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

• Main Authors: Dell'Isola, Francesco, Hutter, Kolumban
• Other Authors: Laboratorio Strutture e Materiali Intelligenti - Fondazione Tullio Levi-Civita, Cisterna di Latina, Dipartimento di Ingegneria Strutturale e Geotecnica, Università degli Studi di Roma "La Sapienza" = Sapienza University Rome, Institut für Mechanik, Technische Universität Darmstadt (TU Darmstadt)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 1998
• Subjects: [SPI.MECA]Engineering Sciences [physics]/Mechanics [physics.med-ph]; Ice Sheet
• Online Access: https://hal.archives-ouvertes.fr/hal-00498007; https://hal.archives-ouvertes.fr/hal-00498007/document; https://hal.archives-ouvertes.fr/hal-00498007/file/hutter-dellisola.pdf

International audience 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.