4.10-4.13 Earth Science Lesson

LAYERS BY COMPOSITION

● The crust is less than 1% of Earth by

mass. The two types are oceanic crust and
continental crust. Continental crust is
felsic and oceanic crust is mafic.

● The mantle is hot, ultramafic rock. It

represents about 68% of Earth's mass.

● The core is mostly iron metal. The core

makes up about 31% of the Earth.

Multiple Choice

What percent of the Earth's mass does the crust make up?

• 1%

• 68%

• 31%

• 92%

Multiple Choice

What percent of the Earth's mass does the mantle make up?

• 1%

• 68%

• 31%

• 92%

Multiple Choice

What percent of the Earth's mass does the core make up?

• 1%

• 68%

• 31%

• 92%

LAYERS BY MECHANICAL PROPERTIES

● The lithosphere is composed of both the

crust and the portion of the upper
mantle and behaves as a brittle, rigid
solid.

● The asthenosphere is partially molten

upper mantle material and behaves
plastically and can flow.

Multiple Choice

The lithosphere is composed

• upper mantle

• crust

• both the crust and the portion of the upper mantle

• both the core and lower mantle

LAYERS BY COMPOSITION

● (1) Crust (2) Mantle (3a) outer core (3b)inner

core (4) Lithosphere (5) Asthenosphere (6) outer
core (7) inner core

4.10: EARTH'S CRUST

● Earth’s outer surface is its crust,

a cold, thin, brittle outer shell
made of rock.

● The crust is very thin relative to

the radius of the planet.

● There are two very different types

of crust,

1) Oceanic

2) Continental

Multiple Select

Which of the following are types of crust? (SELECT ALL THAT APPLY)

• Oceanic

• Continental

• water

• land

EARTH'S CRUST

Crust

Thickness

Density
Compositio
n
Rock types

Oceanic
5-12 km
(3-8 mi)
3.0 g/cm3

Mafic
Basalt and
gabbro

Continental Avg. 35 km

(22 mi)
2.7 g/cm3

Felsic

All types

4.11: EARTH'S MANTLE

● Made of solid rock.

● Hot!

● Made mostly of ultramafic rock peridotite

Multiple Select

Which of the following are true abut the mantle

• Made of solid rock.

• Hot!

• Made mostly of ultramafic rock peridotite

• Is in the center of the planet

HEAT FLOW

● Heat flows in two different ways within the

Earth:

● Conduction: Heat is transferred through rapid

collisions of atoms, which can only happen if the
material is solid.

● Convection: If a material is able to move, even

if it moves very slowly, convection currents can
form.

CONVECTION

Multiple Choice

What causes the continents to move?

• Other Land

• Water currents

• Convection Currents

• all of the above

4.12 EARTH’S CORE

● At the planet’s center lies a dense metallic

core.

● 85% iron metal and 15% nickel metal.

● Metallic meteorites are thought to be

representative of the core.

● Meteorites are also 85% iron and 15% nickel

Multiple Choice

What is the core made up of?

• 55% iron metal and 45% nickel metal

• 85% iron metal and 15% nickel metal

• 90% iron metal and 10% nickel metal

• 50% iron metal and 50% nickel metal

EARTH’S CORE

● Scientists know that the outer core is liquid and

the inner core is solid because:

● S-waves do not go through the outer core.

● The strong magnetic field is caused by convection

in the liquid outer core. Convection currents in
the outer core are due to heat from the even
hotter inner core.

Multiple Select

Scientists know that the outer core is liquid and the inner core is solid because: (select all that apply)

• S-waves do not go through the outer core

• P-waves do not go through the outer core

• The strong magnetic field is caused by convection in the liquid outer core.

• Convection currents in the outer core are due to heat from the even hotter inner core.

4.13: LITHOSPHERE AND ASTHENOSPHERE

● The lithosphere is composed of both the crust and

the portion of the upper mantle that behaves as a
brittle, rigid solid.

● The lithosphere is about 100 kilometers thick.

● The asthenosphere is solid upper mantle material

that is so hot that it behaves plastically and
can flow.

● The lithosphere rides on the asthenosphere.

Multiple Choice

The asthenosphere rides on the lithosphere.

• True

• False