Oceanography Ch 4
Essentials of oceanography
Terms
undefined, object
copy deck
- Continental Shelf
- Gradually sloping submerged extension of continent, comp. of granitic rock overlain in sed.
- Continental Slope
- Sloping transition between the granite of the continent and the basal of the seabed (true edge of continent)
- Seamount
- Circular/ elliptical projection from seafloor, more than 1km heigh
- Continental Rise
- Wedge of sediment forming the gradual transition from the outer (lower) edge of cont slope to abyssal plain; usually ass. w/ passive margins
- Submarine Canyon
- Deep, V-shaped valley running roughly perpendicular to shoreline and cutting across the edge of the cont shelf and slope
- Island Arc
- Curving chain of volcanic islands and seamounts almost always found paralleling the concave edge of a trench
- Ocean Basin
- Deep ocean floor made of basaltic crust
- Transform Fault
- Plane along which rock masses slide horizontally past one another
- Shelf Break
- Abrupt increase in slope at junction btwn cont shelf and cont slope
- Continental Margin
- Submerged outer edge of a continent, made of granitic crust; includes cont shelf+slope
- Active Margin
- Continental margin near an area of lithospheric plate convergence
- Guyot
- Flat-topped, submerged, inactive volcano
- Fracture Zone
- Area of irregular, seismically inactive topography marking position of once-active transform fault
- Oceanic Ridge
- Young seabed at the active spreading center of an ocean, oft unmasked by sed.; bulges above abyssal plain
- Turbidity Current
- Underwater "Avalanche" of abrasive sediments thought responsible for the deep sculpturing of submarine canyons and as a means for sediments accumulating on an abyssal plain
- Passive Margin
- Continental margin near an area of lithospheric plate divergence