ANTARCTIC SUBGLACIAL AND SUBMARINE RELIEF: GEOMORPHOLOGICAL MAPPING OF PRE-GLACIAL RIVER VALLEYS

Abstract

This pilot project was a part of a larger complex geomorphologic mapping of the entire Antarctic continent conducted by the team of researchers from St. Petersburg (Russia). Radar profiling data transformed into digital topographic models were utilized as raw materials for the research. Submarine and subglacial geomorphology is a scientific branch that could provide new findings while studying palaeogeographic environments of the Antarctic. River valleys are one of the clearest evidences of the pre-glacial development of territories. Researchers can initially investigate them using the system-morphological approach established and developed by A. N. Lastochkin. This clear methodological base and corresponding set of mapping methods – including creation of structural networks, compiling of difference maps, analysis of lineaments and vector fields – made it possible to map the main river basins, which are now buried under the ice sheet or represented by only detrital cones on the continental slopes. Such large drainage systems were identified and initially described within the entire Antarctic continent. They are, with no doubt, of pre-glacial age and have only fluvial nature. One of Antarctic regions – Lambert Graben – was studied more closely. We identified there two generations of valleys: river preglacial and pre-icecover ones. The latter are presumably associated with mountain glaciers preceding the formation of the ice sheet. Newer and more detailed profiling data passed through a prism of the system-morphological approach that can multiply our knowledge of subglacial topography as well as the past of Antarctica.

Keywords

• the Antarctic
• subglacial geomorphology
• geomorphological mapping
• pre-glacial river valleys