Oceanography
“The Vast World Ocean”
Random Facts!!
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71% of Earth’s surface is covered by
the global ocean!
Oceanography – draws on the
methods and knowledge of geology,
chemistry, physics, and biology to
study aspects of the ocean.
Main Ocean Basins
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Pacific Ocean –
Largest/Deepest
Atlantic Ocean – ½ the
size of the
Pacific/narrow
Indian Ocean –
southern hemisphere
Arctic Ocean – 7% the
size of the Pacific
Mapping the Ocean Floor
*Bathymetry – the
measurement of
ocean depths and
the charting of the
topography of the
ocean floor.
Mapping the Ocean Floor
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Sonar – bouncing
waves from the ship to
the floor and back
Satellites
Submersibles –
observe sea
creatures/collect data
– Alvin – man driven
– ROV’s – remotely
operated
– AUV – long term
Ocean Floor Features
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3 main types:
– Continental Margins – Transition from
land to ocean
Continental Shelf – submerged
surface/slightly sloping
 Continental Slope – marks the boundary
between ocean/land crust
 Continental Rise – A gradual decline
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Ocean Floor Features
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Ocean Basin Floor – between two
features
– Deep – Ocean Trench – when two plates
come together and one goes into the
mantle.
– Abyssal Plains – Flat deep features
– Seamounts/Guyouts – submerged
volcanic peaks.
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Flat tops formed by waves/plate movements.
Ocean Floor Features
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Mid – Ocean Ridge: Center of most
ocean basins
– Seafloor Spreading – moving apart/new
ocean floor created
– Hydrothermal Vents – Mineral –rich
water/super heated
Resources from the
Seafloor
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Energy Resources –
– Oil/natural Gas
– Gas hydrates – future energy needs?!
Other Resources
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Sand/Gravel
Manganese Nodules – Areas with
many different metals
Evaporative Salts
Oceanography
“The Composition of Seawater”
Salinity (Salt)
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The total amount of solid material
dissolved in water.
– Most is Sodium Chloride (NaCl)
Sources of Sea Salt
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Chemical
Weathering of rocks
Earth’s Interior
– Mixtures are
constant!
Changing Salinity
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Decrease Salinity:
– Precipitation, runoff,
icebergs melting
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Increase Salinity:
– Evaporation, sea ice
forming
Ocean Temperature
Variation
*varies with the amount
of solar radiation
(latitude)
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Thermocline – the
layer of ocean with a
rapid change of
temperature with
depth.
– Creates a barrier