High-resolution Geophysical Mapping of Submarine Glacial Landforms

Wednesday, 17 December 2014: 2:40 PM
Martin Jakobsson1, Julian A. Dowdeswell2, Miquel Canals3, Brian Jeremy Todd4, Evelyn K Dowdeswell2, Kelly A Hogan5 and Larry A Mayer6, (1)Stockholm University, Department of Geological Sciences, Stockholm, Sweden, (2)Scott Polar Research Institute, University of Cambridge, Cambridge, United Kingdom, (3)Universitat de Barcelona, GRC Geociencies Marines, Barcelona, Spain, (4)Geological Survey of Canada Atlantic, Dartmouth, NS, Canada, (5)NERC British Antarctic Survey, Cambridge, United Kingdom, (6)University of New Hampshire Main Campus, Durham, NH, United States
Glacial landforms are generated from the activity of glaciers and display spatial dimensions ranging from below one meter up to tens of kilometers. Glacial landforms are used as diagnostic features of past activity of ice sheets and glaciers; they are specifically important in the field of palaeoglaciology. Mapping of submarine glacial landforms is largely dependent on geophysical survey methods capable of imaging the seafloor and sub-bottom through the water column. Full “global” seafloor mapping coverage, equivalent to what exists for land elevation, is to-date only achieved by the powerful method of deriving bathymetry from altimeters on satellites like GEOSAT and ERS-1. The lateral resolution of satellite derived bathymetry is, however, limited by the footprint of the satellite and the need to average out local wave and wind effects resulting in values of around 15 km. Consequently, mapping submarine glacial landforms requires for the most part higher resolution than is achievable by satellite derived bathymetry. The most widely-used methods for mapping submarine glacial landforms are based on echo-sounding principles. This presentation shows how the evolution of marine geophysical mapping techniques, in particular the advent of side-scan and multibeam bathymetric sonars, has made it possible to study submarine glacial landforms in unprecedented detail. Examples are shown from the Atlas of Submarine Glacial Landforms: Modern, Quaternary and Ancient, which will be published in late 2015 in the Memoir Series of the Geological Society of London.