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
The rate of accumulation is _____________ the rate of abalation, a glacier will advance from a source area
a. less than
b. much less than
c. equal to
d. greater than
d.Greater than
What are large boulders deposited by glaciers called?
a. erratics
b. moraines
c. Loess
d. drumlins
a. Erratics
As you go from lower to higher latitudes either north or south of the equator, the altitude of the snowline should
a. need more information
b. stay the same
c. decrease
d. increase
c.Decrease
The map device that a glacier loses is greater than the amount of snow against, it will
a. stay motionless
b. advance
c. retreat
d. search
c.Retreat
Till is a glacial sediment that occurs in unsorted and on stratified deposit
True or false
True
The North Pole is located in the Antarctic continent, covered by a vast, thick ice sheet
true or false
False
During the most recent Ice Age, about what percentage of the Earth’s land area was covered by glaciers?
a. 20%
b. 50%
c. 70%
d. 30%
d.30%
What is frontal calving, with regard to glaciers?
a. breaking off of icebergs from the back of a glacier that terminates in deep water
b. breaking off of icebergs from the front of a glacier that terminates in deep water
c. breaking off of icebergs from the back of a glacier that terminates in shallow water
d. breaking off of icebergs from the front of a glacier that terminates in shallow water
b. breaking off of icebergs from the front of a glacier that terminates in deep water
Icebergs float with most of their volume above the surface of the sea
true or false
False
The zone of accumulation is generally characterized by
a. striations
b. thick sediment
c. the thickest development of glacial ice
d. abalation
c. the thickest development of glacial ice
Ice ___________ a mineral and snow _____________ a mineral
a. is; is not
b. is not; is
c. is; is
d. is not; is not
c. is; is
Which of the following statements is not true about the snow and ice?
a. are minerals
b. have crystalline structure
c. hexagon on crystal form
d. formed from supercooled water
d. Form from supercooled water
Which of the following facts about Pleistocene glaciations is most relevant to human migration into North America?
–Interglacial/glacial cycles lasted approximately 100,000 years
–Drop in global sea levels exposing land bridges
–The maximum of the most recent glacial cycle was 24,000 years ago
–The Holocene optimum occurred 6000–7000 years ago
–There were more than 30 major interglacial/glacial cycles
–Drop in global sea levels exposing land bridges
. What is the navigational significance of the Northwest Passage?
–Allows ships from the Northwest United States to reach Asia more quickly
–Allows ships from Europe to reach India more quickly
–Allows ships from Europe to reach Asia more quickly
–Allows ships from the Northeast United States to reach Africa more quickly
–Allows ships from the Northeast United States to reach India more quickly
–Allows ships from Europe to reach Asia more quickly
Which of the following is not an impact of global warming?
–More ships may get caught in ice flows
–More regions would be opened up to oil exploration
–Ships would be able to travel freely through the Northwest Passage without ice breakers
–More area will be available and open to research
–More ships may get caught in ice flows
Which of the following is a drawback of oil exploration in the Northwest Passage?
–There is little demand for additional oil
–The costs to bring oil from the Northwest Passage to oil markets would be too high
–In the future, we predict more sea ice cover that would impede exploration
–Oil spills in cold water are extremely difficult to clean up
–Oil spills in cold water are extremely difficult to clean up
The snowline is defined as lower limit of perennial snow.(p.259, text).
If you were in a valley in the Rocky Mountains of Alberta, in which season would you best be able to estimate the snow line on a specific mountain?
- Spring
- Summer
- Fall
- Winter
•Fall
