Transcript EARTHQUAKES 2014x

Earth
Image:
http://images.cdn.fotopedia.com/flickr7375813928-hd.jpg
Quakes
The Earth Shakes
Image:
http://images.cdn.fotopedia.com/flickr7375813928-hd.jpg
Click on the image
of Earth to see a
National Geographic
video on
earthquakes!
The Earth…Quakes
Earth’s Crust in Motion
Image:
http://images.cdn.fotopedia.com/flickr-7375813928-hd.jpg
Earth’s Crust in Motion
Competency/Objectives
➢ 8:4.B Describe the cause and effect relationship between the
composition of and movement within the Earth’s lithosphere.
✓ Seismic wave velocities of earthquakes & volcanoes to lithospheric
plate boundaries using siesmic data;
✓ Volcanoes formed at mid-ocean ridges, within intra-plate regions,
at island arcs, and along some continentl edges;
✓ Modern distribution of continents to the movement of ltihospheric
plates since the formation of Pangea.
http://www.alicechristie.org/classes/stem/stem2/unit/index.htm
Image: MS Clip Art gallery
Earth’s Crust in Motion
I can…
➢
➢
➢
➢
➢
➢
Describe how stress forces affect rock;
Describe the types of faults, why they form, & where they occur;
Describe how movement along faults changes Earth’s surface;
Describe how the energy of an earthquake travels through Earth;
Identify the different kinds o seismic waves;
Discuss the scales used to measure the strength of earthquakes;
http://www.alicechristie.org/classes/stem/stem2/unit/index.htm
Image: MS Clip Art gallery
http://www.proutyproject.com/
Earth’s Crust in Motion
Bell Ringer…
Riddle me this…
What do you, the lithosphere, and spaghetti have in
common? Give as many similarities as you can!
Image:
http://wallpoper.com/wallpaper/the-riddler-63225
http://rev.seis.sc.edu/definition.html
http://westchesterisms.com/tag/deciding-to-sell/
http://2.bp.blogspot.com/-YJT4PpGTHNw/TycWrU8ZqiI/AAAAAAAAAzI/U-qbaCctZj8/s320/2011-05-16-Spaghetti.jpg
Earth’s Crust in Motion
What do you already know?
Pre-Test
Go to the URL (website) listed below.
On the paper provided by Mrs. Carter, answer the following questions to
the best of your ability.
http://www.brainpop.com/science/earthsystem/earthquakes/quiz/
You may have to enter a user name and password:
User Name: phsstem Password: brainpop
Select Classic Quiz
http://img.docstoccdn.com/thumb/orig/120042254.png
Image: MS Clip Art gallery
Earth’s Crust in Motion
Essential Questions
? What are earthquakes (EQ)?
? What causes EQs?
? How are EQs traced and measured?
? What are some of the most well-known EQs & why are they infamous?
? How do EQs change the earth’s surface? Why is this
Important to humans?
http://www.alicechristie.org/classes/stem/stem2/unit/index.htm
Image: MS Clip Art gallery
Earth’s Crust in Motion
Why in the world would I ever want or need to study
earthquakes, fault lines and plate tectonics?
What fault line is nearby? Is it active?
Image:
http://letslearngeology.files.wordpress.com/2012/07/earthquake-clipart.gif
Earth’s Crust in Motion
Earth’s Crust in Motion
How Does Stress Affect Earth’s Crust?
1. Put on your safety goggles.
1. Hold a popsicle stick at both ends. Slowly bend the stick
into an arch.
1. Release the pressure on the popsicle stick. Observe
what happens. Record your observations in your notes.
1. Repeat steps 2 & 3. This time, however, keep bending
the ends of the stick toward each other. What eventually
happens to the wood? Why?
Predicting…
Think of the popsicle stick as a model for the crust of the
Earth. What do you think might happen as the forces of
plate movement bend the crust? Record your thoughts in
your notes.
Image:
http://mollymoocrafts.com/wp-content/uploads/2013/07/craft-stick-shaping4.jpg
Earth’s Crust in Motion
Image:
http://america.aljazeera.com/articles/2014/1/4/new-seismic-zonecouldspelltroubleforuppersouth.html
Earth’s Crust in Motion
Earth’s Crust in Motion
Imagine…
You are at the table eating your
breakfast cereal…
Suddenly, you notice a slight vibration,
and
your glass of OJ begins to shake…
Dishes & glassware in the cabinet begin
to rattle & pictures fall of the wall…
After a few seconds, it all stops and life
returns to normal.
What happened?!?
Image:
http://openclipart.org/detail/190876/earthquake-with-house-by-loveandread-190876
Earth’s Crust in Motion
Earth’s Crust in Motion
!!!!!EARTHQUAKE!!!!!
Image:
http://openclipart.org/detail/190876/earthquake-with-house-by-loveandread-190876
Earth’s Crust in Motion
Earth’s Crust in Motion
Hey y’all!
Earthquakes are just
my reminder to you
that my crust is
always on the move!
☺
Image:
http://timvandevall.com/wp-content/uploads/2014/01/Earth-Clipart.jpg
Earth’s Crust in Motion
Stress in the Crust
What is an earthquake (EQ)?
The shaking & trembling that results from the movement of
the rock beneath Earth’s surface.
The movement of Earth’s plates creates forces powerful enough to
squeeze or pull the rock of the crust. EQs can trigger landslides
or avalanches.
What is stress?
Forces that act on rock to change its shape or volume.
(Volume is the amount of space an object takes up!)
Because stress is a force, it adds energy to the rock.
Energy is stored in the rock until the rock either breaks or
changes shape.
Image:
http://themashupmission.blogspot.com/2012/08/breaking-is-bad.html
http://blogs.besd.net/jamie-kent/2011/05/26/recent-earthquake-activity/
Click on the quaking
house to see a video
about earthquakes.
Earth’s Crust in Motion
Stress in the Crust
Types of Stress Occurring in
Earth’s Crust
Shearing
Tension
Compression
Stress works over millions of years
to change the shape & volume of
rock.
These stressors cause rock to…
become brittle & snap;
or
bend slowly like road tar softened
by the sun
Image:
http://ignoringfriction.blogspot.com/2008/12/physics-behind-famous-bridge-collapses.html
Earth’s Crust in Motion
Types of Stress
Shearing
Stress that pushes the mass of rock in OPPOSITE directions –
may cause the rock to break and slip apart OR change its shape.
http://classconnection.s3.amazonaws.com/648/flashcards/1012648/png/rock1333383778815.png
Earth’s Crust in Motion
Stress in the Crust
Shearing
Image:
http://www.studyblue.com/notes/note/n/pollock-geology-1121h-exam-3/deck/4334173
Earth’s Crust in Motion
Types of Stress
Tension
Stress that pulls on the crust, stretching the rock so that it becomes
thinner in the middle – occurs when two plates are pulling apart .
http://classconnection.s3.amazonaws.com/648/flashcards/1012648/png/rock1333383778815.png
Earth’s Crust in Motion
Stress in the Crust
Tension
Image:
http://blaisesscienceblog.blogspot.com/2011/01/january-27th-section-1-stress-faults.html
Earth’s Crust in Motion
Types of Stress
Compression
squeezes rock until it folds or breaks –
one plate pushing against another compresses the crust
http://classconnection.s3.amazonaws.com/648/flashcards/1012648/png/rock1333383778815.png
Earth’s Crust in Motion
Stress in the Crust
Compression
Image:
http://teamforce.wikispaces.com/KHAY+2.1
Earth’s Crust in Motion
Earth’s Crust in Motion…Types of Stress
BEFORE STRESS
SHEARING
Rock is pushed in OPPOSITE directions.
Associated with: Transform Boundaries
Causes: Strike-Slip Faults
TENSION
COMPRESSION
Rock is stretched, becoming thinner in the middle.
Associated with: Divergent Boundaries
Causes: Normal Faults
Rock is squeezed together, becoming thicker in the middle.
