Earth's Structure

Question 0

True or false: the earth’s overall density is twice that if the rocks near the surface. Explain your answer.

Answer 0

True, because the earths interior is very dense.

Question 1

Formula for density?

Answer 1

Density=mass/volume

Question 2

Why do the layers of the Earth have different densities?

Answer 2

Because they are made from different materials.

Question 3

Do less dense layers float on the more dense layers?

Answer 3

Yes.

Question 4

Is the crust solid or liquid? What are its layers called?

Answer 4

Solid, continental and oceanic

Question 5

Is the mantle more solid or liquid? What word is used to describe it.

Answer 5

More solid than liquid ➡️ plastic

Question 6

Is the outer core solid or liquid? What is it made of?

Answer 6

Liquid, iron and nickel

Question 7

Is the inner core solid or liquid? What is it made of?

Answer 7

Solid, iron

Question 8

What layers make up plates?

Answer 8

The crust and some of the upper mantle.

Question 9

What thicknesses can the plates range from?

Answer 9

15km to 200km

Question 10

True or false: all continents take up only part of their tectonic plate

Answer 10

True.

Question 11

True or false: plates move steadily in definite directions.

Answer 11

True

Question 12

What is used to prove the location of plate boundaries?

Answer 12

Large amounts of seismic, volcanic and geothermal activity.

Question 13

How far do the continents move per year?

Answer 13

5-10cm

Question 14

True or false: Australia will eventually crash into Asia

Answer 14

True

Question 15

What part of the mantle do the plates sit over?

Answer 15

The plastic part.

Question 16

Describe how plates move underneath each other. (Key words: leading edge, plastic)

Answer 16

The leading edge of the plate sinks under gravity and drags the rest of it with it, and the flow of the plastic rock in the mantle drags the plate from below.

Question 17

How is density measured?

Answer 17

Mass by weight, volume by formulas or displacement

Question 18

State the thicknesses of the oceanic, continental, mantle, outer core and inner core.

Answer 18

Oceanic - 10km
Continental - 30km
Mantle - 3000km
Outer - 2300km
Inner - 1200km

Question 19

Difference between oceanic and continental crust?

Answer 19

Continental is deeper but less dense.

Question 20

Where is the ring of fire located and why does it exist?

Answer 20

Located on the Pacific Plate border and exists because volcanoes are created because it’s near a border.

Question 21

How do tsunamis occur?

Answer 21

Waves caused by earthquakes build up in height as the land gets shallower and they slow down and cause mass destruction.

Question 22

Describe the December 26 2004 tsunami.

Answer 22

Sumatra-Andaman Tsunami reached 5000km away from the radius, killing 300,000 people across Asia and Africa.

Question 23

Why does Australia have little volcanic activity?

Answer 23

Because Australia is in the middle of the Indo-Australian plate and not near the border where the action is