Geo Final Unit Flashcards
(29 cards)
What percent of Earth’s water is locked up in ice? What is the name for it?
2%. Cryosphere
Sea level would rise ____ if melted.
250ft
How many major episodes of ice ages are in the rock record?
12
How long are ice age episodes?
10s of millions of years
What is the current climate?
Interglacial period
30% of Earth’s surface was covered how long ago?
18,000 yrs ago
What percent of the surface is covered in ice now?
10%
What is a glacier?
A moving body of ice formed by accumulation and compaction of snow?
Glaciers have an internal….
Plastic flow
Name two of the four snow conversions to ice:
Points of snowflakes sublimate
Some vapor fills in porosity
Pressure melting of flake points
Water refreezes; less porosity
What is a firn?
Compacted snow after 1 season (spherical crystals)
What are the three glacier classifications?
Cirque glaciers, valley glaciers, and Piedmont glaciers
Function of ice caps?
In mountain highlands… Extensive and radiate outward
Where is a good example of a budget of a glacier?
Glacier Bay, Alaska: 2006 - 2012
What is the snow and Avalanche contributions called?
The zone of accumulation
What is the snow and ice loss due to melting and sublimation called?
The zone of ablation
Where is the snowline?
The line of equilibrium between zones.
The terminus advances in the -
Positive budget
The terminus retreats in the -
Negative budget
Glacial drift is…
ANY sediment of glacial origin
Glacial till is…
Ice melting and dropping its unsorted load
What are ridges of till?
Moraines
Name the three moraines:
Lateral moraines, medial moraines, and end moraines
Another word for basin
Cirque
