By Tamara Gerber Aniso… what? Glaciers and ice sheets move by sliding over their bed and by deforming internally under their own weight. How easily the ice deforms depends not only on temperature and stress, but also on the way the ice crystals are arranged. When these crystals become aligned in a preferred orientation, the […]
Anisotropy of Glaciers and Ice sheets Read More »
Videos This video from the BBC shows how glaciers flow, making good use of timelapse imagery.
Introduction | Primary stratification | Longitudinal surface structures | Crevasses | Ogives | Debris cover | Medial moraines | Further reading | References | Comments | Introduction As glaciers flow, they crack and fracture in predictable ways. This brittle failure of the glacier ice yields insights into glacier strain, both in the present day and
Structural glaciology Read More »
Deviatoric stress Normal stress is the stress acting on the bed in the vertical direction. Ice tends to spread out under its own weight, so normal stresses act in all other directions. If the ice is subject to other pushes and pulls, the stresses at location x may differ from the average value[1]. The difference
Longitudinal Stress Read More »
Introduction | Newtown’s Three Laws | Types of stress and strain | Glacier flow | Summary | References | Comments | Introduction to glacier stress and strain In Part I (Deformation and Sliding), we learned that glaciers flow downslope in response to their driving stresses, which are a function of the weight of the ice
Introduction | Surging glacier features | Other kinds of flow instability | References | Comments | Variable glacier flow Although all glaciers flow, the way in which they flow is highly variable. We already know that the thermal regime can impact on glacier flow, with cold-based glaciers being frozen to their bed and flowing very
Glacier mass balance | Glacier flow | Internal deformation | Basal sliding | Subglacial deformation | Different types of glacier flow | References | Comments | Glacier mass balance How do glaciers move? A glacier is a pile of ice, and as such, deforms under the force of gravity. Glaciers flow downslope because they accumulate
Deformation and sliding Read More »
Introduction | Thermal regimes | Warm-based glacial processes | Polythermal glacial processes | Cold-based glacial processes | References | Comments | Introduction Glacial thermal regime is one of the most important factors in determining subglacial processes. The amount of meltwater at the base of a glacier controls entrainment, transfer and deposition of debris, as well
Glacial thermal regime Read More »
