basal sliding

Basal sliding is a key process in glacial movement, particularly for temperate glaciers. These glaciers exist at their pressure-melting point, allowing them to slide over the bedrock beneath them. This sliding is facilitated by two main mechanisms: stress concentrations around bed protuberances causing increased plastic flow, and the melting and refreezing of ice around these bumps (regelation).12

When basal ice is below the pressure-melting point, as in polar glaciers, basal sliding is significantly reduced due to adhesion to the frozen bed and the ice's greater rigidity. Cold-based glaciers primarily move through internal deformation. Temperate glaciers, however, utilize basal sliding as their primary mode of movement, enabling them to effectively erode their beds and shape landscapes. This erosion is enhanced by rock debris embedded in the ice, acting as abrasive tools.1