Download WHAT`S UP WITH PLATE TECTONICS? Earth`s lithosphere is

WHAT’S UP WITH PLATE TECTONICS?
Earth’s lithosphere is broken into uneven pieces
called plates. Earth has 6 major tectonic plates to be
exact: the Eurasian, the African, the Indo-Australian,
the Pacific, the North American, and the South
American plates. These plates meet at boundaries.
Along each boundary plates move in one of three
ways.
At the divergent boundary, plates move apart. When
they move apart magma pushes up and hardens
creating new crust. This process is called sea-floor
spreading. The crust creates volcanic mountains on
the ocean floor and rift valleys on the continents.
Earthquakes do occur along with the creation of these
landforms (features).
At the convergent boundary, plates come together and
collide. What happens depends upon the types of crust
that meet! There are three types of convergent
boundaries. Along with the many landforms (features)
that are created, earthquakes occur!
1. When 2 oceanic plates collide, the denser of the two
plates will sink. The more dense plate is always the
older of the two oceanic plates. This sinking along
with melting is called subduction. Landforms
(features) created are volcanic island arcs & trenches.
2. When a continental plate and an oceanic plate
collide, the more dense oceanic plate slides under the
less dense continental plate. This action forms a
trench where the sinking crust is melted and recycled.
The area where this takes place is called a subduction
zone. Landforms (features) created at these zones
include trenches and volcanic mountains.
3. When 2 continental plates collide, both plates
buckle and push up into mountain ranges. These
mountains are classified as folded mountains due to
the way they were created.
At the transform boundary, two plates slide past each
other. Crust is neither created nor destroyed.
Therefore, no landforms (features) are created!
Earthquakes occur frequently along these boundaries.