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2010 DP Earthquakes and Volcanoes

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2010 DP Earthquakes and Volcanoes Powered By Docstoc
					     2010 Dynamic Planet:
Earthquakes and Volcanoes
        Presented by Linder Winter
Use of this PowerPoint Presentation
   All images and content obtained from the web for use in
    this PowerPoint presentation falls under the Fair Use
    Policy for educational use.
   You may freely burn and distribute as many copies of this
    presentation as you wish.
   Feel free to alter this presentation in any way you wish.
Student Developed PPT. Presentations
 Encourage participants to create their own PowerPoint
  presentations as a way to prepare for this event.
 Suggest that participants first enter the event topics into their
  PowerPoint presentations similar to an outline.
 As participants search the web for specific topics they will
  frequently find information about other topics included in the
  event. They can ―fill-in‖ that information immediately.
 As participants discover better or more relevant informa-tion,
  they may replace previous material with the newly discovered
  material.
 Suggest that students ―hold off‖ developing their resource
  pages until they are well satisfied with their PowerPoints.
Dynamic Planet: Event Rotation
   2009 & 2010: Earthquakes & Volcanoes
   2011 & 2012: Earth’s Fresh Waters
   2013 & 2014: Glaciers
   2015 & 2016: Oceanography
1. DESCRIPTION
   Students will use process skills to complete tasks related
    to earthquakes and volcanoes.
   A team of up to: 2
   Approximate time: 50 minutes
2. EVENT PARAMETERS
   Each team may bring one 8.5‖ x 11‖ two-sided page of
    notes containing information in any print format from any
    source. Each participant may also bring a ―non-graphing‖
    calculator.
THE COMPETITION
   Participants will be presented with one or more tasks,
    many requiring the use of process skills (i.e. observing,
    classifying, measuring, inferring, predicting, communicating
    and using number relationships – source: AAAS) for any
    of the following topics: Each addressed separately.
Coaching Tips and Hints: Resources
   Resources are to knowledge events as projects are to
    construction events.
   Students develop their own resources; no hand-me-downs!
   Participant-produced resources provide an oppor-tunity for
    coaches to frequently and easily monitor participant progress.
   Encourage continual revision of resources, i.e. after each level
    of competition, when participants feel confident with their
    knowledge of specific topics, when new resources are
    discovered, etc.
Coaching Tips and Hints: Resources
Suggested items to include in student resources:
 Definitions of difficult or confusing terms
 Characteristics of the various types of volcanoes
 Diagrams and illustrations (diagrams included in this
  PowerPoint may “be lifted” and pasted onto resource pages.
 Characteristics of P, S and surface seismic waves
Coaching Tips and Hints
 With   the growing complexity of the events, it is very
  difficult, if not impossible, to coach all the events without
  assistance.
 Should you find someone willing to coach the
  Earthquakes and Volcanoes event, give him/her a copy of
  this PowerPoint presentation to provide an overview of
  the event.
Representative Activities
 Interpretation of charts, tables, diagrams (many of the diagrams
  included in this presentation may be developed into an
  activity).
 Locating the epicenter of a volcano
 Patterns of volcanic and earthquake patterns around the world
  (mapping)
 Identification of volcanic features
 Match volcanic features with familiar examples, i.e. Devil’s
  Tower – Volcanic Neck; Crater Lake – Caldera
 Provide images of various volcanoes and have students classify
  these by type.
Coaches’ Resources
 Information  on all topics identified in the event rules may
  easily be found on the web. Choice of ―key words and
  phrases‖ are the means to success!
 Be certain to caution participants to use only professional
  websites in their search for information. These include the
  USGS, college sites, etc.
 Middle/Junior/Senior High Earth Science Textbooks, and
  even Introductory college textbooks
 *The Game of Earth, NEW 2010 Edition
 *The Theory of PLATE TECTONICS CD
                                        *http://www.otherworlds-edu.com
a. Worldwide distribution patterns of
earthquakes and volcanoes
Types of Volcanoes: Shield Volcanoes
   Shield volcanoes are huge
    in size.
   They are built up by many
    layers of runny lava flows
    spilling out of a central
    vent or group of vents.
   The broad shaped, gently-
    sloping cone is formed
    from basaltic lava which
    does not pile up into
    steep mounds.
Types of Volcanoes: Stratovolcanoes
(Composite)
 Tall, conical volcanoes with
  many layers (strata) of
  hardened lava, tephra and
  volcanic ash
 Characterized by steep
  profiles and periodic,
  explosive eruptions
 Lava tends to be viscous
  (very thick)
 Common at subduction
  zones where oceanic crust is
  drawn under continental
  crust
Types of Volcanoes: Cinder Cones
   A cinder cone is a steep
    conical hill of volcanic
    fragments that accumulate
    around and downwind from a
    volcanic vent.
   The rock fragments, often
    called cinders or scoria, are
    glassy and contain numerous
    gas bubbles "frozen" into place
    as magma exploded into the air
    and then cooled quickly.
   Cinder cones range in size
    from tens to hundreds of
    meters tall. Cinder cones are
    made of pyroclastic material.
CONTROLS ON EXPLOSIVITY:
Possible interpretive activity

