OCN 201 Science of the Sea

Syllabus for Ocean 201: The Science of the Sea

Course philosophy

    This course is designed to teach students about our current understanding of the Earth, ocean and atmospheric systems and how they interact with each other.  With the exception of an occasional lecture the entire course is taught by instructional faculty from the Department of Oceanography who are at Associate or Full Professor rank.  In addition to their instructional duties these faculty are all active researchers with international reputations in the field of Oceanography.

     The course presents the students with an understanding of science and the scientific method and shows how the scientific method is applied to the Earth Sciences.  Students are taught how data and observations can be used to formulate testable hypotheses.  In teaching our current understanding of Earth Science processes and their interactions, emphasis is placed on the mechanism by which today’s hypotheses and theories arose.  Students are given historical examples of how hypotheses developed and how new observations that challenged them resulted in their modification.   The concept of the preference for simplicity in scientific theories is presented.  Examples are given in which successive modification of fundamentally incorrect theory over long periods of time resulted in highly complex and unworkable hypotheses which were eventually overthrown by new simpler theories. It is emphasised during the course that the overall Earth system processes that we seek to understand are a result of the synergistic operation of overlapping processes from each of the physical sciences.  Specific examples are given to demonstrate how physical, chemical and biological processes interact in Earth Sciences. Students are shown how an understanding of Earth system processes is critical for prediction of future climatic shifts resulting from anthropogenic activities.

Course structure

    Each lecture title (below) describes a 50 minute lecture and is accompanied by the subject matter that will be covered in each lecture.  Reading material is assigned to each lecture as a chapter number in the required course text “Oceanography, an invitation to marine science” T. Garrison, 3rd ed. Wadsworth, 1998.  In cases where supplementary material is recommended this is defined as handout.  The handouts consist of 8-12 page notes and figures produced by the instructor and are supplied as Xeroxes to the class.

Exams

    Students take two intermediate and one final exam. The exams are spaced such that one occurs at the end of each subsection of the course (i.e. Geology, Chemistry and Physics, Biology).  The exams consist of a mixture of true/false, multiple choice and essay questions.  The final exam is cumulative but emphasises material covered in the last third of the course.  The final stresses the interaction between marine organisms and their environment and requires students to integrate physical and chemical concepts learned in the first part of the course with principles of ecology.  In addition students are required to participate in one field trip and turn in a completed questionnaire at its conclusion.  Students are allowed to participate in more than one field trip on a space-available basis.  An additional non-credit field trip on Atlantis or Voyager submarines is organised for interested students at a reduced price.
 

Lecture titles

Introduction

Introduction of instructing Faculty and Teaching Assistants. Explanation of course goals, brief review of course coverage.  Explanation of exam frequency, type and grading systems used.  Explanation of required and optional field-trips.

Geological section

The scientific method and the origin of the Universe
The scientific method: testing of hypotheses, progression from hypothesis to law.  Predictive value of science.  Development of the theories regarding the origin of the Universe and their modification/overthrow as new observations become available.  Current theories of the origin of the Universe and its possible future.  Reading assignment: parts of Chapter 1.

History of Oceanography

Polynesian voyaging and navigation techniques. The library of Alexandria, discovering the shape of the Earth, early cartography, developing knowledge of the size of the Earth. Determining longitude, early marine scientific expeditions.  Reading assignment: Chapter 2.

Origin of Earth

Formation of the Solar System, formation of the Earth by accretion, formation of Earth's moon by collision, Age of the Earth.  Reading assignment: balance of Chapter 1.

Internal structure and chemical differentiation of the Earth

Early history of the Earth, origin of the oceans and atmosphere by outgassing, internal structure of the Earth, why does Earth have oceans? Comparison of Earth, Venus, Mars, evolution of Earth's ocean-atmosphere system, the rise of free oxygen.  Reading assignment: parts of Chapter 3.

Physiography of the seafloor

Origin of continents and ocean basins:  why do we have dry land? Continental vs. oceanic crust, concept of isostasy, position of the shoreline:  ocean depth vs. continental height, continental margins, mid-ocean ridges and flanks, fracture zones, abyssal hills and plains, seamounts, deep trenches, marginal basins, characteristics of the major ocean basins.  Reading assignment: Chapter 4.

