Contents xvii
10 Glaciers and Ice Sheets ..........................617
10.1 Dynamic Phenomena ........................618
10.1.1WavesonGlaciers......................618
10.1.2Surges ............................619
10.1.3IceStreams..........................624
10.1.4 Ice Shelf Instability . . ...................625
10.1.5TidewaterGlaciers......................625
10.1.6 Jökulhlaups .........................626
10.2TheShallowIceApproximation...................626
10.2.1Glaciers ...........................626
10.2.2 Ice Sheets ..........................631
10.2.3TemperatureEquation....................634
10.2.4 A Simple Non-isothermal Ice Sheet Model .........637
10.2.5UsingtheEquations.....................644
10.2.6 Ice Shelves ..........................647
10.2.7 The Grounding Line . . ...................650
10.2.8 Marine Ice Sheet Instability .................653
10.3 Sliding and Drainage .........................655
10.3.1 Röthlisberger Channels ...................661
10.3.2 Linked Cavities .......................664
10.3.3 Canals ............................666
10.3.4IceStreams..........................668
10.4Waves,SurgesandMega-surges...................673
10.4.1WavesonGlaciers......................673
10.4.2Surges ............................680
10.4.3SlidingandIceStreams ...................682
10.4.4HeinrichEventsandtheHudsonStraitMega-surge.....685
10.5DrumlinsandEskers.........................686
10.5.1Drumlins...........................687
10.5.2Eskers ............................699
10.6GlaciologyonMars .........................704
10.6.1Non-dimensionalisation...................708
10.6.2 Multiple Steady States . ...................712
10.6.3 Trough Formation . . . ...................713
10.6.4 Multiple Troughs . . . ...................716
10.7 Notes and References ........................717
10.8Exercises...............................728
11 Jökulhlaups ................................741
11.1 The Nye Model ...........................742
11.2Non-dimensionalisation .......................744
11.3 Boundary Conditions and Lake Refilling ..............747
11.4 Simplification of the Model . . ...................748
11.5 Periodic Oscillations .........................750
11.5.1 Breaking the Seal . . . ...................751
11.5.2 Wide Channels and the 1996 Eruption . . .........757