Question

Select all of the answers that apply.
Which of the following are signs that an earthquake may occur?
-changes in air temperature
-changes in water levels in wells
-foreshocks
-aftershocks
-changes in the magnetic properties of rocks

Answer 1

You will know if an earthquake is going to happen when there are foreshocks happening, changes in rocks' magnetic properties, and changes in the air's temperature. Foreshocks are small earthquakes which usually or which will possibly occur before a big earthquake will happen. Changes in the rocks' magnetic properties are not so visible and are only determined by rock specialists. Changes in the air's temperature might occur as well 2-5 days before earthquakes will happen.

Answer 2

The most appropriate answers are changes in water levels in wells, foreshocks and changes in the magnetic properties of rocks. The occurence of earthquakes have no effect on air temperature. Aftershocks are smaller earthquakes that occur a major earthquake event.