Continental Drift:  Prelude to Plate Tectonics

Definition of tectonics, tectonic structure of the continents, the shrinking Earth theory, the theory of continental drift.  Evidence for and objections to the theory.  Reading assignment: Chapter 3.

Seafloor Spreading

Revival of the theory of continental drift:  Paleomagnetic evidence from the continents, paleomagnetic evidence from the ocean floor, seafloor spreading.  Reading assignment: Chapter 3.

 Plate Tectonics I

 Plate Tectonics, types of plate boundaries, divergent boundaries, convergent boundaries and their three types, fracture zones and transform faults.  Reading assignment: Chapter 3.

Plate Tectonics II

Video of reconstructed plate motions, 0-800 Ma, terranes and the structure of continents, driving forces for plate tectonics, implications of plate tectonics for Oceanography.  Reading assignment: Chapter 3.

Mantle Plumes and Hawaiian Volcanoes

Atolls and Guyots, three types of volcanism on Earth, mantle plume theory, large igneous provinces and flood basalts.  Reading assignment: Chapter 3.

Hawaiian Volcanoes

The Hawaiian hot spot, the Hawaiian-Emperor Seamount chain, determining absolute plate motions, history of Pacific Plate motion.  Reading assignment: Chapter 3.

Deep Sea Sediments

Location of sediments in the sea, sediment types, classification by size, classification by mode of formation, classification by location and source, classification by degree of lithification, deep sea sediment, sampling methods, factors affecting composition, distribution, the Carbonate Compensation Depth.  Reading assignment: Chapter 5.

Shelf Sediments

Types of sediment, sedimentary rocks, erosion, transport, and deposition, description of typical passive margin, sea level changes and sedimentation.  Reading assignment: Chapter 5.

Coastal Processes

Primary coasts, secondary coasts, estuaries, coastal erosion in Hawaii.  Reading assignment: Chapter 12.

Physical Resources of the Sea

The political regime, offshore oil and gas, sand and gravel, magnesium, salts, freshwater,
future promise.  Reading assignment: Chapter 18.

1st Exam
 Covers the first 15 lectures

Chemical and Physical section

Salinity

Major ions in seawater, constancy of composition.  Minor and trace species.  Sources of chemicals to the sea.  Planetary water balances.  Chemistry of rivers.  Residence time of different chemicals in the ocean.  Reading assignment: Chapter 6.

Hydrothermal vents

Geological origin of hydrothermal vents, mid ocean ridge locations and Loihi.  Chemistry of vent fluids and contributions to global fluxes. Finding vent sites by chemistry and biology.  Chemosynthesis and the unique nature of vent biology.  Reading assignment: Instructor handout

Chemical distributions: the roles of biology and physics

Concept of required nutrients.  Limitation of growth by light or nutrients. Micronutrients. Vertical distribution of nutrients in the ocean and the cause.  Deep water distributions and the role of deep water mass movements.  Chemical tracers of biological processes.  Bomb testing and chemical tracers of water movement.  Reading assignment: Instructor handout

Thermohaline circulation

Concept of density.  Density of pure water as a function of temperature.  Factors affecting the density of seawater.  Temperature structure of the oceans.  Formation of ocean deep water and thermohaline circulation.  Formation of intermediate water from the Mediterranean outflow.  Determining deep water formation rates.  Reading assignment: Chapter 7.

Light and sound in the sea

Basic properties of light: reflection and refraction.  Scattering and absorption, relation to light limitation of growth in the ocean.  Colour absorption and why the ocean appears blue.  Basic properties of sound, speed of sound in water and its relation to temperature and pressure. The SOFAR channel and how it works.  Using acoustics: marine animals, SONAR, use of acoustic tomography near Kauai to monitor the upper ocean.  Reading assignment: Chapter 7.

Atmospheric circulation

Weather and climate.  Heating of the Earth and seasons.  Conduction, convection and radiation. Coriolis effect.  Atmospheric circulation cells.  Tropical cyclones and hurricane formation. Reading assignment: Chapter 8.

