Earth's Interior and Convection Currents

Order Earth's Layers Starting from the Surface

Crust, Upper Mantle, Lower Mantle, Outer Core, Inner Core.

Pressure and Temperature

Differences in temperature and density cause convection currents, and as depth increases pressure and temperature increase too.

Radiation

Direct transfer of energy through empty space (ex. sunlight warming Earth's surface.)

Describe the Convection Currents inside Earth

Earth's hot core and mantle provide a source of heat that drives convection currents in the asthenosphere. The asthenosphere is a layer of the upper mantle that can flow very slowly. The soft plastic material of the asthenosphere slowly rises, spreads out, and pushes cooler material out of the way. Then the cooler material sinks back through the sthenosphere these convection currents have flowed inside of the earth for billions of years.

Convection Currents

Heat transfer within a fluid, convection currents flow in the mantle, and are caused by pressure and temperature.

Order Earth's Layers Starting from the Densest to the Least Dense

Inner Core, Outer Core, Lower Mantle, Upper Mantle, Asthenosphere, Lithosphere, Crust, Oceanic Crust, and Continental Crust.

Outer Core

Made of liquid nickel and iron.

Density

Measure of how much mass there is in a volume of a substance.

Asthenosphere

Part of the mantle that is made of soft rock and bends like plastic.

Earth's Magnetic Field

Results from movement of the liquid outer core.

Plates

Sections of the lithosphere that float on top of the asthenosphere.

Silicon and Oxygen

Two elements that compose most of the crust and mantle.

Be able to tell what is occurring at each point on your convection currents graphic organizers.

1. Density of mantle material is less than material above it, so the materials began to ride. 2. Rising material hits rigid lithosphere and cannot go up any further. 3. The force of gravity is causing denser material to fail. 4. Core heat causes temperature to rise, therefore decreasing the density of material.

Inner Core

Dense ball of solid nickel and iron.

Rock Sample

Geologists drill holes several kilometers into the Earth's crust which provide direct evidence of Earth's interior.

Seismic Waves

Geologists obtain indirect evidence about Earth's interior by studying and recording Seismic Waves.

Convection

Transfer of heat by movement of a heated fluid (ex. soup heating up in a pot.)

Conduction

Transfer of heat through direct contact of particles (ex. frying pan on a burner.)