EARTH SCIENCE

Chapter
1
Introduction to
Earth Science
1.1 What Is Earth Science?
Overview of Earth Science
 Encompasses all sciences that seek
to understand
• Earth
• Earth's neighbors in space
http://www.coexploration.org/geoscienceliteracy/Images/earth_science_literacy_framework12_600px.jpg
http://thespuds.files.wordpress.com/2012/05/earth-science.jpg
Branches of Earth Science
Because one person cannot keep up with the development in
all areas of earth science, most earth scientists today
specialize in one of the following four major areas of study:
• Geology
• Oceanography
• Meteorology
• Astronomy
Geology
Geology – The study of the origin, history and
structure of the solid earth and the processes
that shape the earth
Explore the earth’s crust in search of new deposits of
coal, oil, gas, and other valuable resources.
Study the forces within the earth in order to better
understand earthquakes and volcanic eruptions.
Study fossils to learn more about the earth’s past
Earth Science:
Study of the earth, its history, its changes and its
place in the universe
Branches of Earth science:
Geology- study of the earth’s origin, history and structure
•physical- materials that make up earth and the
processes that shape earth’s surface
•historical-earth’s history
Oceanography
Oceanography – The study of the
earth’s oceans. Oceans cover nearly
three-fourth’s of the earth’s surface.
Work on research ships equipped with
special instruments to study the sea.
Study waves, tides, and ocean currents.
Explore the ocean floor for clues to the
earth’s history and to locate mineral
deposits.
Study marine plant and animal life
Meteorology
Meteorology - The study of the
earth’s atmosphere.
•Meteorologists use satellites, radar, and
other modern technology.
•Study the variations in atmospheric
conditions that produce weather.
•Observe weather, measuring wind speed,
temperature and rainfall. Information is
used to make weather maps
•Use weather maps, satellite images, and
computer data to make weather forecasts
Astronomy
Astronomy – The study of the
universe beyond the earth.
One of the oldest branches of earth
science. Ancient Babylonians charted the
planets and stars nearly 4000 yrs. ago.
Modern astronomers use earth and
space based telescopes and other
instruments to study the universe.
Space probes, such as , Pioneer,
Voyager, Galileo, and Ulysses have
provided much useful data.
• Meteorology- study of the earth’s
atmosphere, weather and climate
• Oceanography- study of the earth’s oceans,
including their physical features, life forms
and natural resources
• Astronomy- study of the universe
• Hydrology- study of earth’s water
Ecology
Earth Scientists primarily study the:
Geosphere – The solid earth
Hydrosphere - The earth’s water
Atmosphere – The gases surrounding the earth
Ecology
• Another area of science in which earth science and biology are
closely linked is Ecology. “Eco” comes from the Greek word
“oikos”meaning house.
• Ecology – The study of relationships between living things and their
environment.
• Ecosystem means the environment a community of organisms
inhabit. The largest ecosystem is called the biosphere.
• The Biosphere encompasses all life an earth and the physical
environment that supports it. It extends from the ocean depths to the
atmosphere a few kilometers above the earths surface.
The Importance of Earth Science
Understanding how natural forces shape our environment can
help better forecast potential disasters.
Studying distant galaxies has led to theories about the origins of
this solar system.
Clues found by studying rock have provided information about
the earth’s past.
The earth provides resources that enrich our lives.
Fuel
Metal
Paper and Ink
• The Earth is continually changing – sometimes rapidly
– like with tornadoes, earthquakes, tsunamis- but,
many changes occur so gradually that they go
unnoticed in a lifetime.
Formation of Earth
 Most researchers conclude that Earth and the
other planets formed at essentially the same
time.
 Nebular Hypothesis
• The solar system evolved from an enormous
rotating cloud called the solar nebula.
A
B
C
D
E
•Nebular Hypothesis
Enormous rotating cloud made up mostly of
hydrogen and helium, with a small percentage of
heavier elements created Solar System
Inner planets were not able to hold the lighter
gases - hydrogen and helium. They were pulled
toward heavier planets.
