Download QUESTION 1 What are the 4 layers of Earth called? Describe each

QUESTION 1
What are the 4 layers of Earth called?
Describe each layer. What is it made of, and why
is this important?
ANSWER TO QUESTION 17
Seismic waves can be : P, S, L.
P = primary. These waves move side to
side, and travel quickly through rock
material. They’re the “early warning”
waves, and aren’t very damaging to the
surface materials.
S = secondary/shear waves. These waves
lift up at right angles to the surface. They
arrive more slowly, and are more
destructive.
L = love waves. These are the slowest,
and they’re rolling waves. They also
disrupt and cause damage to Earth’s
surface.
QUESTION 2
Find the following (write down their locations)
-3 ocean-continental convergent plate boundaries
(world map)
-2 divergent plate boundaries (world map)
-3 transform faults (BC map)
ANSWER TO QUESTION 1
Crust (outer layer) – solid, brittle, made of
rocks. Thinner under the ocean, thicker
on continents. Broken into plates that
move.
Mantle (2nd layer) – viscous
(plasticky/fluid), made of magma (melted
rock). Heat causes convection currents,
which move the plates.
Outer core – liquid, melted metals
(iron/nickel)
Inner core – solid metal (iron/nickel). At
the core’s temperature, this should be
liquid… but there’s too much pressure, so
the particles cram together.
QUESTION 3
Add plate boundary icons to this map in the
appropriate places.
Use:
ANSWER TO QUESTION 2
Ocean-continent:
- Pacific plate into North American (BC)
- Nazca plate into South American
- Pacific plate into Eurasian (Japan)
Divergent:
- Mid-Atlantic ridge (Atlantic Ocean)
- East Pacific Rise (Pacific Ocean)
- African Rift Valley (East Africa)
Transform:
- Queen Charlotte
- Juan De Fuca
- San Andreas
-
QUESTION 4:
What evidence do we have that plates are
moving?
ANSWER TO QUESTION 3
QUESTION 5:
Which of the following locations would create the
most new crust? Explain!
ANSWER TO QUESTION 4:
-Fossils of non-swimming creatures match
up across oceans. This suggests the ocean
didn’t used to separate these 2
continents.
-Puzzle-piece fit of continents
-Types of rocks match up in bands across
continents
-Evidence of glaciers shows some land
used to be closer to the poles, and also
connected
-Magnetic patterns in rocks on the ocean
floor suggest the sea floor is spreading.
-an ocean trench
-a mid-ocean ridge
-a continental volcano
-a transform fault
QUESTION 6:
What is the difference between these 3 terms:
Ridge, Rift, Trench
ANSWER TO QUESTION 5:
The mid-ocean ridge produces new rock
as the plates pull away from the centre
and expose new magma.
Volcanoes also can produce new crust, but
piled on top of existing crust…
Convergence zones (trenches) destroy
crust.
QUESTION 7:
Why do tectonic plates move?
ANSWER TO QUESTION 6:
-Ridges and Rifts are part of the valleys
created as the Earth’s crust pulls apart at a
divergent plate boundary. A ridge is the
raised edge. The rift is the gap.
-Trenches are valleys created at
convergent plate boundaries. As a dense
ocean plate subducts under another plate,
it creates a valley at the point where the 2
plates are being pulled into the Earth.
QUESTION 8:
What are the 2 main differences between oceanic
and continental crust, and why does it matter?
ANSWER TO QUESTION 7:
Heat from the Earth’s core (from
radioactive decay and leftover from
Earth’s formation) warms magma in the
mantle. This magma becomes less dense,
and rises. Cooler magma sinks to take its
place, creating convection currents.
Plates on top of the rising magma zones
are pushed apart:
QUESTION 9:
Name and label 3 features you would find at this
plate boundary:
ANSWER TO QUESTION 8:
Continental crust is thicker than oceanic
crust (it is thick enough to poke up above
the water level, creating land!)
Oceanic crust is denser than continental
crust.
When they collide, the denser plate will
be dragged down (subducted). This
means that ocean plates dive under
continental ones, and not the other way
around.
QUESTION 10:
What is causing these volcanoes? Explain the
process, and give the term.
ANSWER TO QUESTION 9:
QUESTION 11:
At which kind of plate boundary do we find the
largest volcanoes? Explain why.
ANSWER TO QUESTION 10:
The islands are caused by a hot spot. This
is a location of superheated magma that
rises, and pushes through the ocean crust.
As the crustal plate moves over the hot
spot, several islands form.
QUESTION 12:
How can you tell which volcano in a string of hotspot volcanoes is the oldest?
Ex:
ANSWER TO QUESTION 11:
Big volcanoes are found at convergent
plate boundaries where subduction is
taking place. The volcanoes break
through the plate that’s “on top” as
subducted rock get heated below the
surface. There is lots of heat and
pressure, which makes the eruptions
more powerful.
QUESTION 13:
ANSWER TO QUESTION 12:
The islands on the top left are oldest.
Big reason: if the plate is moving as
shown, it must have passed over the hot
spot, made an island, and kept moving.
The first island to form is the one at the
head of the chain.
(Interesting detail: the oldest island has
been eroded and is smaller)
Put the plate boundaries in order, from MOST
POWERFUL earthquakes to WEAKEST earthquakes.
Explain
QUESTION 14:
Which location, X or Y, has the youngest crust?
ANSWER TO QUESTION 13:
Convergent boundaries build up huge
amounts of pressure & friction under the
Earth. These cause LARGE, DEEP
earthquakes.
Transform faults build up pressure, but
release it regularly as the plates slip past
each other. Earthquakes here are
moderate, and frequent.
Divergent boundaries have the smallest
earthquakes. Plates are not being forced
together.
QUESTION 15:
Where is the Ring of Fire?
What is the it?
ANSWER TO QUESTION 14:
X’s crust is youngest. New crust forms at
the ridge, as magma comes to the surface.
This new rock is pulled away from the
centre ridge. Y is further away, so was laid
down longer ago.
QUESTION 16:
ANSWER TO QUESTION 15:
The Ring of Fire is the rim of the Pacific
Ocean. It includes the west coast of North
& South America, Japan, Indonesia, etc.
Explain the difference between the FOCUS and the
EPICENTRE of an earthquake.
It is a series of subduction zones, and has
high earthquake and volcano activity.
QUESTION 17:
Describe the 3 types of Earthquake (seismic)waves
ANSWER TO QUESTION 16:
The FOCUS is the place where the
earthquake started, usually deeper in the
Earth (X in the diagram).
The EPICENTRE is the spot on Earth’s
surface, directly above the focus. It is the
first place on the surface to feel the
earthquake waves.