Chpt 3- Earthquakes

Question 1

What is an earthquake?

Answer 1

A series of seismic waves that shake the ground and buildings

Question 2

What are earthquakes caused by?

Answer 2

Pressure builds up between two plates forcing the rock to break. The surface of the crust may just shake or it could be moved by several metres

Question 3

What is the focus?

Answer 3

Its the place within the crust where the rock breaks and the earthquake begins sending out shockwaves or seismic waves

Question 4

What is the epicentre?

Answer 4

Its on the surface directly above the focus and its where the most servers shocks and tremors occur

Question 5

What are aftershocks?

Answer 5

They are smaller tremors that may cause further damage to weakened buildings

Question 6

Look at page 6 for

Answer 6

Diagrams

Question 7

What is a fault or fault line?

Answer 7

A crack in the earths surface

Question 8

What is a seismograph used for?

Answer 8

To measure the shocks caused by earthquakes

Question 9

What is the richter scale?

Answer 9

The scale on which the force of and earthquake is measured
0-1.9 = only detected by seismograph
2-2.9 = hanging objects may swing
3-3.9 = vibrations of a passing truck
4-4.9 = windows may break
5-5.9 = furniture may move
6-6.9 = some damage to buildings
7-7.9 = buildings may move and cracks may appear in earth
8-8.9 = bridges and buildings destroyed 
9 and over = near total destruction

Question 10

Give three examples of serious earthquakes

Answer 10

12 jan 2010, Haiti, 222570 dead, 7.0 magnitude
21 feb 2011, Christchurch New Zeland, 181 dead, 6.1 magnitude
11 march 2011, east coast japan, 25000 dead, 9.0 magnitude

Question 11

What are some effects of earthquakes?

Answer 11

• movement of the earth
• collapse of buildings
• breaking of gas mains causing fires
• destruction of communication systems -> difficult to organise help
• spread of disease from dirty water
• destruction of local economy as factories and communication links are destroyed.