Chapter 17 Glacial and Periglacial Processes and Landforms Geosystems 6e An Introduction to Physical Geography Robert W. Christopherson Charles E. Thomsen

Glacial and Periglacial Processes and Landforms Rivers of Ice   Glacial Processes   Glacial Landforms   Periglacial Landscapes  

Rivers of Ice   Glacier – a large mass of ice resting on land or floating as an ice shelf in the sea adjacent to land Not stationary Alpine glaciers – a glacier in a mountain range Valley glacier Cirque glacier Peidmont glacier Tidal glacier Iceberg

Rivers of Ice Figure 17.1

Rivers of Ice Continental glaciers – large, continuous mass of ice – ice sheet 81% Greenland 90% Antarctica

Vatnajökull Ice Cap Figure 17.5

Glacial Processes Formation of Glacial Ice Glacial Mass Balance Compaction, recrystallization, and growth of snow and ice Glacial Mass Balance Accumulation Ablation Moraine    Glacial Movement ice regelation – to refreeze

Mass Balance Figure 17.7

Glacial Polish Figure 17.9

Glacial Landforms Erosional and Depositional Landforms Created by Alpine Glaciation   Fjord Till Stratified drift Moraines Erosional and Depositional Landforms Created by Continental Glaciation   Outwash plain kettle

Norwegian Fjord Figure 17.12

Periglacial Landscapes Periglacial – describes frost weathering and freeze-thaw rock shattering Geography of Permafrost  80% Alaska  Ground Ice and Frozen Ground Phenomena  Active layer  Humans and Periglacial Landscapes  

Permafrost Distribution Figure 17.18

Permafrost Melting Figure 17.24