Earthquakes and Volcanoes

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Earthquakes and Volcanoes
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Bell Work 12/8/10

• Describe how earthquakes can make buildings, road
  and other infrastructures break and move?

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Rest of this week and next

• Wednesday (12-8-10)- Slides 1-6 and handout
  science fair packets and talk about it
• Thursday (12-9-10) - Complete slides 7-12 and
  start B/F/F scenario
• Friday (12-10-10)- Complete B/F/F Scenario
• Monday (12-13-10)- B/F/F Scenario is due and
  complete study guide
• Tuesday (12-14-10)- Go to library for science
  fair
• Wednesday- 15 mins just over study guide answers
• Thursday - opportunity to work on their science
  fair project and/or study for upcoming exams.
• Friday Final exam 118-305

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• Earthquakes
• Earthquake is the shaking and trembling that
  results from the sudden movement of part of the
  Earths crust.
• Tsunamis A giant sea wave produced by an
  earthquake.

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• Seismic Waves
• Focus The point beneath the Earths surface
  where the rocks break and move, the underground
  origin of the earthquake.
• Epicenter The point directly above the focus,
  on the earths surface where the origin of an
  earthquake is above ground.

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Faults- Once the elastic limit of rocks is
passed, they break and move along surfaces.

• 3 types of faults are
• Normal Fault- These form at divergent boundaries.
• Reverse Fault- These form at convergent
  boundaries.
• Strike-Slip Fault- These form at transform
  boundaries.

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• Seismic waves earthquake waves. Three types.
• 1. Primary waves (P-waves) arrive at a
  given point before any other type of seismic
  wave. Will pass through solid, liquid and
  gas.(fastest of the three)
• 2. Secondary Waves (S-waves) arrive at a
  given point after the P wave. (second fastest)
  Will only travel thru solids. Will NOT pass
  through liquids and gases thus creating a shadow
  zone.

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• 3. Surface waves (L-waves) slowest
  moving seismic waves. Arrives last.

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• Volcanoes
• Volcano the place in the Earths surface
  through which magma and other materials reach
  the surface.
• Magma rock that exists as a hot liquid deep
  within the earth.
• Lava is magma that reaches the Earths surface.

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• Vent an opening from which lava erupts.
• Crater Steep walled depression around a
  volcanos vent.
• Hot Spot Hot rock that is a result of unusually
  hot areas in the mantle and core where volcanoes
  form on the Earths surface. Hawaii is the result
  of a hot spot.

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• Lava flows
• Basaltic Is lava that contains a lot of water
  and rich in iron and magnesium. Thin and quiet
  eruptions.
• Granitic - this lava contains very little water
  and is rich in silicon and aluminum. Thick heavy
  lava causing gases to trap underneath producing
  large violent eruptions. 

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• Composite Volcanoes are made of alternating
  layers of rock particles and lava. Violent
  eruptions followed by quiet lava flows are the
  reasoning for the alternating layers.

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• Caldera A roughly circular, steep-sided pit at
  the top of a volcanic cone whose diameter is at
  least three times its depth.

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• Andesitic - is a combination of both granitic
  and basaltic lava flows (quieter than granitic
  but more violent than basaltic).
• Gas filled lava This lava cools to form hole
  filled rock that has the appearance of a sponge
  or loaf of bread. This rock type is typically
  light in weight. Pumice and scoria are examples
  of this type of igneous rock.
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• Liquefaction Shaking up of wet soil making it
  unstable. This causes surface object to sink.
• Earthquake preparedness Tie down heavy objects,
  take objects off of high shelves. Build on an
  earthquake proof foundation. Have a plan and
  emergency items.

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• Seismograph is an instrument that detects and
  measures seismic waves.
• Seismogram is the record of waves. (paper
  record)
• Seismologists scientists who study
  earthquakes.
• Richter scale calculation of the strength
  or magnitude of an earthquake.
• For every 1 point rise 30 times the energy is
  released.
• Magnitude - Height of a line traced on a
  seismogram.

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• Tephra bits of rock or solidified lava dropped
  from the air.
• Volcanic Dust Is fragments of rock that are
  blown into the air during a volcanic eruption.
  (very small particles)
• Volcanic Ash Is particles blown into the air
  from a volcano that are bigger than volcanic dust
  yet smaller than anything else.

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• Volcanic Bombs Are large rock particles that
  are blown out during a volcanic eruption.
• Volcanic cinders are smaller volcanic bombs.

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• Cinder cone volcano Volcanoes made mostly of
  cinders and other rock particles that have been
  blown into the air. Narrow bases with steep sides
  due to loosely arranged cinder type eruptions.

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• Shield volcano Volcanoes composed of quiet lava
  flows. Gently sloping sides with very wide base.

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• Dike
• Batholith
• Sill -

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• Dormant (sleeping) has erupted but not in
  modern time.
• Extinct Not known to have erupted in recorded
  time. Usually weathered down to base.
• Active well, it is active in modern time.
• ZONES
• Ring of fire is the zone of active earthquakes
  and volcanoes due to very active tectonic plate
  movement.

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• Mid-Atlantic ridge chain of ridges caused by
  sea floor spreading.

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