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MoMAR a coordinated and multidisciplinary
long-term study of hydrothermal ecosystems at the
Mid-Atlantic Ridge close to the Azores
archipelago.
Hydrothermal circulation at mid-ocean 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 - 36to 40N 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
• 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.

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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.
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 long-term seafloor observatory at
Lucky Strike. In addition, three coordinated
cruise proposals are currently examined by NSF.
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.
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
(gt2010) 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 (escartin_at_ipgp.jussieu.fr) Contact
for MoMAR Integrated Site for the RIDGE 2000 US
Program Dr Susan Humphris (shumphris_at_whoi.edu) Co
ordinator of FP6-STREP EXOCET/D Dr Pierre Marie
Sarradin (pierre.marie.sarradin_at_ifremer.fr) Contac
ts for the Portuguese MoMAR program Dr M.
Miranda (jmmiranda_at_fc.ul.pt) Dr Ricardo Santos
(ricardo_at_notes.horta.uac.pt) Contact for the
French MoMAR program coordinator of FP6-MCRTN
MoMARnet Dr Mathilde Cannat (cannat_at_ipgp.jussieu.
fr)