SiO2     MAGMA        TEMPERATURE      VISCOSITY         GAS        ERUPTION STYLE



          TYPE         (centigrade)                   CONTENT




~50%      mafic          ~1100            low            low         nonexplosive



~60%   intermediate       ~1000       intermediate   intermediate    intermediate



~70%      felsic          ~800           high            high          explosive
Explosive vs. Effusive
Types of Volcanoes: Active, Dormant,
Extinct
   Active volcanoes are in the process of erupting or show
    signs of possible eruption in the very near future.
   Dormant volcanoes are "sleeping." This means they are
    not erupting at this time, but have erupted in recorded
    history.
   An extinct volcano has not erupted in recorded history
    and probably will never erupt again.
Volcanic Hazards
                   Potential activity!
Primary Volcanic Hazards: Pyroclastic Flows
   Pyroclastic flows are fast-moving, avalanche-like, ground-
    hugging incandescent mixtures of hot volcanic debris, ash,
    and gases that can travel at speeds in excess of 150 km
    per hour.
Primary Volcanic Hazards: Lahars
   Lahars, also known as mud flows or debris flows, are
    slurries of muddy debris and water caused by mixing of
    solid debris with water, melted snow, or ice.
Primary Volcanic Hazards: Tephra
 Tephra (ash and coarser debris) is composed of fragments of
  magma or rock blown apart by gas expansion.
 Tephra can cause roofs to collapse, endanger people with
  respiratory problems, and damage machinery.
 Tephra can clog machinery, severely damage aircraft, cause
  respiratory problems, and short out power lines up to
  hundreds of miles downwind of eruptions.
Primary Volcanic Hazards: Gases
   The concentrations of different volcanic gases can vary
    considerably from one volcano to the next.
   Water vapor is typically the most abundant volcanic gas,
    followed by carbon dioxide and sulfur dioxide.
   Other principal volcanic gases include hydrogen sulfide,
    hydrogen chloride and hydrogen fluoride.
   A large number of minor and trace gases are also found in
    volcanic emissions, for example hydrogen, carbon monoxide,
    halocarbons, organic compounds, and volatile metal chlorides.
Primary Volcanic Hazards: Lava Flows
   Lava flows are generally not a threat to people because
    generally lava moves slowly enough to allow people to move
    away; thus they are more of a property threat.
Primary Volcanic Hazards: Flood Basalts
   A flood basalt or trap
    basalt is the result of a
    giant volcanic eruption or
    series of eruptions that
    coats large stretches of
    land or the ocean floor
    with basalt lava.
   Image: Moses Coulee
    showing former, multiple
    flood basalt flows of the
    Columbia River Basalt
    Group.
Secondary Volcanic Hazards: Flooding
    Drainage systems can become blocked by deposition of
     pyroclastic flows and lava flows. Such blockage may create a
     temporary dam that could eventually fill with water and fail
     resulting in floods downstream from the natural dam.

