glacier final exam Flashcards
what are glaciers?
3 mile thick blocks of ice that flow with gravity
Types of glaciers
Mountain glaciers and continental glaciers
form from ice river shapes and flow from high to low elevations in mountain setttings
Mountain glaciers
large land masses covered in ice, flow as function of gravity
continental glaciers
Three conditions to form glaciers
more snow has to fall and stay put, no removal of snow, and can be a function of altitude or latitude
how do glaciers move?
Water flows along base; water reduces the friction
What is meant by brittle flow, plastic flow and basal slip?
Brittle flow refers to the cracks being made at the top due to movement. Plastic flow refers to the ductile characteristic in the deeper parts of the glacier; basal slip refers to the smooth bottom from the water to allow the glacier move with gravity and slide
What is a horn?
result o fmultiple glaciers going away from each other leaving a peak
What is acrete
two glaciers scooping out
what is a cirque?
The area of the mountain that is separated by a moraine
What is a U shaped valley?
The result of cirques and form glacial movement
what are hanging valleys?
Result of glacial retreat and are narrowed U shaped valleys
large boulders out of place
glacial erratics
pile of rubble from glacier usually in edges of sediment and rocks in the middle
medianmoraines
sediment dropped by glacial ice
glacial till
sediment transported in meltwater that is dominated by sand and gravel
outwash plain
pile of sediment that acts as an edge on the side of U shaped valleys
lateral moraine
form at the stable toe of a glacier
end moraines
form at the farthest edge of flow
terminal moraines
form as retreating ice stalls
recessional moraines
long aligned hills of molded lodgment till
drumlins
till left behind by rapid ice retreat
ground moraine
long, sinuous ridges of sand and gravel and form as meltwater channels within or below the ice
eskers
melted stranded ice blocks form hole in land after melting
kettle lakes
changes how earth reactts in the solar system; looks at orbital changes
milankovich cycle
How did milaknovich cycle affect glacial extent and the ice ages
The earth being tilted will have different sun positioning causing it to experience heat n varying time frames. It is also due to the tilt of the earth that sparks ice ages and times of glaciers
