L.O: SWBAT explain the theory of plate tectonics

Earth’s Lithosphere is broken into about 12 large tectonic (crustal) plates and about 24 smaller plates. Each plate consists of the crust and the upper, solid mantle: The Lithosphere These plates rest on the fluid layer of the mantle: The Asthenosphere

The plates move! The plate movement is why we have earthquakes & continental drift.

*Earthquakes, volcanoes, mountain ranges, continental drift & seafloor spreading all happen at the tectonic plate boundaries (where the plates meet)

What are the three ways plates can move? Open to page 5.

3 types of Plate Boundaries 1)Convergent (2) Divergent (3) Transform

Convergent Convergent boundaries: Two plates are moving toward each other. Draw the symbol for convergent plate boundary Notice the side with the rectangle (top hat) stays on top.

3)Continent-Continent Different types of convergent boundaries depend on which TYPE of crust is involved. 1)Ocean-ocean 2)Ocean-Continent 3)Continent-Continent

Oceanic-oceanic Type of Boundary Activity One plate descends beneath the other in a process called SUBDUCTION. Formation Deep-sea trenches

Remember the NAZCA PLATE: It is right next to the south American plate ***Remember the NAZCA PLATE: It is right next to the south American plate. It is a famous subduction zone that they usually mention on the regents.

Oceanic-Continental Type of Boundary Activity Oceanic crust subducts below the continental crust because it is more dense. Formation Volcanoes

Notice: the denser oceanic crust subducts under the less dense continental crust.

Continental -continental Type of Boundary Continental -continental Activity Neither plate subducts. The forces deform and fold the crust. Formation Mountain Ranges

Mt. Everest

What is the name of the trench found at 50oN and 180o?

Divergent boundaries: 2 plates move apart or separate. Draw the symbol for divergent plate boundary Found mostly on the sea floor where they form ocean ridges.

What plate boundary is found on the continent of Africa?

If a divergent plate boundary found on continental crust they form rift valleys.

3) Transform boundary: 2 plates slide past one another horizontally. Draw the symbol for transform plate boundary

the famous transform plate boundary in the USA is the famous transform plate boundary in the USA is *The San Andreas Fault in California . Transform plates=Earthquakes

The San Andreas Fault

The slice of California to the west of the fault is slowly moving north relative to the rest of California. Since motion along the fault is sideways and not vertical, Los Angeles will not crack off and fall into the ocean as popularly thought, but it will simply creep towards San Francisco at about 6 centimeters per year. In about ten million years, the two cities will be side by side.

This is page 5, Tectonic Plates. You are now responsible for it.