Earthquakes and tsunamis

Question 1

What is an earthquake?

Answer 1

Violent shaking of the ground, usually causing great destruction and usually as a result of movements within the earth’s crust.

Question 2

What are some of the causes of earthquakes?

Answer 2

-Movement at plate boundaries (95%)
-Volcanic eruptions/magma movement
-Ancient faults slipping
-Isostatic uplift
-Asteroid impact
-Nuclear explosion
-Fracking

Question 3

Explain how an earthquake occurs,.

Answer 3

-Plates move due to convection currents and slab pull
-Plates get stuck against each other causing pressure to build up
-When the pressure becomes too much, the rock fractures along faults
-Energy is suddenly released as seismic waves causing the ground to shake

Question 4

What is the epicentre?

Answer 4

The point directly above the focus at the Earth’s surface, where the most damage usually occurs.

Question 5

What is the focus?

Answer 5

The point underground where the seismic waves radiate from.

Question 6

What are aftershocks and foreshocks?

Answer 6

Foreshocks occur before the main earthquake and aftershocks occur after the main earthquake, they are usually smaller than the earthquake itself and can act as a warning that an earthquake is imminent.