PLATE BOUNDARIES

Instructional Goals

Explain how each of the three plate boundaries are formed

Predict the resulting landforms from each boundary

Identify examples of plate boundaries

What do you know?

What do you know about earthquakes, mountains, etc?

Plate Boundaries

The place where two plates meet is called a plate boundary

Types of Plate Boundaries

Divergent Convergent Transform

Divergent Boundaries

Plates moving away from each other When do divergent boundaries occur?

Examples of Divergent Boundaries Mid-Atlantic Ridges Iceland (rift area) Red Sea Lake Baikal East African Rift

Convergent Boundaries

Plates are moving towards one another (colliding)

Destroys crust What happens at a convergent boundary

depends on the plates

Oceanic-Continental

- oceanic plate subducts because it is more dense

- examples: Andes Mountains Mount St. Helens (Juan de Fuca subducts

beneath the North American plate)

Oceanic-Oceanic

- oldest crust subducts - volcanic island chains - examples: Philippines Japan Aleutian Islands

Continental-Continental

- neither plate subducts - forms mountains - Examples Himalayas Appalachians Rockies Alps

Transform Boundary

- forms everywhere ridge is not a straight line

- two plates slide past each other - crust is conserved

Examples

San Andreas Fault Pacific Plate is moving faster than

North American plate at a rate of about 2 cm per year

http://www.learner.org/interactives/dynamicearth/plate.html

http://www.classzone.com/books/earth_science/terc/content/visualizations/es0804/es0804page01.cfm?chapter_no=visualization

How does it all connect?

Earth layers Moving Plates

Continental Drift Plate Boundaries

Divergent, convergent, transform fault Earthquakes, volcanoes and mountains

and things

Journal

“Tectonic” comes from the Greek word tektonikos, which means “of a builder”. Why is this word appropriate for tectonic plates? In what ways are tectonic plates responsible for building/destroying features of the Earth’s surface?