1. AIM: Introduce you to scientific study of oceans and seas
Oceans and seas cover about 70% of the earth's surface
Huge volume of water moderates temperatures on earth (enabling organisms like us to survive)
Oceans are a tremendous source of food reserves
Oceans are a huge source of mineral reserves
Oceans are potentially a significant source of energy
Oceans are a place for us to dump our garbage

2. Material covered by SFW
What are the shapes or configurations of the modern ocean basins?
What is the chemical make-up and physical nature of sea water?
How do physical and chemical properties affect, and are in turn affected by, ocean currents?
What is the origin of the tides and waves?
Did the configuration of, chemistry of, or currents in ancient ocean basins differ from those in modern oceans?

3. Material covered by KPH
How are organisms distributed in modern oceans?
How do changes in the chemical composition and physical character of sea water affect the distribution of life in the oceans?
Has marine life changes through time, and if so how?
How have humans affected the oceans, and how might humans continue to affect the oceans?

4. Ocean floors are markedly different from the land we see around us
Sea water hides some of the most striking geomorphic features on the surface of the earth
Submarine canyons
Mid-ocean ridges
Oceanic fracture zones
Deep-ocean trenches
These features have no direct analogs on continents

5. Once earth scientists recognized those features, they were forced to change the way they organized their thoughts about geologic processes
Investigations in marine geology were fundamental to the development of plate tectonic theory, the currently-accepted theoretical framework for geological thought

6. You will be successful in marine science to the extent that you too can adopt a marine perspective on earth
Having raised the issue of perspective, let continue in that vein with a few additional thoughts on how perspective shapes scientific thought

7. The adoption of plate tectonic theory by earth scientists is sometimes cited as a classic example of what the historian of science Thomas Kuhn calls a paradigm shift
Kuhn outlined his ideas on paradigm shifts in a widely read and often-cited book entitled ‘The structure of scientific revolutions’

8. Scientific revolutions, I
Science does not grow by slow, steady, directionless accretion
Science is a discontinuous process, directed along certain paths by ruling paradigms
Paradigm here denotes how a community utilizes a commonly-accepted interpretation or guiding principle to understand a phenomenon or set of phenomena
e.g. Thompson’s versus Bohr’s versus the quantum mechanical view of the atom
Scientific revolutions occur as paradigm shifts

9. Scientific revolutions, II
There is not, nor can there be, a reconciliation of conflicting hypotheses, i.e. the old and new paradigms, by some higher authority
Ruling paradigms change quickly by ‘gaining the consent of the relevant community’
In this sense, ‘revolutionary’ is not a promotional term
‘Revolutionary’ is the technical description of the process by which science moves ahead

10. Special earth sciences perspectives
Many earth scientists use an observation-inference methodology instead of experimental methodologies
Observe and describe objectively features or processes
Interpret features in light of the processes inferred to operate (or have operated) to generate them (using principles from biology, chemistry, or physics)
‘Test’ inferences by making ‘predictions’
Compare ‘predictions’ with observations

11. Methodology leads to the tenet ‘the present is the key to the past’
Observe geologic processes that occur on earth today, and determine how those processes affect rocks at the present time
Assume that analogous processes operated at different times in the past, i.e. throughout geologic time
Infer, by comparing modern and ancient rocks, which processes were responsible for forming ancient rocks

12. Marine geology and the earth system

13. Global topography Highest elevation - Mount Everest
~29,000 ft above sea level
~5.5 miles above sea level
~8.85 km above sea level
Greatest depth - Marianas/Philippine trench
~38,000 ft below sea level
~7.5 miles below sea level
~11 km below sea level
Total range = ~13 miles or ~20 km

14. Radius of earth = 6371 km (3982 mi)
20 km (13 mi) is a large distance to us. Relative to earth’s radius, however, 20 km is small.
Radius of earth = 6371 km (3982 mi)
Diameter of earth ≈ 12,700 km
20 km /6400 km ≈ 0.003
20 km ≈ 0.03% Earth’s radius

15. What is the distribution of elevations on earth?
Is land area distributed ‘normally’ between the two extreme elevations?
No - elevation distribution is bimodal
One common elevation, just above sea level, corresponds to the elevation of continents
A second common elevation, between 3-4 km below sea level, corresponds to the elevation of the ocean floors

16. Greatest changes in average elevation occur between 1 and 3 km below sea level
The best place to locate the transition from continent to ocean is, then, somewhere between 1 and 3 km below sea level
We place the ends of continents at 1 to 3 km below sea level