Title: Science Do Now: 12-8
1ScienceDo Now 12-8
EQ What are plates and how do they move?
- LG Describe the three types of tectonic plate
boundaries, the forces that move them, and how
movement is measured. - HW 7-3 worksheet due Wed,
- Test on Thursday study session at 815
- List 3 types of convergent boundaries use
arrows to show movement - Take out color pencils/markers
- Take out Plate Tectonic notes
- Today
- Complete PPT Theory of Plate Tectonics
- Convection Current Organizer
2 List 3 types of convergent plate boundaries
use arrows to show movement
What is here?
-
- Oceanic-Oceanic
- Oceanic-Continental
- Continental-Continental
What is here?
3The Theory of Plate Tectonics
4Think of a Broken EGG! ?
Plate Boundary
Plate
5Plate Tectonics
- The Earths lithosphere is divided into plates
that move on top of the asthenosphere.
Earths Major Plates
When the water moves beneath the raft, the raft
moves with it. When the asthenosphere moves, the
lithosphere moves with it
6Here is a look at a different map!
Where are most plate boundaries located? What
plate do we live on?
7And another
8Types of Plate Boundaries
- When two plates meet, they form a boundary.
- There are three types of boundaries
9Convergent Boundaries
- Two plates push together
- Term to know SUBDUCTION means the crust is
SINKING! - Three types of convergent boundaries
- 1. Ocean/Ocean TRENCH
- 2. Ocean/Continental TRENCH
- 3. Continental/Continental MOUNTAINS
10Convergent Collision 1 (Oceanic/Oceanic)
- One of the plates will SINK (subduction!) and
form a TRENCH. Magma rises and forms and island
arc of volcanoes.
Subduction Zone
11Convergent Collision 2 (Oceanic/Continental)
- The oceanic plate sinks (subduction!) below the
continent and the continental plate slides over
the top of the oceanic plate. Forms a TRENCH.
Subduction Zone
12Convergent Collision 3(Continental/Continental)
- Both continental plates collide and rise up
forming MOUNTAINS. (Ex. Himilayas)
13Divergent Boundaries
- Two plates pull apart forming a rift valley in
the middle. - Sea-floor spreading is created by a divergent
boundary.
Rift Valley
Click Here to see Divergent Boundaries in
motion!!!
14When the divergent boundary is on land . There
is a HUGE rift valley in east Africa called the
Great Rift Valley
15Transform Boundaries
- Plates slide past each other in a side to side
motion. (Ex. San Andreas Fault)
This fence used to line up!! Before the 1906
Earthquake in California
San Andreas Fault
16WHY do the plates move?
- CONVECTION CURRENTS in the mantleHot rock
(less dense) rises to the surface, cools (more
dense), and sinks back to the mantle.
COOL MOLTEN ROCK SINKS
HOT MOLTENROCK RISES
17Convection Currents
18Less
Rise
More
Sink
Same Volume
More matter
Less matter
Same Volume
More matter
Less matter
Less
Rise
More
Sink
19Convection Currents
Cools off! more dense fall to the bottom
Hot! less dense rise to the top
See Animation
http//education.sdsc.edu/optiputer/flash/convecti
on.htm
20REVIEW BOUNDARIES!