August 22, 2011-Monday
Earth Science Lecture MS-2
Jack Pierce - Instructor
Agenda: SILENCE YOUR CELL PHONE!
• Attendance – Syllabus
• Chapter 1, Intro to Earth Science
• QR’s Intro to ES and Minerals due 8-29-11
Earth Science Monday/Wednesday Labs
• Intro to ES lab will be provide
• Download minerals lab
Earth Sciences –
Jack Pierce – MS 2
Meteorology
Geology
Oceanography
Astronomy
1
What is Earth Science?
Consider these questions?
Why do volcanoes erupt?
What forces produce mountains?
Why is climate so variable?
How old is the earth?
Why do we have ocean tides?
Is there really global warming?
Is there really ice ages?
How do we get water out of the ground?
How does earth “fit” in our universe?
Earth Science:
Studding the earth and surrounding
universe – using geology, meteorology,
oceanography and astronomy
Geology – the study of the earth
Physical Geology:
•Materials that comprise the earth
• rocks, minerals, earths interior,
• processes acting below and above the
surface
Historical Geology
•Understand the origin and development
• Understand the chronological order of
geologic events over 4.6 by old earth
The geologic time scale
Dating various geologic events
The significance of fossils
Physical Oceanography:
• The study of the ocean floor including
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•
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•
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Ocean chemistry
Physics
Sea floor geology
Coastal processes
Sea floor topography
Meteorology:
• Study of the atmosphere and
processes that produce climate and
weather.
Astronomy:
• The study of the universe
• the earth’s place in our universe
• the origin of our earth
• earth is related to all other
objects in the universe
What questions do you have about your earth?
How do you think these questions are answered
with accuracy?
4
How do we find “accuracy” in our answers?
The Scientific Method-Science Inquiry
A set of logical steps scientists use to “get to the truth”
of processes acting in the universe
Making Observations and Measurements
• Collecting facts, asking why questions
Formulating a Hypothesis (predictions as to why)
• Explaining how and why it works (after factfinding), “educated guessing”
Testing the Hypothesis (experimenting)
• performing experimentations that test the
accuracy of the hypothesis
5
How do we find “accuracy” in our answers?
The Scientific Method
Scientific Theory
• well-tested hypothesis – widely accepted view
that explains observable facts
Scientific Law or Principle
• natural phenomena are observed to happen in
the same way – no deviations have ever been
observed
6
The Scientific Method
If you fail, try try
try again.
7
The Scientific Method in Action-- Astronomy
Observation/ Experimentation/ Theory
1,650 years of scientific method
Isaac Newton
Described the 3 laws
C. Ptolemy
N. Copernicus J. Kepler
of motion, Universal
Almagest – Continued with
Developed the
Gravitation, showed
accepted the the
three
earth and planetary
geocentric
heliocentric
planetary
bodies are governed
model over theory– -laws of motion
by universal laws of
the
and was
Revolutionized physics – thus ending
heliocentric widely
astronomy
geocentric theory
model
accepted
Astronomy
Timeline
A.D. 90 – 168 1473-1543
1571-1630
1643-1727
10
I
IC
Earth Science.
Discuss with a friend:
1. Explain why the scientific method is
a useful tool for learning about the
processes that occur in our universe.
2 Define the steps within the scientific
method.
I will get an A on my exams and quizzes.
9
Earth Science studies the relationship between people
and the natural environment.
Natural Hazards:
• volcanoes, floods, tsunami, EQ’s
• landslides, hurricanes
When does a natural hazard become a hazard?
Resources
• water, soil
• metallic and non-metallic minerals
Earth Science deals with the formation and occurrence as well
as maintaining the supply and impact to the environment.
Human Influences:
• Increased demand for resources and higher occurrences
of natural hazards is due to rapid growth in populations.
Paul Ehrlich-Stanford University
• Food supplies will fall short,
and famine will follow.
How does the Earth’s population grow??
Paul Waggoner – an agronomist
• Using current technology,
productivity increases far
beyond population growth.
7 billion
famine
Enough food produced
How does population growth affect the demand for Earth’s resources ?
How is the Earth studied? (Earth System Science)
Various “systems” within the earth that interact
with one another -– called Earth System Science
• Systems are NOT individually studied
• How one system impacts another
system
System:
An integrated set of “parts” that work together to
accomplish a goal or task (objective)
Give an example of various systems. 11
Which system is the Earth?
Earth as a System:
• How systems exchange matter and energy
SUN
SUN
SUN
Isolated
System
Closed
System
No exchange of
matter or energy
Exchange of energy
but not matter
?
Open
System
Exchange of both
matter and energy
12
I
IC
Earth Science.
Discuss with a friend:
1. Define a system as discussed in
earth science.
2. Differentiate between an open, closed,
and isolated system.
3. Explain why earth is considered a closed
system.
I will get an A on my exams and quizzes.
