tag:blogger.com,1999:blog-30496349951484202012011-04-22T09:52:34.483+05:30Something special about earthAjmal Bin Ismailhttp://www.blogger.com/profile/01487819378814988345noreply@blogger.comBlogger11100tag:blogger.com,1999:blog-3049634995148420201.post-35092565536400108742009-01-03T10:24:00.001+05:302009-01-03T10:28:31.913+05:30<span style="font-weight:bold;"><span style="font-weight:bold;">The Structure of earth</span></span><br /><br />The earth is made up of four main layers : Crust, Mantle, Outer Core, and Inner Core.<br /><span style="font-weight:bold;"><br />Crust</span><br />It is the upper portion of the earth where we live and this layer is about 5 to 50 km thick.The temperature increases by 1oC per kilometer<br />Mantle<br />The next layer is mantle, which is composed mainly of ferro-magnesium silicates and so hot with the temperature ranging upto 1600o C. it is about 2900 km thick and is separated into the upper and lower mantle.<br />Outer Core<br />The outer core is about 2300 km thick mainly consists of molten materials of Iron and nickel with the temperature ranging from 2000oC to 5000oC. Earth’s magnetic field is believed to be controlled by the liquid outer core.<br />Inner Core<br />It is about 1200 km thick and has solid iron. <br /><br /><span style="font-weight:bold;">Mountain</span><br /><br />Folded mountains take shape when two continental plates ram into each other, compressing and uplifting the rock. The height of the mountain depends upon the type of the rock and the intensity of the collision. The Appalachian mountains, The Alps and the Himalayas are all folded mountain ranges.<br /><br /><span style="font-weight:bold;">Volcano</span><br /><br />Volcano forms when molten rock(magma) from the interior of the earth reaches the surface. It erupts either as a stream of liquid rock(called Lava when it appears at the surface) or as ash and builds up over the time into a mountain in conical shape.<br /><br /><span style="font-weight:bold;"><span style="font-weight:bold;">Atmosphere</span></span><br /> <br />The atmosphere consists of five layers: troposphere, stratosphere, mesosphere, thermosphere and exosphere. The atmosphere which extends up to 700 km, protects us from the sun’s harmful rays and keeps earth from getting too cold or too hot. <br /><br /><span style="font-weight:bold;">The Troposphere</span><br />This lowest layer, closer to earth varies in height depending upon the temperature of the air. It is about 16 km at the warm equator and only 9 km at poles.<br /><br /><span style="font-weight:bold;">The stratosphere</span><br />It is extended upto 50 km from the earth and has most of the ozone layer, which absorbs the ultraviolet rays from the sun and the air warms up to 40oc.<br /><br /><span style="font-weight:bold;">The mesosphere</span><br />It is the thick coldest layer. It does not absorb much of ultraviolet rays and here the temperature drop to -90oC. T<br /><br /><span style="font-weight:bold;">The thermosphere</span><br />It is a very thin layer extends upto 480 km. It absorb the sun’s ultraviolet rays and it heats the thermosphere upto 1480oC.<br /><br /><span style="font-weight:bold;">The exosphere</span><br />The fifth and the last layer of the atmosphere which fades in to the space contains no air. Its temperature can reach upto 1650oC<div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/3049634995148420201-3509256553640010874?l=earth3111995.blogspot.com' alt='' /></div>Ajmal Bin Ismailhttp://www.blogger.com/profile/01487819378814988345noreply@blogger.com0