Associated with: Convergent Boundaries
Causes: Reverse Faults
Earth’s Crust in Motion
It’s a Stretch
1. Knead a piece of plastic putty until soft.
1. Push the ends of the putty toward the middle.
1. Pull the ends apart.
1. Push half the putty one way and the other half in the opposite
direction.
Classifying
What type of stress does Step 2 represent?
Step 3?
Step 4?
Earth’s Crust in Motion
Stress in the Crust
Deformation
Any change in the volume or shape
of the Earth’s crust caused by the
slow shift of Earth’s plates.
Most deformations occur so slowly
(over millions of years) that they
cannot be observed directly.
Types of Deformation
Bending Stretching Breaking
Tilting Folding Sliding Etc.
(can you think of any others?)
Image:
http://www.geologycafe.com/images/extension.jpg
Earth’s Crust in Motion
Stress in the Crust
Which type of deformation tends to
shorten part of the crust?
Compression
Which type of deformation tends to
lengthen the crust?
Tension
Image:
http://blaisesscienceblog.blogspot.com/2011/01/january-27th-section-1-stress-faults.html
Earth’s Crust in Motion
Stress in the Crust
Let’s take a closer look at the term deformation…
Write the word in your notebook
Deformation
1. Shade the root word in green.
2. Write the definition of the root word in your notes.
3. A SUFFIX is added to the end of a word. Shade the suffix in red. Write the definition of the root word in
your notes.
4. What part of speech does this suffix make the word formation?
5. What does the word formation mean? Write the definition of the word formation in your notes.
6. A PREFIX is added to the beginning of a word. Shade the prefix in blue. What does the prefix in this
word mean? Write the definition of the prefix in your notes.
7. So…if we consider the prefix, root word & suffix, what do you think the word deformation means?
Write your definition in your notes.
8. Did your prediction of the definition match the correct definition?
Earth’s Crust in Motion
Stress in the Crust
So…
DEFORMATION
is any change in the volume or shape
of the Earth’s crust!
How does deformation change Earth’s
surface?
Bending
Stretching Breaking Tilting
Folding Sliding Etc.
(can you think of any others?)
De – (prefix) used to add the
meaning “opposite”,
“remove”, “reduce”
Form – (verb) to give form or shape
to something
ation – (suffix) the action or
process of doing
something; makes the
word become a noun
http://www.wordcentral.com/cgibin//apps/apache/docs/wordcentral.com/cgi-bin/student
http://www.wordcentral.com/cgibin/student?book=Student&va=ation
http://dictionary.cambridge.org/us/dictionary/british/de
Earth’s Crust in Motion
Again, Earth’s Crust in Motion…Types of Stress
BEFORE STRESS
SHEARING
Rock is pushed in OPPOSITE directions.
Associated with: Transform Boundaries
Causes: Strike-Slip Faults
TENSION
COMPRESSION
Rock is stretched, becoming thinner in the middle.
Associated with: Divergent Boundaries
Causes: Normal Faults
Rock is squeezed together, becoming thicker in the middle.
Associated with: Convergent Boundaries
Causes: Reverse Faults
Earth’s Crust in Motion
Kinds of Faults
When enough stress builds up in rock,
the rock bends, creating a fault.
Fault
A break in Earth’s crust where slabs of
crust slip past each other (rocks on
both sides of the fault can move
up/down or sideways)
Faults usually occur along plate
boundaries, where the forces of plate
motion compress, pull, or shear the
crust to the point that it breaks
Three types
Strike-slip Normal Reverse
Image:
http://www3.geosc.psu.edu/Courses/Geosc508/San_Andreas.gif
Earth’s Crust in Motion
Strike – Slip Fault
•Created by shearing (movement in opposite directions)
•Rocks on either side of the fault slip past each other sideways, with
little up/down motion
•Strike – Slip Faults that form a boundary between two plates are
called
transform boundaries
•Example: San Andreas Fault in the western United States
image
http://michaelgivens84.edublogs.org/ch-11-science
Earth’s Crust in Motion
Strike-Slip Fault
Image:
http://www.geo.cornell.edu/geology/classes/geol326/images/sslip.gif
Earth’s Crust in Motion
Strike-Slip Fault
Image:
http://www.geerassociation.org/GEER_Post%20EQ%20Reports/Duzce_1999/Image113.jpg
Earth’s Crust in Motion
Strike-Slip Fault
Image:
http://2.bp.blogspot.com/4YK1wvl0L3Q/UEHs2oGZDMI/AAAAAAAABkw/6MHPNuC3L6g/s1600/Untitled
2.png
Image:
http://www.ncwcom.com/~jones/Geology/pictures/mount/stslip.gif
Earth’s Crust in Motion
Normal Fault
•Created by tension – plates diverge (or pull apart)
•Fault is at an angle – so that one block of rock lies above the fault line
& below the fault line.
•Key Terms to remember
✓ Hanging Wall (HW) – half of the fault that lies above
✓ Foot wall (FW) – half of the fault that lies below
•When movement occurs along a normal fault, the HW slips downward
•Example – Rio Grande Rift Valley in New Mexico, United States
Image:
http://geology1a1.wikispaces.com/file/view/NormalFault.gif/90969209/NormalFault.gif
Image:
http://michaelgivens84.edublogs.org/ch-11-science
Earth’s Crust in Motion
Normal Fault
Normal Fault
hanging wall
moves down
Image:
http://www.anr.state.vt.us/dec/geo/photogalleryp8.htm
Earth’s Crust in Motion
Normal Fault
Image:
http://geo1.tcu.edu/faculty/donovan/10113%20structure%20revision/photoalbum/images/normal%20fault_jpg.jpg
Earth’s Crust in Motion
Normal Fault
Image:
http://www.see.leeds.ac.uk/structure/faults/normal/normalicon.gif
Image:
http://www.srh.noaa.gov/jetstream/tsunami/images/faults.jpg
Earth’s Crust in Motion
Reverse Fault
•Created by compression – plate converge (or come together)
•Just like a normal fault in that the blocks of crust move in opposite
directions.
•Key Item to Remember – HW slides up & over the FW
•Example: part of the Appalachian Mountains in the Eastern United
States
Image:
http://michaelgivens84.edublogs.org/ch-11-science
Earth’s Crust in Motion
Reverse Fault
Reverse fault near Clark County, Montana A view a reverse fault in a road cut on the west side of French
Gulch, south of Sun River in Lewis & Clark County, Montana – 1966. This reverse fault places the lower
beds of Castle Reef Dolomite (light gray) onto the Flood Shale member of the Blackleaf Formation (dark
gray).
Image:
http://www.smate.wwu.edu/teched/geology/GeoHaz/eq-faults/eq-faults-18.JPG
Earth’s Crust in Motion
Reverse Fault
Image:
http://free-downloadz.net/free/reverse%20fault%20line
Earth’s Crust in Motion
Reverse Fault
Image:
http://www.consrv.ca.gov/cgs/information/publications/teacher_features/Pages/
faults.aspx
Image:
http://exchangedownloads.smarttech.com/public/content/ed/ed467877-b1e74591-ab00-c582c8dbc69d/previews/medium/0001.png
Earth’s Crust in Motion
Hanging Wall (HW) & Foot Wall (FW)
Terms are
thought to
be originated
with miners
who
excavated
shafts to
reach ore
deposits in
fault zones.
As they
worked, the
miners
walked on
rocks below
the fault
(footwall)
and hung
their lanterns
on rocks
above the
fault
(hanging
wall)
Image:
http://geophysics.ou.edu/geol1114/notes/structure/structure.html
Earth’s Crust in Motion
Hanging Wall (HW) & Foot Wall (FW)
Hanging Wall
Foot Wall
The part of the fault
that lies above the
other part
The part of the fault
that lies below the
other part
Image:
http://geophysics.ou.edu/geol1114/notes/structure/structure.html
Earth’s Crust in Motion
STRIKE – SLIP
➔
Shearing
Example: San Andreas Fault
Image:
http://whyfiles.org/2010/san-andreas-fault
Earth’s Crust in Motion
NORMAL
➔
Tension
Example: Head-Smashed-In-Buffalo-Jump
Fort MacLeod, AB
Image:
http://www.rossway.net/normal_fault.htm
Earth’s Crust in Motion
REVERSE
➔
Compression
Example: Big Ben National Park
Persimmon Gap
Image:
http://prism.texarkanacollege.edu/bbvirtual/persimmon/persimmon.html
Earth’s Crust in Motion
If a strong EQ occurred,
what do you think would
happen to the road where it
crosses the fault?
