Earth

Question 1

What are the layers of the Earth?

Answer 1

Crust, Mantle, Outer Core, Inner Core

Question 2

Crust -

Answer 2

• Thin outer layer
• Made of solid rock and broken into plates
• Layer that we mine for resources
• 5-70km
• Oceanic and Continental crust
• Less than 1% of the entire Earth’s Mass
• -5 to 1000 degrees Celsius

Question 3

Mantle -

Answer 3

• 2900km
• Lithosphere (Upper, Dense rock)
• Athenosphere (Lower, Plastic like fluid, hotter because its closer to the core.
• Convection currents
• 67% of the Earth’s Mass
• Around 3700 Celsius( different temps throughout the mantle)
• Made up of hot, dense, rock
• Flows very slowly

Question 4

Outer Core -

Answer 4

• Liquid
• Made of Iron and nickel
• not under enough pressure to become solid,
• very high temperatures.
• Moves/flows
• 2200km
• ~5000 Celsius

Question 5

Inner Core -

Answer 5

• Solid
• Iron and nickel
  ~1250km
  ~7000 degrees Celsius
• Solid because of the pressure from the others layers around it
• Melting point increases with high pressure

Question 6

What is the temperature of each layer?

Answer 6

Crust= -5 to 1000 degrees Celsius
Mantle= about 3700 celsius (but the temp. varies)
Outer Core= about 5000 celcius (temp varies)
Inner Core= about 7000 (temp. varies)

Question 7

What is the depth of each layer?

Answer 7

Crust= 5 - 70km
Mantle= About 2900km (densest layer)
Outer Core= 2200km
Inner Core= 1250km

Question 8

What are the different types of crust?

Answer 8

Oceanic and Continental

Question 9

Oceanic crust (characteristics)

Answer 9

thin and dense

Question 10

Why is the oceanic crust more dense than the continental crust?

Answer 10

-it is more compact due to the weight of the ocean above it smooshing it down overtime

Question 11

Continental crust (characteristics)

Answer 11

thick and not as dense as the oceanic crust

Question 12

What happen when the crusts meet?

Answer 12

• a subduction zone forms
• the oceanic crust slips underneath the contenetal crust
• this also causes an earthquake, and then a tsunami
• when the oceanic crust falls, it goes into a hotter area (therefore melting it)
• this magma must go somewhere so it goes back up to the surface forming new crust

Question 13

How did the layers of the earth form

Answer 13

The earth was once a ball of hot lava. As the earth began to cool layers formed due to the
differences in density of what the lava is made up of. The more dense material sank to the
bottom and the less dense material stayed at the top or rose to the top.

Question 14

Why is there convection in the Mantle?

Answer 14

• different temps throughout the mantle
• hotter portion of the substance rises and colder parts sink to the bottom

Question 15

how do earthquakes happen?

Answer 15

• Tectonic plates moving
• most earthquakes happen on fault-lines (LA is right on top of one)
• Tectonic plates are always moving, earthquakes just happen when they suddenly slip because of the pressure build-up

Question 16

Why do the tectonic plates move?

Answer 16

• due to the convection currents in the mantle, it pushes on the tectonic plates
• it either pushes them together (folding), or pulls them apart (forming ridges), or causes them to transform (creating earthquakes)

Question 17

What is the Focus?

Answer 17

• the spot inside the earth where the tectonic plates moved and cause the earthquake

Question 18

What is the Epicenter?

Answer 18

The epicenter is the spot above the focus
- it is right where the earthquake happened and is where the earthquake is strongest

Question 19

What are faults?

Answer 19

• where one tectonic plate ends and one begins

Question 20

How do we measure the strength of an earthquake and how does it work?

Answer 20

• Richter Scale
• It’s a scale from 1-10
• everytime it goes up by 0.1 it is 10 times stronger than before
• ex. a 7.2 earthquake is 100 times stronger than a 7.0 earthquake

Question 21

What is mountain building?

Answer 21

• mountain building is when two crusts converge together
• there is nowhere for the crust to go except for up

Question 22

What is folding?

Answer 22

• Folding is when two crusts converge together and form a “bump” in the earth

Question 23

What is faulting?

Answer 23

• When there is movement along a fault line (where two tectonic plates meet)

Question 24

What is volcanic activity?

Answer 24

• When lava comes up from the mantle to the surface