Embed Size (px)
Citation preview
• There are 3 main types of plate boundaries:
• 1. Divergent
• 2. Convergent
• 3. Transform
Divergent Boundaries
• Also known as spreading centers.
• 2 lithospheric plates are moving APART (diverging).
• Most are found on the seafloor, forming ocean ridges.
Bridge over divergent boundary in Iceland
•Because of this, some of the world’s oceans are getting bigger!
•Ocean ridges have valleys called rift valleys.
•The rift valleys are broken into fracture zones.
•These are the sources of earthquakes and Volcanoes.
Rift Valley in Iceland
Convergent Boundaries
This is when 2 tectonic plates are being pushed TOGETHER.
Three types of convergent boundaries:
1.Ocean-Ocean crust convergence
2.Ocean-Continental crust convergence
3.Continental-Continental crust convergence
Ocean-Ocean Convergence and Ocean-Continental Convergence:
• 2 oceanic plates coming together or 1 ocean plate and one continental plate coming together.
• One plate will be pushed under the other (the Most dense plate goes under the least dense plate).
• This is called subduction.
• Subduction creates trenches.
• The subducted plate melts and this will form volcanoes or island arcs (volcanic islands).
Ocean-Continental Convergence Animation
Ocean-Ocean Convergence Animation
The Andes
Continental-Continental Convergence:
• 2 continental plates are coming together.
• When they collide, NO subduction occurs because continental crust is not very dense and one will not subduct another.
• Instead, the crust gets crumpled and uplifted and often creates mountain ranges.
• The most famous is the Himalayas when India collided with Eurasia.
Old ocean sediments Uplifted
plateau
mountains
Transform Boundaries:• 2 plates SLIDE past each other.• Crust will be deformed and fractured
due to the friction and stress.• This will create faults and cause
earthquakes at these boundaries.• Most famous transform fault is the San
Andreas Fault in California.
Stop Plate TectonicsIt’s Changing The Earth
