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Unit 1: Planetary Systems: Quest for Balance

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What is a system? - interdependency - impact of change on a system - our needs within a system - dynamics of energy flow – PowerPoint PPT presentation

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Title: Unit 1: Planetary Systems: Quest for Balance


1
Unit 1 Planetary Systems Quest for Balance
  • What is a system?- interdependency- impact of
    change on a system- our needs within a system-
    dynamics of energy flow

2
What is a system?
  • Group of independent but interrelated elements
    comprising a _______________
  • Mutuality a reciprocal relation between
    interdependent entities (objects or individuals
    or groups)
  • The Earth system is a complex interaction between
    its subsystems the _______________________________
    ______

3
Impact of change on a system
  • The Sacred Balance?
  • Most systems tend toward a state of
    _______________ where system inputs are balanced
    by system outputs. Though natural systems change
    over long periods of time, on the scale of a
    human lifetime they appear to be static.

4
Impact of change on a system
  • A steady-state equilibrium is reached when the
    rates of system inputs and outputs are equal, and
    the amount of material stored in the system is
    constant over time.

5
Feedback
  • Outputs generated by the functioning of a system
    component either encourages change in the system
    (positive feedbacks)  or discourage changes
    (negative feedbacks). Negative feedbacks act to
    regulate the system to keep it in a state of
    equilibrium.
  • In order for a system to maintain a _____________
    or average condition the system must possess the
    capacity for ____________________.
  • Self-regulation in many systems is controlled by
    negative feedback and positive feedback
    mechanisms

6
Feedback
  • A negative feedback discourages system change. An
    example of a negative feedback is used to support
    the notion of biospheric regulation of the
    atmosphere called the _______________________" 
  • Some feel that the relatively stable conditions
    on Earth (atmospheric gas composition,
    temperature, etc) is due to the regulatory
    influence of the biosphere over the atmosphere

7
GAIA Hypothesis
  • http//www.veoh.com/collection/gaiaselene/watch/v3
    044782PYtPad9
  • http//www.youtube.com/watch?v44yiTg7cOVI
  • What is the Gaia Hypothesis?

8
Gaia Hypothesis
  • In 1965, __________________ published the first
    scientific paper suggesting the Gaia hypothesis
  • A theory that the living organisms of the
    biosphere form a single, complex interacting
    system that creates and maintains a habitable
    Earth named after Gaia, the Greek Earth mother
    goddess.
  • The idea that Earth is a living system. Life
    helps create the environment it needs in order to
    live.
  • In simpler terms, biological responses tend to
    regulate the state of the Earth's environment in
    their favor

9
This theory is important to Physical Geography
and other Earth Sciences for the following
reasons
  • The Gaia theory suggests that the abiotic and
    biotic environment is made up of many complex
    interrelationships
  • Many of these complex interrelationships are
    quite delicate and may be altered by human
    activity to a breaking point and
  • The theory suggests that humans must learn to
    respect Gaia by reducing their intentional
    modification of the Earth's abiotic and biotic
    components.

10
Positive Feedback Encourages Cange
11
Negative Feedback
12
System changes due to an imposed stress
13
Types of systems
  • Systems can be classified as open, closed, or
    isolated.
  • __________________ allow energy and mass to pass
    across the system boundary.  
  •  A _________________allows energy but not mass
    across its system boundary.
  • An _________________ allows neither mass or
    energy to pass across the system boundary. 

14
Open Systems
15
Closed System
  • Closed System - is a system that transfers
    energy, but not matter, across its boundary to
    the surrounding environment. Our planet is often
    viewed as a closed system.

16
Earth as a System!
17
Most systems share the same common
characteristics
  • Systems have a ____________that is defined by its
    parts and processes.
  • Systems tend to function in the same way. This
    involves the _______ and ________ of material
    (energy and/or matter) that is then processed
    causing it to change in some way.
  • The various parts of a system have functional as
    well as structural relationships between each
    other.
  • The fact that functional relationships exist
    between the parts suggests the _________and
    __________of some type of energy and/or matter.
  • Functional relationships can only occur because
    of the presence of a driving force.
  • The parts that make up a system show some degree
    of ______________ - in other words the parts work
    well together.

18
Our needs within a system?
  • Brainstorm with a partner!
  • Example System Element
  • System elements are the kinds of things or
    substances composing the system. They may be
    atoms or molecules, or larger bodies of
    matter-sand grains, rain drops, plants, or cows.

19
Dynamics of energy flow
  • Forces that shape the Earth derive their energy
    from a number of different sources.
    _________________ are those driven by exogenic
    forces that primarily derive their energy from
    solar radiation.

20
Energy Sources
  • For instance, soil erosion is caused by the force
    of wind acting on bare ground. We can trace the
    energy that causes wind erosion to the receipt of
    solar radiation

Texas dust storm during the Dust Bowl (1935) 
21
Energy Sources
  • _____________ are those that get their energy
    from endogenic forces originating deep within the
    Earth.
  • Such as

22
Energy Sources
  • Many of the great mountain systems like the
    Himalayas are a product of the collision of
    lithospheric plates

Mt. Paricutin, a cinder cone volcano
23
Self-Sustaining Systems
  • A spacesuit, out of necessity, is a
    self-sustaining system.

24
Self-Sustaining Systems
  • Biosphere 2 is a structure built in an attempt to
    build an Earth-like system to sustain life and
    constructed in a size small enough to be put into
    space.
  • Located in the Arizona desert outside of Tucson,
    is was built to replicate the Earths environment
    (Biosphere 1)
  • www.bio2.com

25
Self-Sustaining Systems
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