1. Examples of the first seafloor and sub-seafloor acoustic mapping records used to interpret submarine glacial landforms.
Examples of the first seafloor and sub-seafloor acoustic mapping records used to interpret submarine glacial landforms. (a) Location map showing where the SBES profile in (c) was acquired on the crest of the Chukchi Cap, central Arctic Ocean (map from IBCAO v. 3.0). (b) Bathymetric profile collected from the drifting ice station Charlie in 1959 with a 1.8 kHz SBES developed at Lamont Doherty Earth Observatory (data from Hunkins et al. 1962). The seafloor relief was interpreted to be caused by the ploughing action of iceberg keels, which has since been confirmed by more modern MBES data (Polyak et al. 2001; Jakobsson et al. 2005; Dove et al. 2014). (c) Location map of seismic-reflection profile (red line, x–x′) shown in (d) from the Norwegian Channel (map from GEBCO_08). (d) Seismic-reflection profile collected in the early 1970s and interpreted to show that the Norwegian Channel had been shaped primarily by palaeo-ice stream activity (seismic-reflection data from Sellevoll & Sundvor 1974; length scale is not provided in original publication). (e) Side-scan sonar image acquired in the mid-1970s off Wilkes Land in the Weddell Sea, Antarctica, showing features referred to as washboard patterns and interpreted to be caused by the tidal motions of grounded icebergs (side-scan imagery from Lien 1981). (f) Map of Antarctica locating the side-scan sonar image in (e) (from IBCSO v. 1.0). Acquisition system Klein Model 400. Frequency 100 kHz.
M. Jakobsson et al. Geological Society, London, Memoirs 2016;46:17-40
© 2016 The Author(s). Published by The Geological Society of London