Transcript Earth as a System - Bakersfield College

Earth Sciences –
Jack Pierce – MS 2
Meteorology
Geology
Oceanography
Astronomy
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January 20, 2010- Wednesday – Week 1
Agenda:
• Attendance/Syllabus (students read)
• Bring scantron for Monday
January 25th 2010 pretest
• Cornell Note Taking system
• Begin introduction to Earth Sciences
• Questions/Comments
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What is Earth Science??
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• Explores the scientific study of all aspects of earth
• atmosphere, oceans
• minerals, rocks, soils
• deserts, mountains
How is the Earth studied? –
Science asks deeper questions
• How do “things” work and why?
• Why have glaciers retreated and advanced
over geologic time?
• What effects might happen to natural earth
processes if they were inadvertently changed?
Some questions we will explore:
What are minerals and rocks??
Why do volcanoes erupt?
What forces produce mountains?
Why is climate so variable?
How old is the earth?
Why do we have ocean tides?
Do continents move?
Are there really ice ages?
How does earth “fit” in our universe?
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How do we find “accuracy” in our answers?
The Scientific Method
A set of logical steps scientists use to “get to the truth”
of processes acting in the universe
Making Observations
• 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
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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
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The Scientific Method
If you fail, try try
try again.
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In this class,
You will discover centuries
of scientific work. You
will see the products of
millions of observations,
thousands of hypotheses,
and hundreds of theories.
BC
Earth Sci
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I
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.
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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
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Earth System Science –
How does the view of Earth influence the way we
study earth??
What do you see?
Various “systems” within the earth that interact
with one another -– called Earth System Science
• Systems are NOT individually studied
System:
• How one system impacts another
system
A portion of the universe that can be separated from
the rest of the universe for the purpose of observing
changes that happen within
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Earth as a System: Which system is the Earth?
• 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
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The Fragile Earth – A CLOSED system:
• Any change in a closed system will affect other
systems.
• The amount of matter on earth is “fixed” – “We ain’t got
no more” --- This is all we have.
• When we dispose of waste, it’s still here. The waste will
remain within the closed boundaries of earth.
“There is no away to throw things to.”
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X
x x
I
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.
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The fragile earth as a closed system is supported by four
interrelated open systems.
Lithosphere
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
Geosphere
Interaction of
all open systems
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The Life Zone –
Figure 1.8. page 11
• All life on earth lives within a zone no wider than
20 km. The zone marks the interactions between
the lithosphere, hydrosphere, and atmosphere.
Altitude
8 km
6 km
Highest Mountain
Upper limit
of land animals
life
4 km
2 km
most of biosphere lives here
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Life on mid-ocean ridges here
2 km
4 km
6 km
life
Scattered bottom-living animals have been
seen at the greatest depths reached by
underwater cameras 10.5 km.
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How the 4 major open systems are divided into
open subsystems:
Hydrosphere:
oceans, streams, lakes, groundwater, glaciers,
raindrops
Atmosphere:
high/low pressure systems, clouds, atmospheric
layers, interaction of atmospheric gasses
Lithosphere:
plate tectonics, minerals/rocks, rock cycle
Biosphere:
separating different species of animals and
plants
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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?
4. Discuss the implications of positive and
negative feedback mechanisms.
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An Important Aspect of Earth 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
Working to change the system and working to
resist the change maintains balance within the
system.
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Positive/Negative feedback mechanisms
• The balance in the state of an open system is
affected by positive and negative feedback
mechanisms.
• Feedback mechanisms are events that enhance
(positive) or retard (negative) change within an
open system resulting in a balance within the open
system.
weight gain example?
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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.
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I
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
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What is difference between Earth Science and
Earth System Science??
Earth Science
• The scientific study of all aspects of earth
• Geology, Meteorology, Oceanography, Astronomy
Earth System Science (A Portion of Earth Science)
• The study of earth as a closed system
• Composed of interacting open systems
• Various open systems may be changed as a result
of human activities
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Geology – the study of the earth
Physical Geology:
•Materials that comprise the earth
• rocks, minerals, earth’s interior
• processes acting below and above the
surface
Historical Geology:
•Understand the earth’s origin and development
• understand the chronological order of
geologic events over 4.6 b.y.
The geologic time scale
Dating various geologic events
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The significance of fossils
Physical Oceanography:
• The study of the ocean floor including:
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•
•
•
•
Ocean chemistry
Physics
Sea floor geology
Coastal processes
Sea floor topography
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Meteorology:
• Study of the atmosphere and
processes that produce climate and
weather
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Astronomy:
• The study of the universe
• the earth’s place in our universe
• the origin of our earth
• how earth is related to all other
objects in the universe
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I
Earth Science.
Discuss with a friend:
1. Provide a definition and example for
each discipline found in ES.
2. Explain why the earth is a closed
system.
I will get an A on my exams and quizzes
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The earth’s place in the solar system
Uranus
Jupiter
Earth
Venus
Mercury
SUN
Mars
Inner planets
Terrestrial planets
Asteroid Belt
8.
Neptune
Saturn
Outer planets
Jovian planets
Gas planets
Low densities
High densities
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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
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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
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• 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
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Plate Tectonics!!!
Scientists use fossil evidence,
sea floor evidence, and climatic
evidence to reconstruct the
continents!!!!!!– HOT TOPIC
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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.
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Humans and Our Earth
How long have humans inhabited the earth?
Jan
Age of
dinosaurs
Jan
4.6 billion years
Man began inhabiting the earth (2 million years
ago) --December 31, the last 30 seconds of the year!!!!
How has man impacted earth in the last 5000
years (the beginning of reasonably modern times)
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Paul Ehrlich-Stanford University
• food supplies will fall short, and
How
famine
will does
follow.the earth’s population grow??
Paul Waggoner – an agronomist
• using current technology,
productivity increases far
beyond population growth.
6.5 billion
famine
Enough food produced
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Man’s use of renewable/non-renewable resources
•
•
•
•
•
How
How
How
How
How
many
many
many
many
many
live in a house/apartment?
drove/took a bus to school?
ate today?
use lights?
flushed the toilet today??
YOU have used earth’s natural resources!!!
Now, multiply your usage by billions of other humans.
So, what is a natural resource?
Useful materials obtained from the earth’s
spheres that make “life easier.”
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Man’s use of renewable/non-renewable resources
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What are some of earth’s resources?
• building materials (lumber, metal)
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metals (iron, aluminum, precious metals)
oil, coal (energy resources)
biologic resources (crops, plants, animals)
water, soil, and air
Renewable
• Regenerated resources
within a human time span
• biologic resources
• water, soil, and air
Non-renewable
• Regenerated resources that
CANNOT be replenished
in a human time span
• building materials
• metals
• oil, coal
How much impact has man had in “30 seconds?”
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Earth Science.
Discuss with a friend:
1. Ponder the existence of man. How do
you think we have impacted the earth?
2. Define the following:
resource
natural resource
renewable and nonrenewable resource
3. How has man used both renewable and
nonrenewable resources?
I will get an A on my exams and quizzes.
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So, why study Earth Science?
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•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!
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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.
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SQ1- Short Quiz #1
Using 1 sheet of paper, answer the following
question:
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