Glaciers and Ice Sheets Overview

These flashcards cover key concepts about glaciers and ice sheets based on lecture notes, focusing on definitions and significant processes.

Two primary types of glaciers are and glaciers.

Alpine or Valley; Continental.

Alpine glaciers form on and flow downslope into .

mountains; valleys.

Continental glaciers are also known as __.

ice sheets.

Glaciers form where the seasonal amount of snowfall is large enough that it does not all __ in the summer.

melt away.

The Zone of __ is where glacier melting occurs.

Ablation.

In the Zone of __, snow turns to ice and adds volume to the glacier.

Accumulation.

Snowflakes in the zone of accumulation melt and are compacted into __.

firn.

Each layer of ice represents __ year's accumulation of snow.

one.

GLACIAL BUDGET: If accumulation is less than ablation, the glacier __.

will retreat.

If a glacier's accumulation is equal to its ablation, the glacier __.

remains in the same position.

Glaciers move faster at the and .

center; top.

The rate of ice movement decreases due to __ at the glacier's base.

friction.

Crusoe Glacier shows a __ front of advancing glacier.

steep.

Honeycomb Glacier has retreated, forming a __-dammed lake.

moraine.

In cold regions, the ice at the base of a glacier is frozen to the __.

bedrock.

Drumlins are shaped and left behind as the glacier retreats and are found in the __ region.

continental.

Glacial till consists of sediments of many different __.

sizes.

Medial moraines form __ the glaciers.

within.

Lateral moraines are found at the __ of the glacier.

margin.

Kettle lakes form where blocks of glacial ice are left behind and _.

melt.

Glacial erratics are rocks left behind as a glacier __.

retreats.

Loess deposits originated from erosion by __ and ice sheets.

glaciers.

Areas of __ extend across large parts of northern continents.

permafrost.

The Alaska Pipeline is elevated because it is built across areas of __.

permafrost.

Ice sheet coverage during the last ice age was around __ years ago.

20,000.

Great Lakes were formed after the last __ age.

ice.

Glacial features like terminal and recessional moraines indicate the extent of __ during past ice ages.

ice sheets.

Ancient shorelines provide clues about the depth of __ Lake during the last ice age.

Pyramid.

Trona Pinnacles in California are deposits formed during the last __ age.

ice.

Evidence suggests that glacial lakes formed during the __ ice age.

last.

The Channeled Scablands show features indicating large volumes of __ flowed across it.

floodwaters.

Sea level rose as __ and glaciers melted at the end of the last ice age.

ice sheets.

Landforms above the current coastline depict the __ during the last ice age.

sea level.

The Texas coastline was __ miles farther south during the last Ice Age than it is today.

miles.

As temperatures warmed at the end of the last Ice Age, glaciers began to __.

melt.

The sediment deposits in kettles associated with deglaciation often have __ layers or varves.

fine-grained.

The glacier front will recede when __ is greater than ablation.

accumulation.

Glacial U-profiles are characteristic of __ valleys.

glacial.

A fjord is a U-profile glacial valley that is occupied by __.

seawater.

Glacial striations indicate the __ of flow by the alignment of the striations.

direction.

Roche moutonees are bedrock ridges formed by __ and abrasion.

glacier erosion.

Glaciers erode valleys into a __-shaped profile during glaciation.

U.

During glaciation, tributary glaciers contribute to the __ of main glaciers.

erosion.

Hanging valleys are formed as smaller glacial tributary valleys left behind after __.

glaciation.

Crevasses form where a glacier moves over steps in __ topography.

bedrock.

Eskers are meandering ridges of sediments deposited by __ streams beneath a glacier.

outwash.

Glacial features associated with melting ice sheets include karnes, end moraines, and __ lakes.

kettle.