Exam 12: Glaciers and Glaciation

The central portion of a valley glacier moves _____ the sides.

During the most recent ice age, sea level was at least 100 meters lower than at present.

Bodies of till shaped into streamlined hills are called drumlins.

Sharp ridges called ___ separate adjacent glacially carved valleys.

The thicker part of a glacier will flow slower than where it is thinner.

Glaciers in temperate climates may have crevasses that extend to their base.

______ gives us more evidence of the beginning and ending times of glacial episodes than the direct study of glacial deposits.

The boundary between the zone of accumulation and the zone of ablation is an irregular line called the _____.

A glacier will flow faster where it is steeper and _____.

The two types of glaciated terrain on the Earth's surface are alpine and valley.

Unsorted and unlayered rock debris carried or deposited by glaciers is called till.

Where tributary glaciers come together the adjacent lateral moraines join to form a ______ moraine.

The compacted mass of granular snow, transitional between snow and ice, is called firn.

A large trunk glacier erodes downward more rapidly and carves a deeper valley than do smaller tributary glaciers.

A(n) ___________ is an ice-transported boulder that was not derived from the underlying bedrock.

A(n) _____ -shaped valley (in cross section) is characteristic of glacial erosion.

The down-valley part of a glacier is the ____, where melting, evaporation, and calving take place.

Two layers of sediment resulting from one year's deposition in a glacial lake are called ___.

A worldwide decrease of at least _____ $\degree$ C in temperature would bring about a new glacial age.

A large trunk glacier carves a deeper valley than smaller tributaries. After the glacier disappears the tributary valley remains as _____ high above the main valley.