GEOMORPHOMETRIC ANALYSIS FOR CHARACTERIZATION AND MAPPING OF CRUSTAL DEFORMATION IN THE KARAKORAM HIMALAYA

The Karakoram Himalaya exhibits complex topography governed by scale-dependent dynamics involving tectonic, climatic, and surface processes. These dynamics govern the morphological structure of the topography that controls the degree of topographic forcing and the magnitude of processes. Characterizing the nature of morphometry and tectonic process relationships, particularly in terms of properties, magnitude, and extent, is difficult because of polygenetic topographic evolution. Consequently, our research objectives are to attempt to diagnostically characterize and map crustal deformation using drainage network architecture and topographic anisotropy that characterizes topographic structure. Therefore, we evaluate anisotropic properties of the topography and drainage network properties to map and characterize zones of uplift and lateral shear in the Karakoram Himalaya. Specifically, we utilize a Shuttle Radar Topography Mission (SRTM version 3, 30 m) digital elevation model to extract the drainage network from first-order slope-azimuth structure (convergence), and analyze drainage orientation structure and sinuosity, as well as the scale-dependent anisotropic properties of the topography (relief and skyview factor). We use pattern recognition to map semantically modeled features based upon meso-scale anisotropic topographic structure. Preliminary results demonstrate that this approach can be used to accurately characterize rapid uplift zones in the Hunza region, Braldu Valley, and across the Nanga Parbat Massiff given relatively low skyview values and relatively high relief anisotropy. Furthermore, changes in drainage sinuosity, orientation structure, and relief anisotropy demarcate broad regions of lateral shear along the Karakoram and Kilik faults in the Hunza Region, Shaksgam Valley, Braldu Valley, and others. These results demonstrate that regional-scale topographic structure can be used to characterize and map deformation zones in the Karakoram Himalaya.