RV Meteor Expedition M 82/3

The Menez Gwen working area on the Azores Plateau of the Mid-Atlantic Ridge

Aim of the criuse

Menez Gwen is a ridge-centered seamount with hydrothermal activity at 37°N on the Mid-Atlantic Ridge (MAR). The Menez Gwen hydrothermal vent field was chosen as a key study site for interdisciplinary geological, chemical, and biological studies within the Research Area Geo-Biosphere-Interactions: From thermodynamic modelling to biota complexity in vent and seep systems (GB7) of the MARUM. The proposed cruise will center on four questions: 1) Are the unusually high methane concentrations in this basalt-hosted system caused by abiogenic or biogenic processes? 2) How does conductive heating of seawater and conductive cooling of hydrothermal fluids affect the composition of diffuse fluids? 3) What are the dominant sources of energy for microbial life in the subsurface, surface and hydrothermal plume? 4) How has the fluid composition changed in this very young hydrothermal system? Closely integrated geochemical and biological sampling using state of the art in situ technology together with interdisciplinary analyses on board and in the home laboratories will provide information for answering questions central to hydrothermal vent research.

Bathymetric map of the Menez Gwen seamount produced during research cruise POS402 with RV Poseidon in August 2010.