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UNIT 9: DYNAMIC EARTH

PACKET 10: PLATE TECTONICS, EARTHQUAKES &
VOLCANOES
“I feel the
Earth move under
my feet” p.s. I’m
Geno
EARTH SCIENCE
MS. GILL
NOTE PACKET #10
NAME:_____________________ CLASS :____ DATE:______
________
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
Vocabulary:
Asthenosphere
contact Metamorphism
Continental crust
Convergent
Crust
Density
Divergent
Down-warping
Dynamic Equilibrium
Earthquake epicenters
Earthquake magnitude
Earthquakes
Equilibrium
Faulting
Folding
Heat engines
Heat flow
Hot spots
Hydrosphere
Inner core
Island arcs
Lithospheric plates
Magma
Magnetic patterns
Mantle
Mid-ocean ridge
Oceanic crust
Outer core
Plate
Plate tectonics
Radioactive materials
Rate
Refraction
Residual heat
Rock cycle
seismic Waves
Static Equilibrium
Subduction zone
Tectonic forces
Transform
Trenches
Tsunamis
Velocity
Volcanoes
Page # ____
Unit 9: Dynamic Earth
I.
Earth Science - Ms. Gill
Note Packet #10
Earth’s Interior:
Four Layers (see page 10 of Ref Tables)
-INNER CORE: solid, dense, 6,000º C, Iron and
Nickel
-OUTER CORE : Liquid, dense, 3,700º-5,500ºC
(increases with depth), Iron and Nickel
- MANTLE: Solid, minerals rich in Fe, Si, Ma, 1,500º
- 3,200º C
-CRUST: upper layer, rigid, lighter rock, <1,000ºC
Some terms to know:
- _______________________: Upper layer of
the mantle, may act in a semi-fluid (plastic) manner
- _________________: (Mohorovic Discontinuity):
The boundary between the mantle and the crust
- _______________________: Consists of the
crust and the rigid upper mantle
Where is the crust thickest?
______________________________
Where is the crust thinnest?
_______________________________
Why is the core so hot?
-Still retains heat from original formation.
-Radioactive materials releasing energy as they
decay.
-Increased pressure from above
What happens to rock density, going from the crust
to the core? ______________________
What happens to temperature, going from the crust
to the core? ______________________
What happens to pressure, going from the crust to
the core? ________________________
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
II. Mantle Convection Cells:
A convection cell is a stream of heated material that is moving because of ___________
_________________. These convection cells exist in the part of the mantle called the
_______________________.
The two sources of this heat are:
1. Residual (leftover) heat from the __________________ of the Earth
2. Heat generated from _________________________________ from the core of the earth
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
III. The Theory of Plate Tectonics:
The Earth’s lithosphere is made of a number of solid pieces , called ____________ which move in
relation to each other. These plates are “riding” on a more “plastic molten” layer below. This layer is
called the ASTHENOSPHERE.
The evidence shows that approximately _______ million years ago, the major continents
were_______________, and since that time they have been _________________.
A. Theory of Continental Drift:
Proposed by ALFRED WEGENER in 1915. It stated that the Earth’s continents separated and collided as they
have moved over the surface of the Earth for millions of years.
Wegener’s evidence for his theory:
1. When you line up _____________________ and ________________________ they appear to fit like
a puzzle.
2. FOSSILS species have been
found on widely separated parts of the Earth.
3. SOUTH AMERICA and AFRICA have a good match of
ancient continental rocks and tectonic ____________ and ___________ structures.
4. Some mountain chains appear to be continuous from CONTINENT to CONTINENT
5. Evidence of _________________ climates. Example: Finding coal beds which indicate tropical climates
6. Rocks of the ocean basins are _________________________ then continental rocks.
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
Ocean Sea Floor Spreading:
Further evidence of horizontal movement of Earth’s crust was accidently acquired during the WWII
Submarine battles in the Atlantic Ocean helped scientists to begin to explain the phenomenal force that
could separate a continent into two pieces.
