Earth Science : The Final PSAE
Frontier
Which Came First…
• Question: Which came first, the chicken or the
egg?
• Answer: NEITHER!
– Why? We needed a planet before there was life!
We Came From Dust…
• The planet Earth was formed from rocks
and dust in space collided and began to
spin.
• The spinning rocks and dust were called a
nebula.
• When the clumps began to stick as they
hit each other, we called them
planetesimals…and eventually planets!
Nebula and Planetesimals
How is the Earth Like an Onion?
• A. It stinks.
• B. It makes you cry.
• C. You leave it out in the sun, it get all
brown, start sproutin’ little white hairs.
• D. It has layers.
The Earth’s Layers
• 1. Crust- the outermost layer that we live on
top of (also called the LITHOSPHERE)
– More dense under the ocean, less dense under
land.
– Broken in pieces
• 2. Mantle- underneath the crust
– Mostly magma (liquid rock)
– Convection-heat is transferred through the magma.
• 3. Core- the center of the Earth
– Inside= solid, outside= liquid
Layers of the Earth
Shake it Like a Polaroid Picture…
• Plate tectonics- the
movement of the liquid
mantle causes the pieces
of the crust to move.
• Continental Drift- the
continents used to all be
together in a
“supercontinent”, but
have been moving apart
for millions of years!
• What was the name of
the supercontinent?
Continental Drift
Earthquakes Media Clip
Proof? You Can’t Handle the Proof!
• The sides of the continents fit together like
pieces of a puzzle.
• Index Fossils- fossils know to have only existed
at a certain place within a certain time…but are
found across oceans form each other.
• Similar organisms found in very remote, specific
locations today.
• Ancient climates.
• Ocean floor evidence.
Ocean Floor Evidence
• Three types of movement create distinct
features that support the idea that the
crust of the Earth is moving.
– 1. Convergent Plate Boundaries- 2 pieces of
the crust come together
– 2. Divergent Plate Boundaries- 2 pieces of the
crust spread apart
– 3. Transform Boundaries- 2 pieces of the
crust slide past each other
Convergent Boundary
• Ocean Plate – Ocean Plate- ridge formed
Convergent Boundary
• Ocean Plate – Continental Plate- trench formed
on ocean side and volcanic mountains on
continent as the OCEAN CRUST slides under
the CONTINENT
Divergent Boundary
• Two plates spread apart and magma comes up
between them, forming a ridge.
Transform Boundary
• 2 plates slide against each other, causes
earthquakes.
It’s Gettin’ Hot in H’re…The
Volcano That Is
• Three types of volcanoes, depending on the top
of rock that they spew out.
Magma Composition
Composition
Silica
Viscosity
Content
Gas
Tendecy to
Volcanic
Content Form
Landform
Pyroclastics
(ejected rock
fragments)
Basaltic
50%
Little
1-2%
Least
Shield Volcanoes
Basalt Plateaus
Cinder Cones
Andesitic
60%
Medium
3-4%
Intermediate
Composite Cones
Rhyolitic
70%
Greatest
4-6%
Greatest
Pyroclastic Flows
Volcanic Domes
Basaltic Volcanoes
Shield Volcano-Hawaii
Basalt Plateau-Washington
Cinder Cone-Oregon
Andesic Volcanoes
Composite Cone-Alaska
Rhyolitic Volcanoes
Volcanic Dome-California
Pyroclastic Flow
Mt. St. Helens BEFORE eruption
Mt. St. Helen AFTER eruption
Shake ‘N’ Bake…It’s an
Earthquake!
• Elastic Rebound Hypothesis- earthquakes
happen because a rock deforms as it
moves and eventually snaps back to
position.
– Focus- the place where the earthquake starts
– Epicenter-the place on the Earth’s surface
right above the focus
– Fault- a break or crack in the Earth’s surface
and mantle where it has moved.
Richter Scale
• Measures intensity of an earthquake by
measuring the amplitude, or height of the
seismic waves that it creates.
Mercalli Scale
• Measures the intensity of an earthquake by how
much damage is caused.
Let’s ROCK ‘N’ Roll!
