Oceanography Exam I Study Guide – Chapters 1-4

 

I. Introduction to Oceanography – Chapter 1

          A. The Earth is a Dynamic Ever-changing System

                   1. Know the Earth's major subsystems

                  2. Be able to draw/ label the Earth's Cross-section

 

          B. Be able to define Oceanography.

          C. Oceanography and the Scientific Theory

                   1) Know the Scientific Theory approach to nature: the

 basic foundation of all sciences.

·        The basic steps

·        Hypotheses and Theories

·        Observations, Data and Evidence

·        Methods of Testing

·        Interpreting results

                   2) Understand the basics of how the approach works.

                   3) Find/create examples of the ST in the real world.          

                     

D. Be able to describe and explain the commonly-accepted

       explanations for the Origin of Galaxies, the Solar System,

        Earth, Ocean and Moon, and Life.

1) The Big-Bang hypothesis

2) The Solar nebula "cold" accretion hypothesis

3) Moltenization and differentiation periods of early Earth.

4) The origin and evolution of the Earth-Moon system.

5) The origin and evolution of Earth's early atmosphere,

oceans, and continental masses.

                   6) The origins of Life on Earth.

                   7) The “oxygen revolution”

 

          E. Know what makes the Earth such a dynamic planet!

                   1) Generation of INTERNAL HEAT from two key sources

·       Gravitational heat of accretion (core)

·       Radioactive isotopes barbeque (mantle)

                   2) The presence of LOTS OF WATER on the surface.

                   3) Amazing set of balanced physical, chemical, and energy

                             variables that allow water to exist in all three states.

                   5) SOLAR input.

                   6) Know and be able to describe the general physical and

                 chemical features of both, the Earth's interior and surface.

ü         The Earth's subsystems

ü         The global topographic and geographic surface

         patterns, e.g. layout of continental masses,  

      ocean basins, mountain ranges, trenches,

      island arcs, mid-ocean rift valleys, etc.

   

          F. Know what stimulated the voyages of the early seafaring

            civilizations – compare and contrast the

                   intent and purpose for voyaging of the:

                             1) Polynesians and Vikings

                             2) Phoenicians and Greeks

                             3) Chinese and Europeans

 

          G. List and describe the essential types of information

                found in a marine chart (map)

                             1) Longitude and latitude

                             2) Scale

                             3) Coastlines

                             4) Bathymetry (water depths and contours)

                              

          H. Describe the important oceanographic contributions

                   of the most influential people and organizations throughout the

               history oceanography

                             1) People like: Columbus, Megellan, Henry the

                                     Navigator, Darwin, C. Maury, Captain Cook, and

 John Harrison

2) Organizations within governments, military, and private/  

        public research institutions

 

          I. List and Describe key technologic breakthroughs

that helped advance oceanographic research

                             1) Seaworthy ships

2) Compass

3) Sextant

4) Chronometer

5) Power winches

         6) Electronic sensing devices (ex: for salinity, currents)

7) Sonar

8) Satellite

9) GPS

10) Computers and data software

 

II. Plate Tectonics and the Seafloor – Chapter 2

          A. Know The Basics of the Earth's Rock Cycle -

1) What is it? The endless cycle of building-up and

     wearing down of the Earth's crust.

§        Building up by magmatism and crustal uplift.

§        Worn down by weathering and erosion.

§        Destroyed/recycled by subduction.

 

2) A complex physical and chemical interplay of

      processes between five major material reservoirs:

       magma, igneous rocks, sediments, sedimentary

       rocks, and metamorphic rocks.

 

3) Series of related geologic processes occur between

two material reservoirs:

 

                            4) Three Major Rock Types

ü     Each group defines a variety of rock types that have a common origin.

                                      1) Igneous Rocks - Formed by the cooling and

crystallization of either, magma deep beneath

the Earth's surface, or lava extruded on the

                   surface, or consolidation of volcanic ejecta.

           

2) Sedimentary Rocks - Formed from the deposited

                             layers of clastic and/or chemical sediment via

                             compaction and cementation.

 

                                      3) Metamorphic Rocks - Formed by metamorphic

                             reactions of pre-existing solid rock via a unique

                             combination of extreme heat, pressure, fluids, and

                              deviatoric stresses.

