NATURAL DISASTERS Q & A

1.How does an earthquake occur? What damage can it cause? Ans. The Earth’s core is not in a stable state. A lot of movement is going on inside it. At times, there is a lot of pressure which causes strain in the layers of the Earth and breaking of rocks. This in turn causes shakes and tremors to start deep below the surface of the Earth and gradually reach the surface as an earthquake. An Earthquake can cause large cracks in the ground. It can cause dangers due to falling buildings, flying glass, stones and other objects. It can also cause floods, landslides and avalanches.

2. How many types of volcanoes are there? Explain them briefly. Ans. There are 3 types of volcanoes. Active volcanoes: Those volcanoes that have erupted in the last 10,000 years and can erupt again are known as active volcanoes. Mt Etna of Italy is an active volcano. Dormant volcanoes: These volcanoes are in a state of sleep. This means that it had erupted in the past. It can erupt again but at the moment it is asleep. Mt Kea, found in the Hawaiian islands, USA, is an example of dormant volcano.

Extinct volcanoes: Those volcanoes that have been inactive for thousands of years and are not expected to erupt again are known as extinct volcanoes. Mt Pope in Myanmar is an extinct volcano. 3. What is a flood? Why does it occur? Ans. The condition when the rivers spill over their banks or they overflow on to the surrounding areas is known as a flood. This happens when there is a large amount of rain falls in a short period of time.

4. What are the conditions in a drought? Ans. Conditions in a drought are described below: i) The ground has no moisture due to lack of rain. ii) Streams and rivers dry up and no crop can survive. iii) People die of famine, after a long period of drought, since there is an acute shortage of food.