Chapter 1 - Planet Earth Flashcards
How far away is the earth from the sun?
150,000,000km
The crust
- Thinnest layer
- 10km deep under the oceans
- 60km deep under land
The mantle
- Hot semi molten rock
* 4000°C
The core
- 5000-7000°C
* Solid iron and nickel
At what degree is the earth tilted?
23.5°
Place boundary
Where plates meet
Subduction
When plates slide under each other
Uplift
When plates collide
Fault line
Where two plates rub off eachother
Divergent
Plates in separation
Convergent
Plates in collision
Transform
Plates sliding past each other
Convection currents
Movement of magma in the earths mantle
Continental drift
Convection currents in the mantle below cause the plates to move slowly bringing their continents with them. This is known as continental drift
Name the seven tectonic plates
1) Eurasian plate
2) Indian plate
3) African plate
4) American plate
5) Nazca plate
6) Pacific plate
7) Australian plate
How are fold mountains formed?
When the earth plates move towards each other and eventually collide, the rock layers are compressed and buckle. This results in the formation of fold mountains
How do earthquakes occur?
They occur where plates collide or slide past each other. If one plate slips suddenly, a huge amount of pressure is released, resulting in an earthquake
What are the effects of an earthquake?
- •Structural damage
- •Falling objects
- •Fire
- •Tsunamis
- •Disease
- •Economy
How are earthquakes measured?
Seismometer/seismograph identify tremors in the crust. The force is measured using a Richter scale
What is the mid-Atlantic Ridge
In the middle of the Atlantic Ocean there are a series of mountains which formed because the American plate is moving away from the eurasian and African plates.
Mid ocean ridges
When two plates pull away from each other it releases magma which cools and forms a series of mountains on the ocean floor. In some cases these mountains can rise above sea level to create volcanic islands eg Iceland
The Pacific ring of Fire
The worlds most active volcanic and earthquake zone is found along the edges of the Pacific Ocean. This is because many of the world’s major plates meet here
Active volcano
Erupts regularly
Dormant volcano
Hasn’t erupted for a long time but may erupt again
Extinct volcano
Hasn’t erupted in recorded history
What are the eight planets of the solar system?
Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune
Advantages of volcanoes
\+Tourism \+Geysers (electricity) \+Fertile lava soils \+The creation of new land \+Building materials
Disadvantages of volcanoes
- Damage
- Loss of life
- Fire
- Effect on the environment
