quiz 11 Flashcards
Glaciers that move via basal sliding can often undergo surges in which they move at a much faster rate than normal because they
have very low frictional contact with bedrock
The Milankovitch cycles include the effect of the changes in … because of changes in the …. Of Earth relative to the Sun.
eccentricity of orbit; orientation
The polar ice caps on Mars are an example of what type of glacier?
continental
The Mars rover Curiosity has recently found evidence that there was liquid water on the planet’s surface at some point in its history. Because we have not found any liquid water on the planet today, what does this imply about Mars?
The climate was once warm enough that much of the polar ice caps melted.
A glacier will always advance from its source area if the rate of accumulation is greater than the rate of
ablation
…. glaciers cover vast areas of land, whereas.
_______ glaciers are restricted to
mountains.
continental: alpine
The cross-section of valleys carved by glaciers tend to be shaped like the letter ___, whereas valleys carved by water tend to be shaped like the letter …
U; v
By increasing the albedo of Earth, global ice sheets produce conditions that are _______- to their further advance, thus providing an example of _____- _ feedback.
favorable; positive
A(n) …. in estatic sea level is ultimately the result of a …_ event.
decrease; global cooling
Cirques and horns are features associated with
mountain glaciation
An intermediate product in the transformation of snow to glacial ice is
firn
You are hiking in your favorite forest when you encounter a surface that appears to have very fine scratches in it. What are these features?
striations
…. involves the internal flowing of ice under, generally, solid conditions, via the breaking and reforming of chemical bonds.
plastic deformation
glacial ice exhibits … behavior near the top but … behaviour beneath a depth of about 60m
brittle; plastic
sea levels … during glacials and … during interglacials
decreases ; increase
If a volcano were to erupt and release large amounts of ash into the air, how would this affect the climate on Earth?
The ash would increase the albedo and decrease the global temperature.
The Milankovitch Cycles largely describe the relation of the distance between the
Earth and the …. which affects the amount of insolation Earth receives. [Note
that cycles also depend on the inclination of the rotation axis of the Earth.]
sun
Which types of features would you find in a glacially carved mountain landscape?
cirques, arêtes, horns
Sediments deposited directly by glaciers as they melt are termed
till
Cirques, horns, and arêtes form from glacial … whereas moraines, erratics, and till form from glacial ….
erosion; deposition
During the Pleistocene Ice Age glaciers reached as far south as
Long Island, New York, USA
glaciers during the Pleistocene Ice Age stretched all the way to Illinois, Kansas and Nebraska
continental
Ice is a substance with a high albedo, which means it
reflects most of the light that falls on it
… can be recognized as a series of U-shaped hills that are lined up and represent the …. glacier.
Recessional moraines; retreat
During the Pleistocene Ice Age, glaciers covered much of the ___ _ _ _ __ and contained several … centres
Northern Hemisphere; accumulation
Glacial ice forms when snow accumulates in large enough volumes to compact and force …
out and … the ice crystal size.
air; increase
The loss of rain forests through burning or removal of trees for agricultural use of the land would contribute to a(n) ______.
.._ in the atmospheric greenhouse gases, thereby …. global warming.
increase; increasing
