A study of valley-side slope asymmetry based on the application of GIS analysis: Alexander Island, Antarctica

• Published in: Antarctic Science
• Main Authors: Siegmund, Mike, Hall, Kevin
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2000
• Subjects: Geology; Ecology, Evolution, Behavior and Systematics; Oceanography; Alexander Island; Mars Oasis; Antarc*; Antarctic Science; Antarctica
• Online Access: http://dx.doi.org/10.1017/s0954102000000559; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102000000559

Geographic Information System (GIS) data from southern Alexander Island were used to evaluate valley asymmetry from an area where ground observations had suggested that south facing slopes were steeper than north facing. Using digital elevation modelling (DEM), data were collected from 2° and 10° arcs centred on the four cardinal directions in order to determine average slope angles for a whole nunatak area (Mars Oasis). It was found that south facing slopes were significantly steeper (34°) than the north facing (28°); east and west facing slopes were each 31°. Bedrock in this area is (approximately) horizontally bedded and so valley asymmetry is considered to be due to aspect-influenced periglacial weathering processes.