CHAPTER 1
SECTION 1
EARTH’S INTERIOR
1. GEOLOGISTscientists who study
the forces that
make and shape
planet Earth.
2. Geologists study:
-CHEMICAL and PHYSICAL
characteristics of rock
- MAP where different types of rock
are found
- describe LANDFORMS
- study the processes that CREATE
Earth’s features and search for clues
about EARTH’S HISTORY.
3. ROCK – the material
that forms Earth’s
hard surface
4. GEOLOGY – the study
of planet Earth
5. Geologists have
concluded that
Earth’s landforms
are the result of
NATURAL FORCES
that slowly build up
and WEAR DOWN
the land.
6. Geologists divide the forces that change
the surface into two groups:
CONSTRUCTIVE FORCES – forces
that build up mountains and landmasses
DESTRUCTIVE FORCES – forces that
slowly wear away mountains and other
features on the surface.
7. Give one example of a
constructive force and one
example of a destructive force
8. CONTINENT – a great
landmass surrounded by
oceans.
9. Why would a geologist study
the interior of a cave?
TO STUDY MATERIALS THAT
ARE NORMALLY UNDERGROUND
10. The EXTREME CONDITIONS
of Earth’s interior prevent
exploration far below the
surface.
11. Geologists must
rely on
INDIRECT
methods of
observing
Earth’s interior.
12. SEISMIC
WAVES – waves
produced when
earthquakes
occur.
13. The SPEED of seismic waves
and the PATHS they take
reveal how the planet is put
together.
14. How is the earth like an
onion?
IT HAS
LAYERS
15. As you go deep toward the
center of the Earth
TEMPERATURE and PRESSURE
increase.
16. PRESSURE – the force pushing
on a surface or area.
17. Three main layers make up
Earth’s interior:
A. CRUST – a layer of rock that
forms Earth’s outer skin.
-
It includes both the dry LAND
(where it is thickest under
MOUNTAINS) and the OCEAN
floor (where it is thinnest)
- OCEANIC CRUST – crust
beneath the ocean. It consists
mainly of dark, dense rocks
called BASALT.
-
CONTINENTAL CRUST –crust
that forms the continents. It
consists mainly of light colored
less dense rock called
GRANITE.
B. MANTLE – the layer of hot
solid rock, located under the
crust.
- LITHOSPHERE – the rigid layer
consisting of the uppermost
part of the mantle and the
crust together (lithos means
“STONE”)
- ASTHENOSPHERE – the soft
part of the mantle located just
below the lithosphere (asthenos
means “WEAK”).
- The LITHOSPHERE floats on
the ASTHENOSPHERE.
C. The core consists of two parts.
- OUTER CORE –
the liquid
layer of
molten metal
– it behaves
like a thick
liquid.
- INNER CORE –
a dense ball
of solid
metal.
The metals IRON and NICKEL
make up both parts of the
core.
- The inner and outer cores
together are just slightly
smaller than the MOON, yet
they make up about 1/3 of
the Earth’s mass.
18. CURRENTS in the liquid outer core
force the solid inner core to spin at
a slightly FASTER rate than the rest
of the planet. These currents in the
outer core create Earth’s
MAGNETIC FIELD.