302-Lecture 9

General Outline

Glacial and Periglacial Processes and Landforms

I. Causes and location of glaciers

A. glacier types: alpine, piedmont and continental (ice sheet)

B. snow accumulation, firn formation

C. zones of net snow accumulation and net mass ablation (sublimation, melting, calving)

II. Glacier dynamics

A. flow after sufficient thickness to cause internal deformation

B. velocity profile and temperature within ice

C. erosion (abrasion, plucking), transportation, and deposition

III. Pleistocene glaciation

A. Laurentide ice sheet

B. erosional features: bedrock striations, roche moutonnee,

C. direct depositional landforms: till plains, moraines, drumlins

D. glaciofluvial landforms: eskers, outwash plain, kames and kettles

E. glacial history of North America and Europe

IV. Permafrost

A. climate and ground temperature

B. types and distribution of permafrost

C. latitudinal patterns of permafrost and active layer thickness; taliks

V. Periglacial features

A. ground ice: ice wedges, patterned ground, pingos

B. melting ground ice: subsidence and thermokarst

VI. Pluvials and other effects of glaciation

A. paleolakes in western U.S.

B. Lake Missoula and the Channeled Scablands