The use of technology such as Sonar Imagining and Magnetometers discovered interesting characteristics
about the hidden ocean floor:
A. The ocean floor has a system of submerged mountain ranges called
____________________________________
B. There are deep trenches that line the coast of the continents.
C. The ocean floor is magnetic and has parallel stripes of reversed polarities.
Using this information scientist posed the theory of
Sea floor Spreading
- Material from deep within the Earth comes to the surface at the ________________ where is spreads
apart to make __________ ________________ _____. This pushes old ocean crust outward, toward
the trenches, where ocean crust is forced underneath continental crust; this process is called subduction.
D. The two major pieces of evidence are for seafloor
spreading are:
1. ___________________________________________
2. __________________________________________
-You may not know this but, Earth’s magnetic field has
reversed several times in the last 4.6 billion years! Yes, in
ancient times North was South and South was North. If you
had a compass it would point the opposite way during periods
of reversed polarity. The molten lava that spews out of the
Mid-Ocean ridge, contains magnetic minerals that align with
our magnetic earth. When igneous rock solidifies from this
lava it records the magnetic alignment of that time period.
This forms a permanent record of the magnetic field of the
Earth at that time the rock formed. Therefore, rocks found
farther from the ridges have a REVERSED magnetic polarity.
As you move out from the ridge toward the continental shore,
you encounter parallel stripes of normal and reversed
MAGNETISM. This pattern is a mirror image on the other
side of the ridge. This pattern preserves the record of many
reversals of the Earth’s magnetic field.
- The DARK & DENSE (basaltic) igneous rocks of the crust near the ocean ridges are
covered with only a thin layer of sedimentary rock. This is evidence that the earth’s crust
is very young near the ridges. Since, if they were old sedimentary deposits would be
thicker. Deep sea drill confirms this hypothesis.
-Due to seafloor spreading the Earth’s crust is very YOUNG near the ridges. The oldest
parts of the ocean crust are found far from the MID OCEANIC ridges and near the
CONTINENTS.
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
PLATE MOTIONS:
Lithospheric plates ________________ in size and are made up of a combination of
_______________________ crust and _____________________________ crust.
Three kinds of plate motion occur at plate boundaries:
1.____________________ 2. ____________________ 3. ______________________
1) There are three types of CONVERGENT boundaries: Ocean colliding with Continent, Ocean colliding
with Ocean and Continent colliding with Continent
Ocean colliding with Continent
1a. When ocean collides with continent the ______________
ocean plate dives down under or ____________ into the
mantle forming a ________________ ________ and a
Volcanic Mountain range on the continent.
Example: The Andes Mountains in South America form due
to the collision between the Nazca Plate and the S.
American Plate.
Ocean colliding with Ocean
1b. When two ocean plates converge
the ____________,
_______________ ocean plate will
_______________________
forming an ___________________
____________. Example: Indonesian,
Philippines, Japan & Aleutians Islands
formed via this process
Continent colliding with Continent
1c. When two continental plates converge the edges of _____________ are
crumpled up forming __________________ _____________________.
Example: Himalayan Mountains formed because the Eurasian Plate collide
with the Indian Plate (see picture on the right)
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
2) Divergent boundaries: Two plates are moving away from each other due to rising convection currents
in the mantle forming a ridge of volcanic mountains.
At _______________ plate boundaries, the plates move __________ and ___________
flows up forming parallel ridges made of ______ ______________ _____________
Example: Mid-Atlantic Ridge formed because the North American Plate is moving away
from the Eurasian Plate causing seafloor spreading
3. At transform plate boundaries, the plates move
________________ each other causing shallow
________________ ______________________.
Example: San Adreas Fault
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
Directions: Organize the word in the word bank into the concept map provided below. Use all terms.
Continental-Continental
Divergent
Convergent
Continental-Oceanic
Transform
Aleutian Islands
Oceanic-Oceanic
Types of Plate Boundaries
San Andreas Fault
Subduction Zone/Trench (2)
Tonga Trench
Mid Atlantic Ridge
Mountain Building
Shallow Earthquakes
Himalayan Mountains
Rift Valley
Sea Floor Spreading
Volcanic Arc
Island Arc
Ridge
Folded Faulted Tilted Rock
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
Practice Questions: Part 1
1) Below is a map and profile view of the Mid Atlantic Ridge along a line drawn between North America and
Africa. Label the profile with: Mid-Atlantic Ridge, youngest ocean crust, oldest ocean crust, continental
crust, continental rise, and mantle convection currents. Use your reference table to draw and label
appropriate plate boundary symbol along the Mid- Atlantic ridge on the map.
