Marine Geosciences

Hotspots and the crustal structure of the resulting edifices

A collaborative project between:

IUEM/ Univ. de Bretagne Occidentale, Brest (J. Francheteau, F. Avedik)
IFREMER, Brest (L. Geli, J.-L. Olivet, F. Klingelhoefer)
CEA (J.-P. Avouac, J. Talandier)
 

The surface expression of a hotspot, volcanic island chain or oceanic plateau, appears to be a function of its geodynamic setting, intraplate or near the ridge axis. The young Society Islands (< 6 Ma) are considered to be a good example of the former, while the ancient edifice (> 40 Ma) underlying the Tuamotus appears to represent the latter. In order to better constrain the crustal structure of these edifices, more than 800 km of wide- angle seismic data were acquired in 1989 during the MidplateII expedition, however these data remain unpublished. We propose reprocessing these data using modern seismic inversion software. Additionally, integrating recordings from landstations (CEA permanent network) will allow us to extract the most detailed information available from these data and to obtain the best possible model of the deep crustal structure of French Polynesia.
 

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