Page 19 - Super Earth Encyclopedia

“Earth’s FLOATING CONTINENTS

Earth’s cool, brittle shell consists
crust moves at of thick continental crust and
much thinner oceanic crust that
forms the ocean floors. The rocks
roughly the same that form continents are lighter
than ocean-floor rock, so they
float on the dense mantle in the
speed as your same way that ice floats on
water. This is why the continents
fingernails grow.” are higher than the ocean floors.

The tectonic plate
boundary near Japan
causes frequent
earthquakes and
tsunamis.
Many volcanoes
erupt along
destructive plate
boundaries.

A spreading
DRIFTING CONTINENTS rift created the
The continents are rooted in the Atlantic Ocean.
mobile plates of the crust, which
carry them very slowly around the
globe. Over millions of years, they
have been split apart and pushed
together in different arrangements. The giant
The continents we know today are supercontinent UNIQUE EARTH
Pangaea was
fragments of a supercontinent that surrounded by a
existed 270 million years ago, and global ocean.
broke up during the dinosaur era.
270 million years ago 120 million years ago Today
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