RRS Discovery Cruise 249, 19 Aug-10 Sep 2000. History of sedimentation in the Gulf of Cadiz: investigations with the SOC giant piston corer

摘要

This was the third cruise using the new SOC giant piston corer. The objectives were to complete the testing of the giant piston corer which was begun on cruise D219 in November/December 1995 and cruise D225 in February/March 1997, and to collect giant piston cores from the Gulf of Cadiz on sites selected from the TOBI survey carried out on cruise D244 in December 1999. As on previous cruises we had problems with both the ships equipment (outboard sheave on coring gantry), and the giant piston corer. The sheave problem necessitated 2.5 days in port plus transit time. This combined with some weather downtime severely limited the amount of work which could be carried out. Nevertheless, we resolved some coring issues, especially proving that elastic rebound of the kevlar is not a major problem. We also managed to take a consistent series of good cores with a 15 metre barrel, and although all the 27 metre barrel cores bent, the bending took place above the sediment surface leaving a good quality core below. The longest core recovered was 18.1 metres and 21 cores were obtained in all. The cruise also involved testing the scatterometer. This proved to be a failure due to multiple electronic problems and no data was recorded in any of its two deployments.