Why?
What other things might be
deformed or broken at a
fault?
Image:
http://sciencedude.blog.ocregister.com/files/2010/08/sanandreas.jpg
Earth’s Crust in Motion
Name the…
(a) three types of boundaries,
(b) faults
& the
(c) deformation that produces each.
Earth’s Crust in Motion
(A)
(B)
(C)
Boundary
Fault
Caused by…
Transform
(3)
(5)
(1)
Normal
(6)
(2)
(4)
Compression
Earth’s Crust in Motion
Three Basic Faults
Image:
http://www.geosci.usyd.edu.au/users/prey/ACSGT/EReports/eR.2002/Paleostress02/faults.html
Earth’s Crust in Motion
Demonstration
Can you demonstrate the movement at each of the following faults using
your hands?
Strike – Slip
Normal
Reverse
Image:
http://noortasha.wordpress.com/2012/05/09/jawapan-soalan-pengukuhan/clapping-hands/
Earth’s Crust in Motion
This is a reverse fault that formed Mt. Gould in Glacier National Park
(Montana) beginning 60 million years ago.
Which half of the reverse fault slid up and across to form this mountain?
Image:
http://www.summitpost.org/mount-gould-over-swiftcurrent-lake-glacier-national-park-mt/460914
Earth’s Crust in Motion
This is a reverse fault that formed Mt. Gould in Glacier National Park
(Montana) beginning 60 million years ago.
Which half of the reverse fault slid up and across to form this mountain?
The hanging wall slipped up and across. If the footwall had moved up,
the fault wouldn’t be a reverse fault, it would be a normal fault.
Image:
http://www.summitpost.org/mount-gould-over-swiftcurrent-lake-glacier-national-park-mt/460914
Earth’s Crust in Motion
This is a normal fault that in Death Valley California?
Which half of the normal fault slid up and across to form this mountain?
Image:
http://pages.uoregon.edu/millerm/DVNF1.html
Earth’s Crust in Motion
This is a normal fault that in Death Valley California?
Which half of the normal fault slid up and across to form this mountain?
Image:
http://pages.uoregon.edu/millerm/DVNF1.html
Earth’s Crust in Motion
Hanging wall of Chelungpu fault across running
track at Wufeng high school. East side up.
The red line marks equivalent layers on
opposite side of the fault. Since the hanging
wall dropped relative to the footwall, this is
clearly a normal fault.
Image:
http://www.whfreeman.com/Catalog/static/whf/bolt/content/bt00/bt00nn01.htm
Image:
http://www.pitt.edu/~cejones/GeoImages/7Structures/NormalFaults.html
Earth’s Crust in Motion
For the next activity, refer to Figure 26 on pg. 43F
Image
http://www.npenn.org/cms/lib/PA09000087/Centricity/Domain/351/Earth%20Science/Ch.%204%20Plate%20Tectonics/Ch.%204%20Plate%
20Tectonics%20Website%20Images/earths%20lithospheric%20plates.jpg
Earth’s Crust in Motion
• Where are some places on or near land where plates are converging
(coming together)?
• What do you think happens to Earth’s crust in those places as the
plates converge?
• What do you think happens to the solid rock?
• What type of stress force is occurring along these boundaries between
plates?
• What type of fault would you expect to find there?
Earth’s Crust in Motion
(Assessment: It’s All Your Fault)
•
Fold your paper as this example
demonstrates. Put heading information in
this block.
•
Make a sketch of the fault identified in each
block/section.
•
Use arrows to show fault movement.
•
Identify the stress force AND boundary type
for that particular fault.
2.
NORMAL
1. REVERSE
3.
STRIKE – SLIP
Earth’s Crust in Motion
On the back of your paper, number your paper from 1 – 8. Answer the
questions at the bottom of the slide.
(Assignment Name: Fault Lines)
What…
1.
2.
3.
4.
5.
6.
7.
8.
Normal
Compression
Footwall
Strike-Slip
Tension
Shearing
Reverse
Hanging wall
1. Fault is labeled #1?
2. Stress is labeled #2?
3. Is labeled #3?
4. Fault is labeled #4?
5. Stress is labeled #5?
6. Type of stress causes the fault labeled #4?
7. Fault labeled #7?
8. is labeled #8?
Image:
http://www.geosci.usyd.edu.au/users/prey/ACSGT/EReports/eR.2002/Paleostress02/faults.html
Earth’s Crust in Motion
Friction
Determines how rocks move along
a fault
(based on the amount)
The force that opposes the motion
of one surface as it moves across
another surface
Exists because surfaces are not
exactly smooth
Image:
http://whoop-dee-do.blogspot.com/2011_07_01_archive.html
Earth’s Crust in Motion
Friction
What are some examples of LOW
friction you’ve experienced?
What are some examples of HIGH
friction you’ve experienced?
Can friction ever be used for an
advantage?
What are some examples?
Image:
http://whoop-dee-do.blogspot.com/2011_07_01_archive.html
Earth’s Crust in Motion
Friction
High friction – rocks lock together &
do not move. Stress increases
until strong enough to overcome
the friction force
Moderate friction – sides of the faults
together. When they
small
Low friction – rocks on both sides
slide by each other without
much sticking
Danger
jam
eventually jerk free,
earthquakes
occur
Moderate
High
Low
Earth’s Crust in Motion
Friction @ the San Andreas Fault (SAF)
The SAF forms a _?_ boundary between
the North American & Pacific plates?
What do you think the friction is like?
What does this cause the plates to do?
What happens when the stress
builds up?
Image:
http://www.sanandreasfault.org/4020_A.jpg
Earth’s Crust in Motion
Mountain Building
Over millions of years, fault movement can change a flat plain into a
towering mountain range.
Formed when normal faults uplift a block of rock
Key:
Movement along
normal faults
Image:
http://vector.us/browse/195062/rpg_map_symbols_mountain_clip_art
http://7bcore2.wikispaces.com/file/view/fault_block_mountain.jpg/192131618/fault_block_mountain.jpg
Earth’s Crust in Motion
Mountains formed by Faulting
Fault – Block Mountain
Where normal faults uplift a block of rock
Process
Where two plates diverge, tension forces create
normal faults
When two of these faults form parallel to each
other, a block of rock is left lying between them.
As the hanging wall of each normal fault slips
downward, the block between them moves
upward.
Often fault-block mountains have steep fronts &
sloping back sides
Valley
When a block or rock lying between two normal
faults slides downward
Image:
http://resources.woodlands-junior.kent.sch.uk/homework/mountains/types.htm
Earth’s Crust in Motion
Mountains formed by Faulting
Examples:
From Salt Lake City, UT to Los Angeles, CA (the
Great Basin - A region with many ranges of
fault-block mountains separated by basins, or
broad valleys in NV & UT
Sierra Nevada Mountains (western US)
Harz Mountains in Germany
Images:
http://pirate.shu.edu/~schoenma/mountains.htm
Earth’s Crust in Motion
Mountains formed by Folding
Under certain conditions, plate movement
causes the crust to fold.
Folds
Bends in rock that form when compression
shortens the crust – think about a rug that
wrinkles up as you slide across the floor.
Folds can be incredibly small (a few
centimeters) or large (hundreds of kilometers
wide)
Mountains formed by folding are the most
common mountains.
The world’s largest mountain ranges are fold
mountains (formed over millions of years.)
