I. Lecture
Content - Topics Covered
What is Oceanography?
Oceans and Human Civilization
Observing
Nature: Consciousness and the Act of Perception
The
Ocean from a Scientific Perspective - A Systems Approach
Earth's
Hydrologic System
the
Scientific Method & Theory
Origin of Earth and our Solar System
Origin of Life
II. What is Oceanography?
A. Derivation:
Word "ocean" comes from the Latin word "oceanus", which was taken from
the Greek name "okeanos" - the name they gave the great "river" that lay
beyond the Mediterranean Sea.
B. Defined: The Scientific Study of the Earth's Ocean:
1. The process of developing unifying principles and models derived from collected
data from the ocean, marine life, and the lands bordering it.
2. Oceanography divided into two major areas:
· Physical = materials and processes
· Historical = origin and evolution
3. Several different fields of study:
Ø The ocean's structure and composition, its dynamic character (currents, waves, and tides), and the processes that occur within it.
Ø The processes that shape the ocean basins, and the materials that constitute its bottom.
Ø The origin, occurrence, extraction and conservation of the ocean-derived natural resources, including minerals, fossil fuels, energy, and marine life.
Ø The relationship between the ocean and atmosphere and its affects on short and long-term climate changes.
Ø The history of life in the ocean.
C. The Discipline of Oceanography is Very Broad
1. Marine Biology
2. Physical Oceanography
3. Marine Paleontology
4. Economic Oceanography
5. Environmental Oceanography
6. Marine Geochemistry
7. Marine Geology
8. Ocean Engineering
9. Marine physics
10. Climatology
11. Marine Seismology
12. Plate Tectonics
13. Planetary Oceanography
D. Ocean Science Research - "Pure" Versus "Practical"
1. "Pure" = sake of curiosity and scientific knowledge
· Examples: Sex life of jellyfish; Project Moho
2. "Practical" = solving human-related problems or concern
· Examples: Climate affects; Marine Fisheries; Mining
E. Economical & Environmental Aspects of Oceanography
1. Economical = Oceanography impacts local & global economies
· Examples: Mineral & Energy Resources; Fisheries
2. Environmental = Oceanography affects local & globalecosystems
· Examples: Marine Hazards; Pollution; Development
F. Interesting & Rewarding Careers in Oceanography
III. Oceanography and Human Civilization
A. The Human Experience Has Been Shaped by the Ocean
1. Many human societies, past & present, developed their unique character and
perceptions through interaction with the ever-dynamic land and sea
· Weather and Climate
· Natural Disasters
· Habitation & Resources
· Cultural Behaviors & Belief Systems
· Religions & Spirituality
2.
Humans are quickly becoming a major geologic force
B. The Ocean Affects Every Person's Everyday Life
1. Same factors as defined above
C. Important Global, Regional and Local Marine Issues
1. El Nino, Greenhouse Warming & Climate Change
2. Tsunamis
3. Hurricanes
4. Currents, Waves and Tides
5. Mining and Oil Drilling
6. Human-built Shoreline Structures
7. Urban Development and Pollution
8. Marine Fisheries
9. Commerce and Transportation
10. Recreation
IV. Observing Nature Through the Human Experience
A. Making Sense of Mother Nature and the Universe
1. Humans have an amazing capacity for exploring and understanding nature
and the Universe.
2. Humans take great efforts in searching for and defining the order and
relationships between matter, energy, and life amidst a mind-boggling
backdrop of cosmic chaos.
3. Making "sense" of Nature is a way of answering the most basic questions
that humans ask themselves:
Ø Where are we?
Ø Who/what are we?
Ø How did we get here?
Ø Where are we going?
B. Levels of Human Consciousness
1. Environment Awareness
2. Self-Awareness
3. Self-Reflection
4. Holistic Awareness
5.
Holistic Reflection
C. The Tricky Thing We Call (Human) Perception
1. Identification, evaluation and categorization of objects
2. Complex process of comparing different objects & events
3. Prioritizing sensory (experiential) input (objects & events)
4. Constantly (re)creating a "perceived" reality (occurring in the present) from a
"remembered" reality (from the past)
5. Personal and societal perceptions of Life on Earth are based on popularly-
held belief systems
D. The Means of Understanding the Nature of Things
1. Human Senses - Input of Information
2. Human Mind - Information processing (Thinking)
Ø "Mapping" how everything is connected together
Ø How and why things change the way they do.
