The gravity corer is the standard coring system that consists of a head weight (1.5 t) connected to a variable number of 5 m long steel barrels (diameter 12 cm). Plastic tubes are inserted into the barrels and are attached to these by a core catcher fitted inside the end of the lowest barrel. This system is lowered to the sea floor and penetrates by its own weight into the sediments. When being pulled out of the sediments the core catcher closes and secures the sediment column inside the tubes. On deck the core catcher is removed, the plastic liners pulled out the barrels and cut into 1 m sections. |