|10th Training-through-Research Cruise|
|The 10th cruise of the
Training-through-Research programme was carried out on
board R/V Professor Logachev (Russia) from 13
July to 28 August, 2000. The cruise started from Santa
Cruz de Tenerife (Canaries, Spain) and terminated in
Bergen (Norway). The scientific programme of the
expedition included work in seven areas located on the
Portuguese Margin, in the Gulf of Cadiz, in the Lucky
Strike area of the Mid-Atlantic Ridge, on the Rockall
Trough and the Faeroe margins, and on the Vøring
Plateau on the Norwegian Margin.
The work on the Portuguese margin continued investigations conducted during TTR-8 and TTR-9 cruises and was aimed to study main structural elements of the margin and recent fault activities. Number of seismic lines and side-scan sonar profiles were carried out to clarify recent tectonic situation of the area.
Investigations of fluid escape features and gas hydrates accumulations were undertaken in the Gulf of Cadiz. New areas of cold seeps and gas venting were discovered and six new mud volcanoes were mapped with seismics and sidescan sonars. Some of these structures were sampled for the first time with various coring equipment and unique material was collected for further analytical processing. At tops of some of the mud volcanoes deep-water corals were found associating with chemosynthetic communities.
The main task of the study at Mid-Atlantic
Ridge, in the Lucky Strike area was to investigate
relations between volcanic and tectonic structures in
the area and distribution of hydrothermal activities
leading to sulphide ore formation. A sampling
programme based on the previous detailed sidescan
sonar and video observation mapping effort was carried
out with a TV-controlled grab. Spectacular
video-footage of ore build-ups, hot vents and
chemosynthetic communities was obtained. An extensive
collection of sulphide ore of different types, igneous
rocks and bottom fauna was retrieved.
On the Irish margin, a, hitherto poorly known, canyon system was studied with seismics, 3.5 kHz profiler, and 2 types of sidescan sonars. The bottom sampling was aimed to sedimentologically characterise different parts of the system and to ground-truth acoustic facies observed at different frequencies.
In the northern Rockall Trough a field of cold-water carbonate mounds was a target for bottom sampling with TV guided grab. Another targets for sampling were areas covered by coarse glacial lag deposits and sites of Tertiary rocks outcrops on the Wyville-Thomson Ridge and on southern Faeroe margin.
A study area on the Norwegian margin was located at the northern edge of the giant Storegga Slide extending to the southwestern edge of the Vøring Plateau. Previous expeditions (including R/V Professor Logachev cruises in 1994 and 1998) discovered here numerous fluid escape features. This year study was conducted in the area in order to better understand how fluid escape features and gas hydrates accumulations can affect slope instability processes. The distribution of Bottom Simulating Reflector (BSR) below displaced sediments of the Storegga slide was mapped out with seismic profiling. Video records of the seafloor and sampling were made in zones of fluid discharge, exhausting onto the seafloor from beneath of the BSR.
post-cruise meeting abstracts