WHAT CAUSES TECTONIC PLATES TO MOVE?

MOVING TECTONIC PLATES LESSON

Directions:

Print the What Causes the Tectonic Plates to Move reading comprehension passage and questions (see below).

Students should read the passage silently, then answer the questions.  Teachers may also use the text as part of a classroom lesson plan.

Lesson Excerpt

     Scientists believe convection currents are what cause earth's plates to move.  A convection current is caused by differences in temperature.  When a pot of water starts to boil, the water is hotter near the bottom, close to where the heat source is located.  Hotter water is less dense, and so it rises to the top.  The cooler water on top sinks to the bottom.

This is a kind of convection current.  The same type of current moves magma in the mantle of the earth.  The cooler, denser material sinks toward the core. The hot material near the core expands and becomes less dense.  It rises and takes the place of the cooler material.  The sinking material becomes hotter and rises.  This is a continuous circular motion. 

Continued...