Download Introduction to Earth Science

Introduction to Earth Science
Overview: Copy the slides with a yellow background!
Essential Questions
1. What does an Earth Scientist
study?
2. What information do various
maps give to an Earth Scientist?
3. How do Earth Scientists (and all
scientists) seek knowledge?
Overview of Earth Science
• Earth science is the name
of the group of sciences
that deals with Earth and
its neighbors in space.
• Earth science is divided
into four broad categories:
The Earth Sciences
• Geology—the study of the solid
Earth
• Oceanography—the study of the
Earth’s oceans
• Meteorology—the study of the
Earth’s atmosphere
• Astronomy—the study of the
Earth’s place in the universe
Differentiation
• As the newly formed Earth cooled
layers formed through a process
called differentiation.
• Denser elements (iron and nickel)
sink to the Earth’s core.
• Lighter rocks and materials migrate
outward forming the mantle and
crust.
A View of the Earth
• Earth consists of 4 major
spheres:
• Hydrosphere
• Atmosphere
• Geosphere
• Biosphere
Earth’s Major Spheres
• The hydrosphere includes all liquid
water on Earth—both saltwater and
fresh water.
• The atmosphere consists of the
gaseous envelope surrounding the
Earth.
• Although the atmosphere extends
more than 100km up, 90% is within
16km of the surface.
Earth’s Major Spheres
• The biosphere includes all life on Earth.
• The biosphere is concentrated in a zone
that extends from the ocean floor upward
several kilometers in the atmosphere.
• The geosphere consists of the solid parts
of the planet and is not uniform.
• Based on differences in composition it is
divided into three main regions, the core,
the mantle, and the crust.
Geosphere Divisions
• The dense core has two parts; a solid
inner core and a liquid outer core.
• The rocky mantle is divided into an
lower mantle and upper mantle.
• The rock in the upper part of the
upper mantle is somewhat flexible and
pliable—it’s called the asthenosphere
(weak sphere).
Geosphere Divisions
• The outer crust is divided into
continental crust and oceanic
crust.
• This rigid outermost layer is
called the lithosphere (rock
sphere).
Plate Tectonics
• The lithosphere is broken into
several sections called plates.
• The Theory of Plate Tectonics
states that earthquakes, volcanoes,
mountain building, and the
movement of continents are the
result of the movement of
lithospheric plates.
Representing Earth’s Surface
• Specifying a location on Earth’s
surface is done using a grid system of
latitude and longitude.
• Latitude is the distance north or south
of the equator (measured in degrees).
• Longitude is the distance east or west
of the prime meridian (also in degrees).
The Global Grid
Maps and Mapping
• No matter what type of map is
made, some portion of the surface
will always appear too small, big, or
out of place.
• Cartographers (mapmakers) have
found ways to limit the distortion of
shape, size, distance, and direction.
The Mercator Projection
• Made by taking
slices of a globe’s
surface and
stretching the
ends to meet.
• Directions
accurate
• Size and distance
distorted.
Robinson Projection
• Shows most
distances, sizes,
and shapes
accurately.
• Distortions
present along
edges.
Other map projections:
• A conic projection is made by
wrapping a cone around the Earth
at a particular line of latitude.
(almost no distortion at that line)
• A gnomonic projection is made by
placing a sheet of paper on a globe
so that it is touching only one spot.
• See page 13 in text.
Topographic Maps
• Topographic
maps show
Earth’s elevation
using contour
lines.
• All spots along a
particular contour
line have the same
elevation.
Topographic Maps
• The contour interval on a topo map
gives the user the difference in
elevation between each contour
line.
• Geologic Maps are those that also
contain information about the type
and age of rock formations in the
area.
More on maps
• All maps represent
a certain area so a
scale is included
to compare actual
distances.
• Satellites have
made accurate
cartography much
simpler than in the
past.
Earth System Science
• Earth system science aims to study
the Earth as a system made up of
numerous interacting parts, or
subsystems.
• A system can be any size group of
interacting parts that form a
complex whole.
Earth as a System
• The Earth system is powered by 2
sources of energy:
• The Sun– which drives external
processes in the atmosphere,
hydrosphere, and at the surface.
• The Earth’s interior heat—which
drives plate tectonics.
Each system affects the other.
• The actions of nature and people
produce changes in all of the other
parts of the Earth system.
• Resources (some renewable, some
not), population, pollution, global
warming, species extinction, etc.
are some examples.
Scientific Inquiry
• All science is based on two big
assumptions:
1. The universe behaves in a
consistent and predictable
manner.
2. Through study, we can
understand this behavior.
Scientific Method (Phrase)
• Purple
• Hippos
•
•
•
•
Purpose-Reason for experiment
Hypothesis- Educated guess of
outcome
Play
Procedure-Steps/Experiment
Dominoes
Data-Info collected/recorded
And
Analysis-Analyze data for results
Checkers Conclusion-Is hypothesis
correct or not and possibly why
Hypothesis
• Once observations have been
made and data gathered,
scientists try to explain how or
why things happen in the manner
observed.
• They state a possible explanation
called a scientific hypothesis.
Theory vs. Law
• Once further observations have been
made and/or tests performed, scientists
either accept, modify, or reject their
hypothesis.
• A Theory is based on many
observations. A Law is accepted as the
best explanation of observable facts
and proven by experiments.