Earth’s Moving Plates SWBAT describe how Earth’s interior is divided into layers; explain how plates of Earth’s lithosphere move; discuss why Earth’s plates move.

Clues to Earth’s Interior Inner Core –Dense, composed mostly of solid iron. –5000°C Outer Core –Composed of molten metal Mantle –Largest layer –It’s solid but it flows slowly Crust –Thinnest layer –Varies in size –Includes all surface features (mountains, valleys, etc)

Earth’s Plates Lithosphere –the rigid, upper part of Earth’s mantle and the crust. Plate –the sections that move around on the plastic-like asthenosphere. There are about 30 of them. Faults –large sections in rocks along which movement occurs. This movement can cause earthquakes.

3 Ways Plates Move Move apart –New crust forms from lava that escapes through the gap Collide –Crust can pile up if it’s the same density and form mountains.. –If they are different densities one slides under the other (subduction) Slide –Plates move in different directions and grind against each other –It’s called shearing, it happens at transform boundaries

Earth’s Plates Subduction w –when one plate sinks underneath another. Why do plates move? –Convection in the mantle causes uneven heating creating different densities. The plates then move as a result of the circulation of heat in the mantle.

Start your homework Answer review question 1-5 on page 297. You may work with a partner Answer the question in complete sentences Finish for homework