Week 3, Chpt 8, 9

Question 1

How old is the Earth?

Answer 1

4.5 Billion Years

Question 2

The oldest ocean crust is ____ years old.

Answer 2

200 million

Question 3

What kind of seismic wave can travel through both solids and liquids?

Answer 3

P-Wave

Question 4

What kind of seismic wave can only travel through solids and not liquids?

Answer 4

S-Wave

Question 5

Do seismic waves move faster or slow in the mantle?

Answer 5

Faster

Question 6

How can we map out the crust-mantle boundary?

Answer 6

By seeing how fast seismic waves are travelling.

Question 7

Seismometers can detect earthquakes all around the planet except in

Answer 7

shadow zones.

Question 8

Why do we have a solid inner core?

Answer 8

Because pressure increases the melting temperature.

Question 9

How hot is the centre of the Earth?

Answer 9

10, 800 degrees Fahrenheit

Question 10

How thick is the Earth’s crust?

Answer 10

4000 miles

6400 km

Question 11

How thick is the Earth’s mantle?

Answer 11

1802 miles

2900 km

Question 12

How big is the Earth’s core?

Answer 12

760 miles

1220 km

Question 13

Surface of uniform gravity on Earth

Answer 13

Geoid

Question 14

Seismic wave velocities generally ____ with depth

Answer 14

increase

Question 15

Stress of strain causes 3 types of deformation:

Answer 15

Displacement
Rotation
Deformation

Question 16

How do we calculate strain?

Answer 16

Change in length
_____________

Original length

Question 17

Strain is controlled by

Answer 17

Temperature
Pressure
Deformation Rate
Composition

Question 18

Elastic Rebound Theory

Answer 18

Earthquakes happen because of stress build up, causing rock adjacent to the fault to bend elastically until slip on the fault occurs.

Question 19

Focus Point

Answer 19

The point in the Earth where the slip occurs.

Question 20

Epicenter

Answer 20

The point on the surface of the Earth directly above the focus point.

Question 21

Seismic Waves

Answer 21

Earthquake energy travels through rock and sediment in the form of waves.

Question 22

4 Categories of Seismic Waves(from fastest to slowest moving)

Answer 22

P-wave
S-wave
L-wave (surface wave)
R-wave (surface wave)

Question 23

An increase in 1 earthquake magnitude number results in

Answer 23

10x increase in shaking and 32x increase in energy release.

Question 24

Stress causes

Answer 24

strain.

Question 25

Cratons

Answer 25

Portions of continents that consist of old and relatively stable crust.