Susceptibility modelling of hummocky terrain distribution using the information value method (Deception Island, Antarctic Peninsula)

MELO RAQUEL; VIEIRA GONÇALO; CASELLI ALBERTO T.; RAMOS MIGUEL

GEOMORPHOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2012 vol. 155 p. 88 - 95

0169-555X

The hummocky terrains of Deception Island (Antarctic Peninsula) are continuous surfaces with decimetre to metre wide and decimetre depth bumps located mainly in the lower section of sloping lapilli and scoria terrains. A detailed study site between Cerro Caliente and Crater Lake was selected for the detailed mapping of hummocky terrains and for modelling their spatial distribution according to controlling geographical factors. A model of the susceptibility of occurrence of the hummocky terrains was created using the information value method, together with five independent variables: elevation, slope, global summer radiation, total curvature and lithology. Success and prediction rate curves were used for model validation and the Area Under the Curve index was used to quantify the levels of performance and prediction. The results were of high quality with a success rate of 88% and a prediction rate of 78%. The classes of the independent variables with more relevance in the occurrence of hummocky terrains were: elevation between 20?30 m and 60?70 m; concave or rectilinear/flat areas; slopes between 8 and 12º; tuff cones and maar deposits and global summer radiation between 1.8 and 2.0 TJm−2. The good quality of the modelling results supports its use for assessing the future potential for formation of new hummocky terrain areas, or even to estimate the spatial distribution of buried ice within the permafrost environment of Deception Island.