HR: 1340h
AN: T13D-0505 [Abstracts]
TI: The Guyaplac Survey, off French Guyana
AU: Patriat, M
EM: martin.patriat@ifremer.fr
AF: Marine Geosciences Department
Ifremer, Centre de Brest, BP 70, Plouzane, 29280
France
AU: Loubrieu, B
EM: benoit.loubrieu@ifremer.fr
AF: Marine Geosciences Department
Ifremer, Centre de Brest, BP 70, Plouzane, 29280
France
AU: Vially, R
EM: roland.vially@ifp.fr
AF: IFP, 1 et 4, avenue de Bois-Preau, Rueil-Malmaison, 92852
France
AU: * Roest, W R
EM: walter.roest@ifremer.fr
AF: Marine Geosciences Department
Ifremer, Centre de Brest, BP 70, Plouzane, 29280
France
AB:
The UN Convention on the Law of the Sea allows coastal states to claim a legal continental shelf beyond the 200 nautical
miles that constitutes their Exclusive Economic Zone. The Guyaplac survey took place in April 2003 off French Guyana, in the
central Atlantic Ocean and was a collaborative effort between the French Institutes Ifremer and IFP. The survey was designed
by the French EXTRAPLAC (reasoned extension of the continental shelf) program and dedicated to UNCLOS Article 76. This
contribution describes the data acquired on board the French RV L'Atalante during the Guyaplac cruise. In addition to the
multibeam bathymetric data collected with the EM-12 multibeam echo sounder, high-speed seismic data are of particular
interest, as they allow determination of the sediment thickness: information that can contribute to the demonstration of a
continental shelf. The data also allowed the interpretation of basement morphology in this area that is covered by relatively
thick sediments at the edge of the Amazon fan. It is clear that sediment thickness is the main criterion for extension of
the legal continental shelf in this region. Regional magnetic and gravity data seem to delineate distinct structural domains,
and help better understand the margin off French Guyana, which comprises an extensional and a transform segment.
UR: http://www.extraplac.fr
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
DE: 3045 Seafloor morphology, geology, and geophysics
DE: 8105 Continental margins: divergent (1212, 8124)
DE: 8106 Continental margins: transform
SC: Tectonophysics [T]
MN: Fall Meeting 2005