I.
II.
Earth’s Layers
a. Crust: Earth’s outside layer. Made of mostly ________ rock.
i. Continental: ________er; made of mostly granite, forms the continents and
shallow sea beds, floats!
ii. Oceanic: _________er; dense rock such as basalt; lies in ocean basins
b. Mantle:
i. Upper Mantle: Layer under the crust.
1. _______________: rock of the upper mantle
2. _______________: rock under the lithosphere. Made of rock that is
almost at its melting point but is not yet liquid. Has plasticity.
ii. Lower Mantle: made of molten rock (magma)
c. Core
i. Outer Core
1. A ___________ layer; made of mostly iron and nickel
2. Constantly flowing – creating a magnetic field that extends through
planet Earth and even out into space! (Magnetosphere!)
ii. Inner Core
1. The deepest layer of the Earth
2. Extremely hot
3. Also made of iron and nickel but is a __________ layer because of the
___________ from all sides.
Continental Drift
a. Supercontinent - Pangaea
i. Abraham Ortelius, a Dutch mapmaker in the late 1500’s suggested the
continents were once a “supercontinent” that broke up over time.
ii. Alfred Wegener, a German meteorologist, who presented the theory of
_______________________ in 1915.
1. Named the supercontinent ______________
iii. Estimated that over about 200 million years Pangaea broke up into two
supercontinents that then drifted apart.
1. ____________________________: Africa, South America, Australia,
Antarctica, and the subcontinent of India
2. ___________________: North America, Europe, and northern Asia.
b. Evidence:
i. ______________
1. Animals that would not have swam across an ocean but may have
walked across a land bridge
ii. ______________________
1. Appalachian Mountains
iii. __________________________
1. Evidence of glaciers in warm areas, tropical swamps in cold.
iv. Uniformitarianism
III.
1. the same geological process that happen on earth – erosion, mountain
building, etc – happen in the ocean as well
v. Sediment on the floor of the Atlantic Ocean is much thinner than would be
expected – possibly because land was once there - before the continents split
and drifted apart.
vi. Magnetic patterns in rocks on the ocean floor
vii. Mid-Atlantic Ridge
Mapping the Ocean Floor
a. Two-thirds of Earth’s surface is _________________.
b. Mapping the ocean floor is done with ________________________.
i. Boat sends out ping – a high-pitched sound
ii. This sound wave hits the ocean floor and creates an echo
iii. Echo of the ping bounces back to the boat and is caught by a microphone.
iv. The time between releasing the ping and its echo returning are measured by a
machine in order to figure out the distance it has traveled.
v. As the ship travels it continues sending sound waves.
vi. All the different measurements are combined to create a map of depths in the
area the ship traveled over. These maps are called _________________ maps –
meaning they show depth below sea level.
c. Features under the sea
i. Beaches are the edges of the continental crust, also known as the
___________________________ Ocean in this area is shallow and it slopes
downward into the sea.
ii. Continental slope is much steeper than the shelf and continues to the ocean
floor.
1. It is the boundary between the two types of earth’s crust, the
continental and oceanic.
2. The slope is not smooth. There are valleys, gullies and submarine
canyons.
iii. __________________________: made of sediment that eroded from the slope
over time.
iv. _______________________: a flat area at the bottom of the ocean. Is home to
different landforms.
1. Seamount – _______________________________.
2. Guyots - seamounts that are ___________. Their tops have eroded and
are now flat.
3. Deep-sea trenches - narrow valleys in the sea floor.
4. Submarine Volcanoes: volcanoes that have formed on the ocean floor.
If they stay active and grow fast enough, they will become volcanic
islands!
IV.
Plate Tectonics
a. Earth is composed of many tectonic plates – all are different sizes and shapes.
b. Earthquakes occur on the ocean floor – mostly at the boundaries of tectonic plates
i. _____________________________ are instruments used to record data from
earthquakes. This data shows scientists when and where earthquakes have
occurred.
c. Theory of plate tectonics explains that earth’s continents move as part of plates in the
lithosphere
d. ______________________: Has the highest concentration of seismic activity in the
world
e. Three kinds of plate motion:
i. Divergent plate boundaries: plates are moving ___________ and magma is
surfacing.
1. Failed Rift: plates begin to split apart, but do not separate
ii. Convergent plate boundaries: plates are moving ________________________.
1. Continental-continental plate collisions: the pieces of lithosphere get
crumpled, folded, and thrust on top of one another
a. form mountains
2. Oceanic-continental plate subduction: one moves up and on top of the
other, causing the other to sink down into the asthenosphere
a. form deep-sea trenches
3. Oceanic-Oceanic Collisions: One plate sinks slowly sliding beneath the
other
a. may create underwater volcanoes which eventually create
islands
iii. Transform plate boundaries: plates move _____________________________
alongside each other.
1. Form earthquakes
f.
Two forces are the cause of plate motion: _________________ and
____________________
V.
VI.
g. Hot Spots: when volcanic activity occurs within a plate. Hot, molten material rises from
the mantle, melting the crust above it to form volcanoes.
Convection – the transfer of heat by the _______________ or movement of the heated
parts of a liquid or gas.
a. Occurs because of differences in _______________
b. Heat from inner layers of the earth provides energy
c. This heat causes rocks to melt and makes the mantle flow
d. Very _____________ process
i. _______________________
1. Occurs at mid-ocean ridges, which are elevated higher than the rest of
the ocean floor.
2. Heat from rising magma pushes rocks upward from the ridge. As they
cool, they become denser and gravity acts on these raised edges, pulling
them downward and away from one another. This creates room for
more hot magma to well up at the ridge, forming new crust.
ii. _________________________
1. While gravity is pushing on one end of the thick plate, at the other end
cooler, denser crust sinks into the mantle pulling on the rest of the
plate.
Stress On Tectonic Plates
a. _________________: squeezing the rocks of the crust
i. Formed at convergent plate boundaries
b. _________________: pulling the rocks and causing them to stretch or pull apart over a
large area
i. Formed at divergent plate boundaries
c. ________________: pushing the rock of the crust in two opposite directions alongside
one another, resulting in a simple bend or break
i. Formed at transform plate boundaries
a
b
c
d. Faults: a break in the rock along the fault line
i. ______________ wall: rock that leans on the top of the fault line
ii. __________Wall: rock block that is being leaned on
iii. Normal: rocks are _______________________, spreading out
iv. Reverse: rocks are _______________________, one over the other
v. _____________________: rocks bend or break sliding past each other
VII.
Earthquakes
a. _____________: where the earthquake starts. Energy waves travel out from this point
in all directions.
b. _______________________: the point on the surface that is directly above the focus.
c. Seismograph: recordings of an earthquake
i. P waves: pressure waves; primary waves
1. contract and release
ii. S waves: seismic waves; secondary waves
1. move in a s motion