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PCS Earth Science
Chapter 15 Vocabulary - Oceanography
Term | Definition |
---|---|
oceanography | study of Earth's oceans |
side-scan sonar | a technique that directs sound waves to the sea floor at an angle, so that the sides of underwater hills and other topographic features can be mapped |
sea level | ultimate base level; the average level of the ocean's surface at any given time |
salinity | the total amount of dissolved salts in a water sample |
temperature profile | plots changing ocean water temperatures against depth, which varies, depending on location and season |
thermocline | a layer in a large body of water, such as a lake, that sharply separates regions differing in temperature, so that the temperature gradient across the layer is abrupt (upper layer mixed by wind - epilimnion, deep layer not mixed - hypolimnion) |
wave | horizontal distance between the crests or between the troughs of two adjacent waves |
crest | highest point of a wave |
trough | lowest point of a wave |
breaker | collapsing ocean wave that forms in shallow water and breads onto the shore |
tide | the periodic rise and fall of the level of water in the ocean |
density current | circulation pattern in the ocean that forms when a mass of more dense seawater sinks beneath less dense seawater |
surface current | a horizontal movement of ocean water that is caused by wind and that occurs at or near the ocean's surface |
upwelling | the movement of deep, cold, and nutrient-rich water to the surface |