Chapter 3 Flashcards
What is an earthquake
An earthquake is a series of seismic waves that shake the ground and buildings
What causes earthquakes
Caused when plates collide, slide past and separate. The pressure builds between two plates causing the rock to break.
What is the focus
Its the place in the crust where rock breaks and earthquakes begin. It sends out shockwaves or seismic waves
What is the epicentre
It is on the surface above the focus where most severe shocks occur
What are aftershocks
Aftershocks are smaller shocks usually experienced after the earthquake which can cause further damage
What are seismic waves
They are the vibrations sent out by the earthquake which causes buildings to collapse
What are seismographs
They are what is used to measure the shocks or vibrations caused by earthquakes
What is measured on a Richter Scale
The force of the earthquake
What are the effects of earthquakes
Breaking of gas mains
Destruction of communication lines
Spread of disease
Destruction of local economy
Explain the formation of a tsunami
When earthquakes occur under the sea the shocks make very powerful and dangerous waves on the surface
What do tsunamis cause
Destruction and death when they hit land