 

5. Major rock-forming Processes

a. Heating (any rock) Þ Partial Melting Þ Magma

 

b. Transport (magma) Þ Cooling Þ Crystallization Þ Igneous Rock

 

c. Weathering (any rock) Þ Erosion Þ Sediment

 

d. Deposition (sediment) Þ Compaction Þ Cementation Þ Sedimentary

      Rock  

 

e. Heating +/- Pressure +/- Fluids +/- Stress  Þ Metamorphic Rock

                     

                             6. Be Able to Draw A Simple Rock Cycle Diagram

  

 B. Know The Basics of Earth's Hydrologic Cycle

1) What is it?

·        The endless cycling of water via evaporation, precipitation, and runoff on Earth's surface.

·        Major player in controlling Earth's climate

·        Powers weathering and erosion.

·        Plays a key role in mid-ocean hydrothermal systems

·        Plays a key role in subduction zone.          

                             2. Be Able to Draw/Label A Simple Hydrologic Cycle Diagram

 

C.  Wegener's Theory of Continental Drift (TCD)

                   1) Be able to explain the overall basic concept of CD

 

                   2) Know the terms Pangaea, Gonwanaland, and Luarasia

 

                   3) List the major types of evidence supporting TCD

 

                   4) Know the major obstacle that discredited the TCD

 

                             5) Know the key scientists that developed/supported TCD

 

      D. Know All the Basics of the Plate Tectonic Theory --         

                   1)  Stiff, outermost shell of solid Earth consisting of

                    the crust and uppermost mantle called the lithosphere

*      Broken up into 6 major plates & 12 minor plates –

*      Move over the hot, plastic athenosphere mantle.

 

2) Each tectonic plate moves independently: two adjacent

                   plates can interact in one of three ways:

*    Diverge

*    Converge

*      Slide past one another

 

3) Three types of plate boundaries and associated process

*      ·        Divergent = rifting/ seafloor spreading; tensional

*      ·        Convergent = subduction/ collision; compression

*      ·        Transform = strike-slip faulting; shearing

           

4) Spreading centers and Continental rifts form at divergent

                                      boundaries, where two plates are moving away from

                                      each other, forming brand-new oceanic crust.

 

                   5) Subduction zones and magmatic arcs form at convergent

                             boundaries, where an oceanic plate dives beneath

                             either a continental or oceanic plate into the mantle.

 

6) Continental collision zones also form at convergent

           boundaries where two continental masses are

           meeting head-on.

 

7) Great, transform strike-slip fault systems are created

        where two plates slide sideways, past each other.

 

8) Three proposed driving mechanisms of plate tectonics

a.     mantle convection

b.   ridge push

c.    slab pull

 

9) The plate interactions, over time, cause a

number of spectacular phenomena,  including magmatic arcs,

 mountain chains, terrane accretion and ocean basin collapses and

  openings.

·        Describe the terrane accretion process

 

·        Describe the Wilson Cycle

 

                   10) The plate tectonic theory unifies the observation and hypotheses

                            which attempt to explain most geologic phenomena.

 

                   11) The Earth's rock cycle is driven in large part by  the perpetually moving plates

 

E. Seafloor Spreading (SS)

          1) Be able to explain the basic concept of seafloor spreading

 

          2) Know the key terms associated with seafloor spreading

 

          3) List the major types of evidence/discovers behind SS

 

          4) Know the key scientist that proposed

 

F. Subduction

          1) Be able to explain the basic concept of subduction

 

          2) Know the key terms related to subduction

 

          3) List the major evidence/discovers for subduction

 

          4) Know the key scientist that proposed

 

G. Important Points concerning Theory of Plate Tectonics - Know that:

                   1) Plate Tectonics is a unifying theory because it is able

                       to explain many geologic phenomena.

           

        2) The so-called "Wilson Cycle" represents a plate tectonic

     cycle of plate motions where an ocean basin is born,

    grows, then shrinks, and finally collapses.

 

       3) There are 500 million-year Supercontinent Cycles of plate

motions and interactions that begins with the break-up of

an old supercontinent and ends with the formation of a new

supercontinent.

 

              4) Plate tectonics is the cause of Earth's mountain building,

                     magmatism, and never-ending resurfacing of the planet.

 

     5) The Earth's rock cycle is fueled by plate tectonics.

