What is weather?
Weather is short-term changes to the state of the
atmosphere e.g. sunny, cloudy or rainy. It changes
daily or even hourly
What is climate?
Climate is longer term weather patterns in a place
e.g. a tropical climate. It is studied over many years
When/why has temperature increased and decreased?
- Temperature has increased when carbon-dioxide has been high. (Interglacial)
- Temperature has decreased when carbon-dioxide levels have been low. (Glacial)
Freeze-thaw weathering
When water gets into gaps in the valley side., it freezes at night and expands, breaking the rock apart.
Abrasion
Abrasion is a type of erosion. It is when scree scratches along the valley bottom, wearing it away.
Plucking
A form of erosion. It is when the glacier freezes and sticks to the valley. As it melts it plucks rock away.
What are the two types
of glaciers?
Alpine sheets and ice sheets.
When snow falls, what
does it do to the
bottom layer?
Compresses (squashes) it.
What is ice that
survives one year
called?
Firn
When layers of snow fuse
together, what is
formed?
Glacial ice
What do glaciers do to
the land as they move?
They erode the land
How many years ago
did most glaciers
retreat (disappear)?
20,000 years ago
Moraine
A mass of rocks found at the end (terminus) of a glacier.
Why are U-Shaped valleys evidence of glaciation
- A U-shaped valley is form by glacial erosion.
- As the glacier moves downhill the sediment in the sole
(bottom) of the glacier erodes the land through abrasion - Over time this creates a U-shape
- When the glacier melts, the valley is left behind as
evidence
Why are glacial striations evidence of glaciation
- Striations are formed through erosion
- As a glacier moves, the sediment in the sole (bottom) of
the glacier scrape the floor - This is abrasion
- It leaves marks on rock, providing evidence of glaciation
Why are glacial erratics evidence of glaciation
- Erratics are formed through transportation and deposition
- Glaciers transport sediment as they move downhill
- When they melt, they deposit large boulders
- This leaves large boulders in landscapes that they do not look like they belong in
What are the natural causes of climate change?
- Volcanic activity
- Changes in the earth’s orbit
- Solar variations (sunspots)
- Asteroid Collisions
How do volcanic eruptions cause climate change?
Volcanic eruptions release carbon-dioxide, warming the Earth but large eruptions of ash can also block sunlight and cool the Earth for small periods of time.
How do changes in the earths orbit cause climate change?
When it is more elliptical it is cooler as we receive less solar radiation.
When more spherical it is warmer. Right now, Earth’s orbit is becoming more elliptical.
How does solar variations cause climate change?
When solar output is lower it may cause Earth to cool down.
When there are less sun spot it is cooler and when there are more it is warmer.
How do asteroid collisions cause climate change.
Asteroid collisions throw dust clouds up, which block The Sun’s heat. This cools Earth.
What is the greenhouse effect
The process through which heat is trapped in the Earth’s atmosphere by substances known as ‘greenhouse gases.’
Why is the greenhouse effect important?
It keeps the Earth at a inhabitable temperature.
What are periods of cooling and warming known as?
A cooling period is a glacial whereas a warming period is an inter glacial.