Surface circulation

Effect of wind blowing on water, pressure gradients and Coriolis effect.  Ekman spiral and average direction of flow.  Gyre structure of the surface ocean.  Surface currents Kuroshio and Gulf Stream.  Climatic effects of surface currents.  Reading assignment: Chapter 9.

El Nino

Definition of El Nino and Southern Oscillation.  How the ocean circulates when the Easterly wind is strong.  What happens when the wind slackens and El Nino starts.  Feedback between ocean and climate and how it is broken.  Consequences of El Nino and attempts to predict it.  Reading assignment: part of Chapter 9.

Waves and Tides 1

Wave definition and anatomy.  Classification of wave types. Deep and shallow water waves.  Velocity of waves.  Wind wave development and wave trains.  Wave height and wave progression and surf forecasting.  Reading assignment: Chapter 10.

Waves and Tides  2

Interference patterns and use of waves in Polynesian navigation.  Waves approaching the shore, breaking waves.  Wave refraction and diffraction.  Internal waves.  Reading assignment: Chapter 10 and part of Chapter 11

Waves and Tides  3

Storm surges and their origin.  Tsunami origin and propagation.  Earth-Moon gravity system and the origin of tides.  Effect of the Sun.  Spring and Neap tides.  Typical tidal cycles.  Honolulu tides.  Tidal progression and amphidronic points.  The effect of tides on the Earth's rotation.  Reading assignment: Chapter 11.

 The ocean and the climate

Concept of cyclical processes and reservoirs.  Connections between planetary scale cycles.  Greenhouse gases.  Carbon dioxide in the atmosphere, past and present.  Carbon reservoirs and human activity.  The missing carbon dioxide and the oceans.  Relationship between carbon dioxide in the atmosphere and ice-ages.  Recent climatic shifts and their effects.  Reading assignment: Instructor handout.

Modelling climate change

Use of modelling to predict the future.  Problems of models.  Simple models with single inputs.  More complex models with variable inputs.  Example application of simple models to nutrient distributions in the ocean  and fish stocks.  Complex models to predict atmospheric carbon dioxide and the difficulties with them.  Using SIM Earth to construct a simple carbon dioxide feedback model.  Reading assignment: none.

Exam 2
    Covers lectures 16-28

Biological section

Origin and history of life

Origin of life in the oceans. Hypothesis of how life arose through chemical evolution and how the present diversity of living forms arose through biological evolution. Evidence for these ideas.  Reading assignment: Chapters 1 and 13.

Photosynthesis

Chemical process of photosynthesis.  Comparison with respiration.  Reading assignment: Chapter 13.

Phytoplankton

Various types of phytoplankton in the sea and their peculiarities.  Reading assignment: Chapter 14

Primary production

Microscopic cells and phytoplankton. Why plants in the ocean are different from plants
on land and why they are of such small size.  Reading assignment Chapter 3.Reading assignment: Chapter 14.

Zooplankton

Various types of animals that feed on the phytoplankton and their methods of feeding.  Reading assignment: Chapters 14 and 15.

Seasons in the sea

Causes and the effects of seasons and how they differ latitudinally.  Reading assignment: Chapter 14.

Micronekton

Examination of habitats and adaptations of the free-swimming small fishes, squids and shrimps of the open ocean and the causes and effects of their vertical migrations.  Reading assignment: Chapter 17

Nekton 1

The nekton are the large, fast swimming animals that dominate the
surface waters of the open ocean. Fishes and sharks, the factors responsible for their success.  Reading assignment: Chapter 16.

Nekton 2

The reasons for the success of whales and squids in the nekton.  Reading assignment: Chapter 16.

Benthos 1

The rules for surviving on the ocean floor. Modifications animals have made compared to living in the water column.  Reading assignment: Chapters 15 and 17.

Benthos 2

Examination of  two specialised habitats on the ocean floor: Coral reefs and the deep sea. Unusual features of organisms occupying these habitats.  Reading assignment: Chapters 17 and 18.

Fisheries

What limits the amount of food available to humans.  The factors that make the regulation of fisheries so difficult.  Reading assignment: Chapter 19.

Review session

Opportunities in oceanography.  Review for final exam.  Class/Instructor evaluations

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