Friday, January 14, 2011

Dynamic Earth

Plate Tectonics and Volcanoes
Plate tectonics are dramatically changing our Earth slowly by moving. Tectonic plates slide past each other, crash, move away from each other and that moves places. Earths plates are also growing and spreading apart from each other. Also volcanoes come from the inner earth and the is magma there and that is what comes out of the volcano and becomes lava, the magma seeps out the volcano before it erupts and when the magma goes out it becomes lava and when the lava cools, it hardens. There is something called the unreachable frontier and it is the worlds deepest drill hole and it is 12.3 kilometers (7.6 miles) deep! It is beneath Russia's Kola peninsula. There is more than 99% of the distance to Earths center still left! You may wonder about how we can learn so much about the inner Earth when we can not access it, well volcanoes help us to and we predict what the core is because things such as volcanoes give us evidence but we do not know for sure what it is. We can also learn about the inner Earth with special types of rocks that are called peridotites, they come from the upper mantle. Garnet can take a lot of pressure. Also partially the reason some magma is formed is the melting of Garnets. Diamonds are like a reminder to people of Earths incredible temperature and pressure within our planet. The high pressure is found at depths like 150 km (90 miles) to create a diamonds hard and tight structure and that makes it the hardest material known.We find diamonds beneath cartons which are the oldest parts of continents. Meteorites are formed of the solar systems original dust and that provides clues to Earths core. Earth has a magnetic field with two main poles. These poles tell us about the inner Earth. The rotation of our Planet causes molten iron-nickle in its outer core to circulate creating electric currents and a magnetic field.
Earth's poles are not stable they move over the Earths surface. Since the year 1945 they have moved over 12 k,m per year. Also about every 500,000 years Earths magnetic fields get much weaker, vanishes, then reapers with North and South pole reversed. The Inner core of the Earth is very hot and what causes the tectonic plates to move is when the inner heat escapes to the cold outer space. In Earths first 100 million years huge and even larger particles in the solar system collided and stuck together creating a lot of tremendous amounts of heat. Lets say that the Earth was an apple, we live on the crust or the skin of the apple, well Earths crust is about as thin as the skin of an apple, relative to its size. The Earths crust is made up of two types of rock, basalt, the oceanic crust is mostly basalt, and Granite, the continental crust is mostly Granite. The mantle is about 84% of Earths volume. The Core is about 15% of Earths volume and is iron-nickle and the core size of Mars.

Gems and Minerals
Gems are built off of heat, pressure, and fluid. There is a hope diamond and has existed for a billion years since it was formed deep within the Earth. Minerals are used more than just for pretty display pieces, they have other uses. They are also the building blocks of the whole universe! They make up the Earth, the moon, the sun, and the rest of the universe.
Maybe you noticed and maybe you didn't but Earths history is written on pages of stone. You use minerals more than you could imagine! The modern and new civilization relies a lot on minerals.

Rocks and Mining
Rocks can melt just like ice, but the different is that all ice melts at the same temperature and all rocks melt at different temperatures. In a way it is like a race for magma, will it erupt at the surface or will it crystallize and cool below the surface? Two different types of igneous rock come out depending on which one happens. Almost all of the metals that we like and value are spread around in the rocks in Earths crust.

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