Lecture Outlines PowerPoint Chapter 1 Earth Science, 12e Tarbuck

Lecture Outlines
PowerPoint
Chapter 1
Earth Science, 12e
Tarbuck/Lutgens
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 Encompasses all sciences that seek to
understand
•  Earth
•  Earth’s neighbors in space
 Earth Science includes
•  Geology – literally the “study of Earth”
•  a. Physical geology examines the materials
composing Earth
•  b. Historical geology is the study of the origin and
development of Earth
 Earth Science includes
1.  Oceanography – a study of the ocean
a)  Not a separate and distinct science
1. 
2. 
3. 
4. 
Chemistry
Physics
Geology
Biology
•  Meteorology – the study of the atmosphere
and the processes that produce weather
•  Astronomy – the study of the universe
A.  Origin of Earth
1.  Most researchers believe that Earth and the
other planets formed at essentially the same
time
2.  Nebular hypothesis
a)  Solar system evolved from an enormous rotating
cloud called the solar nebula
b)  Nebula was composed mostly of hydrogen and
helium
 Origin of Earth
•  Nebular hypothesis (cont’d)
c) About 5 billion years ago the nebula began to
contract
d) Assumes a flat, disk shape with the protosun
(pre-Sun) at the center
e) Inner planets begin to form from metallic and
rocky clumps
f) Larger outer planets began forming from
fragments with a high percentage of ices
1.  Formation of Earth’s layered structure
1.  As Earth formed, the decay of radioactive
elements and heat from high-velocity
impacts caused the temperature to
increase
1.  Iron and nickel began to melt and sink toward
the center
2.  Lighter rocky components floated outward,
toward the surface
2.  Gaseous material escaped from Earth’s
interior to produce the primitive
atmosphere
Figure 1.8
A.  Hydrosphere
1.  Ocean – the most prominent feature of
the hydrosphere
a)  Nearly 71% of Earth’s surface
b)  About 97% of Earth’s water
2.  Also includes fresh water found in
streams, lakes, and glaciers, as well as
that found underground
B. Atmosphere
1.  Thin, tenuous blanket of air
2.  One-half lies below 5.6 kilometers (3.5
miles)
C. Biosphere
1.  Includes all life
2.  Concentrated near the surface in a zone
that extends from the ocean floor upward
for several kilometers into the atmosphere
3.  Influences other three spheres
D. Geosphere
1.  Based on compositional differences, it
consists of:
a)  crust
b)  mantle
c)  Core
D. Solid Earth
2. Divisions of the outer portion are based on
how materials behave
a)  Lithosphere - rigid outer layer
1.  Crust
2.  Uppermost Mantle
b)  Divisions of Earth’s surface
1.  Continents
2.  Ocean basins
Figure 1.13
A.  Science assumes the natural world is
•  Consistent
•  Predictable
B.  Goal of science
•  To discover patterns in nature
•  To use the knowledge to predict
C.  An idea can become a
1.  Hypothesis (tentative or untested
explanation)
2.  Theory (tested and confirmed hypothesis)
3.  Paradigm (a theory that explains a large
number of interrelated aspects of the
natural world)
C.  Scientific method
1.  Gather facts through observation
2.  Formulate
a)  Hypotheses
b)  theories
E.  Scientific knowledge is gained through
1.  Following systematic steps
a) 
b) 
c) 
d) 
Collecting facts
Developing a hypothesis
Conduct experiments
Reexamine the hypothesis and
1)  accept,
2)  modify,
3)  or reject
•  Theories withstand examination
•  Totally unexpected occurrences?
 Environment
•  Surrounds and influences organisms
•  Physical environment encompasses water,
air, soil, and rock
•  Term “environmental” is usually reserved
for those aspects that focus on the
relationships between people and the
natural environment
 Resources
•  An important focus of the Earth sciences
•  Includes water, soil, minerals, and energy
•  Two broad categories
•  Renewable – can be replenished (examples
include plants and energy from water and wind)
•  Nonrenewable – metals (examples include
metals and fuels)
 Population
•  Population of the planet is growing rapidly
•  Rate of mineral and energy usage has
climbed more rapidly than the overall
growth of population
 Environmental problems
•  Local, regional, and global
•  “Think Globally, Act Locally”
 Environmental problems
•  Human-induced and accentuated
•  Urban air pollution
•  Acid rain
•  Ozone depletion
•  Global warming
 Environmental problems
•  Natural hazards
•  Earthquakes
•  Landslides
•  Floods
•  Hurricanes
•  World population pressures
1.  Earth is a dynamic body with many
separate but highly interacting parts or
spheres
2.  Earth system science studies Earth as
a system composed of numerous
parts, or subsystems
3.  System – any size group of interacting
parts that form a complex whole
 System
 Any size group of interacting parts that
form a complex whole
•  Closed systems are self-contained
•  no matter enters or leaves the system
•  (e.g., an automobile cooling system)
•  Open systems –
•  both energy and matter flow into and out of the
system
•  Most natural systems are open
•  (e.g., a river system)
 Feedback mechanisms
 Mechanisms that enhance change or
stabilization in a system
•  Negative-feedback mechanisms
•  resist change and stabilize the system
•  Maintains status quo
•  Positive-feedback mechanisms
•  enhance the system
•  Drives change
 Earth as a system
•  Consists of a nearly endless array of
subsystems (e.g., hydrologic cycle, rock
cycle)
Figure 1.21
Earth as a system
•  Sources of energy
•  Sun
–  drives external processes
•  such as weather, ocean circulation, and
erosional processes
•  Earth’s interior
–  drives internal processes
•  including volcanoes, earthquakes, and mountain
building
•  Humans are part of the Earth system