2. Natural disaster

 

Earthquake:

 

The sudden shaking of the earth at a place for a short period is called an earthquake. The duration of the earthquake may be a few seconds to some minutes.

 

The point where an earthquake originates is called its ‘focus’. The vertical point at the surface from the focus is called the ‘epicenter’.

 

 

Volcanoes:

 

Volcanoes are openings or vents where lava, small rocks, and steam erupt onto the earth’s surface. On land, volcanoes form when one tectonic plate moves under another.

 

 

Tsunami:

 

Tsunamis are waves generated by earthquakes, volcanic eruptions, and underwater landslides.

 

 

Cyclones:

 

A low-pressure area that is encircled by high-pressure wind is called a cyclone. The warm moist air over the sea rises from the surface in an upward trend, resulting in the formation of the low-pressure zone over the surface.

 

 

Floods:

 

An overflow of a large amount of water, beyond its normal limits, especially in rainfed areas is called a flood.

 

 

Landslide:

 

The movement of a mass of rocks, debris, soil, etc., downslope is called a landslide. Landslides are a kind of "mass wasting," which means any down-slope movement of soil and rock under the direct influence of gravity.

 

 

Avalanche:

 

A large amount of ice, snow, and rock falling quickly down the side of a mountain is called an Avalanche. In mountainous areas, avalanches are the most destructive natural threat to life and property.

 

 

Thunder and lightning:

 

Thunder is a series of sudden electrical discharges resulting from atmospheric conditions. This discharge results in sudden flashes of light and trembling sound waves which are commonly known as thunder and lightning.