INSIDE EARTH
CHAPTER 1: PLATE TECTONICS
Section 1: Earths Interior
GEOLOGY

Geology: the study of planet Earth
Geologists
study the processes that
create Earth’s features and search
for clues about Earth’s history
Geologists have to make predictions about what the Earth’s
interior is made of by making indirect observations of
seismic waves
 Forces beneath the Earth’s surface change the Earth’s
appearance. There are two types of forces:

CONSTRUCTIVE VS. DESTRUCTIVE FORCES
Constructive: forces
that build up mountains
and landmasses

Destructive: forces that
destroy mountains and
other features of land

CONTINENTS

Continents: the seven
great landmasses
surrounded by oceans

the seven
continents:
1. North America
 2. South America
 3. Africa
 4. Europe
 5. Asia
 6. Australia
 7. Antarctica

GEOLOGISTS CANNOT OBSERVE EARTH’S
INTERIOR DIRECTLY.
Use seismic waves:
vibrations that travels
through Earth,
carrying the energy
released during an
earthquake
 determine the speed
and path of these
waves to reveal the
inner Earth’s
structure

TEMPERATURE AND PRESSURE
As the depth of the
Earth increases, so
does the pressure
and temperature.
 Pressure: amount of
force pushing on a
surface (huge amount
of pressure on the
core)

EARTH IS MADE UP OF 3 MAIN LAYERS
1. CRUST
Crust: Layer of rock that forms Earth’s
outer skin (made of Oxygen, Silicon,
Aluminum, Calcium, Iron, Sodium,
Potassium and Magnesium)
 Includes soil and water
 8-40 km thick

Oceanic Crust: crust beneath the ocean
Thin layer of crust
 Made of- basalt: dark dense rock with a fine
texture


Continental Crust: crust that forms the
continents
Thicker layer of crust
 Made of granite- rock that has larger crystals
basalt and is not as dense; usually light in color

2. MANTLE
Mantle: a layer of hot rock under the Earth’s crust
(made of Iron, oxygen, Silicon and Magnesium)
 Lithosphere: a rigid layer made up of the
uppermost part of the mantle and the crust;
about 100km thick- (tectonic plates)
Under the Lithosphere is a layer of hot rock
 Temperature and pressure in the mantle increase
with depth


Asthenosphere: thick, soft material that flows
in the mantle; about 3,000km thick; moves in a
convection current
CORE
3. Core: innermost layer of Earth; consists of 2
parts (made of iron and nickel)
 Outer Core
layer of molten metal that surround the inner core
 Behaves like a thick liquid
 Is under enormous pressure


Inner Core
Dense ball of solid metal
 Extreme pressure makes it a solid

MAGNETIC FIELD

The Earth has a magnetic field that is caused by the
inner core spinning within the outer