Chapter 9 Vocabulary
Order by
21 terms
Terms | Definitions |
|---|---|
 Abyssal Plain | very level area of the deep-ocean floor, usually lying at the foot of the continental rise |
| Atoll | an island consisting of a circular coral reef surrounding a lagoon |
| Biogenous Sediment | seafloor sediments consisting of material of marine-organic orgin |
| Continental Margin | that portion of the seafloor adjacent to the continents. it may include the continental shelf, continental slope, and continental rise |
| Continental Shelf | The flat or gently sloping land that lies submerged around the edges of a continent and that extends from the shoreline out to a continental slope. |
| Continental Slope | the steep gradient that leads to the deep-ocean floor and marks the seaward edge of the continental shelf |
| Continental Rise | the gently sloping surface at the base of the continental slope |
| Deep-Ocean Trench | A narrow elongated depression on the floor of the ocean |
| Deep-Sea Fan | A cone shaped deposit at the base of the continental slope. The sediment is transported to the fan by turbidity currents that follow submarine canyons. |
| Echo Sounder | An instrument used to determine the depth of water by measuring the time interval between emission of a sound signal and the return of its echo from the bottom. |
| Guyot | A large, flat-topped seamount resulting from erosion of an island volcano when it was above sea level. |
| Hydrogenous Sediment | seafloor sediment consisting of minerals that crystallize from seawater; an important example is manganese nodules |
| Hydrothermal Vent | an area where ocean water sinks through cracks in the ocean floor, is heated by the underlying magma, and rises again through the cracks |
| Mid-Ocean Ridge | an underwater moutain chain where new ocean floor is formed |
| Outgassing | the escape of gases that had been dissolved in magma |
| Rift Valley | deep valley formed along the divergent boundary |
| Salinity | the relative proportion of salt in a solution |
| Sonar | a measuring instrument that sends out an acoustic pulse in water and measures distances in terms of the time for the echo of the pulse to return |
| Submarine Canyon | a seaward extension of a valley that was cut on the continental shelf during a time when sea level was lower, or a canyon carved into the outer continental shelf, slope, and rise by turbidity currents |
| Seamount | an isolated volcanic peak that rises at least 1000 meters above the deep-ocean floor |
| Terrigenous Sediment | seafloor sediment derived from weathering and erosion on land |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.