BCLN SCIENCE 10 – Rev May - 2015
Unit 10 ~ Learning Guide
Name:
INSTRUCTIONS
Complete the following practice questions as you work through the related lessons.
You are required to have this package completed BEFORE you write your unit test.
Do your best and ask questions about anything that you don't understand BEFORE you
write the unit test.
10.1 NOTES: Evidence For Continental Drift
General Information
Early maps of the world caused Wegener to propose the continental drift theory.
•
The continents looked as though they might fit together like
.
o The
actually fit together even better.
•
the original supercontinent was named
•
Wegener also realized that other evidence also supported his theory:
o There were matching
and rocks
on different continents.
o There were matching
Mesosaurus, on different continents.
by Wegener.
o There was evidence of different
having previously
existed Paleoglaciation studies showed evidence of glaciers on now-warm
continents. On Antarctica, scientists found fossil ferns and coal beds from
ancient swamps, proving the now-frozen continent had once had a warm
climate.
Page 1 of 16
BCLN SCIENCE 10 – Rev May - 2015
How Can Continents Move?
Wegener’s theory for continental drift did not explain how entire continents could
change locations.
•
New
the
•
It was also noted that
in certain patterns along the edges of tectonic plates.
•
Mapping of the ocean floor also revealed the
a long mountain range running down the middle of the Atlantic Ocean.
allowed scientists to measure
of Earth’s tectonic plates.
appear
,
o The rocks
to the Mid-Atlantic Ridge were found to be the
youngest. The further away from the ridge, the
the rocks were.
o Sediments, which accumulate gradually over time, were
near the Mid-Atlantic Ridge and gradually became
farther away from the ridge.
o Another surprising discovery came from studies of paleomagnetism (the magnetic
properties of ancient rocks). Scientists discovered that the Earth's magnetic field
has
many times over the past 10 million years.
Iron-based rocks record of the
as it existed
at the time those rocks were formed. In paleomagnetic studies of the Mid-Atlantic
Ridge, scientists found that these patterns of magnetic striping on either side of
the ridge are like
of each other.
Page 2 of 16
BCLN SCIENCE 10 – Rev May - 2015
Spreading of the Sea Floor
Hess suggested that magma rose to form new rock at certain places:
•
Magma (melted rock) rises and falls just like any warm and cold liquids creating
currents called
.
•
The rising magma forms
.
where it breaks through Earth’s crust.
o The ridge spreads to both sides, as the older rock is pushed aside by the
.
Wilson then unified the ideas of Wegener and Hess into the plate tectonic theory
including explaining that:
•
Continental drift occurs because
in the molten
magma push the tectonic plates in various directions. The plates
, move past each other, or
, depending
on the direction they are moved by the convection currents.
.
Page 3 of 16
BCLN SCIENCE 10 – Rev May - 2015
10.1 PRACTICE: Evidence For Continental Drift
1. Complete the word search and practice quiz.
2. Identify and discuss four lines of evidence that lead to Alfred Wegener to propose
the Continental Drift Theory. (4 marks)
3. Wegener's theory was not immediately accepted as he could not explain how
continents could move.
a. Identify and explain what modern scientists believe to be the driving force
behind plate tectonic movement. (2 marks)
b. Identify and discuss three modern lines of evidence that support the idea
that tectonic plates are moving. (3 marks)
4. Complete Check your Understanding 10.1
Page 4 of 16
BCLN SCIENCE 10 – Rev May - 2015
10.2 NOTES: Features Of Plate Tectonics
General Information
Earth is over
•
and has
distinct layers.
These layers are the crust, mantle (upper and lower), outer core, and inner core.
(granite on
o Crust:
land, basalt in oceans)
except
o Mantle:
for upper mantle being able to flow like “thick toothpaste”
o Outer core:
o Inner core:
, at tremendous
and
Tectonic plates make up the
, which floats on the
.
•
The lithosphere is the
.
•
The asthenosphere is the
.
o Heat which keeps the asthenosphere molten comes from
.
Page 5 of 16
BCLN SCIENCE 10 – Rev May - 2015
The tectonic plates are floating on the semi-liquid magma of the asthenosphere.
Convection currents in the asthenosphere cause the tectonic plates to move.
•
As magma is heated in the asthenosphere,
•
Rising magma can reach the surface at
(in the oceans) or
(on land).
o The magma cools when it reaches the surface, solidifies, and is pushed
aside as new magma pushes from below. This is called
.
Tectonic plates are all moving at the same time.
•
There are
ones.
•
Where continental and oceanic plates collide,
occurs.
o the denser oceanic plate
the lighter
continental plate.
! by “
” the rest of the plate follows
•
Large earthquakes and volcanoes are found in
.
large tectonic plates and
smaller
Plate Interactions
A
is an area where two plates are in contact.
The way the plates interact is based on the type of plate and the direction the plates are
moving relative to each other. There are 3 types of plate boundaries:
•
plate boundaries – areas where plates are spreading apart
•
plate boundaries – areas where plates meet
•
plate boundaries – areas where plates move past each
other
Page 6 of 16
BCLN SCIENCE 10 – Rev May - 2015
1. Divergent plate boundaries are areas where plates
are
.
•
and
are examples.
• The
is the longest mountain range on Earth.
2. Convergent plate boundaries are areas where plates
a.
• The oceanic plate
under the continental plate,
forming a
.
•
volcanoes can form from
magma seeping to the
surface.
Page 7 of 16
.
plate convergence
BCLN SCIENCE 10 – Rev May - 2015
•
This is how the volcanic belt of the
has formed.
•
Mountain ranges like the
range also form from the collision.
•
can
occur
when
subduction, ridge push, and slab pull stall.
b.
plate convergence
•
The cooler, denser plate will
under the less dense plate.
