Plate Tectonics: Seismicity

Question 1

Earthquakes

Answer 1

Convection currents cause plates to interact at plate boundaries. High levels of stress build up and are eventually released, resulting in earthquakes.

Question 2

Mid-Plate Earthquakes

Answer 2

1. Old plate boundaries e.g. China.
2. Isostatic rebound e.g. Canada.
3. Tropical cyclones.

Question 3

Man-Made Earthquakes

Answer 3

1. Dams: Singchuan 2008.
2. Mining: Newcastle, Australia 1989.
3. Fracking: Lancashire.
4. Tall buildings: Taipai 101.

Question 4

Earthquake Anatomy

Answer 4

The origin of the earthquake is called the focus/hypocentre.
The 3 categories of depth are shallow (0-70km), intermediate (70-300km), and deep (300-700km).
The point on the surface directly above the origin is the epicentre.

Question 5

Seismic Waves

Answer 5

Waves of energy released by the rupture of rock strata at the hypocentre, travelling outwards in all directions. There are two types; P waves and S waves.