The origin of the Earth The age of the Earth was once, and still is, a matter great debate. In 1650 Archbishop Ussher used the Bible to calculate that the Earth was created in 4004BC. Later on in the mid-nineteenth century Charles Darwin believed that the Earth must be extremely old because he recognised that natural selection and evolution required vast amounts of time. Inner core The Inner crust is the second thinnest layer. The inner core is hotter than the surface of the sun. The inner core is made out of iron and nickel. It is 5159 to 6378 km thick. The inner core is extremely hot and is the last layer. The inner core is 5505 degrees celsius. It is a solid because of all the pressure from the other layers putting there weight onto this layer. The inner core grows. The core was discovered in 1971.. Outer core The outer core is a liquid made up of iron and nickel. The temperature of the outer core is around 4400 degrees celsius. The depth of the outer core is 2, 890. This is one of the three layers that is putting pressure on the inner core. It is the second hottest layer, because it is the layer above the inner core, and it is the second farthest from the surface of the earth. Also it is said that the core is rotating faster than the rest of the earth but...... slower than previously believed! the outer core was discovered in 1936 by seismologist, Inge Lehmann. Crust The crust is the first layer of the earth. It is split up into two parts the continental crust, and the oceanic crust. The oceanic crust takes up 71% of the earths crust, and the other 29% of the crust is continental. The continental is made up of igneous rocks, and the oceanic crust is made up of sedimentary and basalt rocks. The continental crust is older than the oceanic crust, some of the rocks are 3.9 billion years old. The density average of the oceanic crust is 3g/cm Mantle The mantle is the second layer of the earth. It is split up into two different parts, the lithosphere (which is the top part) and the asthenosphere (which is the bottom part). The lithosphere is a dense rock made out of iron and nickel, the asthenosphere is a plastic like fluid. The temperature of the lithosphere is around 300 to 500 degrees celsius, and the asthenosphere is around 4500 degrees celsius. The mantle has the biggest volume of all the layers, the volume of it is 84% of the earth. The atmosphere is divided into five layers. It is thickest near the surface and thins out with height until it eventually merges with space. 1) The troposphere is the first layer above the surface and contains half of the Earths atmosphere. Weather occurs in this layer. 2) Many jet aircrafts fly in the stratosphere because it is very stable. Also, the ozone layer absorbs harmful rays from the Sun. 3) Meteors or rock fragments burn up in the mesosphere. 4) The thermosphere is a layer with auroras. It is also where the space shuttle orbits. 5) The atmosphere merges into space in the extremely thin exosphere. This is the upper limit of our atmosphere. mao ra bah neh>??? atoa ass. sa NAT SCI??? txt mo beh kung kulang paba neh.. hehehehehe
Posted on: Mon, 25 Aug 2014 09:26:18 +0000
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