Plate Tectonics - Unit 1

What forms at tectonic plate boundaries, and what causes our plates to move?

Convergent Plate Boundary

A plate boundary where two plates collide.

Divergent Plate Boundary

A plate boundary where two plates move away from each other.

Transform Plate Boundary

A plate boundary where two plates slide past each other horizontally.

Seafloor Spreading

The process by which new oceanic crust is formed at divergent boundaries as tectonic plates move apart, resulting in the creation of new seafloor.

Mid-Ocean Ridges

Underwater mountain ranges formed by plate tectonics at divergent boundaries, where magma rises to create new oceanic crust.

Rift Zones

Regions where tectonic plates are moving apart, creating cracks and fissures in the Earth's crust, often leading to volcanic activity and new material formation.

Trenches

Deep underwater valleys formed at convergent boundaries where one tectonic plate is forced beneath another, often associated with subduction zones.

What forms at a convergent plate boundary?

-Mountains

-Trenches

-Earthquakes

-Volcanoes

What forms at a divergent plate boundary?

-Ocean Basins

-Rift Zones

-Mid-ocean Ridges

-Underwater Mountains

What forms at a transform plate boundary?

-Earthquakes

Who proposed the theory of continental drift?

Alfred Wegener

Who proposed the theory of seafloor spreading?

Harry Hess

Continental Drift

Hypothesis that continents are in constant.

Fossil

Naturally preserved remains, imprints, or traces of organisms. 

What are the layers of the Earth?

Outer:

• Continental Crust

• Oceanic Crust

• Lithosphere

• Asthenosphere

• Mantle

• Mesosphere

• Outer Core

• Inner Core

Mantle

Middle layer of Earth situated between the crust above and the core below.

Pangaea

Ancient supercontinent, composed of land that forms today’s continents.

Convection

Circulation of material caused by differences in temperature and density. This process drives the movement of tectonic plates within the mantle.

Lithosphere

Rigid layer that makes up the tectonic plates. 

Plate Tectonics

Theory that Earth’s surface is made of rock plates that move with respect to each other.

Subduction

Sinking of a denser plate below a more buoyant plate at a convergent plate boundary.

Weathering

The breaking down of rocks and soil by water, wind, ice and chemical.

Erosion

The movement of weathered rocks and soil from one place to another by wind or water.

Deposition

The leaving behind of sediment or rock after erosion has occured.