    Volcanoes in cold climates can melt snow and glacial ice, rapidly
     releasing water into the drainage system and possibly causing
     floods.
Secondary Volcanic Hazards: Famine
   Several eruptions during the past century have caused a
    decline in the average temperature at the Earth's surface
    of up to half a degree Fahrenheit for periods of one to
    three years.
   Tephra falls can cause extensive crop damage and kill
    livestock which may lead to famine.
Types of Earthquakes: Spreading Center
 An  oceanic spreading
  ridge is the fracture zone
  along the ocean bottom
  where molten mantle
  material comes to the
  surface, thus creating new
  crust.
 This fracture can be seen
  beneath the ocean as a
  line of ridges that form as
  molten rock reaches the
  ocean bottom and
  solidifies.
Types of Earthquakes: Subduction Zone
 Major  earthquakes may
  occur along subduction
  zones.
 The most recent sub-
  duction zone type earth-
  quake occurred in 1700.
 Scientists believe, on
  average, one subduction
  zone earthquake occurs
  every 300-600 years.
Types of Earthquakes: Transform Fault
   A transform fault is a
    special variety of strike-
    slip fault that accom-
    modates relative
    horizontal slip between
    other tectonic elements,
    such as oceanic crustal
    plates.
Types of Earthquakes: Intraplate
 Intraplate seismic activity
  occurs in the interior of a
  tectonic plate.
 Intraplate earthquakes are
  rare compared to those
  located at plate
  boundaries.
 Very large intraplate
  earthquakes can inflict       Distribution of seismicity associated with
  very heavy damage.            the New Madrid Seismic Zone since
                                1974.
Primary Earthquake Hazards: Rapid
Ground Shaking
                         Buckled roads and rail tracks
  Structural Damage
Secondary Earthquake Hazards: Rapid
Ground Shaking
   Landslides            Avalanches
Secondary Earthquake Hazards: Rapid
Ground Shaking
  Alterations to Water Courses   Fire resulting from an earthquake
Earthquake Hazards: Shake Map
                   The Shake Map for the 1994
                    magnitude 6.7 Northridge,
                    CA earth-quake shows the
                    epicenter at the location of
                    the green star.
                   The intensity of shaking
                    created by the earthquake is
                    shown by the different color
                    gradients on the map.
                   The magnitude of the
                    earthquake is 6.7 no matter
                    where you are, but the
                    intensities vary by location.
Structural Engineering Practices
 Early  alert capabilities in some cases will allow some
  systems to automatically shut down before the strong
  shaking starts.
 These systems may include elevators, utilities (water and
  gas), and factory assembly lines.
Volcanic Monitoring: Geologic History
 The initial step is to determine a volcano's eruption
 history, i.e. whether it is active, dormant or extinct.
Volcanic Monitoring: Associated Earthquake
Activity
                          ACTIVITY
   Each type of ground-shaking event usually generates a
    unique seismic "signature" that can be recognized and
    identified as having been "written" by a specific event.
   On the next slide, match each ―signature‖ with what
    you believe to be the activity.
Volcanic Monitoring: Associated Earthquake
Activity

         Type of Activity             Signature
   1. ___ Tectonic earthquake near
    Mount Rainier
   2. ___ Glacier sliding noise
   3. ___ Rock falls
   4. ___ Debris flow
   5. ___ Distant earthquake
   6. ___ Tectonic earthquake
    beneath Mount Rainier
Volcanic Monitoring: Associated Earthquake
Activity

         Type of Activity              Signature
   1. C Tectonic earthquake near
    Mount Rainier
   2. F Glacier sliding noise
   3. E Rock falls
   4. A Debris flow
   5. B Distant earthquake
   6. D Tectonic earthquake beneath
    Mount Rainier
Volcanic Monitoring: Associated Earthquake
Activity
   Each type of
   ground-shaking
   event usually
   generates a unique
   seismic "signature"
   that can be
   recognized and
   identified as having
   been "written" by a
   specific event.
   (Match activity with
   signature.)
Volcanic Monitoring: Magma Movement
 Earthquake activity beneath a volcano almost always increases before an eruption because
 magma and volcanic gas must first force their way up through shallow underground
 fractures and passageways.When magma and volcanic gases or fluids move, they will either
 cause rocks to break or cracks to vibrate. When rocks break, high-frequency earthquakes
 are triggered. However, when cracks vibrate either low-frequency earthquakes or a
 continuous shaking called volcanic tremor is triggered.
Volcanic Monitoring: Satellite Data
   Satellites can record infrared radiation where more heat
    or less heat shows up as different colors on a screen.
    When a volcano becomes hotter, an eruption may be
    coming soon.
Volcanic Monitoring: Hazard Maps
Earthquake Monitoring: Identification of
Faultlines




 New Madrid, Tennessee    San Andreas Faultline
Earthquake Monitoring: Remote
Seismograph Positioning
   Scientists consider seismic
    activity as it is registered on a
    seismometer.
   A volcano will usually register
    some small earthquakes as the
    magma pushes its way up
    through cracks and vents in
    rocks as it makes its way to the
    surface of the volcano.
   As a volcano gets closer to
    erupting, the pressure builds up
    in the earth under the volcano
    and the earthquake activity
    becomes more and more
    frequent.
Earthquake Monitoring:
Analog vs. Digital

This is an image of an analog recording of     Below is a digital seismogram. The data is
an earthquake. The relatively flat lines are   stored electronically, easy to access and
periods of quiescence and the large and        manipulate, and much more accurate and
squiggly line is an earthquake.                detailed than the analog recordings.
Earthquake Monitoring: Tiltmeter
   Tiltmeters attached to the
    sides of a volcano detect
    small changes in the slope
    of a volcano.
   When a volcano is about
    to erupt, the earth may
    bulge or swell up a bit.