Formed when two plates collide head-on & the
Image:
edges crumble.
http://grade7geography.wikispaces.com/Fold+mountians
Earth’s Crust in Motion
Mountains formed by Folding
Types of Folds
Upward – Anticlines
Downward – Synclines
Examples of Folding Mountains
Himalayas (Asia)
formed when India crashed into Asia & pushed up the tallest
mountain
Alps (Europe)
Andes (South America)
Formed by the collision of the continental SA plate & the
oceanic Pacific Plate
Rockies (North America)
Urals (Russia)
Image:
http://grade7geography.wikispaces.com/Fold+mountians
Earth’s Crust in Motion
Mountains formed by Faulting
Satellite image showing folded mountains
(Pennsylvania Appalachians) west of
Harrisburg, Pennsylvania
Image:
http://www.faithfreedom.org/debates/NaikCampbellp5.htm
Image:
http://geology1a1.wikispaces.com/file/view/Faults_and_folds.jpg/91052201/Faults_and_folds.jpg
Earth’s Crust in Motion
Anticlines/Synclines
Anticlines
A fold in the rock that bends
UPWARD
↑
Synclines
A fold in the rock that bends
DOWNWARD
↓
(in the middle to form a bowl)
Image:
http://geology1a-1.wikispaces.com/Folds+and+Faults+with+captions
Image: .
http://www.radford.edu/jtso/GeologyofVirginia/Structures/GeologyOfVAStructur
es4-2e.html
Earth’s Crust in Motion
Anticlines/Synclines
Image:
http://www.flickr.com/photos/phocoena/3795322402
Earth’s Crust in Motion
Plateaus
Forces that raise up mountains can
also raise up plateaus.
Plateaus
large areas of flat land elevated
high above sea level.
Formed when vertical faults push
up large, flat blocks of rock.
Made of many different layers & is
wider than it is tall.
Image:
http://www.wisegeek.org/what-is-a-plateau.htm
Earth’s Crust in Motion
Plateaus
Known as tableland in geological
terms
Characterized by an elevated/flat
plain of land that resembles a table.
Created when magma pushes
upwards to the surface of the
Earth’s crust – magma doesn’t
break through but instead raises a
section of the crust.
http://www.brighthub.com/environment/science-environmental/articles/93782.aspx
Image:
http://katiepingram.tripod.com/plateaus2.htm
Earth’s Crust in Motion
Plateaus
Dome Plateau
Colorado Plateau
View is to the north from over the Colorado
River,
Grand County, Utah, United States
Image:
http://www.airphotona.com/image.asp?imageid=2559
Image:
http://www.examiner.com/article/a-slice-of-america-the-colorado-plateaucanyonlands-island-the-sky
Earth’s Crust in Motion
Plateaus
Image:
http://www.wpclipart.com/geography/features/mountain/plateau.png.html
Image:
http://www.bethanylutheran.org/files/html%20files/landforms/plateau.jpg
Earth’s Crust in Motion
Other Key Information
Liquefaction
Occurs when an EQ’s violent
shaking turns soft soil into liquid
mud.
Aftershock
The EQ that follows after a larger
quake has occurred in the same
area – may not occur for hours,
days, or even months later.
Images:
http://www.clccharter.org/maya1/Effects%20of%20Earthquakes/Liquefaction.html
http://keithwoodford.files.wordpress.com/2011/02/liquefaction-in-kilmore-st-asher-trafford2.jpg
Click on the
images for more
information.
Earth’s Crust in Motion
Other Key Information
Liquefaction Demonstration
Click the image to your right to see
a demonstration of soil liquefaction
that sometimes occurs after an
earthquake.
Materials Needed:
Metal, glass or heavy pan (deeper the better)
Sand
Water,
Brick,
Rubber mallet,
Stirring Tool
Explain how this demonstration
accurately depicts liquefaction
following an EQ.
Images:
http://www.geocities.ws/melangellwright/FebruaryLesson.html
Earth’s Crust in Motion
Fill in this concept
map about stress.
Name:
Earth’s Crust in Motion
Name:
01.
__________________
02.
Movement Along
Diagram
Type of Fault
Stressor Force
__________________
the Fault
03.
A
(1)
(2)
(3)
__________________
B
(4)
(5)
(6)
04.
C
(7)
(8)
(9)
__________________
Match the following terms with the correct definitions below. All words
05.
MAY NOT be used.
__________________
06.
10. Any change in the volume or shape of the crust.
11. Formed when normal faults uplift a block of rock.
__________________
12. A rock fold that bends downward in the middle to form a bowl.
07.
13. The shaking & trembling that results from the movement of rock
__________________
along a fault beneath Earth’s surface.
08.
14. A force that acts on rock to change its shape or volume.
__________________
15. A rock fold that bends upward into an arch.
09.
16. A large area of flat land elevated high above sea level.
__________________
AFTERSHOCK ANTICLINE
DEFORMATION
EARTHQUAKE
FAULT-BLOCK MOUNTAIN 10. LIQUEFACTION
PLATEAU
Provide the information requested in the table in the blanks to your right.
STRESS
SYNCLINE
Measuring Earthquakes
Image:
http://images.cdn.fotopedia.com/flickr-7375813928-hd.jpg
Measuring Earthquakes
Waves…
What type of waves have you observed over time?
Ocean? Lake or Pond? Bath tub or Sink? Other types?
Image:
http://www.clker.com/clipart-wave-pattern.html
http://www.wallpapersdb.org/original/864/
http://apievangelist.com/2010/10/06/riding-the-waves-of-change/
http://salestores.com/royals33.html
Measuring Earthquakes
Waves
Think about waves in water.
How would you describe the way they move?
(“outward” from a “push” in the water)
Image:
http://mghariharan.wordpress.com/2011/09/07/effect-of-karma-on-fate-by-mks/
Measuring Earthquakes
How do seismic waves travel through Earth?
1. Stretch a “slinky” across the floor while
your partner holds the other end. (please
don’t overstretch Slinky)
1. Gather approximately 4 coils of the spring
and release them. In what directions did the
coils move?
1. Once the slinky has stopped moving, jerk
one end of the toy from side to side once. In
what direction do the coils move? (Make
sure one of you holds the other end
securely).
1. Describe the two types of wave motion you
observed in the springy toy.
Image:
http://blog.urbanoutfitters.co.uk/?p=9262
Measuring Earthquakes
Did you
know…?
Image:
http://marketablemobile.com/mobile-barcodes/
Measuring Earthquakes
The average rate of motion across the San
Andreas Fault Zone over the past 3 million years
is approximately 56 mm/y.
(that’s just a little bit more than 2.2 inches – that’s about the
same rate your fingernails grow)
http://earthquake.usgs.gov/learn/facts.php
Image:
http://marketablemobile.com/mobile-barcodes/
Measuring Earthquakes
Assuming this rate continues, Los Angeles and
San Francisco will be adjacent to each other
approximately 15 million years from now.
http://earthquake.usgs.gov/learn/facts.php
Image:
http://marketablemobile.com/mobile-barcodes/
Measuring Earthquakes
Most EQs occur at depths of less
than 80 km (50 miles) from the surface.
The deepest quakes usually occur at
plate boundaries where Earth’s crust
subducts back into the mantle
(these can occur as deep as 400 miles below the
surface)
http://earthquake.usgs.gov/learn/facts.php
Image:
http://marketablemobile.com/mobile-barcodes/
Measuring Earthquakes
From 1975 – 1995, there were only four states that
did not have any EQs…
Florida Iowa
North Dakota Wisconsin
http://earthquake.usgs.gov/learn/facts.php
Image:
http://marketablemobile.com/mobile-barcodes/
Measuring Earthquakes
FL & ND have the smallest number of
EQs in the US
AK is the most EQ prone state & one of
the most seismically active regions in the
world.
http://earthquake.usgs.gov/learn/facts.php
Image:
http://marketablemobile.com/mobile-barcodes/
Measuring Earthquakes
There are approximately 500,000
detectable earthquakes in the world annually.
Of these, only 100,000 of them can be felt. Of
those that are felt, only about 100 of them cause
any significant damage.
http://earthquake.usgs.gov/learn/facts.php
Image:
http://marketablemobile.com/mobile-barcodes/
Measuring Earthquakes
You can read these facts and many more about
earthquakes on the USGS website listed
below…
http://earthquake.usgs.gov/learn/facts.php
http://earthquake.usgs.gov/learn/facts.php
Image:
http://marketablemobile.com/mobile-barcodes/
Measuring Earthquakes
Well…
now you know!!
