The pressure from a glacier primarily comes from the weight of the overlying ice. This weight creates a vertical load that increases with ice thickness, resulting in stress at the glacier base. Specifically, the pressure is due to the static load of the ice above, which can be described as the product of the ice density, gravitational acceleration, and ice thickness (σ=ρgh\sigma =\rho ghσ=ρgh)-this normal stress increases from zero at the surface to a maximum at the glacier bed

. This pressure is responsible for basal shear stress, which drives glacier flow by causing deformation of the ice and sliding at the base. The pressure also influences melting at the glacier base because the melting point of ice decreases under higher pressure, allowing meltwater to form even below 0°C, which lubricates the glacier base and facilitates sliding

. In summary, glacier pressure comes from the weight of the ice above pressing down on the ice below and the bedrock, influencing glacier movement and basal melting processes.