Earthquakes

Question 1

earthquake

Answer 1

a sudden violent movement within the earths crust

Question 2

what causes earthquakes?

Answer 2

The plates on the Earth’s crust are always moving and so tensions can build up between rocks.
This stress can suddenly be released when the strain overcomes the elasticity of the rock.
This release of stress can cause parts of the surface to experience an intense shaking motion that lasts for a few seconds.

Question 3

focus

Answer 3

The focus is where the pressure is released underground and where the energy radiates out from

Question 4

epicentre

Answer 4

the point above the surface

Question 5

what is the energy released from the focus called?

Answer 5

seismic waves

Question 6

shallow focus earthquake

Answer 6

0-70km under earth surface

Question 7

deep focus earthquakes

Answer 7

70-700km below earths surface

Question 8

underwater earthquakes

Answer 8

Underwater earthquakes move the seabed, which causes water to get displaced. If enough water is displaced, tsunamis (series of enormous waves) can happen.
Underwater earthquakes can be shallow- or deep-focus. The deeper the focus, the bigger the tsunami.

Question 9

L waves

Answer 9

create significant damage and crustal fracturing
only travel across the surface and have a high amplitude
horizontal vibrations

Question 10

P waves

Answer 10

fastest wave
least damaging
longditudal waves
vibrations caused by compression

Question 11

S waves

Answer 11

secondary
4km p/h
causes ground to shake