Graphic: http://ww2.valdosta.edu/~lmmcfarland/T2C1R1.html
Measuring Earthquakes
When an EQ strong enough to rattle cabinets &
dishes occurs, two questions are always
asked…
How big was it?
&
Where was it centered?
Graphic:
http://krazykk.wordpress.com/quizzes/question/
Measuring Earthquakes
EQ Facts & Statistics
http://earthquake.usgs.gov/earthquakes/map/
Visit this site to find out
(a) where & when the five most recent earthquakes in the United States
occurred.
(a) What was the strength of these quakes?
Image:
http://www.usgs.gov/
Measuring Earthquakes
Well…
What did you find out?
What region of the US seems to be more
seismically active?
Image:
http://marketablemobile.com/mobile-barcodes/
Measuring Earthquakes
Where do most EQs Occur?
EQs occur along plate edges and fault lines.
Usually below the surface
(in the lithosphere within 100 km approximately
(~63 miles beneath the surface)
http://www.geo.mtu.edu/UPSeis/where.html
Image:
http://blogs.agu.org/landslideblog/2010/11/02/the-canterbury-earthquakeimages-of-the-distorted-railway-line/
Measuring Earthquakes
Key Terms
Focus
The point BENEATH Earth’s surface
where rock that is under stress
breaks, triggering an EQ.
Epicenter
The point ON THE SURFACE of
Earth directly above the focus.
Image:
http://www.geologicresources.com/earthquake_seismic_waves.html
Measuring Earthquakes
Key Terms
Seismic
Of, concerning, or resulting from an earthquake.
Seismology
The study of Earthquakes
Seismologist
A geologist who studies Earthquakes
For extra credit points on your test, develop a mnemonic device of your own to help you remember
the definition of seismic. This is due by your next class meeting! See Mrs. Carter after class for
more details!
Image:
http://earthquakeexplorers2011.blogspot.com/2011_03_01_archive.html
Measuring Earthquakes
Seismic Waves
Have you ever played a drum?
What makes the sound
softer/louder?
How hard/soft you strike it.
What does the beating drum
produce?
Vibrations (called waves)
How does the sound travel?
Outward through solid material
Image:
http://maralkaraee.deviantart.com/art/Drum-Player-142382093
Measuring Earthquakes
Seismic Waves
How does this relate to an EQ?
Waves race out from the focus in all directions
(just like the sound waves from the drum)
What are Seismic Waves (SW)?
The vibrations that travel through Earth carrying
energy released during an EQ
These seismic waves move like ripples in a
pond.
Image:
http://mrsmertens.pbworks.com/w/page/33383293/Chapter%202%3A%20%20Earthquakes
Measuring Earthquakes
Seismic Waves: Interpreting Diagrams
The earthquake occurs when
rocks fracture at the focus, deep
in the Earth’s crust.
What point is directly above the
focus of an earthquake?
The epicenter
Graphic
http://7bcore1.wikispaces.com/file/view/focus.jpg/192107398/focus.jpg
Measuring Earthquakes
Seismic Waves – Think it Through…
A pebble is dropped into water.
How are SWs similar to the waves
made by the pebble dropped into
the water?
SW also move outward in concentric rings.
How are they different?
SW move outwardly three – dimensionally (3-D)
in all directions. Water moves only on the
surface.
SW move through solid materials.
What pattern do you see?
Waves move outward from the pebble in
concentric rings.
Graphic
http://www.ciaccess.com/~toveza/ripple.jpg
Measuring Earthquakes
Seismic Waves
SWs carry the energy of an EQ
away from the focus, through
Earth’s interior, and across the
surface.
The energy of SWs that reach the
surface is greatest at the epicenter.
However, the most violent shaking
make occur many miles or
kilometers away from the epicenter.
Rock type & soil around the
epicenter determine where & how
much the ground will shake.
Image:
http://www.kids-fun-science.com/earthquake-epicenter.html
Measuring Earthquakes
Types of Seismic Waves
Primary Waves - (P Waves)
(Also Known as Compressional Waves)
Secondary Waves - (S Waves)
Surface Waves
Image:
http://www.uwgb.edu/dutchs/earthsc202notes/quakes.htm
Measuring Earthquakes
Types of Seismic Waves - Primary Waves
(P Waves)
•
Also known as compressional waves (the P wave
alternately compresses & expands material in the
same direction it is traveling)
•
Fastest wave & therefore the first wave to arrive
@ a location
•
These waves compress & expand the ground like
an accordion
•
Cause buildings to contract & expand
•
CAN travel through all layers of Earth including
both solids & liquids
•
Generally felt by humans as a bang or thump.
Info & Image:
http://earthquake.usgs.gov/learn/eqmonitoring/eq-mon-1.php
Measuring Earthquakes
Primary Waves - (P Waves)
In P waves, the particles of the crust vibrate forward and back along the
path of the wave
Image:
http://www.npenn.org/cms/lib/PA09000087/Centricity/Domain/351/Earth%20Sci
ence/Ch.%205%20Earthquakes/Ch.%205%20Website%20Images/5.2%20Seismic%
20Waves.jpg
Image:
http://cse.ssl.berkeley.edu/img/earthquakes/PWave.gif
Measuring Earthquakes
Types of Seismic Waves – Secondary Waves
(S Waves)
•
Also known as shear waves
•
The S Wave is slower than the P Wave
•
Arrives at a location after the P Wave
•
S Waves vibrate from side – side as well as up &
down shaking the ground back & forth
(perpendicular to the direction of travel.
•
S Waves shake structures violently when they
reach the surface.
•
CANNOT travel through liquids
Info & Image:
http://earthquake.usgs.gov/learn/eqmonitoring/eq-mon-1.php
Measuring Earthquakes
Secondary Waves - (S Waves)
In P waves, the particles of the crust vibrate forward and back along the
path of the wave
Image
http://www.npenn.org/cms/lib/PA09000087/Centricity/Domain/351/Earth%20Sci
ence/Ch.%205%20Earthquakes/Ch.%205%20Website%20Images/5.2%20Seismic%
20Waves.jpg
Image:
http://www.geol.umd.edu/~piccoli/100/CH18.htm
Measuring Earthquakes
Think back on the “Slinky” activity from earlier…
•
When the wave moved straight ahead along
the spring, what type of wave did it model?
P-Wave
•
When the spring moved side to side, which
type of wave did it model?
S-Wave
•
When we used the spring, where was the
focus of the model EQ?
At the end that was compressed & jerked
Images:
ftp://ftpdata.dnr.sc.gov/geology/Education/PDF/Earthquakes.pdf
Measuring Earthquakes
Quick Check
In your notes, describe the
major difference between PWaves and S-Waves.
Use a double – bubble map
or a Venn Diagram!
Image:
http://www.123rf.com/photo_2740768_cartoon-drawing-of-red-checkmark-with-eyes--vector.html
http://www.docstoc.com/docs/105574024/Double-Bubble-Mind-Map-Graphic-Organizer
http://www.math-aids.com/Venn_Diagram/
Measuring Earthquakes
Surface Waves
•
When P & S Waves reach the surface, some
of are transformed into Surface waves (also
known as “Rayleigh” and “Love” Waves).
•
Surface Waves move more slowly than P or
S Waves
•
Surface Waves produce the MOST severe
ground movements
•
May make the ground move like ocean
waves or shake buildings from side – to –
side.
Images:
ftp://ftpdata.dnr.sc.gov/geology/Education/PDF/Earthquakes.pdf
http://www.sms-tsunami-warning.com/pages/seismic-waves
Measuring Earthquakes
Seismic Waves
1. Click on the following URL…
http://wwwrohan.sdsu.edu/~rmellors/lab8/l8maineq.htm
Scroll down to find the heading “TYPES OF
SEISMIC WAVES”.
Watch the animations that explain each type of
seismic waves.
In your notes, explain the three types of seismic
waves to a 3rd grader.