3. Technology - Extension of input and processing abilities
Ø Sensitive, sophisticated instruments
Ø Computers
V. Systems
Approach To Understanding the Earth
A. The Science Perspective of Earth
1. Rational, analytical approach to studying the Earth
2. Based upon empirical, reproducible evidence (facts)
3. Testable interpretations (hypotheses & theories)
4. Always open to debate and modification
B. The System-Subsystem Conceptualization of Earth
1. The Concept of a System - Combination of related parts (subsystems) that
interact in an organized fashion.
2. Individual Systems are characterized by the dynamic transfer of energy,
matter, and information:
· Input = into the system from outside (the system)
· Output = out of the system to outside (the system)
· Process = transfer within/between subsystems
3. Very useful for understanding complex things such as Earth or a human
body.
4. The Earth can be described as being a limited System having a virtually
limitless set of Sub-systems.
C. The Principle Subsystems of Earth
1. Core
2. Mantle
3. Lithosphere
4. Biosphere
5. Hydrosphere
6. Atmosphere
D. Complex Interactions Among Earth's Subsystems
1. The Rock Cycle
2. The Hydrologic Cycle
3. The Biological Cycle
4. Plate Tectonics - the "Supercontinent Cycle"
E. Closer Look at the Hydrologic Subsystem
1. A multi-process (re)cycling of water between the hydrosphere, atmosphere,
and lithosphere
2. Massive, complex transfer/exchange of heat energy and water between the
equator and the poles.
v Heat energy input from the Sun
3. Water reservoirs
· Ocean - the "Biggie"
· Atmosphere
· Glaciers
· Lakes and Rivers
· Groundwater
· Plants
4. Several water-transforming & moving processes
VI. Marine
Studies and the Scientific Method
A. Marine Research is Conducted in a Thoughtful Way
1. Clear stated purpose
2. Well thought out & carefully planned
3. Follows a set of logical and rational guidelines outlined in a step-by-step
method called the Scientific Method
4. Collaboration, review, and debate with fellow geologists
5. Always open to scrutiny, challenge, and modification from the scientific
community and the world at large
B. The Scientific Method - A Set-by-Step Research Plan
1. Observation - Observe something in nature, using your
bodily senses or sensing instruments.
2. Question - Ask a question about what you observe.
3. Hypothesis - Predict what you think the answer to your question might be
4. Method - Figure out a way to test whether or not your hypothesis is correct.
Note that the outcome must be measurable, i.e. quantifiable and
reproducible.
5. Result - Perform the experiment using the method you came up with, and
record the results. Repeat the experiment to confirm you results.
6. Conclusion - You state whether your prediction was confirmed or not and try
to explain your results.
7. Follow up - Repeat above steps (modify research plan) until your hypothesis
confirms your results.