Map A
Profile A
2) Below is a profile view of the white line drawn through the west side of South America in Map B. Draw a
line at sea level on the profile. Label the profile with: Andes Mountains, subduction zone, trench, youngest
ocean crust, oldest ocean crust, continental crust and mantle convection currents. Use your reference table
to draw and label appropriate plate boundary symbol along the coast of South America.
Map B
Profile B
South
America
3) Below is a map and profile view of the East Coast of North America. Label North America, the continental
rise, the abyssal plain and the mantle convection currents. Is there a plate boundary along this profile? ____
Map C
Profile C
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
4) Below is a map and profile of the Aleutian Islands in Alaska. Label the continental shelf, volcanic island arc
ocean trench, Pacific Ocean, abyssal plain and drawn in the convection currents. Use your reference table to
draw and label appropriate plate boundary symbol along the Aleutian Islands.
Map D
Profile D
This profile includes the Bering Sea. Do you think that the profiled section of the Bering Sea is made of
Continental Crust or Oceanic Crust?________________________
5) Below is a profile view of the white line drawn through South America and Africa in Map A. Draw a line at
sea level on the profile. Label the profile with: Mid-Atlantic Ridge, subduction zone, trench, youngest ocean
crust, oldest ocean crust, continental crust and mantle convection currents, continental mountain ranges.
Profile E:
Map E
A
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
Part 2: How far will your plate move? The United Kingdom is on the Eurasian Plate, which moves at around
3 cm per year. This is about as fast as your fingernails grow!
1) Which direction is the Eurasian Plate moving?
________________________
2) If the plate is moving at 3 cm per year, how far
will it have moved in the next 100 (one hundred)
years? ___________ The next 1,000 (one
thousand) years?_________ The next 1,000,000
(one million) years? ____________ The next
1,000,000,000 (one billion) years? ________
Part 3: Global Tectonic Plates
Reading, Interpreting and Understanding the Map of the Earth's Lithospheric
(Tectonic) Plates
Base your answers to the following fill-in questions on the Tectonic Plates map which appears on the back
of this sheet, or from page 5 in the Earth Science Reference Tables.
1. Dark (thick) ruled lines on the Tectonic Plates map indicate the location of which type of plate
boundary? _____________________
2. Light (thin) ruled lines on the Tectonic Plates map indicate the location of which types of plate
boundaries?______________________________________
3.
Which feature is characteristic and diagnostic of most convergent plate boundaries?
____________________ ________
4. Which feature is characteristic and diagnostic of most divergent plate boundaries?
_______________________________
5.
Which plate is framed entirely by convergent plate boundaries?________________________
6. The boundary between the Australian and Pacific Plates is: ______________________________
7. The distance between South America and Africa is ________________________________
8. The distance between India and Eurasia is ______________________________________
9. What is the name of the boundary between the African and Antarctic Plate? _________________
10. The distance between North America and Africa is ___________________
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
Hot Spots:
Places on the Earth’s surface where plumes of ________________ are rising up from the mantle not
located along ________________ ______________ ________________. As a plate passes over a hot
spot, a __________ ___ ___________ _______________ forms. The only mountain that
_______________ ______________ is the mountain located directly over the __________
_____________.
Practice: The following diagrams illustrate the relative motion of the Pacific Plate shown through the
appearance of the Hawaiian islands. Currently there is a mantle hot spot where the islands have formed,
constantly adding new rock to the island over the hot spot through time.
Diagram 1. Plate Motion
Diagram 2. Rock Age vs. Distance
1) Using the rate of change formula, find the distance in kilometers that the Pacific Plate moves on average
per every million years using the islands of Maui and Nihea. Write the formula and solve with units:
2) If an island was located 700 kilometers from Hawaii, what would be the expected age
of the rocks of that island? (hint: use the graph) __________________________
3) What evidence is there on the graph that Hawaii is currently over the hot spot?
