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Goldschmidt 2012

24 June 2012 - 29 June 2012

Goldschmidt 2012
Dates: 24-29 June 2012
Location: Montréal – Canada

For further information:
 http://www.vmgoldschmidt.org/2012/index.htm

Abstract submission is closed.


Relevant sessions:

10a. Proxy development for paleoclimate and paleocean chemistry
Co-convenors: Ann Russell (University of California at Davis) – Pamela Martin (University of Chicago) – Bärbel Hönisch (Lamont-Doherty Earth Observatory

10c. Past and future changes in ocean circulation
Co-convenors: Eric Galbraith (GEOTOP-McGill University) – Laura Robinson (University of Bristol)

11a. Biogeochemical cycling of aerosols and their effects in the evolving Earth’s climate
(co-hosted by Themes 11 and 10)
Co-conveners: Nicholas Meskhidze (North Carolina State University) – Ina Tegen (Institute for Tropospheric Research, Leipzig, Germany)  

12b. Pa and Th distributions in the ocean: controlling mechanisms
(co-hosted by Themes 12 and 13)
Co-convenors: Abel Guihou (SUNY-Stony Brook) – Robert F Anderson (LDEO of Columbia University)

12e. Present and past biogeochemical cycling of nutrients and metals in high latitude marine environments
(co-hosted by Themes 12 and 16)
Co-convenors: Dr. Laura Wehrmann (University of California Riverside, USA) – Dr. Christian März (Newcastle University, UK) 

12g. Contribution of submarine groundwater discharge to oceanic chemical cycles
(co-hosted by Themes 12 and 22)
Co-convenors: Aaron Beck (Virginia Institute of Marine Science) – Richard Peterson (Coastal Carolina University)

13b. Geochemical proxies for past ocean circulation
Co-convenors: Anton Eisenhauer (IFM-GEOMAR/Kiel) – Steven L. Goldstein (Lamont-Doherty Earth Observatory) – Ralph Schneider (Universität Kiel)

13d. GEOTRACES, the international science program
Co-convenors: Géraldine Sarthou (Université de Brest) – Kazuyo Tachikawa (CEREGE, France) – Tina van De Flierdt (Imperial College, London)

17e.The application of synchrotron X-ray techniques to study marine biogeochemical cycles
Co-convenors: Phoebe J. Lam (Woods Hole Oceanographic Institution) – Brandy M. Toner ( University of Minnesota – Twin Cities) – Benjamin S. Twining (Bigelow Laboratory for Ocean Sciences)


Descriptions:

*10a. Proxy development for paleoclimate and paleocean chemistry
(co-hosted by Themes 10 and 13)
Co-convenors: Ann Russell (University of California at Davis) – Pamela Martin (University of Chicago) – Bärbel Hönisch (Lamont-Doherty Earth Observatory)
Development of geochemical proxies for reconstructing past climatic and ocean chemical conditions is a key component of paleoclimate and paleoceanographic research and essential for gleaning insight into the Earth’s future from its history. Archives of paleoenvironmental information include both biogenic and authigenic precipitates and isolating an environmental signal can be convoluted by post-depositional overgrowths. Covariation of environmental parameters can also make it difficult to calibrate the response of a proxy to a single environmental parameter. In deep time, additional complications can arise when the possible controls over proxy relationships are less constrained and different_from_modern seawater chemistry may change proxy relationships from the conditions under which the proxy was calibrated.
This session seeks to share progress on identifying the primary geochemical mechanisms and environmental controls over marine proxies, as well as approaches and tools for addressing post- depositional alteration. We welcome contributions focused on the geochemistry of proxies from carbonates, diatoms, organic material, as well as bulk sediments and authigenic precipitates. We encourage analytic method development and specifically contributions that go beyond empirical correlations between ocean parameters and proxy signals, which may improve the quality of proxy applications by delving into the mechanistic basis for the relationship.
Keynote speaker: TBA