C. The Formulation of Hypotheses and Theories
1. Examples in Oceanography
v Equilibrium theory of tides
v Theory of Plate Tectonics
v Theory of Evolution
2. In-Class Examples
v Lava Lamp Motion hypothesis
v The Spinning Light Propeller hypothesis
VII. Origin of Our Earth and Solar System
A. Solar System Formed from Interstellar Gas & Dust
1. Material came from two sources
ü Mostly just Hydrogen
ü All elements from He to Uranium
ü Both gases and solid matter
2. Coalescing of cold matter done by gravitational fields
· Gravity/shock waves through interstellar space
· Increasing gravity force of condensing matter
B. Earth Accreted from the Rotating Solar Nebula Disc
1. Condensing Solar nebula cloud began rotating
2. Increasing angular momentum caused nebula to flatten from an irregular
mass into a spinning disc-like form
3. Central mass condensed into the "proto" Sun
4. Outer mass coalesced into many planetisimals, which eventually lumped
together to form "proto" planets
5. Over time, the "proto" planets swept up the remaining planetisimals to
become the nine known planets
6. Inner planets, including Earth, formed mainly from the cold accretion of solid
materials (heavier elements)
7. Outer planets, like Jupiter, formed mainly from volatiles and gases (lighter
elements)
8. Segregation of Core and Mantle (Earth entirely molten)
9. Accretion process probably took 1 BYA to 500 MYA
C. Age of Earth & Solar System is about 4.6 Billion Years
v Age comes from the dating of meteorite & Moon samples
v Oldest dated Earth rocks are around 3.8 BYO
D. Infant Earth Underwent Further Changes
1. Theorized collision of a Mars-sized planet with Earth to form the Earth-Moon
system - Extremely violent event
v This occurred sometime between 4.4 & 4.0 BYA
3. Intense period of planetisimal and comet bombardment
v This occurred sometime between 4.0 & 3.8 BYA
4. Sufficient cooling to create a solid, thin, & very mobile lithosphere made up
of many fast-moving micro plates
v Some form of "hyper" plate tectonics
v First real continental crust probably forms
5. Earth's surface also cool enough to harbor liquid water
v Ocean begins to form around 4.0 BYA
v Sources of water from volcanic out-gassing and
abundant comet impacts
6. Earth's atmosphere underwent drastic changes
v Began as mixture rich in nitrogen, carbon dioxide, water, and some methane and ammonia
v Slowly lost most of its carbon dioxide due to ocean absorption and fixation into marine sediments between 3.5 and 1.5 BYA
v Slowly lost most of its water vapor due to dissociation into oxygen and hydrogen by sunlight between 3.5 and 1.5 BYA
v Final major change (and most important to life) was the dawn of (marine) plant life that began a long yet steady buildup of free oxygen in the atmosphere and ocean beginning around 1.5 BYA
VIII. Origin of Life on Earth
A. Infant Earth Had a Very Hostile Environment to Life as We Know It Today
1. Poisonous oxygen-free atmosphere
2. Extreme UV from a youthful Sun
3. High occurrences of meteorites
4. Probably extreme ocean and atmosphere disturbances and fluctuations
5. Only thing that seemed friendly was water - lots of it!
B. Origin
of Life Experiments
1. Classic experiment by Miller and Urey in 1953.
v Building
blocks of life were manufactured in a lab apparatus using primitive gases, UV light
and electrical sparks (simulated lighting).
v Amino
acids and sugars (carbon compounds)
v No
actual living material formed, though.
2. More recent experiments (refinements of Miller and Urey's experiment) yielded even more fruitful results.
v A key requirement was absence of oxygen.
v Small
proteins and nucleotides formed.
v Special
role of water crucial to results
v Again, no actual living matter was
generated.
C. Biosynthesis - The Transformation of Nonliving Matter to a Living Organism
1. Several hypotheses - all of them still very speculative
v Life arose from protected, shallow marine tidepools exposed to sunlight and the atmosphere.
v Life arose from the ocean floor surrounding
hydrothermal vents at the bottom of a partially frozen ocean, that was not
exposed to the sun or the atmosphere.
v Life originated on another planet (namely
Mars) and made it to Earth via a meteorite (from Mars)
D. Evidence of Early Life on Earth
1. Oldest fossils found are dated between 3.5 and 3.4 BYO.
2. These oldest fossils are remnants of photosynthesizing bacteria (blue-green
algae) that look much like today's strains of spirullina.
3. Even older remnants of life have been found that may push the dawn of life
back to 3.8 BYA
4. These fossil ages indicate that life began on Earth not after the ocean formed.
IX. Vocabulary Terms and Concepts
Big Bang
Biosynthesis
Cold Accretion theory
Atmosphere
Condensation theory
Convergent plate boundary
Core (inner and outer)
Crust (continental and oceanic)
Density
Differentiation
Earth System
Galaxy
Gravity
Hydrologic cycle
Hydrosphere
Hypothesis
Lithosphere
Mantle
Ocean
Oceanography
Outgassing
Radioactive decay
Rock
Rock cycle
Scientific method
Solar nebula
Star
Supernova
Theory