Test 1: Earthquakes/Tsunamis

Question 1

What is a Fault?

Answer 1

Movement, fracture, or discontinuity in a rock.

Question 2

What are the results from a rupture of rocks along a fault?

Answer 2

Energy is released in the form of seismic waves.

Question 3

What is an Epicentre?

Answer 3

The point on the surface above the focus.

Question 4

What is the Focus?

Answer 4

Directly below the epicentre

Question 5

What are Seismographs?

Answer 5

Instruments used to record the motion of the ground during an earthquake.

Question 6

Ground motion for a magnitude 3 is ____ than a magnitude 2

Answer 6

10 times more

Question 7

The amount of energy released from an M3 is ____ than an M2

Answer 7

32 times more

M5= 32x32 of an M3

Question 8

The scale is qualitative and based on damage to structures and people’s perceptions.

Answer 8

Modified Mercalli Intensity Scale

Question 9

How are earthquakes measured?

Answer 9

Shaking, the energy released, and peoples perception

Question 10

How to measure faults?

Answer 10

Extract rocks and date it

Question 11

Strike-slip faults

Answer 11

Displacements are horizontal

Question 12

Dip Slip faults

Answer 12

Displacements are verticle

Question 13

Block below the fault plane

A miner would stand here

Answer 13

Footwall

Question 14

Block above the fault plane

Hang a lantern here

Answer 14

Hanging wall

Question 15

A hanging wall goes up relative to the footwall
Due to crustal shortening
The slope of fault is not steep

Answer 15

Thrust or reverse fault

Question 16

The hanging wall goes down relative to the footwall

Due to crustal stretching

Answer 16

Normal Fault

Question 17

Blind Faults:

Answer 17

Mountain building processes

Blind faults do not reach the surface

Question 18

Active faults:

Answer 18

Movement in the past 11,600 years

Question 19

Potentially active faults:

Answer 19

Movement during the past 2.6 million years

Question 20

Inactive faults:

Answer 20

No movement during the past 2.6 million years

Question 21

Tectonic creep:

Answer 21

Occurs when movement along a fault is so gradual that earthquakes are not felt

• Can slowly damage infrastructure

Question 22

Seismic Wave:

Answer 22

A wave is produced by a sudden displacement of rocks along a fault; seismic waves move through or along the surface of the earth.

Question 23

What are the two types of body waves?

Answer 23

P waves and S waves

Question 24

P waves, primary, or compressional waves

Answer 24

P-Waves reach seismic graph first (Travel through solid, liquid, and gas) Compressional (Faster of the two waves, travel at 6km per second

Question 25

S-Waves, secondary, or shear waves

Answer 25

Reach seismic graph second (Only travels through solids; whipping motion)

Question 26

Surface Waves:

Answer 26

Travel along the earth surface horizontally and vertically Moves slower than body waves Damage near the epicentre

Question 27

What are two types of surface waves?

Answer 27

Love waves and Rayleigh Waves

Question 28

What are Love waves?

Answer 28

Cause horizontal shaking

Question 29

What are Rayleigh Waves?

Answer 29

Rolling waves, elliptical motion

Question 30

Which waves turn into Love and Rayleigh waves once they reach the surface?

Answer 30

P and S waves

Question 31

How many stations are needed to find the exact epicentre?

Answer 31

3 stations

Question 32

Distance to epicentre can be found by comparing travel times of waves using ___

Answer 32

triangulation

Question 33

Which period causes stress builds in a fault?

Answer 33

The inactive period causes stress builds in a fault

Question 34

Primary effects of earthquakes?

Answer 34

Shaking and Surface rupture.

Question 35

Secondary effects of earthquakes:

Answer 35

liquefaction, changes in land level, landslides, fire, tsunami and disease.

Question 36

Displacement along the fault causes cracks in the surface.

Answer 36

Ground Rupture

Question 37

Causes damages to buildings, pipes, bridges, tunnels, dams | Measured as ground acceleration

Answer 37

Shaking

Question 38

Occurs when energy is transferred from P and S waves to surface waves.

Answer 38

Amplification

Question 39

A near-surface layer of water-saturated sand changes rapidly from solid to liquid (causes buildings to float)

Answer 39

Liquefaction

Question 40

How are fires caused during earthquakes?

Answer 40

Shaking and surface displacements cause power and gas lines to break and ignite.

Question 41

Earthquakes on the seafloor can generate deathly waves.

Answer 41

Tsunami

Question 42

What is a tsunami?

Answer 42

A series of waves caused by the displacement of a large volume of water.

Question 43

What are tsunamis triggered by?

Answer 43

Large earthquakes cause uplift or subsidence of the seafloor.

Question 44

What happens when a tsunami approaches land?

Answer 44

Loses speed and gains height

Question 45

Tsunami warning system?

Answer 45

Seismographs to detect earthquakes, tidal gauges to determine sea-level changes, buoy sensors to detected tsunamis in open oceans.

Question 46

Can result in building and road collapse.

Answer 46

Changes in land level

Question 47

Disease:

Answer 47

Ruptured sewer and water lines Polluted water Loss of sanitation

Question 48

Earthquake preparations?

Answer 48

Secure large objects, do not panic, leave the building once shaking stops

Question 49

Tsunami Primary effects:

Answer 49

Shortened coastline, damaged structures, debris everywhere, death from drowning and water impact.

Question 50

Tsumani secondary effects:

Answer 50

Fires, contaminated water supplies, diseases.