| Volumes and Issues Contents of Issue 4 Special Issue |
www.biogeosciences-discuss.net/6/6441/2009/
© Author(s) 2009. This work is distributed
under the Creative Commons Attribution 3.0 License.
The role of airborne volcanic ash for the surface ocean biogeochemical iron-cycle: a review
1IFM-GEOMAR, Leibniz-Institute of Marine Sciences, Division Dynamics of the Ocean Floor, Wischhofstrasse 1–3, 24148 Kiel, Germany
2IFM-GEOMAR, Leibniz-Institute of Marine Sciences, Division Marine Biogeochemistry, Düsternbrooker Weg 20, 24105 Kiel, Germany
3Department of Plant and Environmental Sciences, Göteborg University, Carl Skottsberg Gata 22 B, 40530 Göteborg, Sweden
4Department of Chemistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
Abstract. Iron is a key micronutrient for phytoplankton growth in the surface ocean. Yet the significance of volcanism for the marine biogeochemical iron-cycle is poorly constrained. Recent studies, however, suggest that offshore deposition of airborne ash from volcanic eruptions is a way to inject significant amounts of bio-available iron into the surface ocean. Volcanic ash may be transported up to several tens of kilometres high into the atmosphere during large-scale eruptions and fine ash may encircle the globe for years, thereby reaching even the remotest and most iron-starved oceanic areas. Scientific ocean drilling demonstrates that volcanic ash layers and dispersed ash particles are frequently found in marine sediments and that therefore volcanic ash deposition and iron-injection into the oceans took place throughout much of the Earth's history. The data from geochemical and biological experiments, natural evidence and satellite techniques now available suggest that volcanic ash is a so far underestimated source for iron in the surface ocean, possibly of similar importance as aeolian dust. Here we summarise the development of and the knowledge in this fairly young research field. The paper covers a wide range of chemical and biological issues and we make recommendations for future directions in these areas. The review paper may thus be helpful to improve our understanding of the role of volcanic ash for the marine biogeochemical iron-cycle, marine primary productivity and the ocean-atmosphere exchange of CO2 and other gases relevant for climate throughout the Earth's history.
Discussion Paper (PDF, 1190 KB) Interactive Discussion (Closed, 4 Comments) Final Revised Paper (BG)
Citation: Duggen, S., Olgun, N., Croot, P., Hoffmann, L., Dietze, H., and Teschner, C.: The role of airborne volcanic ash for the surface ocean biogeochemical iron-cycle: a review, Biogeosciences Discuss., 6, 6441-6489, 2009. Bibtex EndNote Reference Manager
