II)Convection in the Mantle EQ: How is heat transferred? What causes convection currents?

A) Heat Transfer

In a room why is it cooler near the floor than near the ceiling?

Hot is Hot Cold is Not

Heat

A) Heat Transfer

A)Heat Transfer The movement of energy (heat) from a warmer object to a cooler object. or

There are three types of heat transfer:

1) Radiation

1) Radiation empty space heat transfer through empty space

All these forms of radiation together are called the Solar Wind. a. Heat from the sun The Sun's Radiation:      The sun emits many kinds of radiation. Heat is only a part of what it emits.      The sun also emits light, radio waves, gamma radiation, ultraviolet and infrared radiation.      All these forms of radiation together are called the Solar Wind.

b. heat from an open flame or other local heat source 1) Radiation b. heat from an open flame or other local heat source

Mr. Ray Radiation

2) Conduction

2) Conduction heat transfer by direct contact (touching)

Mr. Conduction Conductor

3) Convection

Heat goes higher. Hot air, hot water, and hot rock all tend to rise. 3) Convection fluid heat transfer by the movement of a heated fluid Heat goes higher. Hot air, hot water, and hot rock all tend to rise. Cold creeps lower. Cold air, cold water, and cool rock all tend to sink.

B)Density

Density Facts (video)

B) Density 1) How much mass there is in a volume of a substance 2) volume is the amount of space an object takes up 3) When a fluid’s temperature increases its particles move faster its particles occupy more space density decreases

C) Convection Currents

C) Convection Currents In this pot, the liquid close to the heat source is hotter and less dense than the liquid near the surface. These differences in the temperature and density cause convection currents. 1) the current created by the rising of a heated liquid and the sinking of a cooling liquid 2) differences in temperature and density along with the force of gravity cause convection currents

D) Convection Currents in the Mantle (video)

What part of Earth’s interior is like the soup in the pot? What part is like the burner on the stove? 1) Heat form Earth’s mantle and core causes convection currents to form in the asthenosphere.

Particles move faster; occupy more space Particles occupy less space Mantle Rock Cools Mantle Rock Rises Particles move faster; occupy more space Mantle rock is heated Mantle rock sinks Particles occupy less space Particles move slower Density decreases Density increases

Review

What is heat transfer? the movement of heat (energy) from a warmer object to a cooler object.

What are the three types of heat transfer? Convection, conduction, and radiation

What is heat transfer through empty space? radiation

What are two forms of RADIATION? sunlight and heat form an open flame (fire)

What is heat transfer by direct contact? conduction

What is heat transfer by the movement of a heated fluid? convection

Explain density. a measure of how much mass there is in a volume of a substance.

What causes convection currents to occur? differences of temperature and density

What happens to the density of a fluid when its temperature increases? it decreases

In what layer of the Earth do convection currents occur? asthenosphere

What is the heat source for the convection currents in the asthenosphere? Earth’s mantle and core