Internal Structure Of The Earth :: essays research papers

What is the evidence for our knowledge of the internal anatomical structure of the Earth?As we enter the twenty first century we be beginning to learn more and more about the report card of the Earth. primeval predictions have thrown up some rather strange and uneven thoughts as to what is making up our Earth, but now days scientists can be confident that the Earth is made up of what they think. As from experiments and other sources of information a picture to what is really worst there is becoming much clearer.So how do these scientists know that the Earths sections are made up of different compositions, and how do we know that the physical evoke of each layer is what it is?The outmost layer of the Earth is the sauciness, this is what we stand on and covers the earth entirely. It is made up of many different rocks and minerals, we know that the composition of the Earths crust is generally the same due to the mines and boreholes that mankind have made down into it. Mines that have been dug go down and still bring up valuable minerals that can be rig just as close to the Earths surface. The deepest goes down around 3km into the earth, and the temperature is 70XC, the only way for miners to work is because of the air conditioning, and still the typecast of rock looks the same all around. Also boreholes that have been drilled as far as half way into the Earths crust bring up rocks that look real similar to the ones on the surface. So scientists can safely say that the Earth has a crust which is very similar in composition all the way down until the curtain is reached.When earthquakes happen they produce two types of waves P-waves and S-waves. Primary waves (p-waves) are the fastest waves, they break down away from a seismic event. Primary waves are longitudinal, they can pass through solids, liquids and gases. The secondary waves (s-waves) travel slower than the primary waves, and are hybridise waves. This type of wave can only travel through s olids. measuring stick these waves is called seismology.Scientists have known for a long time that the lava, which comes out from volcanoes when they erupt, was from the mantle. The asthenosphere is the likely source of much basaltic magma, this is because the velocity in S-waves is slowed down and partly absorbed in the asthenosphere.