Detection and characterization of discontinuous motion on Thompson Glacier, Canadian High Arctic, using speckle tracking and ice-flow modeling

High resolution Synthetic Aperture Radar (SAR) data allow for measurement of multicentimeter-scale glacier motion via a technique known as speckle tracking. In this thesis, I develop an intensity rescaling that improves the performance of speckle tracking and use it to quantify an uncommon form of discontinuous glacier motion, where velocity differences up to 1 cm/d occur across large supraglacial stream channels on Thompson Glacier, Umingmat Nunaat (Axel Heiberg Island), Canadian High Arctic. The intensity rescaling is developed using simulated SAR data and results in a  20% performance improvement. Cross-sectional ice-flow modeling indicates that the discontinuous motion observed can occur without ice fracture and under a wide variety of glacier thermal conditions. This form of cross-channel discontinuous motion is likely uncommon as it requires channels that are sufficiently deep, located in regions of substantial shear stress and that are aligned with shear stresses over substantial spatial scales.