Mantle Convection Powers Plate Tectonics

Understanding Earth's Dynamic Interior Grade 9 Earth Science

What Causes Continents to Move?

Think about what you already know about Earth's structure Consider what forces might be powerful enough to move entire continents Share your initial thoughts with a partner

Earth's Interior Structure

Crust: Thin outer layer where we live Mantle: Hot, dense rock layer beneath the crust Outer Core: Liquid iron and nickel Inner Core: Solid iron and nickel center

What is Mantle Convection?

Heat from Earth's core warms the mantle Hot mantle rock becomes less dense and rises Cool mantle rock becomes denser and sinks This creates circular currents called convection cells

How Convection Drives Plate Movement

Types of Plate Boundaries

{"left":"Divergent: Plates move apart, new crust forms\nConvergent: Plates collide, mountains or trenches form","right":"Transform: Plates slide past each other horizontally"}

Model Building Activity

Create a digital diagram showing mantle convection Include arrows showing hot material rising and cool material sinking Show how this movement affects tectonic plates on the surface Label key features: mantle, core, plates, convection currents

Key Takeaway

"Mantle convection is the engine that drives plate tectonics, shaping our planet's surface through the slow but powerful movement of hot rock deep beneath our feet."