Transcript Plate Tectonic Boundaries

PLATE
TECTONICS
TECTONIC
BOUNDARIES &
SETTINGS
HOW TECTONIC PLATES MOVE
& WHAT LAND FEATURES RESULT
THEORY OF
CONTINENTAL DRIFT
PANGAEA
THE THEORY OF
PLATE TECTONICS
The Earth’s lithosphere is divided into tectonic plates….
THE THEORY OF
PLATE TECTONICS
Earth’s Tectonic Plates
THE THEORY OF
PLATE TECTONICS
that move around on top of the asthenosphere.
THE THEORY OF
PLATE TECTONICS
As a result of tectonic movement we
observe earthquakes, mountains and
volcanoes! Oh my! Evidences plates move!
TECTONIC PLATES
TECTONIC
BOUNDARIES
What “Drives” Tectonic Plate Movement?
Pay attention to the:
models used to represent each boundary
locations on Earth where the boundary occurs
land features that result from each type of plate movement
CONVECTION in the Asthenosphere provides the driving force to
move the tectonic plates (huge pieces of lithosphere)
TECTONIC
BOUNDARIES
Tectonic Boundaries - where plates meet
 Type of boundary depends on how plates move
CONVERGENT
DIVERGENT
TRANSFORM



Divergent
DIVIDE!
Also called
Rift Valleys/Zones!
DIVERGENT
Mid-Ocean Ridge System –
as plates separate MAGMA rises to fill the gap &
cools creating new oceanic lithosphere
 forms VOLCANIC & FAULT block mountains
Rift Valley
Ex. MID-INDIAN RIDGE
MID-INDIAN RIDGE
Recent Mid
Atlantic
Ridge
Activity
Bárðarbunga
Þingvellir
Transform
SLIDE!
Tectonic plates don’t
just “slide” easily!
TRANSFORM
plates grind and jerk as they slide producing
EARTHQUAKES
 forms FAULTS along the plate boundary
(large cracks in lithosphere)
Ex. SAN ANDREAS FAULT
SAN ANDREAS FAULT
TRANSFORM
Convergent
CRASH!
What landform results
depends on the kind of crust
colliding!
CONVERGENT
Continental/Continental
crust buckles & thickens pushing UPWARDS
(too THICK & “LIGHT” to sink)
 forms FOLD & FAULT block mountains (or continental
mountains)
Ex. HIMALAYAS
HIMALAYAS
CONVERGENT
Continental/Oceanic
oceanic (denser) SUBDUCTS (sinks) under continental & into
asthenosphere
 forms VOLCANIC mountains as crust melts in
asthenosphere
Ex. ANDES
subduction zone –
region where
oceanic lithosphere
sinks into
asthenosphere
ANDES MOUNTAINS
CONVERGENT
Oceanic/Oceanic
oceanic (denser) SUBDUCTS (sinks) under continental &
into asthenoshphere
 forms VOLCANIC mountains as crust melts in
asthenosphere
subduction zone –
region where
oceanic lithosphere
sinks into
asthenosphere
Ex. ALEUTIAN ISLANDS
ALEUTIAN ISLANDS
EVIDENCES SUPPORTING
PLATE TECTONICS
Plate Tectonics is the theory that provides an
explanation for why we observe various features
and changes taking place on Earth’s surface!
Remember: The crust is always moving… all you
have to do is look for EVIDENCE!
Mountains
Volcanoes
Earthquakes
WHAT DOES THE
FUTURE HOLD?
Theories allow us to
predict what may
happen in the
future…..