Click on the image to get more information on seismic waves. Use the purple arrows to navigate
the activity. Record your answers in your notes.
Image:
http://www.sms-tsunami-warning.com/pages/seismic-waves#.UzXG76hdX84
Measuring Earthquakes
Surface Waves
Make an Inference…
Why do surface waves produce
more severe ground movements
than P or S waves?
(the surface consists of loose soil, sand, grave,
mud, and small rocks. It is susceptible to
greater movement as particles shift & slide.)
Images:
http://earthquake.usgs.gov/learn/glossary/?term=surface%20wave
Measuring Earthquakes
Quick Check
List & describe the three (3)
types of seismic waves. List
them in order of arrival at a
given location.
Image:
http://www.georesources.co.uk/kobehigh.htm
Measuring Earthquakes
Try This…Recording Seismic Waves
#2 Prediction
#1 Place the science book on the
table.
In your notes, write answers to the following
questions. Place your answers in the form of
complete sentences.
1. Straw Holder – hold
a straw with the
strip of paper wound around it.
•
What do you expect to happen? Why?
1. Pen Holder – hold the pen against the
paper.
1. Book Holder – slowly pull the paper
so it slides across the book.
1. Quake Maker – After a few seconds,
jiggle the book for 10 seconds – first
gently, the increase the intensity.
Image:
http://smarterteacher.blogspot.com/
Measuring Earthquakes
Try This…Recording Seismic Waves, continued…
•
#3 Discussion
#4 Extension
In your notes, write answers in the form of
complete sentences.
Let’s extend this & try different types of
earthquakes!
How did the lines on the paper change when
the earthquake began?
•
What happened to the spikes when the
“jiggling” was weak?
•
What happened to the spikes when the
“jiggling” was strong?
•
Long, slow movement
•
Abrupt movements
•
A strong quake followed by an aftershock
Image:
http://smarterteacher.blogspot.com/
Measuring Earthquakes
Detecting Seismic Waves
Seismographs
Instruments used to record & measure the vibrations of seismic waves by geologists.
Records ground movements caused by seismic waves as they move through earth.
Image:
http://askpari.files.wordpress.com/2010/05/seismograph.gif
Image:
http://slohs.slcusd.org/pages/teachers/rhamley/Plate%20Tectonics/seismo1.j
pg
Measuring Earthquakes
Detecting Seismic Waves
Use details from the text of your article to prove how a mechanical seismograph works?
Articles…
http://www.earthquakescanada.nrcan.gc.ca/info-gen/smeters-smetres/seismograph-eng.php
http://earthquake.usgs.gov/learn/topics/seismology/keeping_track.php
http://www.pbs.org/weta/roughscience/series3/quakers/seismograph.html
Measuring Earthquakes
Seismographs
The mechanical seismograph records seismic waves. The record made by a seismograph shows
the arrival times of different types of seismic waves.
Images:
http://www.npenn.org/page/5063
http://www.boingboing.net/filesroot/seismograph.jpg
Measuring Earthquakes
Try This…Recording Seismic Waves
You and your partners can simulate a seismograph…
Gather your supplies
Your science book,
a straw,
a paper strip (1 m long),
a pen
Accept your job
Book holder,
Straw Holder,
Pen Holder,
Quake Maker
Read the directions first.
Do NOT attempt to do anything
further until you are directed to do so.
Measuring Earthquakes
Seismographs
Today, geologists use electronic seismographs.
http://allshookup.org/quakes/seisgraph.htm
Image:
http://www.pbs.org/wgbh/nova/vesuvius/predict.html
Image:
http://stream2.cma.gov.cn/pub/comet/Environment/TsunamiWarningSystem
s/comet/tsunami/warningsystem/media/graphics/braille_clip_signal.jpg
Measuring Earthquakes
Measuring Earthquakes
Geologists must consider many factors when determining the size of an
EQ.
There are at least twenty (20) different measures for rating EQs.
(we’re going to look at three!)
Magnitude
A measurement of EQ strength based
upon seismic waves & movement along
fault lines.
Intensity
The effect of an EQ on Earth’s surface
http://geology.about.com/od/quakemags/a/Mercalli-Earthquake-IntensityScale.htm
In 3rd grade terms, what is
the difference between
magnitude & intensity?
Magnitude measures how big the
quake, while intensity measures how
bad it is!
Image:
http://www.polyvore.com/decodeunicode.org_decode_right_curly_bra
cket/thing?id=19006697
Measuring Earthquakes
Measuring Earthquakes – Mercalli
Mercalli Scale
The intensity scale currently used in the UA.
The Scale is composed of twelve (12) increasing
levels of intensity that range from imperceptible
(unnoticeable) shaking to catastrophic
destruction.
Each level is designated by Roman Numerals
Mercalli does NOT have a mathematical basis –
instead is an arbitrary ranking based upon
observed facts.
The same EQ can have different Mercalli ratings
because it causes different amounts of damage
at different locations.
http://earthquake.usgs.gov/learn/topics/mercalli.php
Textbook, pg. 67F
Image:
http://www.geo.mtu.edu/UPSeis/Mercalli.html
Measuring Earthquakes
Measuring Earthquakes – Mercalli Scale
The 1994 Northridge Earthquake – rated between X – XII on the Mercalli Scale because there is
total destruction and substantial ground distortion.
http://www.geography-site.co.uk./pages/physical/earth/richt.html
Image:
http://2.bp.blogspot.com/_FTPcx94JYY/TxXmfWSM12I/AAAAAAAAAek/gtJfkvz3ZQ0/s1600/quake.jpg
Image:
http://withfriendship.com/images/i/41943/1994-Northridge-earthquakewallpaper.jpg
Measuring Earthquakes
Measuring Earthquakes – Mercalli Scale
Image:
http://mail.colonial.net/~hkaiter/equakeanimals.html
http://www.docstoc.com/docs/80153368/Modified-Mercalli-Scale-vs-Richter-Scale
Measuring Earthquakes
Measuring Earthquakes – Mercalli Scale
What rating would you give these examples?
Why?
/Image:
http://blogs.agu.org/landslideblog/2010/11/02/the-canterbury-earthquakeimages-of-the-distorted-railway-line
Image:
http://photoblog.nbcnews.com/_news/2012/02/07/10340040-filipinosgrieve-as-earthquake-death-toll-rises?lite
Measuring Earthquakes
Measuring Earthquakes – Richter
Richter Scale
Used to measure the magnitude of an
earthquake - Values range from 0 to over 8.0
Rates the size of seismic waves that was once
measured by a type of mechanical seismograph.
Generally accurate for small, nearby EQs but
does not work well for large or distant EQs.
Uses a Base 10 scale…
A “6” is 10 times greater than a “5”
A “7” is 100 times greater than a “5”
EQ measuring < a “2” on the Richter Scale are
meaningless & can barely be measured, much
less felt.
Image:
http://www2.ljworld.com/stories/2008/may/02/earthquakes_kansas/history_quakes/
Measuring Earthquakes
Measuring Earthquakes – Richter
Largest quake measured by this
scale was a 9.5 in Chile. It caused
damage as far away as Hawaii due
to tsunamis.
http://www.explainstuff.com/2009/05/10/explain-stuff-richter-scale-fact-of-the-day
Image: http://www.ithaca.edu/HPHMComputer/introself.htm
Measuring Earthquakes
Measuring Earthquakes – Richter
Image:
http://sezginalay1.myblog.it/2011/10/06/richter-scale/
Measuring Earthquakes
Measuring Earthquakes – Richter
1976 Tangshan earthquake - 7.8 Richter Scale
Image:
http://en.wikipedia.org/wiki/1976_Tangshan_earthquake
Measuring Earthquakes
Compare & Contrast the Mercalli & Richter Scales
Richter
Richter describes the EQ’s
strength in terms of the size
of its seismic waves – it IS a
precise measurement.
Mercalli
Both of these
scales
describe the
“strength” of
an EQ.
Mercalli describes an EQ’s
strength in terms of its
effects (to what extent
people are affected & the
amount of damage it
causes. It is NOT a precise
measurement.
