Transcript Continental Margins and Ocean Basins Chapter 4

Continental Margins
and Ocean Basins
Chapter 4
Bathymetry
• Bathy=deep
• Meter=measure
• Discovery and study of the ocean
floor
Echo sounding
• The sinking of the Titanic in 1912 finally
ended the use of ropes with weights
• 1914 Reginald Fessenden developed and
iceberg detector and echo depth sounder
• Directs a sound pulse and listen for a
return echo
• The amount of time it takes to return can
be used to calculate distance
Multibeam echo sounders
• Single echo sounders were not
accurate…multibeam can send as
many as 112 beans at one time for
more accurate readings
Satellite Altimetry
• Cannot measure ocean depths directly but
can measure small alterations in the
elevation of surface water sending
thousands of radar pulses per second and
measuring how long it takes to return to
calculate height differences
• The average height of the ocean surface
can be known with great accuracy
Read Trieste
Topography of Ocean Floor
Vocabulary
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Continental margin
Ocean basin
Continental shelf
Continental slope
Continental rise
Ocean ridges
Hydrothermal vents
Transform faults
More vocabulary
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Abyssal plains
Seamounts
Island arcs
Submersible
Alvin
Shinkai
FLIP
Other vessels
Trieste
Notes Ocean Floor
• see Ocean Basins other powerpoint