HMS Challenger Kilo Moana
Oceanography
World map showing land/water Thompson Research Vessel Polar views of Earth distribution
Sonar process—multibeam and Diagram of land/water by latitude Sonar process— sidescan single beam
1 Passive Continental Margin Atlantic oceanic ridge
Satellite Altimeter • Continental shelf • Continental slope • Continental rise
Oceanic Ridge--Atlantic Oceanic Ridge—Indian Oceanic Ridge—Pacific
Atlantic Ocean Pacific and Indian Ocean Floor Sea-floor landforms—California Floor
H:\ES106\PowerPoint\AN12_001.mov
2 Sea floor sediment Seismic data and interpretation Collection of • Derived from land: ‘terra’ sea-floor – Terrigenous sediment cores – Composed of sand, silt and clay • Derived from organisms: ‘biota’ – Biogenous – Composed of shells and skeletons of marine animals and plants • Direct precipitation from sea water: ‘hydro’ – Hydrogenous – Salts, calcium carbonate, metal oxides, metal sulfides (near sea-floor hot springs)
Plankton Marine Sediment distribution Offshore oil platform
Methane Hydrate sample Salt production Methane Hydrate burning
3 Manganese Nodules Submerged edge of continental crust Basin size vs. ridge
• Function of amount of water in the sea • And number and size of oceanic ridges
http://geography.berkeley.edu/ProgramCourses/CoursePagesFA2002/Geog40/Geog40.Week7.html
Active Convergent Lithospheric Plates Continental Active continental Margins • Oceanic plate is subducted Margin—location • Deep-ocean trench is formed • Volcanism above subducted plate
• Narrow continental shelf • Deep sea trench catches terrigenous sediment • ‘Accretionary Wedge’ of caught sediment • At convergent boundary of plates
http://serc.carleton.edu/research_education/cyberinfrastructure/navdat/questions.html http://serc.carleton.edu/research_education/cyberinfrastructure/navdat/questions.html
Deep-Ocean Trenches Pacific and Indian Ocean Floor Passive continental • Active continental margins • Other convergent plate locations Margin— • Most are in the Pacific Ocean location
4 Passive Deep sea sediment fans Turbidity current continental Margin—cross section
Discovery of Turbidity Currents Sea-floor landforms—California Atoll formation
Atoll Oceanic Plateaus Pacific and Indian Ocean Floor
• Figure 10-19—Oceanic Plateaus
5 Atlantic Ocean Pacific Lithosphere Action Oceanic Ridge--Atlantic Floor
http://www.soc.soton.ac.uk/CHD/classroom@sea/carlsberg/science/oceanic_constr.html
Oceanic Ridge—Indian Oceanic Ridge—Pacific Oceanic plate divergence
http://www.soc.soton.ac.uk/CHD/classroom@sea/carlsberg/science/constructive_margins.html
Rift valleys on oceanic ridges
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