Lesson 8 - Primary + Secondary Impacts

Question 1

Define Primary + Secondary impact

Answer 1

P: Direct consequence of earthquake
S: Consequence of Primary impact

Question 2

Give 3 examples of primary impacts

Answer 2

Building collapse
Ground shaking
Ground splitting

Question 3

Give 3 examples of secondary impacts

Answer 3

Tsunami
Landslides
Liquefaction
Avalanche
Rockfall

Question 4

Define liquefaction

Answer 4

When violently shaken solid substances lose their mechanical strength and start to behave like a fluid
Generally due to increased water pressure

Question 5

What is the main impact of liquefaction?

Answer 5

Buildings settle, tilt or even collapse

Question 6

In the San Francisco earthquake of 1989, how much estimated damage was caused by liquefaction?

Answer 6

$100,000 million

Question 7

What must the magnitude of an earthquake register in order for landslides to occur?

Answer 7

4

Question 8

Research by the USGS suggests that, over the last 40 years, what % of earthquake deaths have been attributable to the secondary impact of landslides?

Answer 8

Around 70%

Question 9

Give 3 secondary human impacts of an earthquake

Answer 9

Fires from ruptured gas mains
Scarce or contaminated water supply
Loss of trade due to cessation of industry