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5 Cards in this Set
- Front
- Back
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Bathymetry |
Measurement of depth when mapping and charting the shape of the ocean floor. Bathymetric techniques use sound energy. |
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Echo Sounder (or Sonar) |
(Sound, navigation, and ranging) Primary instrument for measuring depth. Invented in the 1920s, transmits a sound wave into the water to produce an echo when it bounces off an object, a clock measures travel time to fractions of a second. Distance(depth) is calculated with velocity of sound waves in water (1500m/sec): distance (depth)= velocity x time/2 |
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High resolution multi beam Sonar |
(Modern device) employs an array of sound sources and listening devices, obtains narrow strip of sea floor |
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Ophiolite complex |
The structure of the oceanic crust and sequence of rocks. |
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Four layers |
Layer 1: (top) unconsolidated sediments Layer 2: consisting of pillow lavas Layer 3: numerous interconnected dikes called sheeted dike complex Layer 4: (bottom) gabbro |
