Download Plate Tectonics

Plate Tectonics
Ms. Clark
12.10.11
Let’s Discuss…
Has the Earth always looked like
this?
The Effects of Plate Tectonics Video
Vocabulary
These words
can are in the
video…
•Pangaea
•Theory of plate tectonics
•Continental drift
•Sea floor spreading
•Convection currents
•Subsidence
•Boundary
•Convergent boundary
•Divergent boundary
•Transform boundary
•Rift
•Ridge
•Trench
•Fault
•Theory
•Subduction zone
The Effects of Plate Tectonics Video
The most powerful source that alters the earths surface is the movement of tectonic plates.
Tectonic plates are large, solid pieces of earths lithosphere that move in different directions on top of
a hotter flowing layer of the asthenosphere
Wegener theory, called continental drift, explained why identical animal fossils like that of
mesorausaus were found on coastlines separated by vast oceans.
The continental drift theory could also explain the matching of large geological features across
continents.
Sea floor spreading in turn was the first positive proof that there was a force strong enough to move
continents. This was the thing needed to verify Wegners theory.
Plate tectonic theory explains how earth works
Heat from earths interior, creates convection currents which move the lithospheric plates around in
different directions and different speeds.
Plate boundary- the place where two or more plates meet
Faults are cracks in the earths crust that tilt slightly outward from one another
The Effects of Plate Tectonics Video
A convergent boundary is when two tectonic plates move toward or push against each other.
When an oceanic plate converges with a continental plate, the denser oceanic plate slides beneath
the lighter continental plate, into the asthenosphere called the subduction zone.
The tectonic force that pushes the plates together causes the plunging oceanic plate to pull the
continental plate down is called a trench.
Subduction zone is where most of the volcanoes are formed.
The ring of fire is where magma erupts through volcanoes and numerous earthquakes erupt. About
90% of world earthquakes form here
Transform boundaries slide past each other, resulting in a large fault. (Earthquakes)
Folded mountains, trench and subduction zones are formed at the convergent boundary.
Mid ocean ridge, Rift Valley and fault block mountains are located at divergent boundaries.
Pangaea Puzzle
What is Pangaea?
•Pangaea or Pangea is from the Greek origin and means “All
Lands”
•The continents shown on the Pangea Puzzle are not to scale.
•They are in the approximate location of the present day
continents.
•You will be forming the supercontinent, Pangaea.
•Pangaea existed approximately 225-260 million years ago.
QUIZ
Tomorrow
12.13.12