Transcript File - Ms. D. Science CGPA

Land, Air, and Water Resources
Ms. De Los Rios
7th Grade
8-6 Heat Flow Inside Earth
Essential Question:
How Do People use Earth’s Resource?
How Do Mantle Convection Currents Affect Earth?
Pgs. 296-299
Vocabulary
Convection- The transfer of thermal
energy by the movement of a fluid.
Convection Current- The movement
of a fluid, caused by differences in
temperature, that transfers heat from
one part of the fluid to another.
Dr. Diana Roman
My Planet Diary pg. 196
How can you tell when a volcano will erupt? Dr. Diana Roman is trying to find
out. She is a volcanologist, a scientist who studies volcanoes. A professor of
geology at the University of South Florida, she analyzes data about ground
movements to study the motions of magma. Her goal is to find better ways to
measure how magma moves so scientists can make better predictions about
how and when volcanoes will erupt.
Why does Dr. Roman study the motions of magma below Earth’s
surface?
How Do Mantle Convection Currents Affect Earth?
The Earth’s crust is made of minerals, soil, and other important
resources which form from hot, molten material deep beneath the
Earth’s surface.
The Earth is made of 3 main layers:
The crust, mantle, and core (inner and outer).
The temperature inside Earth’s
Layers varies from cool to
Extremely hot.
Earth’s Temperature pg. 297
The top of Earth’s Crust is cool but
as you go deeper inside the Earth the
temperatures increase as depth increases.
Earth’s mantle is hot enough that hard,
solid rock can flow. Earth’s core is even
hotter.
Where does the heat come from?
-Some heat is due to the pressure caused
by Earth’s mass pressing down on all
sides.
-Other heat is due to radioactive substances
that release energy.
-Finally some is left over from Earth’s formation.
Convection in the Mantle pg. 297
The mantle is hot enough that solid rock can flow.
Even though solid- the rock acts like a fluid.
As the rock gets hotter, its density decreases and it rises.
As the rock rises, it gets cooler and its density increases and it sinks.
This process of heat transfer is called convection and is the force
behind the convections currents in the mantle.
Convection currents in the mantle transfer heat
toward the surface. This causes material to rise toward the surface
then sink back into the mantle.
Heat Flow Inside Earth/ Plate Boundaries pg. 298
Mantle Convection Currents cause earthquakes and
volcanic eruptions and help to produce mountains and ocean
basins.
Convergent boundaries are plates moving towards each other.
When two plates collide, they form mountains. Sometimes, one plate
is submerged under the other one, causing part of the plate to melt
into magma. When the magma later rises, volcanic mountains form.
Divergent Boundaries pg. 298
Divergent boundaries are plates moving away from each other. As
plates move away, rift valleys occur. Molten material rises between the
plates, forming ridges. Over time, ocean basins can form between
divergent plates.
Transform Boundaries pg. 298
Transform boundaries are plates moving past each other in
opposite directions.
The jagged edges of these plates can lock them into place. However,
stress can build up until the plates unlock, causing an earthquake.
Heat Flow Inside Earth pg. 298
Plate Movement
Convection currents in Earth’s
mantle move the plates. This
changes Earth’s surface.
-On the map, where you
would expect to find
volcanoes forming?
Put a V in the circles.
Where would you not
expect to find volcanoes?
Put an x in the circles.
Reshaping the Surface pg. 299
When the plates move at convergent, divergent, or transform
boundaries, they reshape the Earth’s surface.
Mountains and volcanoes can form at convergent boundaries.
Rift Valleys and ocean basins can form at divergent boundaries.
Earthquakes can form at transform boundaries.
Most changes caused by heat flow are slow, but earthquakes and
volcanoes can change the surface very quickly.
Assess Your Understanding pg. 299
1a. List – Heat flow and movement of material inside Earth
results in what landforms and events?
b. Explain- How does heat flow inside Earth lead to changes on
Earth’s surface?
I get it! Now I know that heat is transferred in Earth’s mantle by
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