Transcript Introduction -What is Earth Science

Introduction to Earth
Science
Chapter 1
What is Earth
Science
Section 1
Earth Science
• Earth science is a group of sciences
that deals with the Earth and its
surroundings
• The main subdivisions of earth science
are
• Geology
• Oceanography
• Meteorology
• Astronomy
Geology
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Geology literally means “the
study of Earth”
Divided into two areas physical geology and
historical geology
Physical geology is the study
of materials that make up
Earth and how they shape
our planet
Historical geology tries to
understand the processes
that have occurred
throughout Earths history
Oceanography
•
•
Oceanography is the
study of the
composition and
movements of
seawater
They also study
coastal processes, the
seafloor, and marine
life
Meteorology
•
Meteorology is NOT
the study of meteors.
Meteorology is the
study of the
atmosphere and how
weather and climate
change
Astronomy
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•
Astronomy is the study
of the universe
The observations and
findings made by
astronomers can help
us to understand Earth
and its past
•
•
How was Earth
formed?
The nebular hypothesis
gives the most commonly
accepted explanation of
Earths formation
It says that there was a
large cloud of hydrogen
and helium that kept
getting bigger. As it got
bigger, it developed a
center of gravity. Gravity
would cause small clusters
of gas to gather, creating
stars and planets
A View of Earth
Section 2
Earth’s Major
Spheres
• In order to better study earth, scientists
have divided Earth into a few major
spheres, or portions
• Earth’s major spheres are the
hydrosphere, the atmosphere, the
geosphere, and the biosphere
• All four major spheres interact with
each other
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Hydrosphere
Deals with Earths water,
including the water
cycle
97% of Earths water is
located in the oceans.
The remaining 3% of
water is included in
lakes, rivers,
groundwater, and
glaciers
Fresh water is important
for sustaining life for
many living things on
Earth
Atmosphere
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•
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The atmosphere is the
layer of gases that
surround earth
The atmosphere helps to
protect from the sun and
from stellar bodies, like
meteors
It also provides the gases
that we breath
Earths surface might look
similar to the moon, if not
for the atmosphere
Geosphere
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•
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The geosphere is made
up of the rocky parts of
earth
The geosphere is
divided into different
parts, based on what its
made of - the core, the
mantle, and the crust
The crust is the outer
layer and the core is the
innermost layer
Biosphere
•
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The biosphere is made
up of all living things
on Earth.
You will learn more
about the biosphere in
biology - assuming
you pass this class
Plate Tectonics
•
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Earth’s surface is everchanging.
There are two types of
forces working on Earth constructive forces and
destructive forces that
constantly change how
the surface looks
Plate tectonics is a theory
that explains how these
forces change the earth
Representing Earth’s
Surface
Section 3
Why Map? How
Map?
• Maps are used to help get from one
place to another
• In the old days, maps were made from
explorers who charted undiscovered
regions
• Over the years there have been many
styles of maps to be created with
different purposes
Global Grid
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In an effort to make cartography (map making)
easier and more universal, a global system was
adopted
The equator is the imaginary line that circles the
globe half way between the north and south pole.
Latitude is measured in degrees north or south of
the equator
The prime meridian is an imaginary line drawn
from the north pole to the south pole through
Greenwich, England. Longitude is measured in
degrees east or west of the prime meridian
Lines of latitude and
longitude
Types of Maps
• There are several different types of
maps used for different purposes
• No matter what type of map, some part
of the representation will be off - either
shape or size. The types of maps aim
to minimize this distortion
Mercator Projection - size and
distances are distorted, but directions
are accurate
Robinson Projection - map that most
accurately shows size, distance and
direction
Conic Projection - A type of map with little
distortion in lines of longitude, but may have large
distortion over lines of latitude
Gnomonic Projections - a distance and directions
are distorted, but accurately shows the shortest
distance between two points
Topographic Maps
• A topographic is a map used to show
changes in elevation
• Changes in elevation are shown using
contour lines. A contour line is a line
drawn that connects areas of equal
elevation
• A contour interval shows the difference
in elevation between two lines
Topographic Map
1) If black (the first layer of your model) is sea level, what
elevation is each of the following points? (the contour
interval = 10 ft.)
A
_______
B
_______
C
_______
1
_______
2
_______
3
_______
2) Which is the steepest slope on the hill? (north, south, east,
or west?)
How do you know?
3) What is the difference in elevation between the second and
fourth layers of your model?
4) If you were to build a house on this hill, where is the
flattest part of the land form?
Map Scale
• A scale is used to accurately draw a
map so that relative distances remain
the same.
• For example,
a map might use 2
inches to show a real distance of one
mile
• Why are maps scaled?
Geologic Map
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A geologic map is
used to show the
types and ages of the
rocks that are exposed
at the surface
They are useful when
examining the
geologic history of an
area
Earth System
Science
Section 4
What
is
a
System?
• A system is a group of interacting parts
that form a more complex whole
• Earth science is often studied as a
system with several groups interacting
and affecting each other.
• For example, the hydrosphere,
atmosphere, and geosphere all interact
during the water cycle
• So, in order to understand one system,
we often need to understand many
other systems as well
Earth
as
a
System
• The Earth system has two main energy
sources - the sun and the earths interior
• The sun powers the external processes
that occur in the atmosphere,
hydrosphere, at at the surface
• Earths interior powers Earths inner
processes, such as volcanoes and
earthquakes
• A change in one of these systems can
create changes in the other, and viceversa.
What is Scientific
Inquiry
Section 5
Hypothesis
• Any scientist conducting an
investigation follows a general
procedure.
• First there must be a set of
observations that needs to be explained
• In an effort to explain the observations,
we come up with a hypothesis. A
hypothesis is a possible explanation for
a set of observations
• Hypothesis are essentially educated
guesses
• Before a hypothesis can be accepted
by the scientific community, it must be
thoroughly tested and analyzed. If a
hypothesis is proven wrong by
experiments, the scientist must go back
and reformulate a new hypothesis,
which must also be tested.
Theory
• Once a hypothesis has been repeatedly
tested and supported, it becomes a
theory
• A theory is a well tested and widely
accepted belief that best explains
certain observations
• Can a theory be changed?