Oceanography Lecture Outline Notes

 

Intro to Oceanography, The Scientific Method, and the Origins of Earth

 

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:

The ocean's structure and composition, its dynamic character (currents, waves, and tides), and the processes that occur within it.

 

      The processes that shape the ocean basins, and the materials that constitute its bottom.

 

      The origin, occurrence, extraction and conservation of the ocean-derived natural resources, including minerals, fossil fuels, energy, and marine life.

 

      The relationship between the ocean and atmosphere and its affects on short and long-term climate changes.

 

      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:

      Where are we?

      Who/what are we?

      How did we get here?

      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)

      "Mapping" how everything is connected together

      How and why things change the way they do.

 

3. Technology - Extension of input and processing abilities

            Sensitive, sophisticated instruments

            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

      Mostly just Hydrogen

 

      All elements from He to Uranium

      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