Volcanic eruptions: 

Deep under the earth’s surface, it’s so hot that even rock melts. Sometimes this molten rock, called ‘magma’, is pushed up to the surface. At this point it is referred to as lava. And the opening or vent that lets the lava out is a volcano. ‘ A volcano may explode violently throwing out rocks for miles around. It releases various gases and ash into the atmosphere.

Forest fires: 

Forest fire is a moving combustion reaction spreading outwards in a band from it’s ignition point leaving burnt forest behind it and also called as wild fire. It can be large uncontrolled disasters that burnt through hundred to hundred thousand acres.

Causes : 

Natural cause, lightening, volcanic eruptions, sparks from rocks falls and spontaneous combustion. 

Pollution : 

Forest fires release carbon particles (ash) into the air and pollute the air. Sand storms and Tsunamis: A sand storm or a dust storm is a meteorological phenomenon common in arid and semi arid regions. They arise when a gust front or other strong wind blows, loose sand and dirt from a dry surface. Particles are transported by saltation and suspension. The Sahara where sand is more prevalent, soil type than dirt or rock. Causes: As a force of wind passing over loosly held particles increased, the particles of sand first start to vibrate, then to saltate. As they repeatedly strike the ground, they loosen and break off smaller particles of dust, which then begin to travel in suspension. 

Tsunamis: 

1. Tsunami is also called as a ‘seismic sea wave’ is a series of waves in a water body caused by the displacement of a large volume of water. 

2. Tsunami impact is limited to coastal areas. But their destructive power can be enormous, and they can effect entire ocean basin. 

3. The 2004 Indian Ocean tsunami was among the deadliest natural disasters in human history with, at least 2,30,000 people killed or missing in 14 countries bordering the Indian Ocean. 

4. Tsunami causes much damage by two mechanisms. The smashing force of water travelling at a high speed and destructive power of a large volume of water draining of the land and carrying away large amount of debris with it. 

5. About 80% of tsunamis occur in the Pacific ocean, and there is possibility for tsunamis wherever there are large bodies of water including lakes.