CHAPTER 1 SECTION 1
EARTH’S INTERIOR
1.GEOLOGIST-scientists 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.