                                 Installing a tiltmeter
Earthquake Monitoring: Changes in
Groundwater Levels
 Hydrogeologic    responses to large distant earthquakes
  have important scientific implications with regard to our
  earth’s intricate plumbing system.
 The exact mechanism linking hydrogeologic changes and
  earthquakes is not fully understood, but monitoring these
  changes improves our insights into the responsible
  mechanisms, and may improve our frustratingly imprecise
  ability to forecast the timing, magnitude, and impact of
  earthquakes.
Earthquake Monitoring: Observations of
Strange Behaviors in Animals
 The cause of unusual animal behavior seconds before humans
  feel an earthquake can be easily explain-ed. Very few humans
  notice the smaller P wave that travels the fastest from the
  earthquake source and arrives before the larger S wave. But
  many animals with more keen senses are able to feel the P
  wave seconds before the S wave arrives.
 If in fact there are precursors to a significant earthquake that
  we have yet to learn about (such as ground tilting,
  groundwater changes, electrical or magnetic field variations),
  indeed it’s possible that some animals could sense these signals
  and connect the perception with an impending earthquake.
Match each feature on the
diagram with its letter
designation (A-F).

___ Converging margin

___ Hot spot volcano

___ Transform fault

___ Rift volcano

___ Subduction volcano

___ Diverging margin
Match each feature on the
diagram with its letter
designation (A-F).

E Converging margin

D Hot spot volcano

C Transform fault

A Rift volcano

F Subduction volcano

B Diverging margin
Volcanism at Plate Boundaries




            Encyclopædia Britannica, Inc.
Volcanism Over Hot Spots (Oceanic and
Continental)
Volcanism: Hydrothermal Vents
                      A hydrothermal vent is a geyser
                       on the seafloor.
                      In some areas along the Mid-
                       Ocean Ridge, the gigantic plates
                       that form the Earth's crust are
                       moving apart, creating cracks
                       and crevices in the ocean floor.
                      Seawater seeps into these
                       openings and is heated by the
                       molten rock, or magma, that
                       lies beneath the Earth's crust.
                      As the water is heated, it rises
                       and seeks a path back out into
                       the ocean through an opening
                       in the seafloor.
Plate Boundaries: Ocean-Ocean
Convergence
                      When    two oceanic plates
                       converge one is usually
                       subducted beneath the
                       other and in the process a
                       deep oceanic trench is
                       formed.
                      Oceanic-oceanic plate
                       convergence also results
                       in the formation of
                       undersea volcanoes.
Plate Boundaries: Ocean-Continent
Convergence
                      When    an oceanic plate
                       pushes into and subducts
                       under a continental plate,
                       the overriding continental
                       plate is lifted up and a
                       mountain range is created.
                      This type of convergent
                       boundary is similar to the
                       Andes or the Cascade
                       Range in North America.
Plate Boundaries: Continent to Continent
Convergence
                       When   two continents
                       meet head-on, neither is
                       subducted because the
                       continental rocks are
                       relatively light and, like
                       two colliding icebergs,
                       resist downward motion.
                       Instead, the crust tends to
                       buckle and be pushed
                       upward or sideways.
Plate Boundaries: Divergent Plate
Boundaries - Oceanic




  When a divergent boundary occurs beneath oceanic lithosphere, the rising
  convection current below lifts the lithosphere producing a mid-ocean ridge.
Plate Boundaries: Divergent Plate
Boundaries - Continental




