Tectonic plates are large areas of the Earth's crust that move slowly on the upper part of the mantle, often colliding and moving away from each other. Earthquakes and volcanoes are most likely to occur at plate boundaries.
LAYERS The Earth consists of four concentric layers: Inner core, Outer core, Mantle and Crust:
LAYERS THE CRUST is the outer layer of the earth. It is a thin layer between 0-60km thick (). The crust is the solid rock layer upon which we live. It includes the continents and the ocean floor. The crust is made up of tectonic plates There are two different types of crust: continental crust, which carries land, and oceanic crust, which carries water. THE MANTLE: The mantle is a zone of hot rock in the interior of the Earth, located between the outer crust and the molten core. It is the widest section of the Earth with a diameter of approximately 2900km. The mantle is made up of semi-molten rock called magma. In the upper parts of the mantle the rock is hard, but lower down the rock is concentric mantle. THE OUTER CORE: It is the layer surrounding the inner core. It is a liquid layer, also made up of iron and nickel. It is still extremely hot, with temperatures similar to the inner core. THE INNER CORE: It is in the centre and is the hottest part of the Earth. It is solid and made up of iron and nickel with temperatures of up to 5500°C. With its immense heat energy, the inner core is like the engine room of the Earth.
PLATE BOUNDARIES A plate boundary is the region where two or more tectonic plates meet. It is a zone of intense seismic activity Earthquakes and volcanoes are most likely to occur either on or near plate boundaries.
Tensional, constructive or divergent boundary (The plates move apart)
Compressional, destructive or convergent boundary (the plates move towards each other)
Conservative or transform boundary (the plates slide past each other)
UNDERSTANDING QUESTIONS 1. What are tectonic plates? 2. How many principal tectonic plates exist? 3. Which tectonic plates is Colombia on? 4. What are the four layers of the earth? Define them. 5. Which is the layer we live in? 6. Which is the thickest/widest layer? 7. Which is the hottest layer? 8. What is a Plate Boundary? 9. What kinds of plate boundaries exist? Explain each one including a drawing. 10. According to what you learnt today, Why is it important to understand and define tectonic plates?