Download Chapter-1-Introduction

yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

Natural environment wikipedia, lookup

Earth Science, 6e
Edward J. Tarbuck &
Frederick K. Lutgens
Earth's “Spheres"
Earth Science
Encompasses all sciences that seek to
• Earth
• Earth's neighbors in space
Earth Science includes
• Geology - literally the “study of Earth”
• Oceanography – a study of the ocean
Earth Science
Earth Science includes
• Meteorology - the study of the atmosphere and
the processes that produce weather
• Astronomy - the study of the universe
Earth's “Spheres"
• Ocean – the most prominent feature of the
• Nearly 71% of Earth's surface
• About 97% of Earth's water
• Also includes fresh water found in streams,
lakes, and glaciers, as well as that found
Earth's “Spheres"
• Thin, tenuous blanket of air
• One half lies below 5.6 kilometers (3.5 miles)
• Includes all life
• Concentrated near the surface in a zone that
extends from the ocean floor upward for several
kilometers into the atmosphere
Earth's “Spheres"
Solid Earth
• Based on compositional differences, it consists
of the crust, mantle, and core
• Divisions of the outer portion are based on how
materials behave
• Lithosphere - rigid outer layer
• Divisions of Earth’s surface - continents and ocean
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
System - any size group of interacting parts
that form a complex whole
Earth system science
• 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
• Positive feedback mechanisms enhance the
Earth as a system
• Consists of a nearly endless array of
subsystems (e.g. hydrologic cycle)
The hydrologic cycle
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
People and the 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
People and the environment
• 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
People and the environment
• Population of the planet is growing rapidly
• Rate of mineral and energy usage has climbed
more rapidly than the overall growth of
Environmental problems
• Local, regional, and global
Growth of world population
People and the environment
Environmental problems
• Human-induced and accentuated
Urban air pollution
Acid rain
Ozone depletion
Global warming
• Natural hazards
• Earthquakes
• Landslides
People and the environment
Environmental problems
• Natural hazards continued
• Floods
• Hurricanes
• World population pressures
Early evolution of Earth
Origin of Earth
• Most researchers believe that Earth and the
other planets formed at essentially the same
• Nebular hypothesis
• Solar system evolved from an enormous rotating
cloud called the solar nebula
• Nebula was composed mostly of hydrogen and
Early evolution of Earth
Origin of Earth
• Nebular hypothesis continued
• About 5 billion years ago the nebula began to
• Assumes a flat, disk shape with the protosun (preSun) at the center
• Inner planets begin to form from metallic and rocky
• Larger outer planets began forming from fragments
with a high percentage of ices
The Nebular hypothesis
Early evolution of Earth
Formation of Earth’s layered structure
• As Earth formed, the decay of radioactive
elements and heat from high-velocity impacts
caused the temperature to increase
• Iron and nickel began to melt and sink toward the
• Lighter rocky components floated outward, toward
the surface
• Gaseous material escaped from Earth’s interior
to produce the primitive atmosphere
Scientific inquiry
Science assumes the natural world is
• Consistent
• 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 and theories
Scientific inquiry
Scientific knowledge is gained through
• Following systematic steps
Collecting facts
Developing a hypothesis
Conduct experiments
Reexamine the hypothesis and accept, modify, or
• Theories that withstand examination
• Totally unexpected occurrences
End of Introduction