Glaciers & Ice Ages
What is a glacier?
a river of ice
What are erratics?
large, out-of-place rocks were transported far from their origin by ice.
What is till?
The mixture of sand, clay, and rock left after a glacier melts.
What is the Antarctic Treaty?
the international agreement that protects Antarctica from activities like drilling for resources
Name 2 kinds of glaciers.
alpine/mountain and ice sheets
What is an ice sheet?
a massive blanket of ice that spreads over thousands of square kilometers (a type of glacier)
What are drumlins?
smooth, spoon-shaped hills show the direction a glacier once moved
One of the two main ways glaciers erode rock—this one involves scraping. What is it called?
Abrasion
What is the tundra?
A frozen, treeless biome with low-growing plants common in Arctic regions.
How are glaciers formed?
snow accumulating over time, compressing into ice
What is an Ice Age?
A time when Earth’s temperatures dropped and glaciers expanded across continents.
What is a U-shaped valley?
A valley carved by a glacier, wide at the bottom with steep sides.
What is plucking?
The second way glaciers erode rock—this one involves freezing onto rocks and lifting them.
What is the name of the land bridge that connected Asia and North America during the last ice age?
Beringia
Name one landform formed by glacial erosion and one by glacial deposition.
corrie, arete, pyramidal peak
moraine, erratics, drumlins
What is the glacial maximum?
The coldest stage within an ice age, when global ice coverage reaches its largest extent
What is a moraine?
A ridge of rocks and sediment left behind as a glacier melts.
When glaciers melt, what happens to the world's oceans?
sea levels rise
Name a consequence of glaciers melting.
rising sea tides, other answers accepted as well
Give two ways glaciers pick up material as they move.
plucking, abrasion
What is the Milankovitch Cycle?
Slow changes in Earth’s orbit that alter how much sunlight reaches the planet
Lakes and hollows form when glaciers reshape the land. Name two of these landforms.
tarn, ribbon lake
What is a misfit river?
A river that flows in a valley carved by a glacier long ago.
Name one natural factor that can trigger an ice age.
orbital changes
Why are sea levels lower during an ice age?
because large amounts of water are stored in glaciers and ice sheets