Earth's Structure

Question 1

Four layers of Earth?

Answer 1

Inner core, outer core, mantle, crust

Question 2

Describe inner core?

Answer 2

Made of solid metal and is very hot. There is radioactive decay which ultimately leads to convection currents.

Question 3

Describe outer core?

Answer 3

Surrounds inner core, made of of molten metal which contains iron and nickel.

Question 4

Describe mantle?

Answer 4

Surrounds outer core, made of semi molten rock

Question 5

Describe crust?

Answer 5

Final, outer layer. Solid and relatively thin. The crust is where the tectonic plates are found.

Question 6

Two types of crust?

Answer 6

Continental and oceanic

Question 7

Describe continental crust?

Answer 7

Mainly granite, older, thicker (25-70km), lighter, less dense, forms the landmasses

Question 8

Describe oceanic crust?

Answer 8

Mainly basalt, younger, thinner (7-10 km), heavier, more dense, forms the floors of oceans

Question 9

Types of plate boundary

Answer 9

Costructive, destructive, conservative, collision

Question 10

Describe constructive and give example

Answer 10

Plates move apart and the mantle rises through the gap and creates new land. Type of crust is oceanic, there are volcanoes, there are earthquakes but they are gentle, shallow and low magnitude. E.g. Mid-Atlantic Ridge.

Question 11

Describe destructive and give example

Answer 11

Between oceanic and continental plates. Plates move towards each other. Oceanic plate subducts and continental plate buckles and rises. Oceanic plate is destroyed. There are explosive volcanoes, there are violent and high magnitude earthquakes, fold mountainsE.g. Nazca and South American plate

Question 12

Describe conservative and give example

Answer 12

Same direction different speeds or different direction, can be both types of crust, no volcanoes, violent earthquakes. Plates lock together and when pressure is released the plate breaks. San Andreas fault. Pacific and North American plate

Question 13

Describe collision plate and give example

Answer 13

Continental plates moving towards each other. One plate subducts other one buckles, they force each other up. Rarely volcanoes (hot spots) violent earthquakes, fold mountains E.g. himalayas.

Question 14

What are convection currents?

Answer 14

Heat rising and falling inside the mantle creates convection currents generated by radioactive decay in the core.