ODEMAR Cruise
The ODEMAR Cruise (PI: J. Escartin, and M. Andreani - shore based)left Mindelo (Cabo Verde) on the 16th November 2013, and finish at Point-a-Pitre (Guadaloupe, France) on the 19th December 2013, after about 26 days of field work at the Mid-Atlantic Ridge. The cruise will take place onboard the French vessel Pourquoi Pas?, equipped with the robot VICTOR6000 (IFREMER, France), and the autonomous deep-sea vehicle Abyss (GEOMAR, Germany). The science party includes around 40 scientists and engineers, primarily from France, in addition to Germany, United States, Wales, Spain, Norway, and Greece.
This cruise is studying the formation of the oceanic crust along this ridge, in the presence of oceanic detachments (or oceanic core complexes), which are long-lived faults that bring to the surface deep-seated rocks (from several kilometers below) while taking up an important portion of the on-going separation of the American and African continents (~20 mm per year). These detachments can produce curved, smooth and striated massifs raising hundreds of meters above the seafloor. During their formation magmatic activity, tectonic deformation (seismicity) and hydrothermal alteration interact, and the rocks exposed at the seafloor are the witnesses of these interactions. We seek to investigate and unravel these interactions to understand the formation of these structures, that are common along the global mid-ocean ridge system.
The ODEMAR Cruise (PI: J. Escartin, and M. Andreani - shore based)left Mindelo (Cabo Verde) on the 16th November 2013, and finish at Point-a-Pitre (Guadaloupe, France) on the 19th December 2013, after about 26 days of field work at the Mid-Atlantic Ridge. The cruise will take place onboard the French vessel Pourquoi Pas?, equipped with the robot VICTOR6000 (IFREMER, France), and the autonomous deep-sea vehicle Abyss (GEOMAR, Germany). The science party includes around 40 scientists and engineers, primarily from France, in addition to Germany, United States, Wales, Spain, Norway, and Greece.
This cruise is studying the formation of the oceanic crust along this ridge, in the presence of oceanic detachments (or oceanic core complexes), which are long-lived faults that bring to the surface deep-seated rocks (from several kilometers below) while taking up an important portion of the on-going separation of the American and African continents (~20 mm per year). These detachments can produce curved, smooth and striated massifs raising hundreds of meters above the seafloor. During their formation magmatic activity, tectonic deformation (seismicity) and hydrothermal alteration interact, and the rocks exposed at the seafloor are the witnesses of these interactions. We seek to investigate and unravel these interactions to understand the formation of these structures, that are common along the global mid-ocean ridge system.
(Left) Bathymetry of the Mid-Atlantic Ridge around 13°20-30’N showing the location of oceanic detachments, and the transition from detachment to ‘normal’ seafloor (14°N segment) lacking detachments. (Center) Close-up of the 13°20’ and 30’N detachments, active and rooting at the ridge axis. (Right) 3D oblique view of the 13°20’N detachment with sonar imagery draped on bathymetry (see view angle in center panel). The curved and striated fault plane is well exposed at the seafloor since its initiation Ibreakaway) to the termination at the axis, and hosts active and fossil hydrothermal activity. Modified from Smith et al. [2008] (left) and MacLeod et al. [2009] (right).