Earth, Mars and Venus retained heavier gases
including water vapor and carbon dioxide
Outer planets contain high percentages of water,
carbon dioxide, ammonia and methane – Size and
frigid temperatures of outer planets provided
surface gravity to hold heavier gases.
Layers Form on Earth
Decay of radioactive elements and heat of
colliding particles caused interior to melt
Denser materials (Fe & Ni) sank to center
Lighter, rocky material floated to surface.
Sinking and floating still believed to be
occurring on a smaller scale
Interior is not made up of uniform
materials –layers have different properties
Gaseous materials escaped – atmosphere
formed along with the ocean. Composed
mainly of gases released from within the
planet.
1.2 A View of Earth
Earth's Major Spheres
1. Hydrosphere
• Ocean is the most prominent feature of the
hydrosphere.
- Is nearly 71% of Earth's surface
- Holds about 97% of Earth's water
• Also includes fresh water found in streams,
lakes, and glaciers, as well as that found
underground
Earth’s physical environment
divided into 4 major spheres
• Hydrosphere – water portion
– All water on Earth
– What makes Earth unique
– Water continually moves – evaporating and
then returning as precipitation
– 97% of H2O in Oceans
– 3% is Fresh H2O
1.2 A View of Earth
Earth's Major Spheres
2. Atmosphere
• Thin, tenuous blanket of air
• One half lies below 5.6 kilometers (3.5 miles)
3. Biosphere
• Includes all life
• Concentrated near the surface in a zone that
extends from the ocean floor upward for
several kilometers into the atmosphere
• Atmosphere – gaseous envelope
–Extends 100km above the Earth
–90% is within 16km of Earth
–Provides air we breath
–Protects from sun’s intense heat
and radiation
–Produce weather and climate
• http://www.youtube.com/watch?v=fyfN9t_
E0w8
1.2 A View of Earth
Earth's Major Spheres
4. Geosphere
• Based on compositional differences, it
consists of the crust, mantle, and core.
- Crust—the thin, rocky outer layer of Earth.
- Mantle—the 2890-kilometer-thick layer of
Earth located below the crust.
- Core—the innermost layer of Earth, located
beneath the mantle.
Earth’s Layered Structure
• Geosphere
– Divided into 3 main parts
• Core
– Dense
– Made of heavy metals
• Mantle
– Less dense than core
– Thick liquid
• Crust
– Not uniform in thickness
» Thick under the continents, thin under oceans
» Lithosphere
» Rigid outer layer
» Asthenosphere
» Rocks are partially molten and able to slowly
flow
1.2 A View of Earth
Plate Tectonics
 Plate tectonics is the theory that
proposes that Earth’s outer shell
consists of individual plates that interact
in various ways and thereby produce
earthquakes, volcanoes, mountains, and
Earth’s crust itself.
• http://www.youtube.com/watch?v=0mWQs
1_L3fA
Plate Tectonics
• Lithosphere is broken into plates.
• Plates slowly and continuously move
• Movement is caused by unequal heating and
convection
• Movements cause: earthquakes, volcanic activity
and mountains
• Destructive forces
– Weathering and erosion
• Constructive forces
– Mountain building and volcanism
1.4 Earth System Science
What Is a System?
 A system is any size group of interacting
parts that form a complex whole.
 Closed systems are self contained
(e.g., an automobile cooling system).
 Open systems allow both energy and matter
to flow in and out of the system
(e.g., a river system).
1.4 Earth System Science
Earth as a System
 Earth is a dynamic body with many
separate but highly interacting parts
or spheres.
 Earth system science studies Earth
as a system that is composed of
numerous parts, or subsystems.
Earth System Science
• Studies how Earth’s
spheres are interconnected
• Tries to put together what
we know from each branch
of science.
