What term describes the flat, cold, sediment-covered ocean floor between the continental rise and the oceanic ridge at depths of 3,700 to 5,500 meters?

• A. Bathymetry
• B. Abyssal Plain
• C. Epicenter
• D. Active Margin

Answer: (B)

Abyssal plains are the flat, cold, sediment-covered regions of the deep ocean floor that lie beyond the continental margins, forming a smooth expanse between the continental rise and mid-ocean ridges. Fine sediments and pelagic ooze settle down on the oceanic crust here, helping create a very level, featureless surface despite the immense depths. The depth range given, about 3,700 to 5,500 meters, fits this zone well, since abyssal plains commonly occur roughly from 3,000 to 6,000 meters below the surface. This distinguishes them from other features: bathymetry is the measurement of depth and shapes of the sea floor, epicenter refers to the point on the Earth's surface above an earthquake’s focus, and an active margin is a tectonically active edge of a continent with trenches and volcanoes.