1. PHYSICAL OCEANOGRAPHY Part 4: Sound in the Ocean
GEOL 1033
(Lesson 29)

2. Depth determination (study Exercise #4) Echo sounder used
SOUND IN SEAWATER
Sound travels
About 4 times faster in water than in air
Approximately m/s in water
Depth determination (study Exercise #4)
Half travel time X 1500 m/s = depth
Echo sounder used
Record depth profiles
Detects deep scattering layers
Obtain seismic profiles

4. Speed of Sound in Water
“Typical” depth profile of sound speed in seawater

5. Speed of Sound in Water
Arctic & Antarctic profile
Lower latitude profile

6. SOFAR & Shadow Zone
Effects of sound speed minimum and maximum:

7. SOFAR Channel
Sound velocity minimum at about 1000 m depth at low to mid latitudes

8. SOFAR Experiment in 1991
Successful transmission of sound over great distance

9. Associated with a near-surface sound maximum speed depth
Sound Shadow Zone
Associated with a near-surface sound maximum speed depth
At approximately 80 to 100 m
Ideal detection

10. Sound "Shadow Zone" Due to Refraction

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