When a divergent boundary occurs beneath a thick continental plate, the pull-apart
is not vigorous enough to create a clean, single break through the thick plate
material. Here the thick continental plate is arched upwards from the convection
current's lift, pulled thin by extensional forces, and fractured into a rift-shaped
structure.
Plate Boundaries: Transform Plate
Boundaries at Mid-Ocean Ridges
                         Transform-Fault Boundaries
                          are where two plates are
                          sliding horizontally past one
                          another. These are also
                          known as transform
                          boundaries or more
                          commonly as faults.
                         Most transform faults are
                          found on the ocean floor.
                          They commonly offset active
                          spreading ridges, producing
                          zig-zag plate margins, and are
                          generally defined by shallow
                          earthquakes.
Plate Boundaries: Rifting of Continental
Plates
Plate Tectonics: Seafloor Spreading
   Sea-floor spreading — In the early 1960s, Princeton geologist Harry Hess proposed the
    hypothesis of sea-floor spreading, in which basaltic magma from the mantle rises to create
    new ocean floor at mid-ocean ridges.
   On each side of the ridge, sea floor moves from the ridge towards the deep-sea trenches
    where it is subducted and recycled back into the mantle
Geographical features associated with Plate
Tectonics
 Mid-ocean    ridges - Long    Trenches    - Deep, arcuate
 mountain chains on the          features, typically at the
 sea-floor that are elevated     borders of the oceans
 relative to the surrounding     where oceanic crust
 ocean floor.                    meets continental crust.
                                Trenches also occur
                                 where one oceanic plate is
                                 diving below another
                                 oceanic plate.
Geographical features associated with Plate
Tectonics
  Mid-Plate (intraplate) volcanoes - The numerous
  volcanoes found far away from the spreading center, or mid-
  ocean ridge.
 Volcanoes formed either due to hot spots, or actually formed
  at the spreading center but were carried away along with the
  plate.
 Over time, the volcanoes stop accreting new material and sink
  below sea level as the oceanic crust cools. Sea mounts are
  volcanoes below sea level, and guyots are volcanoes below sea
  level in which the top has been planed off.
 Very old submerged volcanoes can become abyssal hills.
Geographical features associated with Plate
Tectonics
 Island  or volcanic arcs - Found adjacent to trenches.
  Site where the rising magma from the subducting plate
  reaches the surface.
 These chains are arcuate owing to the spherical geometry
  of the Earth. Typically, these volcanoes have a mixed
  lithology between continental and oceanic crust
  (andesite).
Evidence of Sea Floor Spreading: Magnetic
Reversals
 Magnetism    on the ocean
  floor is orderly, arranged
  in long strips.
 The strips on the Atlantic
  ocean floor, in particular,
  are parallel to the mid-
  Atlantic ridge.
 Their structure and
  distribution are
  remarkably symmetric on
  both sides.
Evidence of Sea Floor Spreading: Age of Sea
Floor as Opposed to Continents
                       Scientists use the magnetic polarity of
                       the sea floor to determine its age.
                       Very little of the sea floor is older
                       than 150 million years. This is because
                       the oldest sea floor is subducted under
                       other plates and replaces by new
                       surfaces.
                       The tectonic plates are constantly in
                       motion and new surfaces are always
                       being created.
                       This continual motion is evidenced by
                       the occurrence of earthquakes and
                       volcanoes.
Evidence of Sea Floor Spreading: Fossil
Evidence
Density Differences between Continental
and Oceanic Plates
 Continental  margin - Because of the density difference
  between continental and oceanic crust, a particular
  geometry develops where the two types of crust meet.
 Starting from the continent, there is first a broad, flat
  zone called the "continental shelf."
 Then, near the end of continental crust, the angle
  increases and the area is called the "continental slope."
 Further out, at the actual border between the two crusts,
  the slope decreases, thus the "continental rise."
Faults: Dip-Slip - Normal
                         Normal faults happen in
                          areas where the rocks are
                          pulling apart (tensile forces)
                          so that the rocky crust of an
                          area is able to take up more
                          space.
                         The rock on one side of the
                          fault is moved down relative
                          to the rock on the other
                          side of the fault.
                         Normal faults will not make
                          an overhanging rock ledge.
                         In a normal fault it is likely
                          that you could walk on an
                          exposed area of the fault.
Faults: Dip-Slip - Reverse
                         Reverse faults happen in areas
                          where the rocks are pushed
                          together (compression forces)
                          so that the rocky crust of an
                          area must take up less space.
                         The rock on one side of the
                          fault is pushed up relative to
                          rock on the other side.
                         In a reverse fault the exposed
                          area of the fault is often an
                          overhang. Thus you could not
                          walk on it.
                         Thrust faults are a special type of
                          reverse fault. They happen when
                          the fault angle is very low.
Transform (strike-slip) Faults

