EARTH SCIENCE

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EARTH SCIENCE

• A Quick Review

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Where are we?

• 3rd planet from the sun
• About 92 million miles
• Perfect distance to balance warmth
• The Water Planet

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Who are we?

• Geosphere
• Hydrosphere
• Atmosphere
• Biosphere

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Earths History

• About 4.6 billion years old (according to rock
  record)
• Geologic Time scale - broken down into eons,
  eras, periods and epochs. (Precambrian epoch
  87 of time scale)

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Earths History

• Divisions mainly dependent on rise of certain
  types of organisms or major events.

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Earths Composition

• 3 major concentric zones
• Core
• Solid inner due to pressure (Ni Fe)
• Molten outer - creates magnetic field (Fe S)
• Mantle
• Mostly solid
• Asthenosphere slowly flowing
• Lithosphere
• Thin rigid
• Contains the crust

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Earths Magnetic Field
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Earths Crust

• Oceanic crust mostly basalt (more dense,
  3.0g/cm3)
• Continental crust mostly granite (less dense,
  2.7g/cm3)

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Plate Tectonics

• Nuclear decay in the core releases heat into the
  mantle and asthenosphere causing convection
  currents that create plate movement

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Plate Tectonics

• Convection currents have caused the mass movement
  of plates over millions of years.

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Plate Tectonics

• The movement of these plates is called
  Continental Drift.

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Plate Tectonics

• Each individual plate (about 12) is made of
  lithosphere and mantle.

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Plate Tectonics

• Today, the plates are still in motion
• PLATE TECTONICS
• http//sos.noaa.gov/videos/Paleo3.mov

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Plate Tectonics

• The plates today

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Plate tectonics

• Plate boundaries edges of the plates
• Three types convergent, divergent and transform

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Earths Crust

• Convergence
• (subduction)
• Creates mountains and volcanoes

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Earths Crust

• Divergence (ridge formation)
• Creates volcanoes and new crust

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Earths Crust

• Transform plates sliding past one another.
• Creates earthquakes

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Volcanoes

• Active
• Dormant
• Extinct
• Subduction volcanoes
• At plate boundaries
• Hot spot volcanoes
• In the middle of plates

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Volcanoes

• Rift Volcanoes
• Form new oceanic crust

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Earthquakes

• Each black dot is the location of an earthquake

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Earthquakes

• Anatomy
• Fault
• Focus
• Epicenter
• Waves

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Rock Cycle

• Rocks come from rocks
• Time, erosion, pressure and heat create 3 basic
  types
• Igneous
• Sedimentary
• Metamorphic

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Rock Cycle

• Erosion

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Soil

• A crucial link between biotic (living) and
  abiotic (nonliving)

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Earths orbit and rotation

• Revolution, rotation and tilt determine our days
  and seasons.

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Seasons

• Spring in the Northern, Autumn in the Southern

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Seasons

• Summer in the Northern, Winter in the Southern

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Seasons

• Autumn in the Northern, Spring in the Southern

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Seasons

• Winter in the Northern, Summer in the Southern

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The Atmosphere

• A layer of gases held close to the Earth by
  gravity
• With the help of the sun, its where our weather
  and climates occur

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Atmosphere

• Troposphere all of the weather, most of the
  water vapor and clouds.
• Well mixed layer.
• Area of the atmosphere that holds the greenhouse
  gases

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The Greenhouse Effect

• Without the greenhouse gases (CO2, H2O, and CH4)
  in the atmosphere, we wouldnt survive.

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Atmosphere

• Stratosphere not well mixed.
• Contains the ozone layer (O3)

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Atmosphere

• Mesosphere where meteors usually burn up.

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Atmosphere

• Thermosphere (or Ionosphere)
• Thinnest gas layer
• Auroras
• Space shuttles
• Ionization (absorption of solar wind)
• Reflects radio waves

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Atmosphere

• Exosphere
• Satellites
• Lightest gases H2 and He

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Atmosphere

• Magnetosphere area where the magnetic field of
  the earth dominantly controls the movements of
  gas and charged particles.

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Hydrosphere Biosphere

• Well cover these later..