• The Earth is made of
three types of rock,
identified by how they
form.
– 1. Igneous rock
– 2. Sedimentary rock
– 3. Metamorphic Rock
Igneous Rock
• Made when lava at the surface and magma in
the crust when it cools.
– Cools slowly, usually underground =
form
BIG crystals
• Called plutonic or intrusive
• Example= granite
– Cools quickly, usually at the surface) = small crystals
form
• Called volcanic or extrusive
• Example= Obsidian
Sedimentary Rocks
• Formed because processes weather rocks
(like wind and flowing water) or when
rocks are buried under pressure, usually at
the surface.
– Examples= limestone and shale
Metamorphic Rocks
• Formed when there is a HUGE change in
pressure and temperature
– Example = marble
Rock Cycle
Whether It’s Weather or Climate.
1. The past few days have been rainy.
2. Winter was cold this year.
3. For the past 50 years, we’ve had warm falls.
4. April is supposed to be dry in Illinois this year.
5. We get snow in the winter.
6. It is always cooler in Canada than in Chicago.
7. The lee side of the mountain does not get much rain.
Weather/Climate, What’s The
Difference Anyway?
• Weather-
• Climate-
The Sun is a Mass of Incandescent
Gas…A Gigantic Nuclear Furnace
That Affects Our Weather and
Climate
• The Earth gets its heat energy from the
solar radiation that enters through the
atmosphere.
– Seasons change because during different
times of the year, different parts of the Earth
are tilted towards the sun.
– On a day to day basis, clouds may block
some of the sun’s radiation.
Tilt of the Earth
The Motion of the Ocean…Affects
Weather and Climate
• Currents from warmer waters can make an area
warmer.
• Currents from cooler waters can make an area
cooler.
Global Winds…More than a Bunch
of Hot Air
• Global Winds act to balance out the
temperatures on the Earth by bringing warm air
to higher latitudes (further from the equator) and
cool air to the lower latitudes (closer to the
equator).
PSAE: The FINAL Earth Science
Review…Can You Dig It?
1. Continental Crust is found on top of
Ocean Crust because:
A . Oceanic Crust is thicker, so it must be on the
bottom.
B. Oceanic Crust is older, so it must be on the
bottom.
C. Oceanic Crust is denser, so it must be on the
bottom.
D. Oceanic Crust is made of mostly igneous
rock, so it must be on the bottom.
PSAE: The FINAL Earth Science
Review…Can You Dig It?
2. What happens at a subduction zone where an
oceanic plate and a continental plate collide?
A. The denser continental plate subducts under
the oceanic plate causing seafloor spreading.
B. The plates will transform and cause an
earthquake with a well-defined focus.
C. Oceanic and continental plates cannot collide,
because they are in different regions.
D. The denser oceanic plate subducts under the
continental plate and forms a trench along a
continent.
PSAE: The FINAL Earth Science
Review…Can You Dig It?
3. At which of the plate boundaries is an
earthquake most common?
A. Divergent
B. Convergent
C. Transform
D. Intraplate
PSAE: The FINAL Earth Science
Review…Can You Dig It?
4. Motion is caused by a force. The force behind
plate tectonics can be best explained by the fact
that the Earth’s plates are in motion due to:
A. conduction of long range waves of uv
radiation.
B. transfer of energy from the cool ocean
currents to the warm land masses.
C. convection currents in the Earth’s mantle.
D. cells of cooling magma that rise to the surface
and push the plates around.
PSAE: The FINAL Earth Science
Review…Can You Dig It?
5. A certain igneous rock called obsidion is
broken down by weathering and deposited
as sediments. What is most likely the next
rock type to form from the sediment?
A. It will remain igneous.
B. It will become sedimentary rock.
C. It will become metamorphic rock.
D. It will melt and become a component of
magma.
PSAE: The FINAL Earth Science
Review…Can You Dig It?
6. Why does seafloor spreading help to support
the concept of continental drift?
A. new ocean crust is formed, causing there to
be more ocean
B. two plates are moving apart and pushing the
plates around them
C. ridges are formed
D. sea animals avoid these areas because they
are afraid that they will drift away from the
continent that they are most closely associated
with