                         The movement along a strike
                          slip fault is horizontal with
                          the block of rock on one
                          side of the fault moving in
                          one direction and the block
                          of rock along the other side
                          of the fault moving in the
                          other direction.
                         Strike slip faults do not make
                          cliffs or fault scarps because
                          the blocks of rock are not
                          moving up or down relative
                          to each other.
Faults: Normal and Reverse
   Normal – Normal faults
    form when the hanging wall
    drops down. The forces that
    create normal faults are
    pulling the sides apart
    (extensional).
   Reverse – Reverse faults
    form when the hanging wall
    moves up. Forces creating
    reverse faults are
    compressional, pushing the
    sides together.
HANGING WALL VS FOOTWALL
                  Vertical faults are the result
                   of up or down movement
                   along a break in the rocks.
                  Actually, both blocks may
                   move up or both blocks may
                   drop, or one might go up
                   and one might go down.
                  It is the end result of the
                   movement that classifies the
                   relationship between the
                   blocks.
HANGING WALL VS FOOTWALL
                  The hanging wall block is
                   the one on the left and
                   the foot wall block is the
                   one on the right.
Faults: Strike-Slip
   Strike-slip faults have
    walls that move
    sideways, not up or
    down.
   The forces creating
    these faults are lateral
    or horizontal, carrying
    the sides past each
    other.
Faults: Transform
                       Transform boundaries occur
                        when the two plates move past
                        one another. This is primarily a
                        function of equal density of the
                        plates; however, it also occurs
                        due to the direction of
                        movement.
                       The boundary of movement is
                        called the transform fault. In
                        reality, it is rarely a singular
                        fault but rather a zone.
                       Outlying the transform faults
                        are records of past tectonic
                        activity called "fracture zones."
Climatic Effects of Volcanic Ejecta
   Volcanic dust blasted into the atmosphere causes
    temporary cooling.
   Volcanoes that release huge amounts of sulfur
    compounds affect the climate more strongly than those
    that eject just dust. Combined with atmospheric water,
    they form a haze of sulfuric acid that reflects a great deal
    of sunlight which may cause global cooling for up to two
    years. Much more at:
    http://www.cotf.edu/ete/modules/volcanoes/vclimate.html
Tsunamis
Tsunamis: Origin
Tsunamis can be generated by:
   Large Earthquakes (megathrust events such as Sumatra, Dec.
    26, 2004)
   Underwater or near-surface volcanic eruptions (Krakatoa,
    1883)
    Comet or asteroid impacts (evidence for tsunami deposits
    from the Chicxulub impact 65 mya)
    Large landslides that extend into water (Lituya Bay, AK, 1958)
    Large undersea landslides (evidence for prehistoric undersea
    landslides in Hawaii and off the east coast of North America)
Tsunamis: Origin
Tsunamis: Wave Characteristics




  Tsunami wave propagation characteristics – note that as water
  depth becomes smaller, waves slow down, become shorter
  wavelength, and have larger amplitude.
Tsunamis: Warning System
 A tsunami warning system is
  a system to detect tsunamis
  and issue warnings to
  prevent loss of life and
  property.
 It consists of two equally
  important components: (1) a
  network of sensors to
  detect tsunamis and (2) a        Tsunami Monitoring Buoy:
  communications                   Reports rises in the water
  infrastructure to issue timely   column and tsunami events
  alarms to permit evacuation
  of coastal areas.
Stages in the “life” of a Tsunamis : Initiation
                         Near the source of sub-
                          marine earthquakes, the
                          seafloor is "permanently"
                          uplifted and down-dropped,
                          pushing the entire water
                          column up and down.
                         The potential energy that
                          results from pushing water
                          above mean sea level is then
                          transferred to horizontal
                          propagation of the tsunami
                          wave (kinetic energy).
Stages in the “life” of a Tsunamis: Split
                       Within  several minutes of
                       the earthquake, the initial
                       tsunami is split into a
                       tsunami that travels out to
                       the deep ocean (distant
                       tsunami) and another
                       tsunami that travels
                       towards the nearby coast
                       (local tsunami).
Stages in the “life” of a Tsunamis:
Amplification
                         Several things happen as
                          the local tsunami travels
                          over the continental slope.
                          Most obvious is that the
                          amplitude increases. In
                          addition, the wavelength
                          decreases. This results in
                          steepening of the leading
                          wave--an important
                          control of wave runup at
                          the coast.
Stages in the “life” of a Tsunamis: Runup
                        Tsunami  runup occurs
                         when a peak in the
                         tsunami wave travels from
                         the near-shore region
                         onto shore.
                        Runup is a measure-ment
                         of the height of the water
                         onshore observed above a
                         reference sea level.
Seismic Waves: Primary (P)
   P-waves are the fastest
    type of seismic wave. As P-
    waves travel, the
    surrounding rock is
    repeatedly compressed
    and then stretched.
   (Note: S and P waves are
    classified as ―body‖
    waves.)
Seismic Waves: Secondary (S)
   S-waves arrive after P-
    waves because they travel
    more slowly. The rock is
    shifted up and down or
    side to side as the wave
    travels through it.
Seismic Waves: Surface Waves
   Rayleigh waves, also called
    ground roll, travel like
    ocean waves over the
    surface of the Earth,
    moving the ground surface
    up and down. They cause
    most of the shaking at the
    ground surface during an
    earthquake.
   Love waves are fast and
    move the ground from
    side to side.
       Seismic Waves:
       Primary (P)
       The  fastest wave,
       and therefore the first
       to arrive at a given
       location.
       Also   known as
       compressional waves,
       the P wave alternately
       compresses and
       expands material in
       the same direction it
       is traveling.
       Can    travel through
USGS   all layers of the Earth.
       Seismic Waves:
       Secondary Waves (S)
       The   S wave is slower
       than the P wave and
       arrives next, shaking
       the ground up and
       down and back and
       forth perpendicular to
       the direction it is
       traveling.
       Also    know as shear
       waves.



