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A Level Physical Geography > Seismic Hazards > Flashcards

Flashcards in Seismic Hazards Deck (15)
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1

Describe how an earthquake is caused

Tension builds up between two plates within the lithosphere
Tension becomes to great, plates slide past each other
Sends shockwaves out

2

Describe:
Primary body waves
Secondary body waves
Love waves
Rayleigh waves

Primary - fastest, high frequency travel through the mantle in compressional movements
Secondary - slower travel through mantle as transverse waves
Love waves - cant pass through liquid so slower, side to side movement
Rayleigh waves - only move along surface, move in a rolling fashion

3

Give two scales that earthquakes can be measured on

Mercalii scale - subjective 1-12 measuring damage done to people
Richter scale - magnitude logarithmic scale

4

Give three secondary impacts of an earthquake

Tsunamis - large amounts of water displaced, up to 960km/h
Landslides - unconsolidated ground slips causing rapid mass movement, after rainfall more likely as more lubricated
Liquefaction- saturated soil acts like a liquid when shaken soil deforms and stuff sinks in

5

What date and time was the sichuan earthquake

Monday 12th may 2008
14:28

6

What was the magnitude of the sichuan earthquake?

7.9

7

What was the inital death toll and unoffical death toll in sichuan?

69,000
But 18,500 missing likely dead

8

What plate margin did the sichuan earthquake occur at?

Indian Eurasian plate, shallow focus of 10Km

9

Describe some economic impacts of the sichuan earthquake

5.6 million collapsed buildings
5300km road destroyed

Secondary
Oil prices fell
Loss of power
Loss of tourism

10

The timing of the sichuan earthquake gave rise to a terrible impact...

School time
11,000 school children died
Schools in this area were very poorly maintained hence very vulnerable

11

Describe the primary social impacts of the sichuan earthquake

69,000 dead
374,200 injured
11 million homeless

12

Describe secondary social impacts of the Sichuan earthquake

Cut off communications
Roads damaged
Rescue workers killed

13

What were the environmental impacts of the sichuan earthquake?

Chemical factories released toxic gases e.g. Ammonia
32 million animals deaths
Many pandas died v endangered
Irrigation systems damaged (links to economic as farming worsened)

14

Describe the short term response in the sichuan earthquake

140,000 chinese troops
100,000 volunteers
Temporary camps
250,000 evacuated
$1.5 billion donated by public

15

Give three longer term responses to the Sichuan earthquake

Beichuan left as memorial town
One child policy relaxed
Schools built to a better standard