Chapter 9 - The Cryosphere Flashcards
What is the cryosphere?
the part of Earth’s surface that remains parentally frozen is the cryosphere.
- sea ice
- glaciers (10% of earth’s land surface)
- frozen ground ( 20% of Earth’s land)
What is snow?
Snow is precipitation that consists of solid H2O in crystalline form. It results from the condensation and crystallization of tiny water droplets into feathery ice crystals at very low temperatures in clouds.
What is ice?
Ice is a solid form of H2O.
What is glacier ice?
Glacier ice forms by the accumulation, compression, and recrystallization of snow, but some ice crystallizes directly from water in the atmosphere and falls is icy precipitation.
Describe the process of “ from snow to ice” (snowflake)
As a snowflake is slowly converted into a granule of old snow and eventually into glacial ice, melting and evaporation because it’s delicate points to disappear. The resulting meltwater re-freezes, and vapour condenses near the centre of the crystal, making it denser and less porous.
In ________ _________ annual snowfall is very _____ because the air is too ______ to hold ___________. This is referred to as: ______ ___________.
polar regions, low, too cold, moisture, polar deserts
What is the snowline?
The lower limit of perennial snow as the snow line
- its shape is controlled by variations in thickness of winter snowpack and local topography
- altitude typically changes from year to year dependent on winter snow accumulation and summer melting.
What is a glacier?
When snow and ice become so sick that the pull of gravity causes the frozen mass to move, this is a glacier.
Glacier ice is considered a rock
true or false
True
Why would a glacier advance or retreat?
A glacier’s advance or retreat is the balance of the amount of snow and ice added (accumulation) and lost (ablation)
- upper zone is the accumulation area
- below this zone is the ablation area
- between these is the equilibrium line
- the front of the glacier is called the terminus
Describe basal sliding
Melt water at the base acts as a lubricant
What is frontal calving?
Coastal glacier retreat is characterized by frontal calving.
- where the terminus is in deep water
- front brakes off to form icebergs
What is more dense ice or water?
Water has a higher density than ice
The earth fluctuates between periods of extended cooler and warmer temperatures leading to either glaciations or interglacials. describe both
Glaciations: glaciers expand, and new ones form
interglacials: ice sheets retreat, sea level rises
we are currently in an interglacial period
Which of the following glacial features cannot be used to determine the direction of ice movement?
a. Boulder trains
b. striations
c. drumlins
d. loess
d. loess
Where the earth’s large ice sheets now exist?
a. Greenland and Antarctica
b. Antarctica and Asia
c. Canada and Greenland
d. Greenland and Asia
a. Greenland and Antarctica
Glaciers generally develop below sea level in the polar regions
true or false
False
What is the typical crystal structure of snow?
a. Hexagonal
b. Pentagonal
c. octagonal
d. tetrahedral
a. hexagonal
If you were to analyze a deep ice core, what would expect to be the relative sizes of the ice crystals that make up the core? Start from the top layer and work your way down to the bottom layer
a. Large, medium, small
b. small, medium, large
c. medium, small, large
d. large, small, medium
b. Small, medium, large
Solifluction is a common mass wasting process in which waterlogged regolith in a thawed, active layer moves slowly downslope
True or false
True
What is the highest point called at which a glaciers winter snow cover is lost during a given season?
a. Equilibrium line
b. tree line
c. frost line
d. boundary line
e. snow line
e.Snowline
The huge continental ice sheets of Greenland and Antarctica contain about 95% of existing glacial ice
True or false
True
Where does the medial Moraine develop?
a. At the top of the glacier
b. near the bottom of the glacier
c. on the side of a glacier
d. in the middle of two coalesced glaciers
d. in the middle of two coalesced glaciers
Where would one find the equilibrium line on a glacier?
a. The point where net mass loss is greater than net mass gain
b. the point where net mass loss is less than net mass gain
c. the point where net mass loss equals net mass gain
c. the point where net mass loss equals net mass gain
