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Ice streams and their frozen fringes

Please note Seminar is on Wednesday 17th April at 4p.m.  Room A2-002.

MACSI at the department of Mathematics and Statistics at the University of Limerick invites you to a seminar

Date: Wednesday,  17th April  2019, Room A2-002 @ 16.00

Speaker:  Dr  Colin Meyer, University of Oregon

Title: Ice streams and their frozen fringes

Abstract: Fast glacier flow is facilitated by slip along the basal interface where ice meets the underlying sediments. High pore pressures within the sediments offset a large fraction of glacier overburden (weight), leading to low effective stresses at this interface. The shear strength of subglacial sediments is proportional to this effective stress so high pore pressures lead to sediment failure, which manifests as glacier slip. As the effective stress increases (pore pressure decreases) above a threshold set by the surface energy and sediment particle size, a film of premelted water separating ice and sediment particles thins and allows the ice to infiltrate into the sediments. The basal zone of sediments infiltrated by interstitial ice, known as the frozen fringe, modulates the effective stress and therefore the strength of the sediments. Here we describe a model for frozen fringe formation and use this model to elucidate glacier sliding and Heinrich events, as examples of the processes controlling how sediment freezes on to the base of ice streams.

Further Information: If you have any questions regarding this seminar, please direct them to Romina Gaburro (061 2131930, email romina.gaburro@ul.ie  or Clifford Nolan (061 202766), clifford.nolan@ul.ie).

Supported by Science Foundation Ireland funding, MACSI - the Mathematics Applications Consortium for Science and Industry (www.macsi.ul.ie), centred at the University of Limerick, is dedicated to the mathematical modelling and solution of problems which arise in science, engineering and industry in Ireland.

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