Earth structure and internal energy sources

Question 1

What is the core

Answer 1

The densest and hottest part of the planet made of rocks rich in iron and nickel.

Question 2

What is the core divided into

Answer 2

The semi-molten outer core and solid inner core

Question 3

What can temps exceed in the core

Answer 3

5000 degrees

Question 4

What is the mantle

Answer 4

Surrounds the core, mainly silicate rocks rich in iron and magnesium. Most of the mantle is semi molten and is known as the asthenosphere

Question 5

What is the crust

Answer 5

Thinnest layer made of the coolest, less dense rocks, which are rich in silicon, oxygen, aluminium, potassium and sodium

Question 6

What are the 2 types of crust

Answer 6

Oceanic crust

Continental crust

Question 7

What is the crust and rigid upper mantle known as together

Answer 7

The lithosphere

Question 8

What are the 2 processes that the temps near the are core produced as a result of

Answer 8

Primordial heat- left over from the earth’s formation
Radiogenic heat- produced by the radiogenic heat produced by the radioactive decay of isotopes, particularly Uranium-238, Thorium-232 and Potassium-40

Question 9

What do the processes that produces heat in core provide

Answer 9

A continuous but diminishing heat. Without this internal energy source the earth would be a completely dead and inert planet

Question 10

What does the intense heat in the core generate

Answer 10

Convection currents within the mantle above. These currents spread slowly within the asthenosphere

Question 11

Characteristics of oceanic crust

Answer 11

Found beneath the world’s oceans and is formed at spreading centres on oceanic ridges at constructive plate margins.
Composed of basalt
Approx 6 km thick

Question 12

Characteristics of continental crust

Answer 12

Thicker (35 km) and older than oceanic crust. 
Less dense than oceanic crust 
Mainly composed of granite
More structurally complex
Formed at subduction