Earth's Structure

Question 1

describe the Earth’s inner core

Answer 1

• centre of Earth
• solid iron ball
• 8,000 miles thick
• 6,000 ºC

Question 2

describe the Earth’s outer core

Answer 2

• hot liquid rock
• melted iron & nickle
• in charge of Earth’s magnetic field
• 1,400 miles thick
• 4,000 ºC

Question 3

describe the Earth’s mantle

Answer 3

• magma (hot liquid molten rock)
• 1,800 miles thick (thickest layer)
• 2,200 ºC

Question 4

describe the Earth’s crust

Answer 4

• on Earth’s surface
• rock
• 3-45 miles thick
• split into continental plates (land) + oceanic plates (sea) which are always moving and floating above the liquid mantle

Question 5

who created the theory of plate tectonics?

Answer 5

Alfred Wegener

German scientist

1912

Question 6

explain Wegener’s theory of plate tectonics?

Answer 6

250 million years ago

one supercontinent called Pangea

split into smaller continents

drifted away from each other = Continental Drift

Question 8

How deep is the continental crust?

Answer 8

40-50 km

Question 9

What rock type forms the continental crust?

Answer 9

granite

Question 10

How deep is oceanic crust?

Answer 10

7km

Question 11

what are plate boundaries

Answer 11

where different plates meet each other

Question 13

Why do tectonic plates move

Answer 13

Earth’s mantle is made from liquid rock

tectonic plates float on top

so plates can move around freely and drift alongside, away and into each other