Glacition Flashcards
What is an ice age
A glacial period when temperatures are particularly cold and glaciers or ice sheets extend over a lager part of the planet
When was the last ice age
About 15000 yrs ago
What is a land bridge and how are they formed
During an ice age the sea level is much lower because the water is frozen so it exposes dry land between country’s that are normally separated by water
What is an ice sheet
Large amounts of thick ice (2km) e.g. Antartica
What is an ice cap
Smaller areas of ice e.g. On Iceland
What are glaciers a major threat of global warming
Because if they melt it will lead to a rise in sea levels and flooding
Why do ice ages happen (3)
- variations in the suns energy
- changes in the earths orbit
- volcanic eruptions were ash blocks the sun
What is frost shattering
A type of weathering where water repeatedly freezes and puts pressure on the rocks to break them
What is abrasion
A process of erosion when moraine carried by the glacier wears away the sides and floor of the valley
What is plucking
a process of erosion here glacial ice freezes onto rocks and as it moves away pulls large pieces of rock with it
What are arétes
Arétes are the knife edge ridges firmed between two corries
What is a pyramidal peak
Pyramidal peaks are when 3 or more corries erode backwards into the same mountain
