Forms Of Seismic Hazards

Question 1

Primary/pressure shockwave

Answer 1

fastest and reach the surface first, high frequency and push in the direction of travel (travel upwards towards the surface)

Question 2

Secondary/shear shockwaves

Answer 2

half as fast as primary waves and reach the surface next, high frequency, shaped like a skipping rope (wave at a right angle to the surface)

Question 3

Love shockwave

Answer 3

Travel across the surface from the epicentre in a side to side motion, slowest wave but causes the most damage (side to side)

Question 4

Rayleigh shockwave

Answer 4

Travel across the surface from the epicentre in an up and down motion (like a wave)

Question 5

Wave height out at sea

Answer 5

Less than 1 metre

Question 6

Wave height at shore

Answer 6

Over 25 metres

Question 7

Wave length out at sea

Answer 7

Over 100 metres

Question 8

Speed of tsunami waves

Answer 8

640-960 kilometres

Question 9

Percentage of tsunamis associated with the Pacific Ring of Fire

Answer 9

90%

Question 10

What’s the warning system for tsunamis called?

Answer 10

Pacific Tsunami Warning System

Question 11

What’s the first sign of a tsunami wave?

Answer 11

Draining away of the sea at the front of the wave

Question 12

On what soil does liquefaction occur?

Answer 12

Granular sediment

Question 13

Explain what liquefaction is

Answer 13

Soils with high water content lose their mechanical strength and behave like a fluid, the ground shaking means the ground is unable to support the weight of buildings, meaning they can sink and tilt

Question 14

What magnitude of earthquakes trigger landslides?

Answer 14

4<

Question 15

What can slope material become?

Answer 15

Debris flow or mudflow