Question

(a) Explain how earthquakes are caused.
(b) List some human activities that can result in earthquakes.

Answer 1

(a) Earthquakes are caused by the movement of tectonic plates. These plates are part of the earth's surface and float on the molten magma present in the mantle. When two plates converge, they push against each other with enormous strength, and one might slide over the other. This causes disturbances on the earth's crust, because of which earthquake tremors are felt.

(b) Some activities that can result in earthquakes are given below.

1. Construction of large dams. The weight of the water that collects in dams exerts a huge amount of force on the land below, and may cause the land to shift.
2. Implementation of more geothermal energy projects
3. Extraction of substances from the ground. Example: Mining.
4. Construction of huge skyscrapers, which can trigger a movement of fault because of the enormous pressure exerted by thousands of tonnes of building material.