______________________________________________________________________________
____________________________________________________
4) Which island was over the hot spot about 5.0 million years ago? ________________
5) According to the graph, which island is the oldest? How do you know?
______________________________________________________________________________
____________________________________________________
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
IX. Volcanoes
A ______________________ is both the opening in the Earth’s crust through which molten rock flows,
and the landform that develops around it.
Where volcanoes form:
1. At ____________________________________: Subducted plate material melts to form new magma
Hot magma is less dense than surrounding rock, so it rises. Magma reaches the surface to form volcanoes
2. At _______________________________________________: Magma forms at mid-ocean ridges.
Iceland formed as the result of volcanoes along the Mid-Atlantic Ridge.
3. At ___________________________: Caused by plumes of hot material from deep within the mantle.
Hawaiian Islands were formed in this way.As plate moves over hot spot, new islands form.
Page # ____
Unit 9: Dynamic Earth
II.
Earth Science - Ms. Gill
Note Packet #10
LOCAL EVIDENCE OF CRUSTAL MOTIONS:
A. ________________________ & _________________________wears down the Earth’s
crust.
_________________________
____________________________ creates new mountains.
B. Sedimentary beds are deposited as _________________________
_______________ or
_______________________________
C. Evidence of motions within the Earth’s crust is indicated by:
(label the diagrams)
1. ______________________
2. _____________________
3. _____________________
D. _______________________________________
provide direct evidence of crustal
movement. ____________________
_________________ and ________________
__________________are two changes that can be observed after an earthquake.
E. ______________________ ____________________ are used in mapping surveys and
indicate exact positions and elevations. Changes in ______________________ of benchmarks are
evidence that the land is either _________________________ or _______________________.
F. Displaced fossils found in mountains have 2 interpretations:
1. Higher sea levels ___________________ mountains
2. Rocks were _________________ from a previous ocean bottom
G. _________________________________ is the RISING OF THE CRUST
_________________________________is the SINKING OF THE CRUST
Page # ____
Unit 9: Dynamic Earth
II.
Earth Science - Ms. Gill
Note Packet #10
EARTHQUAKES:
A. Two processes that cause earthquakes:
1. The movement of _________________________ inside ___________________________.
2. _______________________ is the movement of rock along a surface where the rocks are broken.
B. ___________________ movement of the crust over long periods of time builds _______________
within the rocks. Increased pressure causes the ___________________ ______________________
to break creating a _________________________. When faulting occurs energy radiates through the
Earth as __________________ ________________ that cause the ground to ________________.
The distribution of earthquakes is primarily along _________________________________________
There are three types of faults:
(label the diagrams below)
Fault #1___________________________
Fault #2____________________________
Fault #3_______________________
Page # ____
Unit 9: Dynamic Earth
III.
Earth Science - Ms. Gill
Note Packet #10
MEASURING THE EARTHQUAKES:
A. There are 2 scales to measure earthquakes
1.
________________________________
2. ____________________________________
B. _________________________________ scale is based upon the observations of people and the
damage caused. It measures the ____________________ of the earthquake from ______ to ______
C. _________________________ uses the seismograph to determine the _____________________
Magnitude is the total _______________________ released by the earthquake.
It’s numerical scale is _________ to _________. Each numeric step represents a _______ increase.
What Controls the Level of Shaking?
______________________________ : More energy released
_______________________________: Shaking decays with distance
_______________________________: Amplify the shaking
Effects of Earthquakes:
1. Ground Shaking
2. Surface Faulting
3. Liquifaction:________________________________________________________
4. Landslides
5. Fires
6. Tsunamis:__________________________________________________________
7. Seismic Waves:__________________________________________________________
Will California eventually fall into the ocean??? _______
Page # ____
Unit 9: Dynamic Earth
III.
Earth Science - Ms. Gill
Note Packet #10
PARTS OF THE EARTHQUAKE:
A. The place underground where the break or fault occurs is the
_____________ of the quake
The _________________________ is the location along the
surface of the earth just above the focus where the quake is felt most strongly
B. The two most important energy waves are:
____________________________________________
____________________________________________
QuickTime™ and a
d eco mpres sor
are nee ded to s ee this picture.
