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EXERCISES
Examination and evaluation of real-time oceanographic data on the internet

PRELIMINARY

I: TECTONICS
and OCEAN BASINS
Earthquakes and Plate Tectonics
Spreading Rates
CA Earthquakes
Volcanoes
Topography of the Ocean Floor
History of Ocean Basins

II: OCEANS/ ATMOSPHERIC GASES

III: OCEAN/
ATMOSPHERE DYNAMICS

IV: INTEGRATED TOPICS

 
TOPOGRAPHY OF THE OCEAN FLOOR

Introduction to Terminology Describing the Topography of the Ocean Floor:

  • Definitions of terms and annotated images of features from lectures
    • abyssal plain
    • passive continental margin with shelf, slope and rise
    • fracture zone
    • mid-ocean ridge or spreading ridge
    • lateral ridge
    • deep sea trench
    • island chains and seamounts
    • triple point junction

 
Images
Definitions
Images
abyssal plain: flat ocean-basin floor extending seaward from the base of the continental slope and rise, typically 4-6km deep
continental margin: zone separating continents from the deep sea floor.  passive, if seismically inactive.
continental shelf: zone bordering a continent from shoreline to depth where a marked change in deoth occurs (shelf break).

continental slope: relatively steep downward slope from shelf to depth.

continental rise: gentle slope at the base of the continental slope.

fracture zone: linear zone of irregular bathymetry associated with fault zones and offsetting mid-ocean ridges.
mid-ocean ridge (MOR): spreading ridge at divergent plate boundary.
lateral ridges: volcanic ridges often separating ocean basins that are not divergent plate boundaries
seamounts: isolate volcanic peaks that rise >1km above the ocean floor, often in island chains formed by 'hot spots.'
trenches: long, deep and narrow depressions of the sea floor with relatively steep sides that are associated with subduction zones.
triple point junction: a point where three plates meet

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