29 March

Long-Term Ocean Climate Observations (LOCO) – D301/302

Cruise Diary – 29^th March 2006

Connecting the dredge to the wire

Wednesday - Dragging. That was done the whole day and at the moment of writing we are still doing this. The procedure is that first of all the location of the releases at the seafloor is determined as accurate as possible by surveying around a guessed position and measuring on different locations the distance between the ship and the releases. Knowing the water depth, a circle can be drawn around the location of the measurement. The releases should be somewhere on this circle and the crossing of a few circles give a good estimate. Then a long cable (on our first trial old mooring cable of some 9000 m long was used) was laid on the seafloor on a circle with a radius of some 350 m around the releases. This is rather difficult here where the water depth is about 2700 m. Anyhow, we started this way, but without success.

We now think that the entire mooring must have sunk to the seafloor. Therefore during our second trial we do not use the relatively weak mooring cable but a much thicker wire from the ship. Attached to this cable are some dredges (see picture) that are presently heaved over the seafloor. These are rather lengthy operations. We decided to finish dragging after this second trial, also if it is not successful. Tomorrow we will continue again with the redeployment of moorings on the western site of the channel.

Ross playing guitar on the after deck

Paying out the dragging wire