European Geosciences Union (EGU) General Assembly 2009

04/19/2009 00:00
04/24/2009 17:00

European Geosciences Union
General Assembly 2009
Vienna, Austria, 19 - 24 April 2009

Sessions of interest to InterRidge:
GM9.3: Seafloor expression of tectonic and geomorphic processes
Conveners: Sebastian Krastel, Colin Jacobs, Dina Vachtman
Seafloor depth records preserve a wealth of information about tectonic (e.g. fault scarps), geomorphic (e.g. channel erosion and landsliding), volcanic and geodynamic processes. High quality bathymetry, especially when combined with sub-seafloor measurement, provides an exciting opportunity to combine geomorphology and geophysics and to extend quantitative geomorphology offshore.
This interdisciplinary session aims to examine the causes and consequences of the underwater landscape. The goal is to stimulate interdisciplinary work by bringing together researchers who quantify and characterize the shapes that form the seafloor, seek to understand the sub-surface processes at work and their impacts, or use bathymetry as a model input. A range of depths from oceanic (e.g. oceanic plateaus and abyssal hills), through mid-ocean ridges to accretionary wedges and continental margin are expected. Datasets from satellite-predicted depth to ultra high-resolution deep tow swath are anticipated.
We welcome any exciting submissions in the spirit of the session, even if your particular process or bathymetric expression has not been explicitly mentioned, e.g.: Hot-spot ridge interaction; Submerged glacial geomorphology; What governs the relative dominance of canyon erosion and landsliding as mass wasting processes?

GMPV7: New perspectives on the nature and evolution of the oceanic

Conveners: Costanza Bonadiman, Marguerite Godard, Else-Ragnhild Neumann
Recent geochemical, petrological and geophysical data have revised our picture of how the oceanic lithosphere is formed and what it represents for the solid earth.
The most recent developments and results in these different fields have underlined the strong heterogeneities in the structure and composition of the oceanic lithosphere, and have invoked processes such as melt/rock interactions at the asthenosphere- lithosphere transition, asthenospheric rejuvenation of the subcontinental lithospheric mantle (SCLM), large scale movements of lithospheric fragments subducted and recycled in the convective mantle and the preservation of the geochemical characteristics of such fragments over long periods of time, in addition to the well-established process of depletion of the oceanic mantle lithosphere after MORB extraction.
In this session, we encourage contributions which investigate mantle xenoliths from oceanic islands, ophiolitic complexes and dredged and drilled material from the oceanic lithosphere (i.e. IODP) and cover the entire spectrum of geological sciences, from petrology, geochemistry, geophysical measurements to physical and thermodynamic modelling, mineral physics, experimental petrology and rock deformation studies.

GMPV11: Deep-sea hydrothermal systems: new insights from experiments, theory, and observations
Convener: L. Ruepke
Co-Conveners: C. Devey, W. Bach
The discovery of hydrothermal systems at mid-ocean ridges in the late 1970s was one of the most exciting achievements in oceanography – not least because of its importance for different fields of geosciences. Hydrothermal systems efficiently mine heat from the young ocean crust, thermal springs at the seafloor host unique ecosystems in extreme environmental conditions and commercially interesting high-quality ore deposits form as a byproduct of hydrothermal venting.
Much has been learned from marine surveys of mid-ocean ridge segments and direct observations of vent sites at the ocean floor. The deep chemical and physical processes that control hydrothermalism remain, however, largely inaccessible to direct sampling and observations. Understanding those remote physicochemical processes requires interdisciplinary research including experiments of fluid-rock interaction, theoretical work on the thermodynamics of the key reactions, numerical simulations of reactive transport through fractured rock, detailed seafloor imaging and sampling, and studies of fossil hydrothermal systems at ophiolite complexes.
This session aims at bringing together researchers working in these different fields to discuss the recent advances in cross-disciplinary research on deep-sea hydrothermal systems.

TS5.1: Couplings between magmatic, tectonic and hydrothermal processes at mid-ocean ridges
Convener: F. Fontaine
Co-Conveners: J. Lissenberg, J. Escartin, A. Delacour, M. Andreani
Multidisciplinary investigations of mid-ocean ridges over the last decades reveal that accretion of oceanic crust results from the complex interplay of magmatic and tectonic processes and that fluid circulation within the crust has a major role in hydrothermal activity and deformation processes. However, many aspects concerning fluid-rock interaction, hydrothermal circulation, melt migration and cooling, melt distribution and mantle outcropping at ultra-slow ridges, magmatic or amagmatic extension, evolution of oceanic core complexes, and formation of fault zones, are still debated. This session aims to bring together scientists from various disciplines (geophysics, geochemistry, mineralogy, structural geology, numerical modeling) interested in these different themes and in the formation and evolution of the oceanic crust along ridges, and the interactions between magmatic, tectonic and hydrothermal processes.

TS9.2: Plate tectonics in the Indian Ocean: a tribute to Roland Schlich
Convener: J. Dyment (
Co-Conveners: M. Schaming, D. Weis
Roland Schlich is one of the pioneers who sailed and explored the structure, age, and evolution of the Indian Ocean from the sixties to the early nineties, at a time when GPS and satellite altimetry were not available, even in dreams. In recognition to his achievements, we propose a session dedicated to geophysical, geological or geochemical studies of the mid-ocean ridges, the adjacent oceanic basins, the numerous hotspots and associated aseismic ridges and plateaus, and more generally the geodynamics and plate tectonic history of the Indian Ocean. We particularly encourage papers presenting the outcome of recent seagoing expeditions.