1. Natural Disasters
Natural disasters are events that result from the Earth's natural phenomena. It is categorized into many types based on its occurrence.
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 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.
Tsunamis are waves generated by earthquakes, volcanic eruptions, and underwater landslides.
Tsunami is a Japanese term that means "harbor wave".
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.
An overflow of a large amount of water, beyond its normal limits, especially in rainfed areas is called a flood.
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.
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.