USGS
       Seismic Waves:
       Surface Waves
       Surface waves follow
       the P and S waves.
       Also  known as
       Rayleigh and Love
       waves.
       These  waves travel
       along the surface of
       the earth.




USGS
Seismic Waves Measurement:
Intensity vs. Magnitude
   Intensity scales measure the        Magnitude scales, like the
    amount of shaking at a               Richter magnitude and moment
    particular location.                 magnitude, measure the size of
   The intensity of an earthquake       the earthquake at its source.
    will vary depending on where        Magnitude does not depend on
    you are.                             where the measurement of the
                                         earthquake is made.
                                        On the Richter scale, an
                                         increase of one unit of
                                         magnitude (for example, from
                                         4.6 to 5.6) represents a 10-fold
                                         increase in wave amplitude on
                                         a seismogram or approximately
                                         a 30-fold increase in the energy
                                         released.
Seismic Waves Measurement: Intensity
   I. Not felt except by a very few under especially favorable conditions.
   II. Felt only by a few persons at rest, especially on upper floors of buildings.
   III. Felt quite noticeably by persons indoors, especially on upper floors of buildings. Many people do not recognize it as an
    earthquake. Standing motor cars may rock slightly. Vibrations similar to the passing of a truck. Duration estimated.
   IV. Felt indoors by many, outdoors by few during the day. At night, some awakened. Dishes, windows, doors disturbed; walls
    make cracking sound. Sensation like heavy truck striking building. Standing motor cars rocked noticeably.
   V. Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects overturned. Pendulum clocks may
    stop.
   VI. Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight.
   VII. Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures;
    considerable damage in poorly built or badly designed structures; some chimneys broken.
   VIII. Damage slight in specially designed structures; considerable damage in ordinary substantial buildings with partial
    collapse. Damage great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture
    overturned.
   IX. Damage considerable in specially designed structures; well-designed frame structures thrown out of plumb. Damage great
    in substantial buildings, with partial collapse. Buildings shifted off foundations.
   X. Some well-built wooden structures destroyed; most masonry and frame structures destroyed with foundations. Rails bent.
   XI. Few, if any (masonry) structures remain standing. Bridges destroyed. Rails bent greatly.
   XII. Damage total. Lines of sight and level are distorted. Objects thrown into the air.
Seismic Waves Measurement: Focal Depth
                       The vibrations produced by
                        earthquakes are detected,
                        recorded, and measured by
                        instruments call seismographs.
                       The zig-zag line made by a
                        seismograph, called a
                        "seismogram," reflects the
                        changing intensity of the vibrations
                        by responding to the motion of
                        the ground surface beneath the
                        instrument.
                       From the data expressed in
                        seismograms, scientists can
                        determine the time, the epicenter,
                        the focal depth, and the type of
                        faulting of an earthquake and can
                        estimate how much energy was
                        released.
    EARTHQUAKE & VOLCANOES QUIZ
   Check your knowledge of Earthquakes and Volcanoes.
    Number from 1 to 10 on a sheet of scratch paper.You will
