Earthquakes 1

Question 1

What is a Earthquake?

Answer 1

Shaking (vibration) produced by the rapid release of energy

Question 2

What does a Earthquake Generate?

Answer 2

Seismic waves (travel through Earth)

Question 3

What is the “Focus”?

Answer 3

Point of energy release; radiates out in all directions

Question 4

What is the “Epicentre”?

Answer 4

Point of Earth’s surface directly above the focus

Question 5

Where do Earthquakes occur?

Answer 5

Ring of Fire, Along faults associated with plate boundaries, accur on tectonic plates

Question 6

is divergent shallow or deep?

Answer 6

Shallow

Question 7

is convergent shallow or deep?

Answer 7

Can be shallow to deep

Question 8

is shallow more or less damage from an Earthquake

Answer 8

More Damage

Question 9

explain how strength of shaking from earthquake decreases?

Answer 9

diminishes with increasing distance from focus

Question 10

what are Intraplate Earthquakes?

Answer 10

single plate, far from boundary, typically shallow

Question 11

what are interplate earthquakes?

Answer 11

occur at boundaires between tectonic plates

Question 12

What is the Earthquake Early Warning System

Answer 12

Rapid detection, real-time estimation of shaking hazard
- seconds to tens-of seconfs notice before strong shaking starts (detects energy)

Question 13

Explain Earthquake magnitude and Frequency

Answer 13

The higher the magnitude the lower the frequency

Question 14

Explain Nepal Earthquake

Answer 14

Mw =7.8 (modified mercalli intensity scale)
- Shallow (around 8km)

Question 15

What is Earthquake Magnitude?

Answer 15

measurement of the energy released by an Earthquake
- measures amplitude of seismic waves on seismograph or amount of energy released

Question 16

What is the Richter Magnitude?

Answer 16

based on distance and amplitude or size of largest seismic wave produced during an earthquake (logarithmic and moment magnitude)

Question 17

What is Moment Magnitude?

Answer 17

measure of amount of energy released by earthquake
- Logarithmic; more effective for larger earthquakes

Question 18

What do Richter magnitude and Moment magnitude have in common?

Answer 18

both are quantitative

Question 19

What’s the difference between Richter Magnitude and Moment Magnitude

Answer 19

Richter is based on distance and amplitude, Moment is based on amount of energy released

Question 20

Explain Earthquake Magnitude

Answer 20

quantitative measure of amount of energy released at its source
- Earthquake is one magnitude (not variable)

Question 21

Explain Earthquake Intensity

Answer 21

Qualitative, amount of shaking, variable (depends on location)

Question 22

What is faulting?

Answer 22

A response to stress

Question 23

What is a “Fault”?

Answer 23

break between 2 blocks of rocks; blocks can move relative to each other (slowly or rapidly)

Question 24

Within Faulting and Deformation explain the difference between “Elastic” and “Brittle” Deformation

Answer 24

Elastic is reversible, Brittle is permenant ruptures

Question 25

explain how rupture occurs?

Answer 25

starts at the focus and propagates outwards (produces waves of energy called Seismic Waves)

Question 26

What are the Three types of Faults?

Answer 26

Normal Fault, Reverse Fault, Strike-slip Fault

Question 27

Explain Divergent, Convergent, and Transform Boundaries

Answer 27

- Divergent: plates goes opposite directions (left and right) - Convergent: Plates going towards each other - Transform: One plate up other plate down

Question 28

which type of boundary are normal, reverse, and strike-slip faults?

Answer 28

- Normal: Divergent - Reverse: Convergent - Strike-Slip: Transform

Question 28

What is Seismic Waves

Answer 28

Release of energy along fault

Question 29

what are the three types of seismic waves?

Answer 29

P-Wave (primary)(body) S-Wave (secondary)(body) R-Wave (Rayleigh)(surface)

Question 30

Explain P-wave

Answer 30

- Compressional waves - Arrives first - travels through solids, liquids, and gas

Question 31

Explain S-Wave

Answer 31

- Shear waves - Arrives second - Travel only through a solid

Question 32

Explain Rayleigh Waves

Answer 32

- Surface Waves - Arrive after body waves - Most damaging of all waves

Question 33

How long is Wave period?

Answer 33

10 seconds

Question 34

What is Attenuation?

Answer 34

weakening or removal of high-frequency waves - occurs with increased distance; low frequency waves travel further

Question 35

Why did mexico city recieve so much damage from earthquake?

Answer 35

a) low frequency waves affecting tall buildings b) Material amplification - subsurface materials respond differently to seismic waves