What are the dominant thermomechanical processes in the basal sediment layer of large ice sheets?

The till–layer below the temperate base of an ice sheet is modelled as a saturated viscous solid–fluid mixture. Its solid mass grows by abrading material from the underlying rock–bed, and the water balance is affected by the draining of water into the rock–bed and melting of ice at the interface of the overlying ice sheet. This latter process is influenced by the dissipation due to the power expended by: (i) the stresses; and (ii) Darcy–type interaction forces; as well as (iii) the sliding of the ice over the till–layer and of the latter over the rock–bed. All these mechanisms are likely to influence the thermodynamics of the layer, a fact which is corroborated by a scaling analysis.