Apologies for cross/multiple postings:

May I draw your attention to the following three sessions on mid-ocean ridge related science to be held at the next EGU meeting in Vienna, 15-20 April 2007.

The deadline for abstract submission is January 15.

The deadline for support to students and young researchers (registration fees) is December 9.

More info can be found at: http://meetings.copernicus.org/egu2007

Best wishes,

Antony Morris

_________________________________

TS8.4/GD06.1/GMPV16: Structure and Dynamics of Mid-Ocean Ridges

Convener: Anne Briais

Co-conveners: Antony Morris, Fabrice Fontaine and Valerie Chavagnac

Co-sponsors: InterRidge and MOMARNET

Session description:

Mid-ocean ridges represent a unique window on mantle processes. After several decades of efforts from the marine geosciences community, many aspects are still debated, including mantle circulation and melting, melt migration and cooling, lower crustal accretion, magmatic or amagmatic extension, evolution of oceanic core complexes, melt distribution and mantle outcropping at ultra-slow ridges, interaction of various scales of mantle convection near hotspots ...etc. The session with bring together scientists from a large variety of disciplines, to compare and review observables and models of the structure and dynamics of mid-ocean ridges and associated mantle sources and circulation.

TS8.5/GD06.2/GMPV17:   Tracing hydrothermal circulation at Mid-ocean ridges using geochemistry, geophysics and modelling

Convener:        Valerie Chavagnac

Co-Conveners:    Fabrice Fontaine; Anne Briais; Antony Morris

Co-sponsors: InterRidge and MOMARNET

Session description:

The circulation of seawater within the axial zones and flanks of mid-ocean ridges: (i) influences heat transport from the lithosphere to the hydrosphere; (ii) modifies the bulk and isotopic chemical composition of the oceanic crust and its physical properties (magnetism, porosity, density and seismic velocity) via fluid-rock interaction and the formation of secondary minerals; and (iii) alters the chemistry of seawater through the expulsion of high to low temperature hydrothermal fluids at various depths.

This session will bring together geophysicists, geochemists, mineralogists and modellers interested in the complexities of oceanic hydrothermal circulation. Within this broad remit, papers that aim to improve understanding of seawater circulation pathways through the oceanic crust and the role of hydrothermal cycling in heat, chemical and material fluxes between the lithosphere and the hydrosphere are particularly welcome.

BG6.05 Biogeochemical interactions in chemosynthetic deep-se ecosystems: methods, tools and strategies

Convener:         N. Le Bris (IFREMER, France). 

Co-conveners: C. R. German (WHOI, USA), W. Bach (RCOM, U. Bremen, Germany), S. Duperron (U. Paris6, France)

Co-sponsor : InterRidge

Session description:

The past decade has raised challenging issues about the nature of processes driving the interactions between the biotic and abiotic components of hydrothermal and other deep-sea chemosynthetic ecosystems (methane seeps, massive organic falls,..) and their role in the response of ecosystems to disturbance. The respective importance of microbial metabolisms in carbon fixation, mineralisation and rocks alteration, the interplay between invertebrate diversity, small-scale structuration of physico-chemical gradients and the dynamics of microbial energy and element fluxes are major questions that need to be answered.

This session will address advanced inter-disciplinary research to understand basic mechanisms linking geochemical, biogeochemical, geobiological and biological processes, including the development of new instrumental devices for the exploration, observation, experimentation and monitoring at relevant scales on the seafloor.

_______________________________________

Dr. Antony Morris,

Geodynamics and Palaeomagnetism Group,

School of Earth, Ocean & Environmental Sciences,

University of Plymouth,

Drake Circus,

Plymouth PL4 8AA,

United Kingdom.