Objective Hydrothermal activity, resulting of oceanic crust/ocean interaction, represents one of the key sources of material entering the oceans. As well as representing an important source of heat and mass from fresh-formed underlying oceanic crust, hydrothermal activity also plays host to ecosystems of perhaps unequalled originality and evolutionary significance. One of the major objectives of the MARFLUX/ATJ MAST 2 project was to locate hydrothermal sites in the area of the Azores Triple Junction. Two hydrothermal sites have actually been discovered within E.U.'s EEZ. In addition, hydrothermal anomalies in the water column have been detected at several locations along the Mid-Atlantic Ridge southwest of the Azores Triple Junction. The gradually southward changing properties of the ocean crust from the ATJ are direct or indirect consequences of the Azores Hot Spot-(i) depth (from 800m to 2800m), (ii) chemical properties of rocks, (iii) nature of volcanism (explosive at depths shallower than 900m), and (iv) segmentation of the ridge axis. We propose to study (i) the physical, chemical and biological fluxes from 4 contrasted hydrothermal fields as heat and matter are dispersed through a hydrothermal plume into the adjoining mid-Atlantic Ridge rift-valley (ii) highan low-temperature fluxes (physical and chemical) and structure of the hydrothermal system at the hydrothermal vent field scale (iii) the influence of depth through chemical, physical and biological processes on hydrothermal vent ecosystems. Four cruises constitute the core of the project: A surface cruise, (1) 'FLAME' (1997) aboard U.K. R/V "Darwin" will be dedicated to the quantification of the heat and mass fluxes from a hydrothermal vent-field, up to the scale of a complete segment of the MAR. Its main objectives are to characterize the first-order physical, chemical and biological variations between plumes overlying known vent-fields. Three diving cruises using the French submersible 'Nautile' and its support vessel 'Nadir' (2)'FLORES' (1997) to document highand low-temperature fluxes (physical and chemical) and the structure of the hydrothermal systems. An important point will be to compare the hydrothermal fluxes issuing from different types of hydrothermal processes and document the relative importance of each of them on the fluxes in the ocean; (3)'MARVEL' (1997), to the study the influence of depth through chemical, physical and biological processes on hydrothermal vent ecosystems: composition (microbial and faunal) including the relative contributions from chemosynthetically and photosynthetically derived inputs, population structure and dynamics, species adaptations to toxicity of the vent fluid, the life cycles and strategies in a discontinuous (space and time), unpredictable and extreme environment;(4) 'PICO', a short diving cruise (1998)devoted to the recovery of long term experiments and measurements. In addition, work will be done under the 'related studies' section to coordinate our effort with studies funded outside MAST. It will further the objectives of the core project in the area of Azores triple junction and constrain the regional context. Fields of science natural sciencesearth and related environmental sciencesgeologyvolcanologynatural sciencesbiological sciencesecologyecosystems Programme(s) FP4-MAST 3 - Specific programme of research and technological development in the field of marine science and technology, 1994-1998 Topic(s) 010201 - The deep sea floor in the North Atlantic and the Mediterranean Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator IFREMER - INSTITUT FRANÇAIS DE RECHERCHE POUR L'EXPLOITATION DE LA MER EU contribution No data Address Centre de Brest 29280 Plouzane France See on map Total cost No data Participants (18) Sort alphabetically Sort by EU Contribution Expand all Collapse all CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE France EU contribution No data Address Place George Tessier 29682 ROSCOFF See on map Total cost No data Centre for Applied Microbiology and Research (CAMR) United Kingdom EU contribution No data Address Porton Down SP4 0JG Salisbury See on map Total cost No data Commissariat à l'Energie Atomique (CEA) France EU contribution No data Address Centre d'Etudes de Saclay 91191 Gif-sur-Yvette See on map Total cost No data Era-Maptec Ltd. Ireland EU contribution No data Address 5,South Leinster Street 2 Dublin See on map Total cost No data IFREMER - INSTITUT FRANÇAIS DE RECHERCHE POUR L'EXPLOITATION DE LA MER France EU contribution No data Address Technopole Brest Iroise 29280 PLOUZANE See on map Total cost No data INSTITUTE OF MARINE RESEARCH Portugal EU contribution No data Address Estrada do Guincho 2750 CASCAIS See on map Total cost No data NATIONAL UNIVERSITY OF IRELAND, GALWAY Ireland EU contribution No data Address NUI, Galway 90 GALWAY See on map Total cost No data NATURAL ENVIRONMENT RESEARCH COUNCIL United Kingdom EU contribution No data Address Empress Dock, European Way SO14 3ZH SOUTHAMPTON See on map Total cost No data NERC Centre of Coastal and Marine Sciences United Kingdom EU contribution No data Address Prospect Place West Hoe PL1 3DH Plymouth See on map Total cost No data UNIVERSITY OF DURHAM United Kingdom EU contribution No data Address South Road, Science Laboratory DH1 3LE DURHAM See on map Total cost No data UNIVERSITY OF WALES - BANGOR United Kingdom EU contribution No data Address Askew Street LL59 5EY GWYNEDD See on map Total cost No data University of Bristol United Kingdom EU contribution No data Address Queens' Road BS8 1RJ Bristol See on map Total cost No data University of Cambridge United Kingdom EU contribution No data Address Downing Street CB2 3EQ Cambridge See on map Total cost No data University of Southampton United Kingdom EU contribution No data Address European Way SO14 3ZH Southampton See on map Total cost No data Université Pierre et Marie Curie - Paris VI France EU contribution No data Address 4,Place Jussieu 75252 Paris See on map Total cost No data Université de Bretagne Occidentale France EU contribution No data Address 6,Avenue Victor Le Gorgeu 29275 Brest See on map Total cost No data Université de Bretagne Occidentale France EU contribution No data Address Pointe du Diable 29280 Plouzane See on map Total cost No data Vrije Universiteit Brussel Belgium EU contribution No data Address 2,Pleinlaan 2 1050 Bruxelles See on map Total cost No data