كيف تتحرك الصفائح التكتونية

Alfred Wgner was the first scientist to propose that the continents fit together like puzzle and over time moved apart. His idea was brilliant, but he had problem. He couldn't explain how the plates moved apart. Welcome to Mumu Math and Science. Since this time, scientists have proposed at least four mechanisms to explain how tectonic plates move over the Earth's surface. These four mechanisms include mantle convection, ridge push, slab pull, and slab suction. The core of the earth is extremely hot, and it's so hot it turns rock into liquid called magma. The hottest magma rises upward, and as this magma reaches the surface, it cools and sinks back down. This creates convection current. The convection currents are similar to the movement of these beans. Notice how the beans rise, cool, and then sink back down. Ridge push occurs when newly formed rock at the mid ocean ridge is warmer and less dense than the older rock. The less dense rock rests on top of the older, more dense rock. As result, the older rock will slope downward and away from the ridge. This downward force called ridge push pushes the plate away from the mid ocean ridge. At subduction zones, the denser tectonic plate will sink and subduct beneath the less dense tectonic plate. The leading edge of the subducting plate sinks into the mantel and pulls the rest of the plate with it. This process is called slab pull. This process relies on gravity to pull down the tectonic plate and cause movement. Slab suction occurs when smallcale convection current in the mantle wedge pushes the plate further away from the ridge and back into the mantle. These actions cause the plates to move roughly 10 cm year. Now, how do the tectonic plates move? When they move towards one another, this is called convergent plate boundary. When they move away from one another, this is called divergent plate boundary. And when they move in opposite directions, it is called transform plate boundary. Thanks for watching and remember, kindness multiplies kindness. Be kind to somebody today.