Desserts are large expanses of land that receive less than 25cm of rainfall each year. Desserts are very dry regions and comprise of sand, sand dunes, snow, snowdrifts and cacti and other plants suited to adapt themselves and grow in such dry areas where water is scarce. There are two types of desserts – 1) Hot deserts that experience very hot weather. E.g. The Sahara, and 2) Cold deserts that experience very chill weather, sometimes even below freezing point. The Earth is covered by 33% of desert land.
Moving air is called wind. The strongest winds found on a planet in our Solar system are found on planets like Saturn and Neptune. Very strong winds that carry on for a long period of time are called hurricanes, typhoons, tornados or gales. Wind usually moves from high pressure regions to regions of low pressure and thus maintains a balance. If there is a major difference in pressure then it results in storms, cyclones, hurricanes and typhoons. Winds are capable of moving soil especially in the desserts while cold winds could have an adverse effect on livestock.
The Earth is made up of different layers. It has a solid crust of silicate, a mantle that is viscous in nature and a very hard inner core. The outer layer which is the crust is solid and comprises of silicon, aluminum and oxygen. Below the crust is the mantle which is liquid in nature and mostly made up of oxygen, magnesium and silicon. The core is the innermost layer and comprises of solid ion and nickel with a pressure that ranges between 5000 to 6000 degrees centigrade.
The violent shifting or moving of rocks under the earth’s crust is called an earthquake. It is also referred to as a tremor of quake and usually occurs for a very brief period of time. Earthquakes occur as a result of energy that is suddenly released from within the earth’s crust creating seismic waves through the Earth.