The earth is divided into three main layers: the core, the mantle and the crust. The core is further divided into the solid inner core and the liquid outer core. This layer is mostly iron and nickel and is extremely hot. The mantle is divided into the lower and upper mantle and is composed mostly of iron, magnesium, silicon, and oxygen. The outermost layer, which contains all life on earth, is the crust. This layer is rich in oxygen and silicon as well as aluminum, iron, magnesium, calcium, potassium, and sodium. It is in between the crust and the mantle that we find tectonic plates. The outermost layers of the earth are divided into two categories based on their physical properties. The asthenosphere is the lower of these cate

It is generally believed that there are 12 plates that make up the earth's surface. The majority of these plates are a combination of oceanic and continental lithosphere, while the Nazca, Pacific and Juan de Fuca Plates are made up of mostly oceanic lithosphere. Most of the continents have their own plate or plates, with the exception of Europe and Asia, which share the massive Eurasian Plate. Along the edges of these plates there is a large occurrence of geologic activity. "Earthquakes and volcanoes, evidence of unrest in the Earth, help locate the edges of plates." This unrest is caused by movement of the plates, which can be broken down into three general types. A divergent plate boundary is where the plates are pulling and moving away from one another. An example of this is the Mid-Atlantic ridge. Conversely, the Western banks of South America show evidence of convergent plate boundary, where the plates are pushing and moving towards one another, in this case the Nazca and South American Plates. The last type of boundary is a transition, which is illustrated by the San Andreas Fault in California. In this case, the edges of the plate are sliding past each other.

Plate tectonics are an amazing display of the earth's ability to constantly change and adapt. Through this process mountains and trenches are created, earthquakes swallow up huge amounts of land in seconds and new islands are formed by the eruption of volcanoes. There are parts of the world where this process is evident on a daily basis. One such area is the ring of fire in the Pacific Ocean. This is the boundary between the Pacific plate and several other plates. Also, the San Andreas Fault, in California, which is situated on the boundary between the Pacific and North American Plates, sees a large amount of earthquake activity. Another dangerous effect of plate movement which is common in the Asian Pacific is the Tsunami, a huge ocean wave created by earthquakes and plate movements deep under the ocean's surface. While these events can all be seen as natural disasters, the benefits tectonic plates have to offer the human race are plentiful. Volcanoes produce some

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Approximate Word count = 1458
Approximate Pages = 6 (250 words per page double spaced)