Obj: What is the Theory of Plate Tectonics? Copy the following questions in your notebook: TABLE 1 (7)- What is a mid ocean ridge? TABLE 2 (8)-What is the difference between a convergent, divergent and transform boundary? TABLE 3 (9)- What is the ring of fire? TABLE 4 (10)- Describe the three types of faults? TABLE 5-What causes Earthquakes? TABLE 6-What evidence supports the theory of plate tectonics?

How did the continents drift apart?

What is the Theory of Plate Tectonics? Copy the following words in your notebook. Mid-ocean Ridge Trench Seafloor Spreading Rift Valley Continental Drift Pangaea Subduction Zone Convergent Boundary Divergent Boundary Plate Tectonics Transform Boundary Normal Fault Reverse Fault Strike-slip Fault

The lithosphere floats on top of the asthenosphere.

Describe what happens in a subduction zone? A subduction zone occurs in a Convergent Boundary where two plates collide.

What is sea floor spreading? A mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, typically having a valley known as a rift valley running along its spine, formed by plate tectonics. This type of oceanic ridge is characteristic of what is known as an oceanic spreading center, which is responsible for seafloor spreading. The rift valley occurs at divergent boundaries. This occurs when two tectonic plates are pulled apart.

Magma comes out of the mid-ocean ridge. As the magma comes out and solidifies, it pushes the oceanic floor towards the subduction zones and into the trenches. Volcanoes, mountain formations and earthquakes occur because of seafloor spreading and subduction zones.

DIVERGENT BOUNDARY In a divergent boundary, the plates are moving apart.

CONVERGENT BOUNDARY In a convergent boundary, the plates are coming together.

TRANSFORM BOUNDARY A transform boundary occurs when two plates slide past each other.

WHAT ARE TECTONIC PLATES The crust is divided into seven main plates. The theory of plate tectonics explains the movements of the continents.

What is the Ring of Fire? Many earthquakes and volcanoes occur at the edges of the Pacific plate. This area is known as the Ring of Fire.

Evidence for Plate Tectonics

FAULTS: are caused by breaks in the Earth’s surface. The movement of plates can cause Earthquakes.