Measuring Earthquakes
Compare & Contrast the Mercalli & Richter Scales
Question…
On which scale would an
EQ’s strength vary from
one place to another?
Answer…
The Mercalli Scale
Because the amount of shaking people
would feel & the damage to objects
would be greater in a place closer to the
epicenter and less in a place farther
away. Therefore, the intensity rating in
the two places would be different
Image:
http://www.clker.com/inc/svgedit/svg-editor.html?paramurl=/inc/clean.html?id=166956
Measuring Earthquakes
Measuring Earthquakes – Moment Magnitude Scale
Moment Magnitude Scale
Devised after the 1960 Chilean & 1964 Alaskan
EQs that we so large the Richter Scale could not
adequately show their magnitude & size.
http://www.kids-fun-science.com/moment-magnitude-scale.html
Moment Magnitude (MM) is the measure of total
energy released by an EQ.
MM is the measurement generally preferred by
scientist/seismologists because it is more
precise.
MM is NOT based on instrumental recording of
an EQ – but on the area of the fault that ruptured
in the quake.
http://quake.ualr.edu/public/moment.htm
Image:
http://els.allshookup.org/
Measuring Earthquakes
Measuring Earthquakes – Moment Magnitude Scale
Moment Magnitude Scale
MM is more accurate than the Richter scale.
MM can be used to rate quakes of all sizes, both
near & far.
EQ on the MM with a magnitude rating below 5.0
are small and cause little damage. Quakes with
a rating above 5.0 can produce massive
destruction.
A magnitude 6.0 quake releases 32 times the
amount of energy as a magnitude 5.0 quake,
and nearly 1,000 times as much as a 4.0 quake.
An increase of one magnitude unit indicates a
ten-fold increase in seismic shaking.
http://www.mbmg.mtech.edu/kids/shakin.htm
Textbook, pg. 68F
Image:
http://kindertraeumeonline.de/blog/earthquake-scale-magnitude
Measuring Earthquakes
Measuring Earthquakes – Moment Magnitude Scale
The photo above is what remains of a house destroyed in a 6.3 magnitude quake that struck
Christchurch, New Zealand, in Feb 2011. Five months earlier, in September of 2010, a magnitude
7.1 quake struck this area as well.
Image:
http://www.brisbanetimes.com.au/christchurch-earthquake
Measuring Earthquakes
Measuring Earthquakes – Moment Magnitude Scale
Earthquake
Magnitudes
This table lists the moment
magnitudes for some of the 20th
century’s biggest quakes.
Earthquake
San Francisco, CA
1906
Southern Chile
1960
Anchorage, AL
1964
Lorna Prieta, CA
1989
Northridge/Los Angeles, CA
1994
Moment
Magnitude
7.7
9.5
9.2
7.2
6.7
Measuring Earthquakes
Locating the Epicenter
Let’s review for a
moment…
What is the epicenter?
The point on the
surface directly above
the focus.
Image:
http://www.clker.com/inc/svgedit/svg-editor.html?paramurl=/inc/clean.html?id=166956
Measuring Earthquakes
Locating the Epicenter
Geologists use seismic waves to locate the
epicenter of an EQ.
SW travel at different speeds.
P waves arrive first, with S waves not far
behind.
To tell how far the epicenter is from the
seismograph, scientists measure the difference
of the arrival times of the P & S waves.
The farther away an EQ is, the greater the time
between the P & S waves.
Image:
http://www.studyblue.com/notes/note/n/chapter-6-earthquakes/deck/2071080
Measuring Earthquakes
Locating the Epicenter
Geologists draw at least three (3) circles using
data from different seismographs set up at
stations all over the world.
The center of each circle is a particular
seismograph's location.
The radius of each circle is the distance from
the seismograph to the epicenter.
The point where the three (3) circles intersect is
the location of the epicenter.
Two circles would intersect at two points, not
one, & identify two possible epicenters.
Image:
http://www.npenn.org/page/5063
Measuring Earthquakes
Locating the Epicenter
Why would drawing
only two (2) circles not
be enough to locate
the EQ’s epicenter?
Two circles would
intersect at two points,
not one, & identify two
possible epicenters.
Locating the Epicenter Activity
Click on the link below…
http://www.glencoe.com/sites/common_ass
ets/science/virtual_labs/ES09/ES09.html
Complete this activity to learn how
seismologists determine the epicenter of an
earthquake!
Measuring Earthquakes
Check-Up
Draw & Label a sketch
(without referring to pictures or your notes),
showing an EQ’s…
(use the graphic to your right to help you.)
(a) Focus underground
(b) Its epicenter on the surface,
(c) Different motions of P & S waves moving
outward from the focus,
(d) Surface waves moving outward from the
epicenter.
Image:
http://www.georesources.co.uk/kobehigh.htm
http://mrescience.com/earth_slides_05.php
Measuring Earthquakes
(Assignment: Measuring Earthquakes)
Part 1 – Answer the following using complete sentences. Provide a page number from text confirming your answers.
(You do NOT have to write the question unless you ask!)
01.
02.
03.
04.
05.
06.
07.
08.
09.
10.
11.
12.
13.
14.
15.
What are seismic waves?
What is seismology?
Explain the process seismologists use to locate the epicenter of an EQ.
What is the difference in magnitude & intensity?
In what order do the 3 types of seismic waves arrive at a seismograph?
Which of the 3 scales discussed do most scientists prefer to use in measuring EQs and why?
Where do most EQs occur?
What is the difference in the focus & epicenter of an EQ?
What are seismographs?
What determines where & how much the ground will shake during an EQ?
List & describe the three (3) types of seismic waves. List them in order of arrival at a given location.
What is the difference in the Richter & Mercalli Scales?
Which type of seismic waves produce the most severe ground movements?
On which scale would an EQ’s strength vary from one place to another? Why?
Why would drawing only two (2) circles not be enough to locate the EQ’s epicenter?
Part 2 – Match each term with its definition. You only have to write the answer unless you ask!
Epicenter
16.
17.
18.
19.
20.
Focus
Magnitude
Seismograph
Surface Waves
Records ground movements caused by seismic waves as they move through Earth.
The slowest seismic waves that produce the most severe ground movements.
The point beneath Earth’s surface where rock under stress breaks and triggers and earthquake.
A measurement of earthquake strength.
The point on the surface directly above where an earthquake occurs.
WebQuest: Earthquakes
Click the image above to visit the Earthquakes Web Quest site.
Image:
http://www.rtmsd.org/page/1847
WebQuest: Earthquakes
Web Quest: Earthquakes
✓ An earthquake is the result of a sudden release of energy in the Earth’s
crust that creates seismic waves.
✓ Earthquakes are recorded with seismometers (aka seismographs).
✓ The Moment Magnitude or the Richter Magnitude is the measurement
that is usually reported by the media when describing an earthquake.
✓ Quakes with a rating of 3 or less are usually unnoticeable. However,
quakes that rate a magnitude of 7 or higher are consistently
catastrophic.
✓ The intensity of shaking is measured on the modified Mercalli scale.
http://www.rtmsd.org/page/1847
WebQuest: Earthquakes
Web Quest: Earthquakes
✓ On the surface, quakes usually manifest themselves by shaking and
displacing the ground.
✓ When the epicenter of a large EQ is located offshore, the sea bed
sometimes undergoes enough displacement to cause a tsunami.
✓ The tremors associated with EQ can also activate landslides and
possibly volcanic activity.
✓ As a rule, the term earthquake is used to describe any seismic event
whether it be natural or man made.
http://www.rtmsd.org/page/1847
WebQuest: Earthquakes
Web Quest: Earthquakes
✓ Earthquakes are usually caused by a rupture at a fault line, but it may
also be caused by volcanic activity, landslides, mine blasts, or nuclear
experiments.
✓ The point beneath Earth’s surface where rock that is under stress
breaks, triggering an EQ, is called its focus or hypocenter.
✓ The point on the surface directly above the focus is called the
epicenter.
