Glaciers and Glacial Mechanics I Glacier Origins and

I. Glacier Origins and Types A. Glacier (def): a body of moving ice that

B. Critical Requirements 1. Must be formed from the accumulation and ‘metamorphism’ of snow.

I. Glacier Origins and Types C. The recrystallization of snow

II. The Movement of Glaciers A. Basal Sliding

II. The Movement of Glaciers A. Basal Sliding B. Plastic Flow/Internal Shearing C. Internal

II. The Movement of Glaciers A. Basal Sliding B. Plastic Flow/Internal Shearing

II. The Movement of Glaciers C. Crevassing (Zone of Fracture)

III. • • • The Glacial Budget Zone of Accumulation Zone of Ablation Equilibrium

IV. Classification of Glaciers A. Descriptive-based B. Process-based

IV. Classification of Glaciers A. Descriptive-based * Cirque Glaciers * Valley Glaciers * Ice

IV. Classification of Glaciers A. Descriptive-based B. Process-based 1. Dynamic classification scheme * Active

Cirques Tarn Lakes Pater Noster Lakes Horns Aretes U shaped Valleys Hanging Valleys Fjords

Glacial Erosion Glacial Striations and grooves

VI. Depositional Landforms Glacial Till Stratified drift

VI. Depositional Landforms Moraines Lateral Medial

Eskers, Drumlins, Kames, Kettles, Outwash Plains, Erratics

The Pleistocene Epoch Milankovitch Cycles Eccentricity Tilting Wobble

Milankovitch Cycles • Individual cycles vs. multiple cycles

400, 000 years of change Note how climate slowly cools going into a glacial

The Pleistocene Ice Ages: Glacial Periods Wisconsinan Illinoian Kansan Nebraskan

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Glaciers and Glacial Mechanics

I. Glacier Origins and Types

I. Glacier Origins and Types A. Glacier (def): a body of moving ice that has been formed on land by compaction and recrystallization of snow.

I. Glacier Origins and Types A. Glacier (def): a body of moving ice that has been formed on land by compaction and recrystallization of snow. B. Critical Requirements

B. Critical Requirements 1. Must be formed from the accumulation and ‘metamorphism’ of snow.

B. Critical Requirements 1. Must be formed from the accumulation and ‘metamorphism’ of snow. 2. Ice must be moving under its own weight.

B. Critical Requirements 1. Must be formed from the accumulation and ‘metamorphism’ of snow. 2. Ice must be moving under its own weight. 3. Must originate on land

B. Critical Requirements 1. Must be formed from the accumulation and ‘metamorphism’ of snow. 2. Ice must be moving under its own weight. 3. Must originate on land 4. Persist from year-to-year

I. Glacier Origins and Types C. The recrystallization of snow

II. The Movement of Glaciers

II. The Movement of Glaciers A. Basal Sliding

II. The Movement of Glaciers A. Basal Sliding B. Plastic Flow/Internal Shearing C. Internal Shearing

II. The Movement of Glaciers A. Basal Sliding B. Plastic Flow/Internal Shearing

II. The Movement of Glaciers C. Crevassing (Zone of Fracture)

Crevasses

III. • • • The Glacial Budget Zone of Accumulation Zone of Ablation Equilibrium Line

“fastest velocity at equilibrium line”

IV. Classification of Glaciers

IV. Classification of Glaciers A. Descriptive-based B. Process-based

IV. Classification of Glaciers A. Descriptive-based * Cirque Glaciers * Valley Glaciers * Ice Sheets

IV. Classification of Glaciers A. Descriptive-based B. Process-based 1. Dynamic classification scheme * Active * Passive * Dead

IV. Classification of Glaciers A. Descriptive-based B. Process-based 1. Dynamic classification scheme * Active * Passive * Dead 2. Thermal classification scheme * Temperate Glaciers

IV. Classification of Glaciers A. Descriptive-based B. Process-based 1. Dynamic classification scheme * Active * Passive * Dead 2. Thermal classification scheme * Temperate Glaciers * Polar Glaciers --sub polar --high polar

V. Erosional Glacial Landforms

Cirques Tarn Lakes Pater Noster Lakes Horns Aretes U shaped Valleys Hanging Valleys Fjords

Erosional Landforms