Chapter 5 Section 1

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Transcript Chapter 5 Section 1

Earth’s Interior
Let’s Take a Journey to the
Center of the Earth
•
There are three main layers of Earth
1. The CRUST
2. The MANTLE
3. The CORE
– All three layers differ in size,
composition, temperature, pressure
& density
Temperature
•
As you travel to the center of the
Earth the temperature gets warmer
•
For every 40 meters you descend the
temperature increases 1 degree
Celsius
Pressure
• PRESSURE – results when a force is
pressing on an area
• Pressure increases as you go deeper
into the Earth
The Crust
• CRUST – layer of rock
that forms Earth’s
outer skin
– Includes both dry land
and the ocean floor
– Also the soil and water
that covers earth’s
surface
– Thin layer
– Thickest under
mountains; thinnest
beneath ocean
– Between 5 – 70 km
thick
– Crust beneath
oceans = oceanic
crust
• Made up of BASALT –
dark rock/fine texture
– Crust that forms
continents =
continental crust
• Made mainly of
GRANITE – light
color/coarse texture
The Mantle
• layer of hot rock (but solid)
• Over 3,000 km thick
• Divided into 2 layers
1. Upper Mantle
a. Lithosphere – crust and uppermost part of the
mantle; about 100 km thick
b. Asthenosphere – upper mantle just below the
lithosphere
a. Hotter and under more pressure
b. Softer/bends like plastic (but still solid)
2. Lower Mantle
The Core
• Made up of metals iron and nickel
• 2 parts…
• OUTER CORE – layer of molten metal that
surrounds the inner core
• INNER CORE – dense ball of solid metal
– Pressure squeezes the atoms of nickel and iron
so much to where they cannot spread out, so
they become liquid
• Scientists think the movements in the liquid
outer core create Earth’s magnetic field
Spell o roma
Lith (o sphere)
As then (o sphere)
Review Questions
1. Why is it difficult to determine Earth’s inner
structure?
2. What is the difference between the lithosphere
and the asthenosphere?
3. How do temperature and pressure change as
you go deeper into the Earth?
4. How are oceanic and continental crusts alike
and different?
5. Place these terms in correct order so they
begin at Earth’s surface and move toward the
center:
inner core, asthenosphere, crust,
lithosphere, and outer core
More Review Questions
6. Write whether each statement is true or
false
a. continental crust is made up of rocks
such as granite
b. the relatively soft layer of the mantle is
called the asthenosphere
c. the Earth’s core is made up of iron and
copper