Earth as a System
(Sect 1-2 & 1-4)
Satellite image of ash cloud being spewed from fissure in Chile’s Puyehue-Cordón Caulle
Volcanic Range, June 7, 2011
A. System
• A system is an organized group of related objects or
components that work independently and interact to
create a whole.
• Systems have matter and energy that flow freely
through the system.
• How matter and energy are transferred determines
whether the system is closed or open.
•
A closed system is a system where only energy is
transferred or exchanged with its surroundings.
• Matter is not part of this exchange.
A. System
Example of a Closed System
• Energy, in the form of
light, can enter.
• Energy can leave, too, as
heat passes out through
the glass walls of the jar.
But if the jar is tipped
over, the tea stays in.
• As a closed system, the
jar of tea does not share
matter with its surroundings.
A. System
An open system includes the transfer and exchange of
both matter and energy with the system's surroundings.
An example of a open
system: The jar of iced tea
would become an open
system if the lid of the jar
were to be removed,
allowing some of the tea to
evaporate. If a lemon slice
were added, new matter
would enter the system.
B. Earth’s Major Spheres
Atmosphere
Biosphere
All Air, gases
All Living Things
Geosphere
Hydrosphere
All Rock material
All Liquid/Frozen Water
C. Atmosphere
C. Atmosphere
• Thin gaseous envelope that surrounds the Earth
• Approximately 100 km above the Earth’s surface.
The Atmosphere Provides:
• Air we breath
• Protection (solar heat and radiation)
• Energy exchanged between space, atmosphere and
Earth’s surface produce weather and climate.
D. The Geosphere
• Geosphere is divided into 3 main parts based
on composition of material (Crust,Mantle
Core):
D. The Geosphere
• Crust:
– Continental (thicker less dense)
– Oceanic (thinner, more dense)
C. The Geosphere
• Mantle:
– Lithosphere = crust + uppermost rigid mantle
– Asthenosphere = upper mantle that is softer, flows
– Lower mantle = also called mesosphere
D. The Geosphere
• Core: made of iron and nickel
– Outer core (liquid), causes magnetic field
– Inner Core (solid): even though hotter, pressure
too high for liquid state)
D. The Geosphere
• The surface of Earth is covered with plates:
• Plate Tectonics: Theory (i.e., an explanation) as to
why continents have moved and the occurrence
of EQs and volcanic eruptions.
• Constructive and destructive process
E. Biosphere
E. Biosphere
• Includes all life on Earth
• Extends from the ocean floor upward into the
atmosphere.
• Living things form ecological communities called
biomes.
• Examples of biomes include:
• Deserts
• Grasslands
• Tropical Rainforests
F. Hydrosphere
F. Hydrosphere
• All of the Earth’s water makes up the hydrosphere.
• Water is continually moving
• Evaporation
• Precipitation
• Running Water (i.e. streams and rivers)
• Oceans account for 97% .
• Fresh water accounts for 3%
• Groundwater, streams, lakes and glaciers
• Sustaining life
• Creates Earths Features
• Availability of fresh water determines where many
organisms can live.
F. Hydrosphere
Atmosphere
Biosphere
Geosphere
Hydrosphere
•Spheres are interconnected and interdependent
•Soil is an interface between all of these
G. Earth as a System
• The Sun (light) drives external processes that
occur in atmosphere, hydrosphere and
biosphere
H. People and The Environment
• Humans can alter the system as well.
• Environmental Science: focuses on relationships
between people and natural world.
• Resources that society depends on are formed by
natural processes on Earth
– Water, soil, metal and nonmetal minerals (ores), and
energy
Sample from a zinc ore
mine in Franklain, NJ
H. People and The Environment
Renewable Resources
Nonrenewable Resources
•Replenished over short
•Replenished only over
time
VERY long time periods
•Ex: plants/animals for
because process to create is
food, natural fibers, forest
SLOW
products for lumber and
•Ex: Aluminum, Copper
paper
(though these can recycle)
•Energy: flowing water,
•Energy: fossil fuels like oil,
wind, solar energy
natural gas, coal
H. People and The Environment
Population
•How long will supplies of
basic resources last???
http://www.census.gov/main
/www/popclock.html
• As population increases,
so does demand for
resources. Especially as
world societies become
developed.