Chapter 14 Glaciers

A glaciers budget is balanced when a. additions to the zone of accumulation equal losses in the zone of wastage. b. losses in the zone of accumulation equal additions to the zone of wastage. c. the zone of accumulation receives more input than the zone of wastage. d. the zone of wastage does not lose material.

A. Additions to the zone of accumulation equal losses in the zone of wastage

A glacial landform produced primarily by plucking rocks on the downstream side and smoothing by the glacier on the upstream side is called a(n) ____. a. roche moutonnée b. esker c. kame d. terminal moraine e. cirque

A. Roche Moutonnee

When did the Pleistocene Ice Age end? a. 1.8 million years ago b. 10,000 years ago c. 1,300 years ago d. 200 years ago e. It still hasn't ended.

B. 10,000 years ago

A glacier begins to flow when the ice reaches what critical thickness? a. 100 meters b. 40 meters c. 20 meters d. 10 meters e. 5 meters

B. 40 meters

Straight scratches on rock surfaces created by glacial abrasion are known as what? a. rock flour b. glacial striations c. glacial till d. varves e. moraines

B. Glacial Striations

In a cross-section of a glacier, where do the greatest flow velocities occur? a. at the surface b. in the few tens of meters below the surface c. in the few tens of meters above the base d. at the base e. in the center of the flow

B. In the few ten of meters below the surface

In the process of sublimation a. ice melts to become liquid water, which then evaporates. b. fresh snow becomes firn and then glacial ice. c. ice changes directly into water vapor. d. white ice becomes denser so that blue wavelengths are transmitted and scattered and the ice appears blue.

C. Ice changes directly into water vapor

If glacial ice were a rock it would be a(n) _______ rock. a. igneous b. sedimentary c. metamorphic d. glacial ice cannot be a rock

C. Metamorphic

What is a lake formed within a cirque called? a. arête b. esker c. tarn d. fjord e. drumlin

C. Tarn

Ice Ages a. have been common through Earth history. b. have glacial episodes separated by very short interglacial stages. c. are caused primarily by plate tectonics. d. are the result of variations in the amount of solar heat received.

D. Are the result of variations in the amount of solar heat received

Glacial till is ____. a. any sediment deposited as a result of glacial activity b. boulders transported long distances and deposited by glaciers c. an elongated spoon-shaped hill that has been shaped by an overriding glacier d. unstratified sediment deposited directly by a glacier e. a lake within an outwash plain.

D. Unstratified sediment deposited directly by a glacier

A glacier that is unconfined by topography and has tributaries is a a. ice cap. b. tributary glacier. c. continental glacier. d. valley glacier.

D. valley glacier

Where is the largest existing glacier located? a. Greenland b. Alaska c. The Alps d. Patagonia e. Antarctica

E. Antarctica

Which is the only continent that does not presently have glaciers? a. South America b. North America c. Africa d. Europe e. Australia

E. Australia

A glacial landform that forms at the head of glacial valleys or troughs is called a(n) ____. a. roche moutonnée b. esker c. kame d. arête e. cirque

E. Cirque

A conical hill of stratified drift is an esker. t/f

False

A strong correlation has been established between periods of intense volcanism and short-term glacial cooling. t/f

False

There is good evidence that variation in solar energy, as evinced by sunspot activity cycles, is responsible for short-term climatic variations. t/f

False

Valleys carved by glaciers are distinctive because they are V-shaped in cross-section t/f

False

A steep-walled, pyramidal peak formed by headward erosion of cirques. t/f

True

Basal slip becomes a more important means of glacier movement in warmer months when more meltwater collects at a glacier's base. t/f

True

Earth's orbit varies from nearly circular to more elliptical in a roughly 100,000-year cycle. t/f

True

End moraines continue to grow as long as the ice front remains stationary. t/f

True

Glaciers are geologically important because they erode, transport, and deposit so much material t/f

True

The Little Ice Age ended in the mid to late 1800s t/f

True

The decade from 2000 to 2009 was the hottest on record so far. t/f

True