Extensional forces within the Antarctic Plate have produced the Transantarctic Mountains rift-flank uplift
along the West Antarctic rift margin. Large-scale linear morphologic features within the mountains are controlled by
bedrock structure and can be recognized and mapped from satellite imagery and digital elevation models (DEMs). This
study employed the Antarctic Digital Database DEM to obtain slope steepness and aspect maps of the Transantarctic
Mountains (TAM) between the Royal Society Range and the Churchill Mountains, allowing definition of the position
and orientation of the morphological axis of the rift-flank. The TAM axis, interpreted as a fault-controlled escarpment
formed by coast-parallel retreat, provides a marker for the orientation of the faulted boundary between the TAM and the
rift system. Changes in position and orientation of the TAM axis suggests the rift flank is segmented into tectonic
blocks bounded by relay ramps and transverse accommodation zones. The transverse boundaries coincide with major
outlet glaciers, supporting interpretation of rift structures between them. The pronounced morphological change across
Byrd Glacier points to control by structures inherited from the Ross orogen.