Water depths and seafloor topography are now routinely determined by ________.
ship-mounted echo sounders
Which one of the following would most likely be covered with thick turbidite layers?
deep-sea fan at the base of a continental slope
The gently sloping submerged surface extending from the shoreline toward the deep ocean is termed the ________.
Seafloor spreading occurs along relatively narrow areas at the crests of oceanic ridges called ________.
Oceanic ridges are elevated compared to the surrounding ocean floor because ________.
ly formed lithosphere is hotter and therefore less dense than the surrounding rocks
Where in the oceans are biological communities thriving without sunlight?
around seafloor hot spring vents
________ develop where oceanic lithosphere bends downward and sinks into the mantle.
Deep ocean trenches
Spreading rates of ________ are common along the Mid-Atlantic and the Mid-Indian ridges.
1 to 5 centimeters per year
Basaltic rocks of the oceanic crust are altered by heated seawater moving through fractures in a process known as ________.
East Africa, the Rhine Valley, and the Baikal in Siberia are all examples of ________.
Plate subduction occurs because the ________, not the oceanic crust, is denser than the underlying asthenosphere.
An echo sounder operates by measuring the time required for a ________.
sound pulse to travel from a ship to the seafloor and back
Which one of the following would typically have the widest continental shelf?
A tectonically passive, trailing continental margin