3. Convection Currents

CONVECTION CURRENTS

LESSON 1

Plate movement and Convection Currents

PLATE MOVEMENT

The earth's crust is made up of pieces we call plates. These large

pieces of crust are moving. Earthquakes are caused by the crust moving. Earthquakes can happen anywhere on a plate, but if two plates move beside each other, there can be massive earthquakes and catastrophic damage. The edge of plates are called plate boundaries. When plates move beside each other massive earthquakes occur at the plate boundary. Some plates have large landmasses on them we call continents. The North American Continent (land) sits on the North American Tectonic Plate.

CONVECTION CURRENTS

No single plate can move without affecting others.

The plates are being moved by energy created by convection currents from the mantle below.

Convection currents are currents of magma magma that is heated at the core, rises to the underside of the crust and is either redirected under the crust (pushing/pulling the crust with it), or sometimes it breaks through the crust creating ridges or volcanoes. As the current of magma flows flows below the crust it cools and begins to descend back to the core. At the core it is heated again and repeats the cycle over and over. There many individual pockets of convection currents under the crust we call convection cells. These convection cells are what moves the earth’s crust and causes earthquakes.

CONVECTION CELLS Convection cells are the result of the moving convection currents of magma in the mantle heating and cooling and reheating This moving "river" of magma pulls on the underside of the crust. If there are convection currents moving in different directions under neighboring plates, the force can cause the plates to collide, move apart or sometimes slide by each other in different directions. As magma is heated, it becomes less dense (lighter) and moves away from the core towards the crust. As it travels below the crust, the magma cools, becoming more dense (heavier) causing it to descend back to wards the core. This is what creates convection currents and convection cells.

  • Go to the interactive site about thermal convection and complete the questions
        • Use the keyboard to interact with diagram
        • You might have to decrease zoom to 90% of screen to see keyboard instructions.

3. Thermal Convection

  • Go to the interactive site about thermal convection and complete t

2. Journey to the Center of the Earth

  • Take a dive on land and in the ocean.

BRANDING