           

 

      F. Be Able to Identify All Major Plate Tectonic Boundaries

                   On a Map or Globe

                   1) Circum-Pacific basin and adjoining continents

                   2) North and South Atlantic basin and adjoining continents

                   3) Indian Ocean and adjoining continents

 

      G. Be Able to Identify Elements of Plate Tectonics in a

                   Geographic Illustration (see online practice exam)

)1 Match plate processes (ex. seafloor spreading)

with associated geographic features (ex. mid- ocean ridges)

 

H. Understand and be able to explain the concept of isostacy.

 

III. Marine Provinces  -- Chapter 3

A. Know the Geographic Significance of Seafloors

1) Oceans and seas cover over 70% of Earth's surface

 

2) Earth's seafloors constitute a global-scale topographic

       region of low-lying relief that contrasts to the high-

      standing relief of the continents

 

3) Seafloors represent the most vast (by far) depositional

       environment on Earth

·  Site of massive sedimentation and region of sedimentary

    rock production

 

4) The evidence used to establish and support the Theory

      of Plate Tectonics was established from the scientific

       study of seafloors and its sediments

 

B. Know Components and Nature of Continental Margins

·        Shelf – flat portion nearest shoreline

·        Slope – steep outer edge of shelf

·        Rise – base of slope where continebt and oceanic crust meet

  

                    1) Shelf-slope break, Submarine canyons, Turbidity currents

  

                   2) Continental margin seafloors consist mainly of

                              Granitic crust = outer edges of continents

                               Covered primarily by Terriginous sediments

 

3) Water depths are shallow; up to 200 meters on shelves

 

                   4) Explain difference between Passive versus Active

                       continental margins

 

C. Know Components and Nature of Deep Ocean Basins

§        Abyssal plains and hills

§        Oceanic trenches

§        Oceanic ridge systems and fracture zones

§        Hydrothermal vents

§        Oceanic islands, atolls, guyouts, and seamounts

 

1) Ocean basins have rugged, variable topography

 

2) Oceanic basin seafloors consist of

·        Basaltic crust = ophiolite package

·        Pelagic clays and oozes (sediments)

·         Pelagic clays derived from continents

·         Oozes consist mainly of skeletons of microscopic marine organisms

 3) Water depth of deep ocean average 4,000 meters

 

IV. Seafloor Sediments - Chapter 4

D. List and Describe the Types of Seafloor Sediments

          1) Four types of marine-based sediment - See Table 5.2

·        Lithogeneous

·        Biogenous

·        Hydrogeneous

·        Cosmogenous

 

2) Pelagic clays derived from primarily three land-based

       sources

·        Rivers

·        Volcanic eruption (ash falls)

·        Windblown material

·        Consist mainly of quartz and clay

 

3) Describe the two main types of Biogenous Oozes

·       Calcium carbonate oozes

·        Siliceous oozes

·        Constitute fecal pellets from larger animals

·        Fine sand- to silt-size particles

 

4) Define the sources of calcium carbonate oozes

·        Foraminifera

·        Cocoliths

·        Found on bottoms less than 4,500 meters deep (CCCD)

 

5) Define the sources of siliceous oozes

·       Tropical Radiolarians

·        Polar Diatoms

 

6) Define types of hydrogenous sediments

·        Manganese nodules

·       Phosphate nodules

·       Massive metal sulfide deposits

·        Evaporites

 

E. Describe and Explain the Distribution of Seafloor

      Sediments -

          1) Study Table 5.3 very carefully

 

2)  Study Figure 5.13 very carefully

 

3) Distribution of each sediment type controlled by several

              environmental factors:

·               Proximity to sediment source

·        Rate of sedimentation (each specific sediment type)

·        Chemical stability at site of deposition

 

4) Unique distribution pattern for each sediment type

          Study Distribution Map shown in Figure 5.13

·        Lithogeneous -

·        Biogenous

·        Hydrogeneous

·        Cosmogenous

 

F. Define the Rates of Seafloor Sedimentation

          1) Deep ocean sedimentation rates are very low

 

2) Each type of deep seafloor sediment has specific rate

·        Lithogeneous -  2 millimeters per 1000 years

·        Biogenous - 1 to 6 centimeters per 1000 years

·        Hydrogeneous - 1 to 10 millimeters per 1 million years

·        Cosmogenous - Negligible

 

G. List and Describe Methods of Seafloor Sediment

       Sampling

·        Piston Coring samplers

·        Drag bucket and Clamshell samplers

 

      H.  List and Describe Types of Seafloor Mineral Resources

          1) Continental Margins

§       Oil and gas (hydrocarbons)

§       Sand and Gravel

 

2) Deep Ocean basins

·       Manganese nodules

·       Massive metal-sulphide deposits

·        NO gold and silver

 

V. Vocabulary Lists - Chapters 1-4

A. Study the Terms and Concepts Lists Found at the End

     of Each Chapter

          1) Attempt to remember them

          2) Be ready to define many of these (at least the

            ones that I have included in this study guide)