Stay tuned for instructions on how to turn in your completed Earthquakes
Web Quest
http://www.rtmsd.org/page/1847
WebQuest: Earthquakes
Web Quest: Earthquakes
Questions…
Part 1: Reuters News Service
Click on the following link to read the article.
Be sure to take note of the article’s date.
Use evidence from the text to answer the
questions to your right. Be prepared to cite
paragraph and line number.
1. Describe the quake…
(a) Where was the quake’s epicenter?
(b) How deep was the epicenter?
(c) What magnitude did it register?
2. When (date & time) did the quake strike?
3. What might be one reason earthquakes
frequently strike Taiwan?
http://www.reuters.com/article/worldNews/idUST
RE4B10X520081202
4. Describe one of Taiwan’s worst recorded
quakes.
(a)
(b)
(c)
(d)
http://www.rtmsd.org/page/1847
When?
What did it measure?
Casualties?
Structural damage?
WebQuest: Earthquakes
Web Quest: Earthquakes
Part 2: Earthquake Hazards
Program
Click on the following link to read the article.
Use evidence from the text to answer the
questions to your right. Be prepared to cite
paragraph and line number.
http://earthquake.usgs.gov/
Questions…
1. Find the information on the most recent quake…
(a) Magnitude
(b) Location
(c) Time
(d) Latitude & Longitude
(d) Death
2. Where was the most recent quake closest to
Jackson, MS? Provide the details for
this quake as requested in #1 above.
Double-click the USGS latest EQ map to answer
the following questions.
http://earthquake.usgs.gov/
http://www.rtmsd.org/page/1847
WebQuest: Earthquakes
Web Quest: Earthquakes
Questions…
Part 3: USGS Archives
Click on the following link to read the article.
Use evidence from the text to answer the
questions to your right. Be prepared to cite
paragraph and line number.
http://earthquake.usgs.gov/eqcenter/eqarchi
ves/
1. What was the deadliest earthquake in U.S.
history? How many casualties were
there?
2. Describe the largest earthquake MS has
experienced…
(a) Where
(b) When (local date/time)
(c) Magnitude
(d) Intensity
(e) Damage?
3. What are the top 10 earthquake states?
http://www.rtmsd.org/page/1847
WebQuest: Earthquakes
Web Quest: Earthquakes
Part 4: USGS Earthquake Hazards
Program – North American Map
Be sure to notice & understand the map key &
symbols!
If necessary, click on List of Earthquakes on
this Map to help you find your information.
http://earthquake.usgs.gov/eqcenter/recenteqsw
w/Maps/region/N_America.php
http://www.rtmsd.org/page/1847
Questions…
1. Describe the most recently recorded
earthquake according to this website.
(Latest Earthquakes)
(a) Magnitude
(b) Date/Time
(c) Latitude & Longitude
(d) Depth
(e) Region
2. Find information on the earthquake that
occurred in Iquique, Chile, on April 1,
2014. Include all the information
requested in #1 above. In addition to all of
the information requested in #1, what was
another concern of people regarding this
quake?
WebQuest: Earthquakes
Web Quest: Earthquakes
Part 5: FEMA Earthquake
Questions…
http://www.fema.gov/hazard/earthquake/index.s
htm
1 of 2
(a) Intense ground shaking can trigger many natural
hazards. What are some of these hazards?
Scroll down the page to find
“Learn About Earthquakes”
For question #1,. Click on
Why Earthquakes Occur.
For question #2, scroll down the page to click
on
Earthquake Fast Facts.
http://www.rtmsd.org/page/1847
(a) What are the three (3) major ways people can be
affected by earthquake hazards?
2 of 2
(a) Where do most EQ occur in the US? Which state
most often experiences the most damaging
quakes? Which state usually has the most
quakes?
(a) Where were the largest quakes felt in the US?
What magnitude were these quakes? Where
were they felt?
(a) What usually causes most EQ related injuries?
WebQuest: Earthquakes
Web Quest: Earthquakes
Part 6: National Geographic:
Tsunami 2004
http://news.nationalgeographic.com/news/2004/
12/1227_041226_tsunami.html
Read this article carefully at least twice before
you attempt to answer any questions.
Questions…
1. Why was it suggested that this might be the most
destructive tsunami in history?
2. How large was the EQ that caused the tsunami?
Where was the epicenter located?
3. Using previous knowledge, identify the plate boundary
& fault caused the EQ that triggered this tsunami?
4. How could a tsunami go unnoticed in the open ocean?
5. How tall were the waves that struck the coastlines
around the earthquake epicenter?
6. How did the tsunami announce its upcoming arrival in
some places? How much advanced warning did
this occurrence give?
7. Describe the behavior of animals just before the
tsunami struck.
http://www.rtmsd.org/page/1847
WebQuest: Earthquakes
Web Quest: Earthquakes
Helpful Links
Earthquakes
http://www.thetruthbehindthescenes.org/2011/08/24/5-9-earthquake-in-virginia-felt-in-washington-new-york-city-north-carolina-aug-23-2011/
https://sites.google.com/a/chadwickschool.org/earth-science-news2/earthquakes/eq-1
http://www.nationalatlas.gov/articles/geology/a_geohazards.html
http://mail.colonial.net/~hkaiter/equakeanimals.html
http://www.wiley.com/college/murck/QUAKE.HTM
http://www.sanandreasfault.org/EQS.html
http://www.brisbanetimes.com.au/christchurch-earthquake
http://www.mbmg.mtech.edu/kids/shakin.htm
http://talkinstuff.wordpress.com/2008/07/29/earthquake/
http://www.theatlantic.com/infocus/2011/03/japans-earthquake---the-aftermath/100023/
http://www.livescience.com/6187-13-crazy-earthquake-facts.html
http://www.npenn.org/page/5063
http://www.fema.gov/earthquake/why-earthquakes-occur
WebQuest: Earthquakes
Web Quest: Earthquakes
Helpful Links
Scales
http://www.buzzle.com/articles/richter-scale-vs-mercalli-scale.html
Article
http://www.scholastic.com/browse/article.jsp?id=3755944
http://www.ehow.com/list_7238883_scales-used-measure-earthquakes.html
http://www.geography-site.co.uk/pages/physical/earth/richt.html
WebQuest: Earthquakes
Web Quest: Earthquakes
Helpful Links
Richter Scale
Article
http://www.buzzle.com/articles/richter-scale-for-kids.html
http://science.howstuffworks.com/nature/natural-disasters/earthquake6.htm
http://earthquakefacts.net/Richter-Scale.html
http://www.scholastic.com/browse/article.jsp?id=4892
WebQuest: Earthquakes
Web Quest: Earthquakes
Helpful Links
Mercalli Scale
http://www.kids-fun-science.com/mercalli-scale.html
Activity
http://www.teachengineering.org/view_activity.php?url=collection/cub_/activities/cub_natdis/cub_natdis_lesson03_activity3.xml
www.kids-fun-science.com/mercalli-scale.html
http://geology.about.com/od/quakemags/a/Mercalli-Earthquake-Intensity-Scale.htm
http://earthquake.usgs.gov/learn/topics/mercalli.php
http://quake.abag.ca.gov/shaking/mmi/
WebQuest: Earthquakes
Web Quest: Earthquakes
Helpful Links
Moment Magnitude Scale
http://www.kids-fun-science.com/moment-magnitude-scale.html
http://www.the-science-site.com/moment-magnitude-scale.html
http://quake.ualr.edu/public/moment.htm
WebQuest: Earthquakes
Web Quest: Earthquakes
Helpful Links
Epicenter
http://www.kids-earth-science.com/earthquake-epicenter.html
Compare P & S Waves to lightning & thunder
http://earthquake.usgs.gov/learn/kids/eqscience.php
Article on how to locate an epicenter
http://gcn.com/Articles/2010/07/16/Washington-DC-Earthquake.aspx?Page=3&p=1
Virtual EQ – finding the epicenter
http://www.sciencecourseware.com/virtualearthquake/vquakeexecute.html
http://www.cacegypt.org/sinai/homework/greg/pages/q2_04/epicenterlab.html