WAVELET ANALYSIS OF GLACIER TOPOGRAPHIC PROPERTIES FOR CHARACTERIZING GLACIER DYNAMICS AND SENSITIVITY TO CLIMATE CHANGE IN THE KARAKORAM, HIMALAYA

The Karakoram Himalaya exhibits complex climate-glacier dynamics that operate within a mountain geodynamics framework. Unfortunately, we do not have a good understanding of the dominant forcing factors that regulate many glacier processes such as erosion and surging. Furthermore, it is difficult to characterize glacier dynamic states, assess glacier sensitivity to climate change, and assess glacier spatial trends in complex mountain environments. Consequently, we evaluated a new approach for characterizing supraglacial process-form relationships and glacier dynamics over the Karakoram Himalaya, where unique spatial patterns of glacier states and dynamics have been documented. We accomplish this by utilizing the Shuttle Radar Topographic Mission (SRTM; 30m) digital elevation model to derive topographic parameters that control glacier supraglacial sediment flux, ablation, ice-flow velocity and erosion dynamics. These parameters include relief, slope angle, divergence/convergence, curvature, and topographic shielding. Specifically, we generate parameter-altitude profiles for glaciers and analyzed parameter-altitude trends and periodic variations using one-dimensional wavelet analysis. Preliminary results indicate that glaciers in the Karakoram exhibit different altitudinal trends and periodicity transitions with respect to various geomorphometric parameters. Furthermore, wavelet analysis results depict glaciers exhibiting unique altitudinal patterns of scale-dependent topographic periodicity that are associated with ablation/sediment dynamics related to surging, downwasting, supraglacial debris shielding, supraglacial ponding and ice cliff retreat, and suprafluvial activity. Our results demonstrate that glacier topographic structure characterizes the nature of various glacier process dynamics, and that glaciers in the Karakoram exhibit significant spatial variations in their dynamics and sensitivity to climate forcing.