The Restless Earth: Earthquake - Cause and Measurement

Question 1

Name the 3 plate boundaries?

Answer 1

Destructive.
Constructive.
Conservative.

Question 2

Earthquakes are caused by what?

Answer 2

Tension that builds up at the plate boundaries.

Question 3

How does tension build up at a destructive plate boundary’s?

Answer 3

When one plate gets stuck as it’s moving down past the other into the mantle.

Question 4

How does tension build up at a constructive plate boundary’s?

Answer 4

Along cracks within the plates as they move away from each other.

Question 5

How does tension build up at conservative plate boundary’s?

Answer 5

When plates that are grinding past each other get stuck.

Question 6

The plates eventually jerk past each other sending

Answer 6

Shock waves(vibrations).

Question 7

What are the vibrations?

Answer 7

The earthquake.

Question 8

Shock waves spread out from where?

Answer 8

The focus.

Question 9

What is the focus?

Answer 9

The point in the earth where the earthquake starts .

Question 10

What happens near the focus?

Answer 10

Waves are stronger and cause more damage.

Question 11

What is the epicentre?

Answer 11

The point on the Earth’s surface straight above the focus.

Question 12

Weak earthquakes happen…

Answer 12

Often.

Question 13

Strong earthquakes happen…

Answer 13

Rarely.

Question 14

Earthquakes can be…

Answer 14

Measured.

Question 15

Name the 2 ways earthquakes can be measured?

Answer 15

The richter scale.

The mercalli scale.

Question 16

What does the richter scale measure?

Answer 16

Amount of energy released by the earthquake.

Question 17

What is the magnitude?

Answer 17

Measurement of the amount of energy released.

Question 18

What is magnitude measured using?

Answer 18

Seismometer.

Question 19

What is a seismometer?

Answer 19

A machine with an arm that moves with vibrations of the earth.

Question 20

What doesn’t a Richter scale have?

Answer 20

An upper limit.

Question 21

The Richter scale is…

Answer 21

Logarithmic.

Question 22

What does logarithmic mean?

Answer 22

Earthquake with a magnitude of 5 is ten times more powerful than one with a magnitude of 4.

Question 23

Most people don’t feel earthquakes of a magnitude of…

Answer 23

1-2.

Major earthquakes are above 5.

Question 24

What does the mercalli scale measure?

Answer 24

Effects of an earthquake.

Question 25

How are the effects measured?

Answer 25

Asking eye witnesses for observations of what happened.

Words or photos.

Question 26

What does the mercalli scale range from?

Answer 26

1 to 12.

Question 27

On the mercalli scale what happens at 5?

Answer 27

Felt by everyone.

Objects moved.

Question 28

On the mercalli scale what happens at 12?

Answer 28

Total destruction.

Question 29

On the mercalli scale what happens at 1?

Answer 29

Only detected by instruments.