14
The fragile earth as a closed system is supported by four
interrelated open systems.
Lithosphere (geosphere)
Represents the solid earth:
minerals, rocks, and interior
Biosphere:
Includes all living
organisms on land,
in water, and in air
Atmosphere:
Thin blanket of gas keeping
life alive, warm, and protected
Hydrosphere:
Interaction of all water processes,
only planet with water,
71% ocean 12,500 feet deep,
streams, lakes, groundwater
I
Earth Science.
Discuss with a friend:
1. Define the following:
lithosphere, biosphere, hydrosphere,
atmosphere
2. Provide an earth process that takes
place between two open systems.
3. What is the meaning of geosphere?
18
An Important Aspect of Earth System Science
• The earth maintains balance between the
open systems through positive and negative
feedback mechanisms.
Positive feedback works to change the system
Negative feedback works to resist the change
“Tug of War”
Working to change the system and working to
resist the change maintains balance within the
system.
weight gain example
19
Positive/Negative Feedback Example:
Earth’s climatic system – positive/negative feedback
Positive feedback
Negative feedback
Reflecting sunlight
SUN
water vapor –increases
air temperature
Evaporates
sea water
Ocean
Water vapor condenses,
forming clouds
Ocean
Increasing evaporation
(working to change the system)
Decreasing evaporation
(working to resist change)
Atmosphere maintains balance.
20
I
IC
Earth Science.
1. Describe the meaning of positive and
negative feedback mechanisms.
2. Explain how positive and negative
feedback mechanisms keep the earth
balanced.
3. Think of at least 2 positive/negative
feedbacks that balance the earth.
Discuss with a friend:
I will get an A on my exams and quizzes
21
8.
The earth’s place in the solar system
Uranus
Jupiter
Earth
Mars
Venus
Mercury
SUN
Inner planets
Terrestrial planets
High densities
Asteroid Belt
Neptune
Saturn
Outer planets
Jovian planets
Gas planets
Low densities
28
Lithosphere
Cont/ocean crust
Upper mantle
2.8 g/cm3
Crust
Asthenosphere
ductile rock
Mantle -Solid
Si,O,Fe,Mg,Ca
5.5 g/cm3
Mantle
Outer Core
Molten – Ni, Fe
11.5 g/cm3
Core
Inner Core
Solid- Ni, Fe
12.5 g/cm3
Temp:
5000 C
Source of
magnetic
field
Why are densities
arranged from
heavy (core) to
lightest (crust)?
Chemical
Differentiation
29
The earth’s interior
What makes
earth unique??
Oxygen, water, life
• oxygen atmosphere
• no O2 on other planets
• the hydrologic cycle
Soil accumulation
• weathering of rocks
• various soil types
Plate Tectonics
30
• moving continents
• formation of landforms
from interacting plates
Plate Tectonics
• The movement and interactions of large
fragments of earth lithosphere (called plates)
• earthquakes
• new landforms
• volcanoes
• new climatic regions on the earth
• creation of new rock types on the crust
Oceanic Crust
• Thin, dense (Fe, Mg) young rock –basalt
underlying the ocean floor
Continental Crust
• Thicker, less dense (Si,O) older rock – granite
making the bulk of the earth’s land
31
Plate Tectonic Overview
Divergent Boundary
“Continents on the move”
Convergent Boundary
The Earth is made up of rigid
plates (lithospheric plates) that
Transform Boundary
are in constant motion. Plates
separate, converge, and slide
past one another producing the
various Earth features we observe
today and in the past.
I
Earth Science.
Discuss with a friend:
1. Name the planets in their proper order.
2. Describe the layering of the earth
using lithosphere, asthenosphere,
mantle, and core; explain properties.
3. Describe chemical differentiation.
4. Present at least 3 reasons why the
earth is unique.
I will get an A on my exams and quizzes.
33
So, why study Earth Science?
39
•We depend on earth’s resources.
•
where to find resources and how to
manage the resources
• Understand earth (geologic) hazards
• how earthquakes, land sliding, volcanic
eruptions, floods, hurricanes, tornados,
“just to name a few” processes, work!
• Understand the complexity of the
interactions between the earth’s spheres
• open system relationships between the
lithosphere, atmosphere, biosphere, and
hydrosphere
Oh yeah, so you get your science requirement!
Career Opportunities in the Geosciences
• Employment growth of 22% expected between
2006 and 2016. Growth is much faster than the
average for all occupations.
• Average salary for geologists with BS, MS degrees = 85K
• More MS students are employed.
• Fewer BS students are employed.
Opportunities are cyclic and dependent
on the demand of commodities.
• Hot Geology Fields
• petroleum industry
• environmental geology
• Engineering
Bottom line: Choose the geosciences because you love it!
I
Earth Science.
Discuss with a friend:
1. Explain why earth science is important
to study, even for a non-scientist.
I will get an A on my exams and quizzes.