Earth as a System

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Chapter 1.1

• Earth as a System

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Branches of Science

• Earth Science
• The study of the Earth, its atmosphere, and the
  universe surrounding it.
• Biology
• Also referred to as Life Science.
• The study of living things.
• Chemistry
• The study of the interaction of matter.
• Physics
• The study of motion.

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Past ViewBranches of Earth Science

• In the past, Earth Science was viewed as having 4
  distinct and separate branches.
• Geology
• The study of the solid Earth as well as the
  processes that change and shape it.
• Examples) rocks, volcanoes, rivers, glaciers
• Astronomy
• The study of the universe beyond Earth
• Examples) stars, the Sun, the Moon, planets
• Oceanography
• The study of the Earth's oceans
• Examples) ocean temperatures, saline (salt)
  levels
• Meteorology
• The study of the Earths atmosphere
• Examples) weather patterns, tropical storms

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Today's viewEarth System Science

• Earth is more than a collection of parts
• Each branch of Earth Science is connected to one
  another

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What is a System?

• A system is a kind of model a part of the
  universe that can be studied separately
• A model is a representation of an object, a
  process or a phenomenon.
• Scientists often describe the natural world by
  using models such as open and closed systems

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Closed System

• Energy, such as sunlight, may enter, but matter
  doesnt enter or leave
• Example) Sun Tea
• Sunlight can enter
• Heat can leave
• If jar is tipped, tea stays in
• The jar of tea does not share matter with its
  surroundings, only energy

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Another Example

• Deep-Sea Submersible
• Minimal loss of energy to surrounding ocean
• Keeps water out protecting researchers
• Keeps air in so researchers can breathe

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Open System

• The system and its surroundings freely exchange
  both energy and matter
• Example) glass of iced tea
• Tea can evaporate
• A bug can fly in (ew!)
• A lemon slice and a straw are added

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Another Example

• An island
• Sunlight strikes the surface warming it
• Rain falls onto the island
• Sediment runs off into the ocean

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Is Earth Open or Closed?

• Scientists consider Earth to be essentially
  closed
• Energy is received from the sun and most is
  reflected back
• Overall Earths mass remains relatively constant
• System is not entirely closed
• Atmosphere loses hydrogen atoms to space
• Meteorites enter the atmosphere