Earths Layers

Question 1

How many layers of the Earth are there and what are they called?

Answer 1

1. Crust
2. Mantle
3. Outer Core
4. Inner Core

Question 2

What does mafic mean?

Answer 2

Mafic is dark in colour and is identifiable through its high magnesium, iron and silicon

Question 3

What does felsic mean?

Answer 3

Felsic is light in colour and is identifiable through its high aluminium and silicon

Question 4

What is the thickest layer of the Earth?

Answer 4

The Mantle

Question 5

What are the layers of the crust?

Answer 5

1. Oceanic crust
2. Continental crust

Question 6

What layer of the Earth is a liquid?

Answer 6

The Outer Core

Question 7

What layer of the Earth is a solid that moves? What is the scientific term for that?

Answer 7

The Mantle is a plastic

Question 8

What layer of the crust is thicker? Why?

Answer 8

Continental crust because

Question 9

What layer of the crust is denser?

Answer 9

Oceanic crust

Question 10

What is the composition of both the Continental and oceanic crust?

Answer 10

1. Oceanic crust is mafic
2. Continental crust is felsic

Question 11

What does ultramafic mean?

Question 12

What is convection and how does it occur in the mantle

Answer 12

1. Convection is movement caused within a fluid by the tendency of hotter, less dense material to rise and colder, denser material to sink because of gravity, which then results in a transfer of heat
2. Heat from the outer core heats up the mantle. This heating causes the mantle to convert due to differences in density. The currents formed from this drive plate tectonics and influence the crust

Question 13

What is Gravitational separation/differentiation?

Answer 13

Accretion of smaller meteorites under gravity. Heat of accretion causes rock to melt, and mass increases strength of gravity. Dense molten metal is less buoyant, sinks, while lighter molten rock in buoyant, floats due to effect of gravity. The core of the Earth is mostly metal, the mantle and crust is metal depleted rock.

Question 14

What is Accretion?

Answer 14

Accretion is the joining of matter because of gravity to form a larger body (e.g., meteorites)

Question 15

How do we know the Earths core is metal?

Answer 15

There are 3 stages to Meteorites. Each of these stages show different parts to the Earth. The composition of Earth should match the meteorites. They don’t. It has less iron and nickel than the meteorites. So, where did it go? The core. We know larger asteroids form metallic cores, and this must have also happened to Earth. It explains why Earth has led Iron and Nickel than meteors

Question 16

What are the three types of meteors?

Answer 16

1. Chondrites
2. Pallasites
3. Metallic

Question 17

What are the types of seismic waves?

Answer 17

1. P Waves
2. S Waves

Question 18

What materials can the different seismic waves travel through?

Answer 18

1. P waves can travel through solids and liquids
2. S waves can travel through solids only

Question 19

What type of seismic wave is faster?

Answer 19

P waves by roughly 60%

Question 20

What is a seismic shadow zone?

Answer 20

A seismic shadow zone is an area of the Earths surface where seismographs cannot detect P or S waves.

Question 21

Why does Earth have a magnetic field?

Answer 21

Earth has a magnetic field because the Inner Core is hotter than the Outer Core causing convection in the Outer Core. The moving metal on the Outer Core creates a magnetic field.