Download Earth`s Moving Plates

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