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 Plate movement
What happens to the crust? The crust is created
What do you get as a result? Sea floor spreading
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) Plate movement What happens at a convergent boundary depends on the plates
What happens to the crust? The crust is destroyed
What do you get as a result? What happens at a convergent boundary depends on the plates Three types of convergent boundaries Oceanic-continental Oceanic-oceanic Continental-continental
Oceanic-Continental: Results - Subduction Oceanic sinks because its more dense Examples: Andes Mountains Mount St. Helens (Juan de Fuca subducts beneath the North American plate)
Oceanic-Oceanic: Results oldest crust subducts volcanic island chains examples: Philippines Japan
Continental-Continental: Results mountains Examples Himalayas Appalachians Rockies Alps
Transform Boundary forms everywhere ridge is not a straight line two plates slide past each other
What happens to the crust? The crust is conserved
What do you get as a result? Faults
Examples San Andreas Fault Pacific Plate is moving faster than North American plate at a rate of about 2 cm per year
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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?