CIRCEA Oceanographic Cruise

* June 16 – June 30 2012 *

CIRCEA (CIRCulation in East Asian seas) on board the R. V. Marion Dufresne (French Polar Institute) in the northern part of the South China Sea.

Chief scientists: Catherine KISSEL (LSCE) and Zhimin JIAN (Tongji University)

During this coring cruise we collected long marine sedimentary cores at key locations with respect to the oceanic water masses and to the terrigeneous inputs from the Pearl River to allow the reconstruction of the past variations of the east Asian monsoon and evolution of precipitation on land at every time scale, and the the past variability of the intermediate and deep oceanic circulation.

7 coring stations (with each time a CASQ core and a long CALYPSO core) were investigated. Given their distribution in space and in water depth, they will allow to examine:

1) the intermediate water mass, never sampled so far, to understand the past variability of the exchanges between the South China Sea and the Pacific ocean. The first three coring stations are located at the top (667 m), the middle (903 m) and the basis of this intermediate water mass. We could conclude with the first observations made on board that these three locations are characterized by highly varying sedimentation rates.

2) How the terrigeneous sediment is delivered at sea from the Pearl River and how it is then transported by the different water masses. Four stations out of 7 constitute a depth transect along the axis of the river, from the continental plateau to the deep basin around 3900 m.

An educational programs “Teachers at Sea” (co-sponsored by the European Geosciences Union and IPEV), dedicated to high school teachers (responsible Carlo LAJ) has taken place alongside with the scientific program on board during the cruise.