddell Gyre. Biogeosciences, v. 5, p. 1373–1386

Geibert, W. (2008) Appendix A: Charts of the ²³⁸U, ²³⁵U, ²³²Th, and ²⁴¹Am Decay Series with Principal Modes of Decay, their Intensities and Energies-In: Krishnaswami, S. and Cochran, J.K. (Eds.), U and Th Series Radionuclides in Aquatic Systems, p. 417-423. Elsevier

Rutgers van der Loeff, M. M. and Geibert, W. (2008) U/Th series nuclides as tracers of particle dynamics, scavenging and biogeochemical cycles in the oceans.-In: Krishnaswami, S. and Cochran, J.K. (Eds.), U and Th Series Radionuclides in Aquatic Systems, p. 227-268. Elsevier

Geibert, W., Vöge, I. (2008). Progress in the determination of ²²⁷Ac in sea water, Marine Chemistry 109, p. 238-249. doi: 10.1016/j.marchem.2007.07.012

Geibert, W., Charette, M., Moore, W. S., Guebuem, K., Street, J., Young, M., Paytan, A. (2008). The release of dissolved actinium to the ocean: a global comparison of different end-members, Marine Chemistry 109, p. 409-420. doi: 10.1016/j.marchem.2007.07.005

Francois, R., Frank, M., Rutgers van der Loeff, M. M., Bacon, M. P., Geibert, W., Kienast, S., Anderson, R. F., Bradtmiller, L., Chase, Z., Henderson, G., Marcantonio, F., Allen, S. E. (2007). Comment on Do geochemical estimates of sediment focusing pass the sediment test in the equatorial Pacific? by Lyle et al., Paleoceanography, 22, PA1216. doi:10.1029/2005PA001235

Hanfland, C., Geibert, W., Voege, I., Rutgers van der Loeff, M.M. (2007) Atom-Uhren im Suedlichen Ozean. In Arktis und Antarktis zu Hause - 25 Jahre Forschungsschiff Polarstern. Delius Klasing Verlag.

Geibert, W., Rutgers van der Loeff, M. M., Usbeck, R., Gersonde, R., Kuhn, G., Seeberg-Elverfeldt, J. (2005). Quantifying the opal belt in the Atlantic and southeast Pacific sector of the Southern Ocean by means of 230Th normalization, Global biogeochemical cycles, 19, GB4001. doi:10.1029/2005GB002465

Geibert, W., Usbeck, R. (2004). The adsorption of Thorium and Protactinium onto different particle types: Experimental Findings, Geochimica et cosmochimica acta, 68(7), 1489-1501. doi:10.1016/j.gca.2003.10.011

Rutgers van der Loeff, M.M., Friedrich, J., Geibert, W., Hanfland, C., Höltzen, H., Vöge, I., Walter, H.J. (2004). Radionuclides as tracers for particle flux and transport of water masses in the Atlantic sector of the Southern Ocean, The South Atlantic in the Late Quaternary - Reconstruction of Material Budget and Current systems. Wefer, G., Ratmeyer, V. and Meinecke, G. (Eds.), Springer-Verlag : Berlin, Heidelberg, New York, Tokyo: 47-63.

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 (1/2), 147-165. doi:10.1016/S0012-821X(02)00512-5

Geibert, W. (2001). Actinium-227 als Tracer fuer Advektion und Mischung in der Tiefsee, Berichte zur Polar- und Meeresforschung, 385, 112pp, Universitaet Bremen. (Doctoral dissertation)

Walter, H. J., Geibert, W., Rutgers van der Loeff, M. M., Fischer, G., Bathmann, U. (2001). Shallow vs. deep-water scavenging of ²³¹Pa and ²³⁰Th in radionuclide enriched waters of the Atlantic sector of the Southern Ocean, Deep-Sea Research I, 48(2), 471-493. doi:10.1016/S0967-0637(00)00046-7

Selected presentations:

Kretschmer, S., Geibert, W., Schnabel, C., van der Loeff, M. R. & Mollenhauer, G. (2008). Distribution of Th-230, Be-10 and Pa-231 in sediment particle classes. Geochimica Et Cosmochimica Acta 72, A498-A498 (conference abstract of the Goldschmidt Conference 2008)

Geibert, W., Hanfland, C., van Beek, P. and Masque, P. (2008). Potential applications of the ²²⁷Ac/²²⁸Ra pair as a tracer for water masses. Talk during a workshop at the UNESCO office in Venice, Italy, 7-11 April 2008

Geibert, W. (2006). Applications of ²²⁷Ac as a tracer. Overview Lecture during a workshop at the Marine Environmantal Laboratory of the IAEA, Monaco, 2-6 October 2006

Geibert, W., Usbeck, R., Rutgers van der Loeff, M. M. (2003). Actinium-227 as a tracer for diapycnal mixing and deep upwelling, Keynote Lecture, 13th Annual Goldschmidt Conference, Kurashiki, Japan, Sept. 7-12, 2003.

Geibert, W., Walter, H. -J., Hanfland, C., Rutgers van der Loeff, M. M. (1998). Surface concentrations of ²²⁸Th, ²³⁰Th and ²³¹Pa in the Atlantic Sector of the Southern Ocean-the effects on paleoenvironmental applications, Mineralogical magazine, 62A, 511-512 (Goldschmidt conference abstract volume).

For more click here

Educational and career history

Diploma in Applied Physical Geography at the University of Trier, Germany, with a focus in Geology and Hydrology (1997)

PhD studies at the Alfred Wegener Institute for Polar and Marine Research (AWI), Bremerhaven, Germany, Marine Geochemistry
PhD (Dr rer nat) awarded at Bremen University (2000)

Postdoctoral Researcher, funded by Deutsche Forschungsgemeinschaft (DFG) at AWI, Bremerhaven, Germany (2001-2004)
Title of the project: "Actinium-227, Radium-223 and Radium-224 as tracers for fluxes in the deep sea"

Research Associate at AWI, Bremerhaven, Germany
Installing a HR-ICP-MS facility (Element2) for the analysis of natural radionuclides of the Th/U series (230Thxs, 231Pa, U-isotopes) and combined multielement analysis on marine sediments and sea water samples (2004-2007)

2007-now
Senior Research Fellow at SAMS/University of Edinburgh


Other (e.g. measures of esteem)

Reviews

WG is regularly active as a reviewer for several journals and funding agencies, including:

Earth an Planetary Science Letters, Deep-Sea Research Part I and Part II, Marine Chemistry, the US National Science Foundation, and more

Expeditions

1997/1998 9 weeks Weddell Gyre and Antarctica (RV “Polarstern”, Cape Town-Cape Town)²³¹Pa, ²³⁰Th and ²³⁴Th in surface waters, collecting suspended particles

2000 5 weeks Atlantic (RV “Polarstern”, Punta Arenas-Bremerhaven) Experimental studies on Pa/Th sorption, collecting suspended particles

2002/2003 9 weeks Weddell Gyre and Antarctica (RV “Polarstern”, Cape Town- Cape Town) “Synpart” study: Biogeochemistry and radiochemistry of the Eastern Weddell Gyre (chlorophyll, nutrients, 227Ac, 230Th, 234Th)

2005 5 days German Bight, (RV “Heincke”, North Sea), sampling radium isotopes for coastal mixing studies

2005 4 weeks Atlantic (RV “Polarstern”, Vigo - Cape Town) pre-GEOTRACES expedition, sorption experiments investigating the role of colloids for Th sorption, collecting suspended particles