Boundary Notes EQ 1 What happens along plate

Boundary Notes EQ #1 What happens along plate boundaries?

Motion in the Earth n https: //www. youtube. com/watch? v=0 m. WQs 1_L 3 f. A

Plate tectonics There are 19 tectonic plates that make up earths crust (lithosphere) n The edges of these plates are identified by earthquakes, rift valleys, volcanoes and mountain ranges n These are called SEISMIC ACTIVITY n

Divergent Boundaries • Move apart from each other • As they separate, lava flows up and forms new crust. • The form ridges and Rift valleys.

Divergent Boundaries • Ex: Mid-Atlantic ridge and Great African Rift Valley

Divergent Boundaries

Convergent Boundaries • Move toward each other • Features depend on types of crust colliding

Convergent Boundaries • Oceanic - Oceanic • One plate SUBDUCTS the other, forming a TRENCH • Forms an ISLAND ARC

Convergent Boundaries • Example: Marianas Trench and Marianas Islands • Might have volcanoes

Convergent Boundaries O-O

Convergent Boundaries • Oceanic - Continental • Oceanic plate SUBDUCTS Continental • Sinking plate melts and forms VOLCANIC MOUNTAINS

Convergent Boundaries • Example: Mt. St Helens, Andes Mountains

Convergent Boundaries O-C

Convergent Boundaries • Continental - Continental • NO Subduction • Huge Folded mountains form

Convergent Boundaries • Example: Himalayan Mountains

Convergent Boundaries C-C

$Transform Boundaries n Slide past one another. n Crust is fractured and many faults$

Transform Boundaries n Slide past one another. n Crust is fractured and many faults form. n Example : San Andreas Fault in California

Transform Boundaries

Driving force for plate tectonics n. Convection Currents in the asthenosphere

Driving force for plate tectonics