CHARACTERIZATION AND UTILIZATION OF TOPOGRAPHIC ANISOTROPY AND GEOMORPHOMETRIC SIGNATURES FOR INVESTIGATING MOUNTAIN GEODYNAMICS IN THE KARAKORAM HIMALAYA

Common geomorphometric analysis approaches using local morphometric parameters do not adequately account for the inherent scale dependencies of mountain geodynamics. Complex interactions involving climate, surface processes and tectonics govern anisotropic scale-dependent topographic structure. The topographic anisotropic patterns that result from erosion and deformation dynamics have not been adequately characterized in areas of active orogenesis such as the Karakoram Himalaya. Consequently, we investigate the concept of topographic anisotropy and utilize multiple morphometric properties to generate scale-dependent morphometric signatures for a particular location. Our primary objective is to determine the uniqueness of such morphometric signatures for characterizing specific process regimes and erosion-coupled systems that govern topographic evolution. Furthermore, we attempt to determine if these morphometric signatures are diagnostic of specific process-form relationships. Specifically, we utilize a Shuttle Radar Topography Mission (SRTM) digital elevation model to produce scale and direction dependent morphometric signatures. A scale-dependent morphometric signature is based upon direction and distance, defining the morphometric boundaries of topographic structure. We utilize a multitude of analysis approaches to characterize meso-scale relief, topographic prominence, symmetry, and direction and magnitude of anisotropy. Preliminary results reveal that when these signatures are combined they are unique in their magnitude and shape over most of the Karakoram Himalaya, based upon Monte Carlo simulations. These signatures were found to exhibit unique shapes, differentiating ablation dynamics and glacier surface structure. Furthermore, topographic anisotropy can be used to identify the locations of fault systems, given extreme relief variation. Anisotropic distributions can vary significantly depending upon landform presence and distribution that is governed by process regimes and crustal deformation. These results clearly reveal that geomorphometric signatures that characterize topographic anisotropy can be used to map and investigate erosion-uplift dynamics in the Karakoram Himalaya.