•
Convergence may produce
a
,
such as those found in
, Indonesia, and Alaska’s Aleutian Islands.
c.
plate convergence
•
Since both are continental
plates, their
.
•
As they collide, their edges
fold and crumple, forming
.
•
The
are the world’s youngest (and tallest)
mountain range, formed as Asia and Africa plates collided 40
million years ago.
•
They are still
.
Page 8 of 16
BCLN SCIENCE 10 – Rev May - 2015
3.
plate boundaries are where
plates move past each other.
•
Usually
•
Since rock slides past rock,
or
are
found
near
form.
•
and faults are
very common.
Earthquakes often form from
.
•
This accounts for
•
The
of Vancouver Island has many earthquakes.
o Large earthquakes hit this region every
.
of all earthquakes.
plate boundary west
Describing Earthquakes
Earthquakes are very difficult to predict.
•
Scientists understand
predict their
•
Their
periods of time.
•
What we do understand has helped us to
.
•
The
released.
of the earthquake is where the pressure is finally
•
The
is the point on the surface directly above the focus.
they happen, but it is very difficult to
.
build-up happens underground, over very long
Page 9 of 16
BCLN SCIENCE 10 – Rev May - 2015
•
Earthquakes occur at
plates involved.
o Earthquakes at the
, depending on the
tend to cause
.
Earthquakes produce
waves.
•
is the study of these waves.
•
These waves reveal the
an earthquake.
•
They also help us learn about the composition and distances of the
.
•
Types of earthquake waves include:
•
Seismic waves behave
of
o Knowing this, scientists can learn about earthquakes and Earth’s interior.
Seismometers are
Page 10 of 16
BCLN SCIENCE 10 – Rev May - 2015
•
Early seismometers just measured whether the
•
Some seismometers measure horizontal movement, others vertical movement.
o A
is produced, showing
and earthquake started, how
it lasted and the
o
increase in magnitude =
! A magnitude 6 earthquake is
than a magnitude 4.
o Since
seismic
waves
travel
.
Page 11 of 16
.
stronger
more powerful
at
different
graph can
speeds,
a
BCLN SCIENCE 10 – Rev May - 2015
Volcanoes
The movement of tectonic plates causes volcano formation. There are 3 key types of
volcanoes:
1.
•
•
•
– found along plate boundaries
Layers of ash and thick lava form a
.
As magma reaches the
surface, it cools, hardens and
.
Pressure builds; eventually,
.
– these are not found at plate boundaries
2.
but instead form over hot spots.
•
magma/lava flows out from a hot spot and forms a
.
•
are an example
of a chain of shield volcanoes.
3.
•
These
are
– occur along long cracks in the lithosphere
, but they release
of lava
Mount St. Helens pictured below is a composite volcano.
Page 12 of 16
BCLN SCIENCE 10 – Rev May - 2015
10.2 PRACTICE: Features Of Plate Tectonics
Instructions:
1. Complete the Plate Interactions Challenge.
Attach it here.
Do a screenshot of your result.
2. Complete the 10.2 Check Your Understanding.
3. Access and complete Virtual Earthquake (LAB). You may answer the questions
in the space provided below however, you will need to access the earthquake
simulation from the website.
a. Read all intro information and then state which region you chose:
b. Record the time at each station in the table below (also remember to
type it in the boxes on the webpage or you will not be able to continue
on).
Station Number
Time btw S and P waves (sec)
1
2
3
c. Find and record the distance at each station by reading it from the
bottom of the S-P graph. (record on website also)
Station Number
S-P Interval
Epicenter Distance
(same as above)
(km)
1
2
3
d. Click on “View True Epicenter” and record the actual measurements in
the table below:
Station Number
S-P Interval
(same as above)
1
2
Page 13 of 16
Epicenter Distance
(km)
BCLN SCIENCE 10 – Rev May - 2015
3
e. Name the closest town to your epicenter:
This portion of the lab is all that is required however,
you may continue on to find the magnitude for your own interests.
2. Compare and contrast primary waves, secondary waves and surface waves
(also known as Love waves). (6 marks)
3. The Richter scale is used to describe the magnitude (strength/size) of an
Earthquake:
a. Each whole number increase on the Richter scale represents a
increase in earthquake strength/size. (1 mark)
b. How many times stronger/bigger is a magnitude 8 earthquake
compared to a magnitude 2 earthquake? (1 mark)
Page 14 of 16
BCLN SCIENCE 10 – Rev May - 2015
4. P waves travel faster than S waves, thus the S-P time interval can be used to
determine how
the focus of an
earthquake is from a seismometer. The larger the S-P interval the
the focus occurred from the
seismometer. (2 marks)
5. Compare and contrast composite volcanoes, shield volcanoes and rift
eruptions. (6 marks)
6. Complete the Unit 10 Review.
Page 15 of 16
BCLN SCIENCE 10 – Rev May - 2015
Unit 10 Learning Guide Answer Key
10.1 – Evidence for Continental Drift
2) directly from online notes, 3) a. Discuss how the new crust conveyor belt works, b.
discuss magnetic striping, hot spots and sea floor spreading.
10.2 – Features of Plate Tectonics
1) a-b. answers directly from activity, c. Continental crust since it is less dense, 2) a.
Oceanic crust since it is more dense, b. trench, c. convergent, d. composite and explain,
e. answers will vary, 3) a ridge, b. divergent, c. new crust formation, d. answers will
vary, 4) a. trench, b, convergent, c. more dense, volcanos, d. answers will vary, 5)
answers will vary, 6-7) directly from notes, 8)b. 1,000,000x, 9) far away, further, 10)
directly from the notes.
Page 16 of 16