Earth/Environmental Science Essential Vocabulary
Chapter 14
1. Oceanography- the scientific study of the oceans and oceanic phenomena
2. Bathymetry- the measurement of ocean depths and the charting of the shape
or topography of the ocean floor
3. Sonar- An electronic depth-sounding mechanism
4. Submersible- a small underwater craft used for deep-sea research
5. Continental margin- that portion of the seafloor adjacent to the continents; It
may include the continental shelf, continental slope, and continental rise.
6. Continental shelf- the gently sloping submerged portion of the continental
margin, extending from the shoreline to the continental slope
7. Continental slope- the steep gradient that leads to the deep-ocean floor and
marks the seaward edge of the continental shelf
8. Submarine canyon- a seaward extension of a valley that was cut on the
continental shelf during a time when sea level was lower
9. Turbidity current- a downslope movement of dense, sediment-laden water
created when sand and mud on the continental shelf and slope are dislodged
and thrown into suspension
10. Continental rise- the gently sloping surface at the base of the continental
slope
11. Ocean basin floor- area of the deep-ocean floor between the continental
margin and the oceanic ridge
12. Abyssal plain- very level area of the deep-ocean floor, usually lying at the
foot of the continental rise
13. Seamounts- an isolated volcanic peak that rises at least 1000 meters above
the deep-ocean floor
14. Mid-ocean ridge- a continuous elevated zone on the floor of all the major
ocean basins and varying in width from 1000 to 4000 kilometers;
15. Seafloor spreading- the process by which plate tectonics produces new
oceanic lithosphere at ocean ridges
16. Terrigenous sediment- seafloor sediment derived from eroded rocks on
land
17. Biogenous sediment- seafloor sediment of biological origin, such as shells
and skeletons of marine life
18. Calcareous ooze- ooze thick, common biogenous sediment produced by
dissolving calcium carbonate shells
19. Siliceous ooze- biogenous sediment composed of the silica-based shells of
single-celled animals and algae
20. Hydrogenous sediment- seafloor sediment consisting of minerals that
crystallize from seawater
21. Gas hydrates- a gas, such as methane, trapped in a lattice-like structure of
water molecules
22. Manganese nodules- rounded lump of hydrogenous sediment scattered on
the ocean floor, consisting mainly of manganese and iron and usually containing
small amounts of copper, nickel, and cobalt