Terrain model of the eastern slope of the Porcupine Seabight (50 m grid size)

The topography of the eastern margin of the Porcupine Seabight was surveyed in June 2000 utilizing swath bathymetry. The survey was carried out during RV Polarstern cruise ANT XVII/4 as part of the GEOMOUND project. The main objective was to map and investigate the seafloor topography of this region. The investigated area contains a variability of morphological features such as deep sea channels and giant mounds. The survey was planned and realized on the basis of existing data so as to guarantee the complete coverage of the margin. In order to achieve a resolution of the final digital terrain model (DTM) that meets the project demands, data processing was adjusted accordingly. The grid spacing of the DTM was set to 50 m and an accuracy better than 1% of the water depth was achieved for 96% of the soundings.

Planktonic foraminifera in late Eocene to Pleistocene sediments of ODP Hole 120-747A and 120-749B

Late Eocene to Pleistocene planktonic foraminifers from Leg 120 Holes 747A and 749B on the Kerguelen Plateau were quantitatively analyzed. Microperforate tenuitellid forms dominate the Oligocene to middle Miocene, and 17 species (including the new species Tenuitella jamesi and Tenuitellinata selleyi) are recorded. A lineage zonation of tenuitellid foraminifers is proposed as an alternative scheme for refinement of the Oligocene-Miocene biostratigraphy in high latitudes. Progressive or abrupt alterations in morphological characters within this lineage, producing different morphotypes or species, coincided with prolonged or sudden changes in paleoclimate. These microperforate planktonic foraminifers thus appear to have potential as indicators of cold-water masses and temperature fluctuations in post-Eocene oceans.