Subglacial bedrock structure in the Transantarctic Mountains and its influence on ice sheet flow: insights from RADARSAT SAR imagery

The Transantarctic Mountains represent a major Cenozoic rift-flank uplift that crosses the interior of Antarctica. On one side of the mountains lies the Ross embayment, a submarine portion of the West Antarctic rift system. The East Antarctic Ice Sheet overlies the cratonic margin of the mountains. The Transantarctic Mountains restrict flow of the ice sheet to lower elevations within the Ross embayment. Using RADARSAT imagery, radio-echo sounding data and field-based structural data, we demonstrate that RADARSAT imagery can be used for regional structural mapping of the Transantarctic Mountains and, in particular, that bedrock structures can be traced subglacially beneath the ice-covered mountain flanks. Our analysis shows that regional structures in the mountains have provided preferred pathways for ice flow from the East Antarctic Ice Sheet across the Transantarctic Mountains barrier to the Ross embayment in West Antarctica. Further regional mapping using RADARSAT imagery has the potential to delineate the regional structural architecture of the Transantarctic Mountains and to establish the degree of spatial coupling between structures associated with mountain uplift and regional drainage patterns of the Antarctic ice sheets.