*10c. Past and future changes in ocean circulation
Co-convenors: Eric Galbraith (GEOTOP-McGill University) – Laura Robinson (University of Bristol)
Despite decades of research, the large-scale drivers of deep-ocean circulation – and its susceptibility to change – remain poorly understood. Ocean mixing, especially vertical mixing, is of critical importance to this circulation, but is difficult to observe in the modern ocean. Paleoceanographic records offer great potential in constraining past changes in ocean circulation, which can help reveal natural variability of ocean mixing, while ocean models can provide insight into mechanisms, constrained by present-day observations. Together, these approaches help to predict the biogeochemical impacts of future changes in ocean circulation. This session aims to bring together geochemical observations and theory that can shed light on ocean mixing and its impacts on ocean circulation, and gas and nutrient cycling in the past, present and future. We invite contributions that can constrain or quantify deep ocean circulation on any timescale, and particularly encourage contributions that bear on vertical mixing in the ocean. We also welcome theoretical and modeling contributions that address the role of ocean circulation on biogeochemistry, or that help to interpret geochemical observations.
Keynote speaker: TBA

*11a. Biogeochemical cycling of aerosols and their effects in the evolving Earth’s climate
(co-hosted by Themes 11 and 10)
Co-conveners: Nicholas Meskhidze (North Carolina State University) – Ina Tegen (Institute for Tropospheric Research, Leipzig, Germany)
Climate projections remain an important scientific goal for the earth science community. A large fraction of the uncertainty in predicting climate change lies in the uncertainties associated with feedbacks in the carbon cycle and aerosol forcing. These feedbacks are the result of land-atmosphere-ocean natural and anthropogenic interactions. Understanding those interactions is of great importance for characterizing possible future changes in the evolving Earth. While aerosols are a source of micronutrients (iron, phosphorus, nitrogen) for the ecosystems, the emission and transformation processes of many aerosols (e.g. desert dust or secondary organic aerosols of biogenic sources) can themselves be influenced by biogeochemical processes. We invite submissions on lab/field measurements, remote sensing, and modeling that lead to process-level understanding of biogeochemical land-atmosphere-ocean interactions. Interdisciplinary research on deposition of dust and volcanic particles, heterogeneous chemical/photochemical transformation of aerosols, and in-situ studies for the effects of aerosols on ocean/terrestrial biogeochemistry are welcome. The earth system models with aerosol deposition coupled to the land-ocean biogeochemistry are in their infancy. Until such models can reliably reproduce the effect of aerosol deposition on carbon cycle, it will be problematic to estimate how changes in aerosol deposition over time might have affected the evolving climate of the Earth.

*12b. Pa and Th distributions in the ocean: controlling mechanisms
(co-hosted by Themes 12 and 13)
Co-convenors: Abel Guihou (SUNY-Stony Brook) – Robert F Anderson (LDEO of Columbia University)
231Pa and long-lived Th isotopes are naturally occurring radionuclides. Their potential to provide quantitative information of modern and past oceanographic processes (such as large scale ocean circulation and particle fluxes and dissolution) has been acknowledged for decades. However, some uncertainties still remain regarding what actually controls their distribution in the ocean. This session invites contributions aimed to better understand these mechanisms such has new dissolved and particulate water column profiles, new views on the distribution of these radionuclides onto particles from natural samples or from laboratory experiments as well as modeling studies.
Keynote speaker: Michiel Rutgers van der Loeff (Alfred Wegener Institute for Polar and Marine Research)

*12e. Present and past biogeochemical cycling of nutrients and metals in high latitude marine environments
(co-hosted by Themes 12 and 16)
Co-convenors: Dr. Laura Wehrmann (University of California Riverside, USA) – Dr. Christian März (Newcastle University, UK) 
This session targets the emerging field of biogeochemical research in Arctic and Antarctic environments, with a focus on understanding the role of the high latitudes for global element cycles (C, N, P, S, Si, transition metals) at present and in the past. We welcome contributions elucidating the cycling of these elements in the water column, at the ice-sediment and sediment-water interface, in shallow as well as in deeply buried marine sediments of high latitude environments. This session aims to gather scientists studying Arctic and Antarctic fjords, estuaries and river mouths, glacial and pro-glacial environments, as well as associated continental shelves, slopes, and the deep oceans. Topics of particular interest include, but are not limited to the (coupled) cycling of carbon, sulphur, phosphorus, iron and manganese in Arctic and Antarctic sediments; the overprint of paleoclimate proxies by biogeochemical processes; the role of microbial processes in shaping the diagenetic characteristics of high latitude environments; biogeochemical interactions between glaciers and the coastal ocean; the role of high latitude environments for global biogeochemical cycles in the past. We especially encourage contributions that apply multidisciplinary approaches, novel analytical techniques, and computer modelling to natural samples and/or in laboratory experiments.
Keynote speaker: Prof. Rob Raiswell (Emeritus), School of Earth and Environment, University of Leeds, UK

