Geophysical Investigations of the North Scotia Ridge

This report describes results of marine geophysical surveys of the North Scotia Ridge (western South Atlantic) conducted by the Geoscience Division of the British Antarctic Survey (BAS). These investigations were initiated as part of a wider programme of research into Scotia Sea tectonic evolution and palaeo-circulation (BAS project B6153). The data which form the basis of this work were obtained on BAS scientific cruises between 1987 and 1993, and include bathymetric soundings, high-resolution sub-bottom profiles, multi-channel seismic reflection profiles, long-range side-scan sonographs and marine gravity measurements. F or clarity, interpretations have been arranged into three separate studies: (1) a long-range side-scan sonar survey of the southern Falkland Plateau, Falkland Trough and North Scotia Ridge between 40 and 58°W; (2) a multi-channel seismic reflection survey of the North Scotia Ridge near 46°W (Aurora Bank); and (3) a 3.5 kHz sub-bottom profile and bathymetry survey of the Falkland Trough east of 50oW. Essential background information describing the tectonic, sedimentary and oceanographic framework of the North Scotia Ridge region has been included, so that each study may be considered separately. Some of the work described in this thesis has been completed with the assistance of others, and these contributions have been acknowledged in the text. Published results are reproduced in Appendix A of this report