Qu ic kTime ™ a nd a
d ec omp res so r
a re n ee de d to se e t his p ic tu re.
Characteristics of P and S waves: (you need to memorize these)
C. Characteristics of P-waves (primary)
-Faster in speed
-Arrives first (because it’s faster)
-Travels through both solids and fluids
-Compressional wave motion (particle motion is
parallel to wave direction)
D.
Characteristics of S-waves (secondary)
-Slower than p-waves
-Arrives after the p-wave (because it’s slower)
-Only can travel through solids (not liquids or gases)
-Transverse wave motion (particle motion is perpendicular to wave direction)
E. Both S and P waves travel FASTER through
____________________ material.
(remember domino demo)
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
V. Finding the Epicenter:
A. The seismograph records the __________________________ and
________________________________________________________________________________
(Use the chard on page 11 of your reference table)
B. The step for calculating your distance fro the epicenter
1) Subtract arrival time of P from arrival time of S
Show subtraction here:
01:20:00
01:10:00
2) Mark the interval on Y-axis
3) Slide marks to match P & S curve
Find the best
fit on the curve
and read the
distance below
Mark off the
Mark off the
difference in arrival
time of S and Pdifference in arrival
time
waves on a piece
of of S and P
waves on a piece of
paper
paper
4) Follow down to x-axis and read distance Note: Do not forget the (x 103) & Units are in Kilometers
Subtraction time can be tricky!!! Do NOT use a calculator: practice these problems
A.
B.
C.
D
02:30:54
-01:26:14
11:45:15
- 09:37:57
06:02:53
- 03:34:22
10:15:12
- 9:39:48
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
Practice Questions:
1. The arrival of the P-wave is 12:03:00 The arrival of an S-wave is 12:07:00
The difference is __________________________
How far is this earthquake from this seismic station? ________________________
2. The arrival time of the P-wave is 2:05:00 The arrival time of the S-wave is 2:08:00
The difference is: ________________________________
How far is this earthquake from the seismic station? __________________________
3. If the difference in arrival time between P and S waves is 2min. 35 sec. What is the distance
from the earthquake to the seismograph station? ___________________________
4. How long does it take for a P-wave to travel from the focus of an earthquake to a seismograph station
2,000 km. away? _______________________________________
How long will the S-wave take to travel to this same station? ___________________
5. What is the difference in arrival time between P and S waves for an earthquake that is
5,000 kilometers away from the seismograph station? __________________________
VII. THE ORIGIN TIME OF AN EARTHQUAKE:
A. An earthquake wave detected at __________________________ times by observers at
____________________ distances from the epicenter.
B. To find the origin time seismologists need to know:
1. _____________________________________________________________________
2. _____________________________________________________________________
Example:
A seismograph recording station located 5,700 kilometers from an epicenter.
It receives a P-wave at 2:45 P.M. At what time did the earthquake actually occur at the epicenter?
Travel Time:____________________ Origin Time:_________________
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
VIII. THE LAYERS OF THE EARTH:
A. The crusts thickness ______________________.
It is __________________ under the oceans
and ____________________ under the continents.
Continental crust is mostly ____________, __________ density & _________________________
The ocean basins are mostly ______________ and ________________ or __________________
B. Inferred characteristics of the Earth’s Interior:
1. Studying the ____________________________ of
_____________________ _________________
allows us to make inferences about the structure
and composition of the Earth’s interior.
2. The _______________________ of a seismic wave changes with the ________________ of
the material it travels through. Waves are also ___________________________________
as they travel through materials with different densities.
We know that P-waves can be transmitted through ___________ __________ & ___________
S-Waves can be transmitted through ONLY
________________
3. Earth Quake Shadow Zones:
When an earthquake occurs both ____________ are received from most of the earth.
Opposite sides of the earth where the epicenter is, receives ____ but NO _______ because
S-waves cannot penetrate the ________________ outer core.
______________________ (bending) occurs at the __________________ ( boundaries)
Page # ____
Unit 9: Dynamic Earth
Earth Science - Ms. Gill
Note Packet #10
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