Tectonic Plates

Divergent Plate Boundary

The plates move apart from each other in opposite directions.

Divergent Plate Boundary Features

Common features are mid-ocean ridges, rift valleys, and the formation of new crust.

Divergent Plate Boundary Examples

Examples of this are the Red Sea and East African Rift Valley.

Transform Plate Boundary

The plates slide in opposite vertical direction away from each other.

Transform Plate Boundary Locations

Found along mid-ocean ridges and continental margins.

Transform Plate Boundary Effects

Common effects of this are earthquakes, ridges, and valleys.

Transform Plate Boundary Example

Example of this is the San Andreas Fault in California.

Convergent Plate Boundary (Collision)

Two plates move towards each other and collide.

Convergent Plate Boundary (Collision) Effects

Common effects of this are volcanoes, mountain ranges, ocean trenches, and earthquakes.

Convergent Plate Boundary (Collision) Example

An example of this is the Himalaya Mountains in Asia.

Convergent Plate Boundary Subduction (Oceanic-Continental)

Happens when a more dense plate gets subducted under a less dense plate.

Convergent Plate Boundary Subduction (Oceanic-Continental) Example

Example of this is the Cascades Mountain Range in North America.

Convergent Plate Boundary Subduction (Oceanic-Oceanic)

Happens when a more dense plate is subducted under a less dense plate.

Convergent Plate Boundary Subduction (Oceanic-Oceanic) Characteristics

The 2 plates have different densities.

Convergent Plate Boundary Subduction (Oceanic-Oceanic) Example

An example of this is the Mariana Trench.

Mountains Formation

Mountains form when 2 convergent plate boundaries collide and push upwards.

Mountains Characteristics

The rock does not crumble when this happens.

Mountains Current Status

Mountains are still forming today.

Continental Drift Theory Creator

Alfred Wegener created the theory on Continental Drift.

Seafloor Spreading Theory Discoverer

Harry Hess discovered the theory of Seafloor Spreading.

Continents Fit Theory Discoverer

Abraham Ortelium discovered that the continents fit together like a puzzle piece.

Continental Drift Theory Evidence

Distance between Greenland and Europe was seen increasing.

Continental Drift Theory Fossil Evidence

The same animal fossils found in Africa and South America.

Continental Drift Theory Coal Evidence

Coal was found in Antarctica.

Continental Drift Theory Rock Evidence

The same rocks were found in different continents across the earth.

Continental Drift Theory Glacial Evidence

Glacial striations found in places that currently don't have glaciers.

Plates Characteristics

Plates are various sizes and shapes.

Plates Density

Oceanic plates are more dense; Continental Plates are less dense.

Plates Movement Cause

The earth's plates move due to convection currents.

Convection Currents Definition

Convection currents are formed when a fluid, like air or water, is heated unevenly, causing areas of the fluid to become less dense and rise, while cooler, denser areas sink.

Convection Currents Energy Source

Thermal energy heats the convection currents.

Gravity's Role in Plate Movement

Gravity drives the direction in which the plate moves.