Explain CONVECTION in your own words. 2/26/2014 Explain CONVECTION in your own words.

Today’s Goal: I CAN explain what plate tectonics is, what causes it, and forms from it.

Today’s Plan Finish continental drift questions Special demonstration (reward for students with finished work) 2. Vocabulary Practice

What are “Plates?” The Earth’s Plates are a lot like the cracked shell of a hard boiled egg. Earth’s LITHOSPHERE, its solid outer shell, is broken into pieces separated by jagged cracks.

And Subduction of Earth’s Plates How Plates Move Theory of Plate Tectonics: Pieces of Earth’s Lithosphere are in slow, constant motion, driven by convection currents in the mantle. This theory explains: The Formation, The Movement, And Subduction of Earth’s Plates

Plate Boundaries Three types of Plate Boundaries: DIVERGENT: Where two plates move APART. -CONVERGENT: Where two plates come TOGETHER.

Plate Boundaries Types of Plate Boundaries: TRANSFORM: Where two plates slide past each other, moving in opposite directions.

How the Plates Move The movement of convection currents in the mantle is the major force that causes plate motion.

Convection Currents Convection: When a fluid is heated and becomes less dense it rises, and when it cools down it becomes more dense and sinks

Convection happens in the ASTHENOSPHERE

Let’s take a closer look at how this works: COOL by crust Heat gives particles more energy and they spread apart becoming less dense Particles lose energy, slow down and move together, becoming more dense HEAT from core

Other contributors to plate movement Ridge Push: gravity pulls oceanic lithosphere downhill, especially at mid-ocean ridges

Other contributors to plate movement Slab Pull: oceanic lithosphere is more dense than hot asthenosphere, so the oceanic lithosphere will sink when it meets the asthenosphere

Other contributors to plate movement Subduction: when one plate goes under another plate (part of slab pull at convergent boundary)

Vocabulary Practice You need to write a definition AND draw/color a picture for each of the following 8 words: Pages 108-110 will help you. The picture should be ¼ of page. (So this will take 2 pages) Plate Tectonics Slab Pull Divergent Subduction Convergent Transform Convection Ridge Push