User talk:Gaurav4291/CL7 SST

Environment

 * It is the natural, man-made things around us
 * Lithosphere – is the hard top layer of earth
 * Hydrosphere – domain of water
 * Atmosphere – thin layer of air above earth surface – it is held by gravity
 * Biosphere – it is a narrow zone of earth where land, air and water interact to support life
 * Ecosystem – is the system formed by interaction of living organisms with each other and with physical and chemical factors of the environment they live in

Inside our earth

 * Crust – mantle – core
 * Crust – main constituents – Silica and Alumina (SiAl)
 * Mantle – SiMa (Silica and Magnesium)
 * Core – Nickel and Iron (NiFe)
 * Igneous rocks – when molten lava solidifies – also called as primary rocks
 * When it solidifies outside earth’s surface – it is called Extrusive igneous rocks – since it cools down rapidly they have fine grain structure – ex- basalt – deccan plateau is made of basalt
 * When it solidifies under the earth’s surface – it is called intrusive rocks – since it cools slowly – have coarse grain structure – Ex – Granite
 * Sedimentary rocks – sediments deposited by water, air. Ex – sandstones
 * Igneous and sedimentary rocks can change into metamorphic rocks under high pressure and temperature – ex – clay into slate and limestone into marble

Our Changing earth

 * Lithospheric Plates – lithosphere is divided into a number of plates and these plates move since molten lava moves
 * Endogenic forces – that acts inside the earths surface
 * Exogenic forces – that acts outside the earth’s surface
 * Earthquake – P waves (longitudinal), S waves ( Transverse) and L waves (surface waves)

Air

 * Easterlies and westerlies

Water

 * Neap tide – moon, Sun and Earth makes 90 deg – low tide
 * Spring tide – moon, earth and sun in straight line – high tide