RV Pelagia Cruise 64PE219, 05 Nov – 24 Nov 2003. TOBI surveys of Setubal and Nazarre Canyons and of the MV Prestige wreck site, west of Iberia

The main objective of the cruise was to collect TOBI sidescan sonar imagery over three areas of the continental margin west of Iberia, where sediment transport studies are being undertaken as part of the EC funded ‘EUROSTRATFORM’ project. The three study areas were: 1. The Setubal Canyon, between 38° to 38° 20’N on the continental margin. Here it was planned to image the canyon with a single 6 km-wide swath from the shelf edge near 200m to the abyssal plain at depths exceeding 4800m 2. The Nazarre Canyon, between 39° 30’ and 40°N on the continental margin. The survey plan was similar to that for Setubal Canyon, but with two parallel swaths over the lower reaches of the canyon, where it broadens into a 10 km wide channel crossing the continental rise. 3. The Prestige tanker wreck site, at 42°N, 12°W, on the west flank of Galicia Bank, off northwest Spain. Here the aim was to investigate the stability of the slope where the tanker was lying. This part of the project was carried out jointly with UTM-CMIMA (CSIC), Barcelona, Spain. Although some time was lost to bad weather and equipment problems, excellent TOBI images were obtained over all three of the areas studied during Pelagia cruise 219. The cruise objectives were fully completed in areas 1 and 3, and about 60% of the expected area was surveyed in area 2, where almost three days were lost to bad weather.