- The solid portion of the earth on which we live—
- Comprises the rocks of the earth’s crust and the thin layers of soil that contain nutrient elements which sustain organisms
- Continents- large landmasses
- Ocean basins- the huge water bodies
- The gaseous layers that surround the earth— where oxygen, nitrogen, carbon dioxide and other gases are found and interact
- Provides the air we breathe + Protects us from the harmful effects of sun’s rays
- The changes in the atmosphere produce changes in the weather and climate
- Extends up to a height of about 1,600 kilometres
- Gravitational force of the earth holds the atmosphere around it
- Divided into five layers based on composition, temperature and other properties— troposphere, the stratosphere, the mesosphere, the thermosphere and the exosphere.
- Composed mainly of—
Nitrogen and oxygen, which make up about 99 per cent of clean, dry air.
Nitrogen (helps in the growth of living organisms) 78 percent, oxygen 21 per cent and other gases like carbon dioxide, argon and others comprise 1 per cent by volume
Carbon dioxide: Present in minute amount but is important as it absorbs heat radiated by the earth, thereby keeping the planet warm and also essential for the growth of plants.
- Density of the atmosphere: Maximum at the sea level and decreases rapidly as we go up
- Wind: Moves from high pressure to low pressure
- The temperature also decreases as we go upwards.
- Air moves from high pressure to low pressure.
- Moving air is known as wind.
- NITROGEN helps in the growth of living organisms.
- Water-covered regions of Earth; comprises water in all its forms, that is, ice, water and water vapour
- Earth: A blue planet
- More than 97% of the Earth’s water is found in the oceans and is too salty for human use
- Oceans— Always mobile: the waves, the tides and the ocean currents
- Largest- spread over one-third of the earth
- Deepest part of the earth: Mariana Trench
- Circular in shape
- Countries: Asia, Australia, North and South Americas Atlantic Ocean:
- Second largest Ocean; S-shaped
- North and South Americas on the eastern side
- Europe and Africa on the western side
- Coastline: highly indented; provides ideal location for natural harbours and ports
- The busiest Ocean Indian Ocean:
- Only ocean named after a country; triangular shaped
- Bound by Asia in the north, in the west by Africa and in the east by Australia
- Located within the Arctic Circle and surrounds the North Pole Connected with the Pacific Ocean by a narrow stretch of shallow water known as Berring strait (Refer Map)
- Bound by northern coasts of North America and Eurasia
- The Southern Ocean encircles the continent of Antarctica and extends northward to 60 degrees south latitude.
- The narrow zone where we find land, water and air together, which contains all forms of life Division: Plant kingdom and the animal kingdom
- The three domains of the earth interact with each other and affect each other in some way or the other
- Need to limit the use of resources of the earth to maintain the balance of nature between the domains of the lithosphere, the atmosphere and the hydrosphere.
1,912 total views, 26 views today