Download CH01

Earth Science 101
Introduction to Earth Science
Chapter 1
Instructor : Pete Kozich
Earth Science
Encompasses all sciences that seek to
understand
• Earth
• Earth's neighbors in space
Earth is a dynamic body with many
interacting parts and a long complex
history
Earth Science
Earth Science includes
• Geology - literally the “study of Earth”
• Oceanography – a study of the ocean,
youngest and newest study
• Meteorology - the study of the atmosphere
and the processes that produce weather
• Astronomy - the study of the universe, oldest
discipline
Geology-”study of Earth”
• Physical geology: examines the material
composing Earth and seeks to understand
the many processes that operate beneath
and upon the surface
– Mountain building, volcanoes, erosion,
earthquakes
• Historical geology: understand the origin of
Earth and the development of the planet
through its 4.6 billion-year history
Oceanography
• Application of all sciences in a
comprehensive interrelated study of
oceans in all their aspects
– Chemistry, physics, geology, and biology (old)
– Oceanography is now becoming legitimate in
its own right via fluid dynamics and modeling.
• Study of composition and movement of
seawater, coastal processes, seafloor
topography and marine life.
Meteorology
• Study of the atmosphere and all the
processes that produce weather and
climate
• Involves the application of other sciences
into an integrated study of the atmosphere
• Many disciplines within the whole such as
synoptic, mesoscale, boundary layer,
turbulence, and climatology
People and the environment
Environment
• Surrounds and influences organisms or
“small” entities
• Physical environment encompasses water,
air, soil, and rock
People and the 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, fossil fuels, for
example
People and the environment
Population
• Population of the planet is growing rapidly
• Rate of mineral and energy usage has
climbed more rapidly than the overall
growth of population
• As population expands, the demand for
resources expands too
Environmental problems
• Local, regional, and global
People and the environment
Environmental problems
• Human-induced and accentuated
•
•
•
•
Urban air pollution
Acid rain
Ozone depletion
Global warming (probable)
• Natural hazards
• Earthquakes
• Landslides
People and the environment
Environmental problems
• Natural hazards continued
• Floods
• Hurricanes
• World population pressures
• Increased rate of mineral and energy usage
• US ~ 5% of world population and uses 25%
annual production of mineral and energy
resources.
Scientific inquiry
Science assumes the natural world is
• Consistent
• Comprehensible through careful,
systematic study
• Because of this, science is Predictable
Goal of science
• To discover patterns in nature
• To use the knowledge to predict
Scientific inquiry
An idea can become a
• Hypothesis (tentative or untested explanation)
• Theory (tested and confirmed hypothesis)
• Paradigm (a theory that explains a large number
of interrelated aspects of the natural world)
Scientific method
• Gather facts through observation
• Formulate hypotheses that may eventually
become theories
Scientific inquiry
 Scientific knowledge is gained through
• Following systematic steps (Scientific Method)
•
•
•
•
Collecting facts
Developing a hypothesis
Conduct experiments
Re-examine the hypothesis and accept, modify, or reject
• Theories withstand examination
• Totally unexpected occurrences a challenge-> is hypothesis
correct as is?
 Scientific Law – a basic principle that describes nature’s
behavior and is narrow in scope
• Consistent with observations and measurements
• Rarely discarded
Earth's “Spheres"
Hydrosphere
• a dynamic mass of liquid that is always on the
move from the oceans to the atmosphere
precipitating back onto the land, then running back
to the oceans again.
• Water makes the earth unique
• Ocean – the most prominent feature of the
hydrosphere
• 71% of Earth's surface
• 97% of Earth's water
• Average depth ~4000 m
• Also includes fresh water found in streams, lakes,
and glaciers, as well as that found underground
Earth's “Spheres"
 Atmosphere
• Thin envelope of gases surrounding the earth able
to maintain life
• Provides air to breathe, while protecting us from
the Sun’s intense heat and harmful radiation.
• Without the atmosphere our planet may be lifeless
and resemble the surface of the moon.
• Half of mass lies below 5.6 kilometers (3.5 miles)
• Compare to a radius of earth ~6400 km (4000 miles)
Earth's “Spheres"
Biosphere
• Extends from the ocean floor upward into the
atmosphere.
• Consists of parts of the hydrosphere,
atmosphere and geosphere
• Includes all life
• Organisms don’t just adapt to their
environment, countless interactions have
allowed organisms to maintain and alter their
environment.
Earth's “Spheres"
Geosphere
• Extends from the surface to the center of the
planet (depth of 6400 km)
• Largest of the four spheres
• Based on compositional differences, it consists of:
•
•
•
•
Dense core
Less dense mantle
Crust (very thin, light outer skin of the Earth)
Crust is not uniformly thick, but ranges from very thin
under the oceans to thickest where mountains are
located.
Earth’s layered structure
Earth system science
Earth is a dynamic body with many
separate but highly interacting parts or
spheres
Earth system science studies Earth as a
system composed of numerous parts, or
subsystems
System - any size group of interacting
parts that form a complex whole
Earth system science
System
• Closed systems are self-contained (e.g. an
automobile cooling system)
• Open systems - both energy and matter
flow into and out of the system (e.g. a river
system)
Earth system science
Feedback mechanisms
• Negative-feedback mechanisms resist change and
stabilize the system (human sweating – cooling
phenomena)
• Positive-feedback mechanisms enhance the system
(you somewhat like art and take an art class; get more
enthusiastic about it, take it as major; find much
satisfaction and a job, make a living out of it)
Earth as a system
• Consists of a nearly endless array of subsystems (e.g.
hydrologic cycle, rock cycle)
Earth system cycles
Figure 1.17
Earth system science
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
• Parts of the system are connected
• Change in one part can produce change in one or all
other parts
• Complex, nonlinear, hard to predict