    be asked a series of ten questions. The answer to each
    question will appear on the slide immediately following
    each question.
    EARTHQUAKE & VOLCANOES QUIZ
   1. The time lag between which two seismic waves may be
    used to determine the distance from the focus of an
    earthquake?
    EARTHQUAKE & VOLCANOES QUIZ
   1. The time lag between which two seismic waves may be
    used to determine the distance from the focus of an
    earthquake? P and S
    EARTHQUAKE & VOLCANOES QUIZ
   2. Is new oceanic crust added at divergent or convergent
    plate boundaries?
    EARTHQUAKE & VOLCANOES QUIZ
   2. Is new oceanic crust added at divergent or convergent
    plate boundaries? DIVERGENT
    EARTHQUAKE & VOLCANOES QUIZ
   3. Does an ocean basin decrease or increase in size when
    its rate of subduction exceeds its rate of crust
    production?
    EARTHQUAKE & VOLCANOES QUIZ
   3. Does an ocean basin decrease or increase in size when
    its rate of subduction exceeds its rate of crust
    production? DECREASE
    EARTHQUAKE & VOLCANOES QUIZ
   4. What nearly landlocked sea was formed during rifting
    of the African and Eurasian plates?
    EARTHQUAKE & VOLCANOES QUIZ
   4. What nearly landlocked sea was formed during rifting
    of the African and Eurasian plates? MEDITERRANEAN
    EARTHQUAKE & VOLCANOES QUIZ
   5. Identify the world’s deepest ocean trench, located
    where the Pacific Plate is slipping beneath the Philippine
    plate.
    EARTHQUAKE & VOLCANOES QUIZ
   5. Identify the world’s deepest ocean trench, located
    where the Pacific Plate is slipping beneath the Philippine
    plate. MARIANAS
    EARTHQUAKE & VOLCANOES QUIZ
   6. From the name of which mythological Roman
    blacksmith was the term ―volcano‖ derived?
    EARTHQUAKE & VOLCANOES QUIZ
   6. From the name of which mythological Roman
    blacksmith was the term ―volcano‖ derived? VULCAN
    EARTHQUAKE & VOLCANOES QUIZ
   7. What unifying theory attempts to explain the major
    events in the evolution of Earth’s surface?
    EARTHQUAKE & VOLCANOES QUIZ
   7. What unifying theory attempts to explain the major
    events in the evolution of Earth’s surface? PLATE
    TECTONICS
    EARTHQUAKE & VOLCANOES QUIZ
   8. Are stratovolcanoes associated with subduction zones
    or hot spots?
    EARTHQUAKE & VOLCANOES QUIZ
   8. Are stratovolcanoes associated with subduction zones
    or hot spots? SUBDUCTION ZONES
    EARTHQUAKE & VOLCANOES QUIZ
   9. What tectonic feature lies directly above the focus of
    an earthquake?
    EARTHQUAKE & VOLCANOES QUIZ
   9. What tectonic feature lies directly above the focus of
    an earthquake? EPICENTER
    EARTHQUAKE & VOLCANOES QUIZ
   10. What surface depression is created by the collapse of
    an empty magma chamber?
    EARTHQUAKE & VOLCANOES QUIZ
   10. What surface depression is created by the collapse of
    an empty magma chamber? CALDERA
    EARTHQUAKE & VOLCANOES QUIZ
   Source of questions:
    New 2010 version of ―The Game of EARTH‖
    www.otherworlds-edu.com
5. Scoring
 Pointswill be awarded for the quality and accuracy of
 responses. Ties will be broken by the accuracy and/or
 quality of answers to pre-selected questions.
5. Scoring
 Pointswill be awarded for the quality and accuracy of
 responses. Ties will be broken by the accuracy and/or
 quality of answers to pre-selected questions.
7. NATIONAL SCIENCE EDUCATION
STANDARDS
 Content  Standard D. Structure of the Earth System;
 Earth’s history.
Additional Resources
 Volcanic Hazards & Prediction of Volcanic Eruptions:
  http://www.tulane.edu/~sanelson/geol204/volhaz&pred.ht
  m
 NSTA PowerPoint Presentation on Tsunamis
  http://web.ics.purdue.edu/~braile/edumod/tsunami/Ts
  unami!.ppt
 Hydrothermal vents
http://www.ceoe.udel.edu/deepsea/level-
  2/geology/vents.html
 Plate boundaries
http://www.platetectonics.com/book/page_5.asp
Additional Resources
 PowerPoint  of Seafloor Spreading
http://www.sci.csuhayward.edu/~lstrayer/geol2101/2101
  _Ch19_03.pdf
 Windows to the Universe: Earthquakes
http://www.windows.ucar.edu/tour/link=/earth/geology/
  quake_1.html

				
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