18 terms

Earth Science 14-2 Ocean Floor Features

continental margins
shallow portions of the ocean floor that are made of continental crust
ocean basin floor
area of deep-ocean floor between the continental margin and the oceanic ridge
mid-ocean ridge
An underwater moutain chain where new ocean floor is formed
Atlantic Ocean
thick layers of undisturbed sediment cover continental margins
very litle volcanic or earthquake activity
Pacific Ocean
crust plunging beneath continental crust- narrow continental margin - results in volcanoes and earthquakes
continental shelf
gently sloping submerged surface extending from shore line contains oil, natural gas, sand, gravel
continental slope
a steep incline leading down from the edge of the continental shelf
submarine canyons
deep, steep-sided valleys cut into the continental slope
turbidity canyons
down slope movements of dense, sediment-laden water
-sand and mud on the continental shelf
continental rise
the gently sloping surface at the base of the continental slope
deep ocean trenches
a deep valley along the ocean floor through which oceanic crust slowly sinks towards the mantle
Mariana Trench
deepest known place on Earth
Ring of Fire
major belt of volcanoes that rims the Pacific Ocean
Abyssal Plains
flat, sediment covered areas in the ocean basin
volcanic peaks that have not reached the ocean surface
flattened seamounts caused by erosion from waves and currents
sea floor spreading
occurs where two lithospheric plates are moving apart
hypothermal vents
zones where heated, mineral-rich water ecapes through cracks in ocean crust