Hazardos Earth Flashcards
What is the crust made of?
Rock
How thick is the crust?
Varies between 5-70 km thick
How thick is the mantle?
2900 km
What are the two parts of the upper mantle?
Lithosphere and asthenosphere
Where is the lithosphere?
Part of the mantle closest to the crust
What is the lithosphere made out of?
Liquid (molten rock)
Where is the asthenosphere?
Part of the mantle, underneath the lithosphere
What is the asthenosphere made out of?
More rock than molten rock (liquid)
What is beneath the upper mantle?
The lower mantle
What is beneath the lower mantle?
The outer core
How thick is the outer core?
2266km
How hot is the outer core?
4000-5700 degrees centigrade
What is the outer core made out of?
Molten iron and nickel
How thick is the inner core?
1200km
What is the inner core made out of?
Mostly solid iron and nickel
How hot is the inner core?
The same temperature as the surface of the sun
What is the order of the layers inside the earth?
- crust
- lithosphere
- asthenosphere
- lower mantle
- outer core
- inner core
How thick is oceanic crust?
Very thin (1-3 miles)
What is oceanic crust made out of?
Basalt p. The same kind of rock found in the mantle.
Where is the oceanic crust?
The ocean floor
Has the oceanic crust got a hazard got a high or low density?
High density
What is continental crust made out of?
Thick granite
How thick is continental crust?
10-50 miles
Where does continental crust form?
On land
Is it deeper than oceanic crust?
Yes it is the deepest and thickest
What is radioactive decay?
Some elements are naturally unstable and radioactive (e.g uranium), atoms of these elements release particles from the nuclei and give off heat. This is called radioactive decay
What are convection currents?
The movement of the earths crystal plates is due to convection currents which occur in the mantle. These convection currents are created by heat from within the earth.
What is the divergent plate movement?
The tectonic plates move apart.
What is the convergent plate movement?
One plate moves under the other
What is the conservative plate movement?
The plates slide past each other.
What is the collision plate movement?
The plates move towards each other.
Who’s theory proved continental drift and Pangea?
Wegner’s
What was the super continent called?
Pangea
When was Pangea a continent?
250 million years ago
What were the 2 continents called?
Laurasia and Gonclwanaland
When were the the continents Laurasia and Gondwanaland
200 million years ago
What are divergent plates?
When two plates move apart.
What are convergent plates?
One plate moves under the other
What is conservative plates?
Plates slide past each other
What are collision plates?
Plates that move towards each other.
What type of crust do you find divergent plates on?
Oceanic
What tectonic activity do divergent plates cause?
Gentle earthquakes, volcanoes are less violent, but can be more constant.