Dr. Tobias Goldhammer

• Research activities
• Curriculum vitae
• Pipeline

Motivation of my research is to contribute to the understanding of global biogeochemical cycles and the influence of changing environmental conditions on ecosystems over time - both in geological history and today. In the oceans, I am particularly interested in the closely coupled cycling of carbon, iron and phosphorus, both in the open water and in the seabed, and the role that microorganisms play in the various transformations of these elements.

I use a wide set of techniques - from bench-scale incubation experiments to sediment sampling in the open ocean, accompanied by geochemical analyses on aqueous and solidphase samples and analytical and numerical modelling. I am particularly fond of stable and radioisotope tracing techniques, as they provide elegant tools to discover microbial pathways of element cycles.

In MARUM project GB2, we investigate fluxes and transformations of the nutrients nitrogen, iron and phosphorus in the water column, the benthic boundary layer, and the upper seabed.

Pictures from left to right: First - That Grand Subject. Second - Micro-precipitation of silver phosphate. We investigate oxygen isotopes in ultra-low amounts of natural phosphate as found e.g. in pore waters of marine sediments. Third - Microscopy of the large sulfur bacterium Thiomargarita namibiensis (A). We use beta-radiography to visualize the phosphate uptake of these organisms with a radioactive phosphate tracer (B).

Desk

• Goldhammer T, et al. (in prep.) Understanding the marine phosphate oxygen isotope continuum: isotope concepts versus environmental data.

Peer-reviewed papers

• Lin YS, Heuer VB, Goldhammer T, Kellermann MY, Zabel M, Hinrichs KU (2012) Towards constraining H2 concentration in subseafloor sediment: a proposal for combined analysis by two distinct approaches. Geochimica et Cosmochimica Acta 77 186-201 doi:10.1016/j.gca.2011.11.008
• Goldhammer T, Brunner B, Bernasconi S, Ferdelman T, Zabel M (2011) Phosphate oxygen isotopes: insights into sedimentary phosphorus cycling from the Benguela upwelling system. Geochimica et Cosmochimica Acta 75(13) 3741-3756 doi:10.1016/j.gca.2011.04.006
• Goldhammer T, Max T, Brunner B , Einsiedl F, Zabel M (2011) Marine sediment pore-water profiles of phosphate δ18O using a refined micro-extraction. Limnology and Oceanography: Methods 9 110-120 doi:10.4319/lom.2011.9.110
• Goldhammer T, Brüchert V, Ferdelman TG, Zabel M (2010) Microbial sequestration of phosphorus in anoxic upwelling sediments. Nature Geoscience 3 557-561 doi:10.1038/ngeo913
• Von Suchodoletz H, Oberhänsli H, Faust D, Fuchs M, Blanchet C, Goldhammer T, Zöller L (2010) The evolution of Saharan dust input on Lanzarote (Canary Islands) - influenced by human activity in the northwest Sahara during the Early Holocene? The Holocene 20(2) 1-11 doi:10.1177/0959683609350385
• Goldhammer T, Einsiedl F, Blodau C (2008) In situ determination of sulfate turnover in peatlands: a downscaled push-pull tracer technique. Journal of Plant Nutrition and Soil Science 171(5) 740-750doi:10.1002/jpln.200700225
• Goldhammer T, Blodau C (2008) Dessication and product accumulation constrain heterotrophic anaerobic respiration in peats of an ombrotrophic temperate bog. Soil Biology and Biochemistry 40(8) 2007-2015 doi:10.1016/j.soilbio.2008.03.005
• Heitmann T, Goldhammer T, Beer J, Blodau C (2007) Electron transfer processes of dissolved organic matter and their potential significance for anaerobic respiration in a northern bog. Global Change Biology 13(8) 1771-1785 doi:10.1111/j.1365-2486.2007.01382.x

Posters + Talks

• Goldhammer T (2011) Isotope studies of the benthic phosphorus cycle. Invited seminar at Institute of Landscape Ecology, University of Münster, 20.12.2011. more...
• Yoshinaga MY, Pohlman JW, Goldhammer T, Broda N, Riedel M, Elvert M, Hinrichs KU (2011) Methane fluxes modulating the molecular and carbon isotopic composition of microbial lipids in gas hydrate bearing sediments from the northern Cascadia margin. Abstract P-451, IMOG, Interlaken, 18.-23.09.2011
• Goldhammer T (2011) Isotope signatures of marine microbial phosphorus cycling. Invited Seminar, Climate Geology, ETH D-ERDW, Zurich, 24.05.2011
• Goldhammer T, Bernasconi S, Brüchert V, Brunner B, Ferdelman T, Zabel M (2009) Isotope investigations of microbial P cycling in Benguela sediments. Invited Talk, Microbiogeochemistry Seminar, ICBM Oldenburg, 01.12.2009
• Goldhammer T, Brunner B, Ferdelman T, Zabel M (2009) Phosphate oxygen isotopes and microbial activity in the marine subsurface. Goldschmidt Conference, Davos, Switzerland, 21.-26.06.2009
• Brunner B, Goldhammer T, Templer S, Bernasconi S (2009) Dissimilatory sulfate reduction: why is the oxygen isotope equilibrium value where it is? Goldschmidt Conference, Davos, Switzerland, 21.-26.06.2009
• Brüchert V, Goldhammer T, Ferdelman T, Zabel M (2009) Sulfide-oxidizing bacteria mediate apatite formation in phosphorite-bearing sediments of the Namibian upwelling system – evidence from 33P-labeling experiments. Goldschmidt Conference, Davos, Switzerland, 21.-26.06.2009
• Blanchet CL, Broder T, Goldhammer T, Freudenthal T, Stuut JB (2009) Sedimentary patterns on Cape Ghir margin (Morocco) during the past 30 kyr deciphered by their magnetic and geochemical properties. EGU General Assembly, Geophysical Research Abstracts 11, EGU2009-XXX
• Arnold GL, Goldhammer T, Formolo M, Brunner B, Ferdelman T (2008) Molybdenum cycling in upwelling sediments: an example from Namibian margin sediments. Poster, AGU Fall Meeting, San Francisco
• Blanchet CL, Broder T, Goldhammer T (2008) Sedimentary dynamics off Cape Ghir margin (Morocco). Clues from magnetic and geochemical properties. EGU General Assembly, Geophysical Research Abstracts 10, EGU2008-A-07220
• Blanchet CL, Broder T, Goldhammer T, Kuhlmann H (2007) Sedimentary dynamics on Cape Ghir margin (Morocco). International Conference and 97th Annual Meeting of the Geologische Vereinigung, Bremen
• Goldhammer T, Zabel M (2007) Tracking microbial life in the marine subsurface. Geochimica et Cosmochimica Acta 71(15):Goldschmidt Conference Supplement 1, A338
• Goldhammer T, Blodau C (2007) Anaerobic peat respiration at its limits - effects of dessication and product accumulation. Poster, PeatNet Carbon Conference, Wageningen, The Netherlands, 15.-17.04.2007
• Blodau C, Goldhammer T, Heitmann T (2006) Electron transfer of DOM during a water table fluctuation and its significance for carbon and sulfur cycling in a northern bog. EOS Transactions, AGU, 87(52), Fall Meeting Supplement, Abstract B33A-1166
• Goldhammer T, Blodau C (2005) In situ determination of sulfate reduction in peatlands: a downscaled push-pull test technique. EOS Transactions, AGU, 86(52), Fall Meeting Supplement, Abstract B33E-1078