Transcript MoMAR

MoMAR : a coordinated and multidisciplinary long-term study of hydrothermal
ecosystems at the Mid-Atlantic Ridge close to the Azores archipelago.
Hydrothermal circulation at midocean ridges is a fundamental
process that impacts the transfer
of energy and matter from the
interior of the Earth to the crust,
hydrosphere and biosphere.
Seawater circulates through the
permeable upper oceanic crust at
mid-ocean ridges, exchanges
chemicals with the surrounding
rocks, and is heated up to
temperatures of a few hundred
degrees Celsius. This hot fluid
flows up and is expelled at
hydrothermal sites, in the form of
black smokers, or diffuse vents.
The unique faunal communities
that develop near these vents are
sustained by chemosynthetic
microbes that use the chemicals
in the hot fluids as a source of
energy.
MoMAR Objective :
to constrain the dynamics of hydrothermal vent
ecosystems at the Mid-Atlantic Ridge
The MoMAR area :
# Slow-spreading Mid-Atlantic Ridge - 36°to 40°N
# In proximity to the Azores harbours and shore-based
facilities
# 4 known vent fields / 3 distinct hydrothermal
environments
# Has been the target of over 20 scientific cruises
under projects funded by EC MAST II,
MAST III, FP4, FP5, FP6 leading to 15 years
of multidisciplinary data.
International participation to MoMAR:
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Strong european participation (14 labs in 8 countries), 3 funded FP6 initiatives have MoMAR-related
objectives (MCRTN MoMARnet, STREP EXOCET/D & IP NEREIS).
Selected as Integrated Study Site by the US Ridge 2000 Program.
International coordination under the auspices of the InterRidge Program.
Strategy :
(as last updated at the MoMAR
International Workshop of Lisbon in april
2005)
Support comparative studies of
hydrothermal vents in MoMAR area.
Focus on the Rainbow and Lucky
Strike vent fields, with IODP
instrumented drilling planned at
Rainbow and integrated & multiscale
long-term monitoring at Lucky Strike.
Rainbow is an
exceptionnal target for the
study of ultramafic-hosted
ridge hydrothermal
systems. This site is
characterized by the
abundance of iron, an
element which plays a
major role at all scales in
the ecosystem.
Actions in 2005-2006 :
IODP proposal submitted. Three
cruises have taken place in 2005. Two
are scheduled for 2006, that will
deploy the first elements of the longterm seafloor observatory at Lucky
Strike. In addition, three coordinated
cruise proposals are currently
examined by NSF.
Rimicaris exoculata: a new type of
symbiosis based on iron oxidation
The objective there is to turn the vent field into a natural laboratory for the study of
ultramafic-hosted, iron-rich hydrothermal ecosystems. The experimental design at
Rainbow involves instrumented IODP drilling of the hydrothermal stockwerk, as
well as extensive site surveys and repeated sampling.
Lucky Strike is the selected MoMAR site for
integrated & multiscale long-term monitoring of ridge
hydrothermal processes and ecosystems.
Sketch of proposed Lucky Strike
observatory design
Lucky Strike central
volcanoe
(bathymetry, viewed from SW, east wall of
rift valley in background)
Lucky Strike observatory design 2006-2010
The Lucky Strike vent field is located on
top of the volcanoe. It comprises more
than 40 individual vents, with a
remarkable density of faunal
communities. It is part of a planned
Marine Protected Area within portuguese
ZEE.
The objective there is to set up a permanent seafloor observatory to record and relate seismicity, seafloor deformation, fluid flow,
temperature and composition, with the dynamics of vent communities (including microbes)
The design shown above reflects planning by international partners at the recent MoMAR meeting in Lisbon. Implementation will
begin in 2005-2006 for seafloor deformation, near vents faunal communities monitoring, vent fluid temperature, and seismicity. In
a first stage, sensors will be autonomous or linked acoustically to an ASSEM junction box. The ultimate objective (>2010) is to
implement an integrated monitoring infrastructure with real time data satellite transmission (stage 1) followed by cable energy
supply and data transmission (stage 2).
Contacts :
MoMAR Web Page : http://www.momar.org
Chair of International MoMAR steering group: Dr Javier Escartin ([email protected])
Contact for MoMAR Integrated Site for the RIDGE 2000 US Program: Dr Susan Humphris ([email protected])
Coordinator of FP6-STREP EXOCET/D: Dr Pierre Marie Sarradin ([email protected])
Contacts for the Portuguese MoMAR program: Dr M. Miranda ([email protected])
& Dr Ricardo Santos ([email protected])
Contact for the French MoMAR program & coordinator of FP6-MCRTN MoMARnet: Dr Mathilde Cannat ([email protected])