*12g. Contribution of submarine groundwater discharge to oceanic chemical cycles
(co-hosted by Themes 12 and 22)
Co-convenors: Aaron Beck (Virginia Institute of Marine Science) – Richard Peterson (Coastal Carolina University)
Submarine groundwater discharge (SGD) comprises all water transported by advection across the permeable sediment-water interface, including both fresh groundwater and recirculated seawater. Biogeochemical reactions such as ion exchange, dissolution and precipitation, and metal redox cycling occur in the subsurface mixing zone of fresh and saline groundwaters (the “subterranean estuary”), resulting in brackish SGD that can be very different in composition from either of the original end-members. Further, the advection of groundwater through the diagenetic zone can mobilize regenerated nutrients, and serve as a transport pathway of these recycled nutrients back to the water column. A growing body of work demonstrates the importance of SGD and subterranean estuaries to marine budgets of nutrients, radionuclides, and trace elements. Understanding current SGD-driven chemical fluxes is critical for predicting how future changes in the hydrologic cycle, coastal margins, and anthropogenic factors may affect chemical cycling in the ocean. This session will explore the role of SGD and the subterranean estuary in controlling chemical fluxes between land and sea. We especially encourage studies that assess the ecological impact of these fluxes, which is yet relatively unrepresented in this field.

*13b. Geochemical proxies for past ocean circulation
Co-convenors: Anton Eisenhauer (IFM-GEOMAR/Kiel) – Steven L. Goldstein (Lamont-Doherty Earth Observatory) – Ralph Schneider (Universität Kiel) 
The ocean circulation is an important aspect for the marine trace metal and nutrient cycling for the Present and in the Past. In particular, ocean circulation interferes with the global carbon cycle influencing atmospheric pCO2 as well as long and short term climate change. In order to better understand present and past biogeochemical cycles it is most important to document and understand ocean dynamics on all time scales. Past changes in ocean circulation can only be reconstructed from geological archives, among others, through the application and interpretation of geochemical proxies. This session invites contributions addressing new developments and findings, both experimental and theoretical, on the application of geochemical proxies, trace elements and isotopes to reconstruct past ocean dynamics.
Keynote speaker: Gerald H. Haug (ETH Zürich) 

*13d. GEOTRACES, the international science program
Co-convenors: Géraldine Sarthou (Université de Brest) – Kazuyo Tachikawa (CEREGE, France) – Tina van De Flierdt (Imperial College, London)
Many trace elements are critical for marine life, and affect the functioning of ocean ecosystems. On the other hand, some trace elements and isotopes are used to track modern ocean processes, and if they are recorded faithfully in marine archives, they are powerful indicators of past changes. International science program GEOTRACES aims at identifying processes, quantifying fluxes and establishing the sensitivity of the distribution of key trace elements and isotopes. We invite contributions that focus on fluxes and processes at ocean interfaces, internal cycle of the trace elements and isotopes, and development of proxies for past changes, based on experimental and/or modelling approaches. Results from the recent GEOTRACES cruise are particularly welcome.

*17e.The application of synchrotron X-ray techniques to study marine biogeochemical cycles
Co-convenors: Phoebe J. Lam (Woods Hole Oceanographic Institution) – Brandy M. Toner ( University of Minnesota – Twin Cities) – Benjamin S. Twining (Bigelow Laboratory for Ocean Sciences)
Synchrotron X-ray techniques in the soft, “tender”, and hard x-ray energy ranges are increasingly applied to address questions in marine science. Applications have included two- and three-dimensional element-specific imaging at nanometer to micron scales to determine cell quotas and elemental distributions and function, and spectroscopic analyses to determine the speciation, provenance, and bioavailability of key nutrients such as phosphorus and iron. We invite abstracts from researchers who are already applying synchrotron techniques to marine problems, as well as those whose work in other areas of Earth science might be applicable to topics in marine biogeochemical cycling. For example, poorly understood processes such as scavenging of trace metals in the ocean might be informed by studies of complexation of surface-adsorbed species onto model minerals and microorganisms. Similarly, mechanisms of elemental substitution in inorganic and biominerals may change the stability and thus biogeochemical role of these minerals in the oceans. We envision a session enabling cross-fertilization of ideas between laboratory and field researchers, and biologists and geochemists.
Keynote speaker: Jay Brandes (Skidaway Institute of Oceanography)

 

Details

Start:
24 June 2012
End:
29 June 2012
Event Category:

Rechercher