Chapter 1: Earth as a System

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Chapter 1 Earth as a System
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Chapter 1.1
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A New View of Earth
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Past Perceptions Meet New Issues

• Scientist in Earth Science use to specialize, one
  would steady the rocks on a mountain while
  another study the water and another life forms.
• Today Scientists realize that Earth is more than
  a collection of parts. Earth System Science is
  the study of and interaction of all parts.

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The rise of Earth System Science

• Came about due to advances in Technology
• Satellites, deep diving subs, geographic
  information systems
• Better models to represent objects, processes and
  phenomenon.

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What is a system?

• Its a kind of model that can be defined as part
  of the universe that can be studied separately.
• Include time as a variable figure future or
  past
• Closed System something enters but cant leave
• Sun tea the closed jar doesnt share matter
  with its surroundings.
• Open Systems the system and its surrounding
  freely exchange both energy and matter
• Earth System Science scientists study the flow
  of energy and matter between the components of
  the Earth System.

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A Planetary System

• Earth is considered a closed system. However, it
  is not entirely closed. The atmosphere looses
  hydrogen atoms to space and meteorites enter the
  earth.
• Considered closed because the resource of earth
  are finite (limited)

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Nature, Science and Human Policy

• Changes humans are making after realizing their
  impact on Earth.
• Recycle
• Environmental concerns before growth
• Flagstaff AZ ---water
• Not easy to balance human needs and wants
• Global warming
• Ozone
• Water and air pollution

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Chapter 1.2
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The Earth Systems Four Spheres

• The four systems interact continually affecting
  the others.

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Atmosphere

• Its the gaseous envelop that surrounds the
  Earth.
• It provides oxygen, Co2, ozone, water, vapor,
  clouds, rains, and snow.
• It is the only atmosphere in the solar system to
  contain free oxygen.

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Geosphere

• Made up of all physical features on the planet
  except water
• Rock, mountains, beaches, rock layers, ocean
  basins, mantle, core, volcanoes

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Hydrosphere

• Contains all the water on Earths surface
• Liquid, gas, ice
• Most of Earths water is salty.
• Only 3 is fresh of that 70 is in the form of
  ice.
• Only ½ of 1 is usable fresh water.
• All water is recycled. The water you drank today
  may have been some of the same water a dinosaur
  drank before.

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Biosphere

• Includes all living things on Earth even people.

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Interactions among the spheres

• All 4 spheres interact with each other
• Volcanoes (geo) erupts, sending ash and gases
  into the air (atmos) and lava and ash down into
  surrounding forest (bio)

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Interactions change the spheres

• Short change
• A late freeze kills vegetable plants
• A downpour cause roads to cave in
• Long term change Erosion the continual
  breakdown and transportation of the solid
• Humans can be affected by the interaction of the
  spheres and they can affect the spheres
• Burning of fossil fuels leads to more CO2 in the
  atmosphere

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Chapter 1.3
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Cycles of Earth

• A cycle is a sequence of events that repeats

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The Water Cycle

• A continuous circulation of water through the
  hydrosphere (p 13 diagram)
• Some water evaporates quickly of breathed out
  (transpired) by leaves of plants
• Evapotranspiration cycling of water into the
  atmosphere by evaporation and transpiration

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The Carbon Cycle

• A biogeochemical cycle involving the element
  carbon
• Things that release carbon into the atmosphere
• Breathing, decaying organic matter, burning of
  fossil fuels, forest fires, volcanoes

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• Things that remove carbon
• Caron Sink where carbon is stored due to the
  death and burial of organisms with carbon in
  their tissues
• The ocean removes about 40 of the carbon in the
  atmosphere

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The Energy Cycle

• Is the movement of energy into and out of the
  earth system
• The amount of energy in should equal the amount
  out. If it doesnt the climate would get warmer.
• 99.985 of the energy on earths surface comes
  from the sun as solar energy. Drives wind,
  currents and waves

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• .013 is energy from the earth geothermal energy.
  Powers lithosphere (plate movement) volcanoes,
  geysers earth quakes and the rock cycle
• .0002 is tidal energy due to the pull of the moon
  on the oceans waters.
• To maintain the energy budget of the incoming
  energy 40 reflected back to space the rest is
  used in the earth system.

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Law of Thermodynamics

• 1st Law Energy can not be created or destroyed
  only changed form one form to another.
• 2nd Law when energy changes it is converted
  from a more useful, more concentrated form to a
  less useful, less concentrated form. Energy can
  never be recycled (like water)

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The Effects of Earths Surface

• Due to the differences on earths surface
  (glaciers, water, light land and dark land) it
  will reflect solar energy differently.
• Albedo is the percent of energy that is
  reflected without being changed.

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• Lighter colors have a higher albedo (e.g. ice)
  than darker colors (e.g. forest) which have a low
  albedo.
• An areas albedo can change green field vs. a
  plowed field, summer green vs. winter white

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Human Activities and the Cycles

• Human Activity can affect the interaction of the
  spheres and cycles
• Burning fossil fuels adds more carbon to the
  atmosphere
• All the actions of humans have an effect on the
  earth. Earth Science System tries to figure out
  how far and deep the effect travels.