Natural systems
• Driven by sources of energy that move
matter and/or energy from one place to
another
• Closed system – energy moves in and out of
the system, but no matter enters or leaves
• Open system – energy and matter move in
and out of the system
• Example – river
1.4 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
Energy comes from 2 sources:
• Sun
• Drives external processes that occur
in the atmosphere, hydrosphere and
at Earth’s surface
• Powers:
–Weather
–Climate
–Ocean circulation
–Erosional processes
• Earth’s Interior
»Heat from time Earth formed
»Generated by decay of
radioactive elements
»Powers:
»Volcanoes
»Earthquakes
»Mountain building
1.4 Earth System Science
Earth as a System
 Consists of a nearly endless array of
subsystems (e.g., hydrologic cycle)
 Humans are part of the Earth system.
1.4 Earth System Science
People and the Environment
 Environment
• Surrounds and influences organisms
• Physical environment encompasses water,
air, soil, and rock
• The term environmental is usually reserved for
those aspects that focus on the relationships
between people and the natural environment.
Environment
–Everything that surrounds and
influences an organism
–Can be biological, nonliving and
social
1.4 Earth System Science
People and the Environment
 Resources
• Include water, soil, minerals, and energy
• Two broad categories
1. Renewable—can be replenished (e.g.,
plants, energy from water and wind)
2. Nonrenewable—cannot be replenished in
the near future (e.g., metals, fuels)
• http://www.youtube.com/watch?v=pBTnVo
EIb98
Resources
•Include:
–Water and soil
–Metallic and nonmetallic
minerals
–Energy
Renewable
• Can be replenished over relatively
short times
• Examples:
–Plants and animals for food
–Natural fibers for clothing
–Forest products for lumber and paper
–Energy from water, wind and sun
Nonrenewable
• Processes that create them are so slow
that it takes millions of years for significant
deposits to accumulate
• Examples:
– Iron, aluminum, copper
– Fossil fuels
» Oil
» Natural gas
» Coal
• Earth contains limited quantities
• Some can be recycled – aluminum*
1.4 Earth System Science
People and the Environment
 Population
• Population of the planet is growing rapidly
• Use of minerals/energy has climbed more
rapidly than the overall growth of population
Growth of World Population
Population
• As population grows, so
does demand for resources
• Rate of mineral and energy
resource usage has
increased more rapidly than
growth of population
http://conservationreport.files.wordpress.com/2010/02/amount-ofnatural-resources-left.jpg
1.4 Earth System Science
Environmental Problems
 Local, regional, and global
 Caused by people and societies
•
•
•
•
Urban air pollution
Acid rain
Ozone depletion
Global warming
 Caused by natural hazards
• Earthquakes
• Landslides
Environmental Pollution
Pollution – The contamination of the
environment with waste products or impurities.
Environmental Problems
– Humans and nature cause environmental
problems
– Significant threats:
•
•
•
•
•
•
•
Air pollution
Acid rain
Ozone depletion
Global warming
Loss of fertile soils to erosion
Disposal of toxic wastes
Contamination and depletion of water sources
Biodegradable – Substances that can be broken
down by microorganisms into harmless substances that
are little threat to our environment.
Some waste products are
biodegradable and pose little
threat to our environment.
Nonbiodegradable Waste
Some modern waste products
cannot be broken down and are a
threat to ecosystems.
Protecting Our Environment
Water, Land and Air Quality
• Ozone – Helps protect plant and animal life from the
sun’s harmful UV rays
• CFC’s - Chlorofluorocarbons
Review –
answer in complete sentences to be turned in to me!
1. What are the four major branches of
earth science?
2. Describe the work of meteorologists.
3. What is ecology?
4. Give an example of an ecosystem and
explain how it is self- supporting.
5. How might the study of earth science
contribute to the survival of the
biosphere?
Environmental hazards are
natural processes
• Examples
–Earthquakes
–Landslides
–Floods
–Hurricanes
–Drought