Lesson 7 Plate Tectonics PDF

The Structure of the Earth  The Structure of the Earth Mantle The Earth is made up of 3 main layers: Outer core Core Inner core Mantle Crust Crust  Seismic waves waves of e...

The Structure of the Earth  The Structure of the Earth Mantle The Earth is made up of 3 main layers: Outer core Core Inner core Mantle Crust Crust  Seismic waves waves of energy caused by the sudden breaking of rock within the earth Body Surface waves waves Body waves Surface waves  They travel at different speeds depending on the composition Waves travel faster through a solid than a liquid S waves cannot travel through liquids P waves can travel through solids and What is Plate Tectonics? If you look at a map of the world, you may notice that some of the continents could fit together like pieces of a puzzle.  Tectonic Plates – The crust is composed of massive and irregularly shaped slabs of solid rock. Three types of plate boundary SUBDUCTION Convergent Boundaries: Continent-continent collision Continent-oceanic crust collision Ocean-ocean collision Continent-Continent Collision Forms mountains, e.g. European Alps, Himalayas The continental plate is lifted and mountains may form. Continent-Oceanic Crust Collision Oceanic lithosphere subducts underneath the continental lithosphere Oceanic lithosphere heats and dehydrates as it subsides The melt rises forming volcanism. E.g. The Andes Subduction Ocean-Ocean Plate Collision When two oceanic plates collide, one runs over the other which causes it to sink into the mantle forming a subduction zone. The worlds deepest parts of the ocean are found along trenches. E.g. The Mariana Trench is 11 km deep! EARTHQUAKE A simple definition of an earthquake is the release of mechanical energy felt in waves as strain is released from rocks in the earth's crust. They occur because of the pressure underneath Earth’s crust that pushes blocks of rocks to move along fault lines. PARTS OF AN EARTHQUAKE Earthqu ake Magnit ude Scale