Science Vocabulary Quiz Chapter 13

Salinity

a measure of the amount of dissolved salts in a given amount of liquid

Water Cycle

The continuous movement of water from the ocean to the atmosphere to the land and back to the ocean

Surface Zone

The warm, top layer of ocean water. It can extend to 300 m below sea level. Sunlight heats the top of this zone. Surface currents mix the heated water with cooler water below..

Thermocline

The second layer of ocean water that can extend from 300 m below sea level to about 700 m. Temperature drops with increased depth faster than it does in the other two zones.

Deep Zone

The bottom layer that extends from the base of the thermocline to the bottom of the ocean. The temperature here ranges from about 1 degree C to 3 degrees C.

Continental Shelf

the gently sloping section of the continental margin located between the shoreline and the continental slope

Continental Slope

the steeply inclined section of the continental margin located between the continental rise and the continental shelf

Continental Rise

the gently sloping section of the continental margin located between the continental slope and the abyssal plain

Abyssal Plain

a large, flat, almost level area of the deep-ocean basin

Mid-Ocean Ridge

a long, undersea mountain chain that forms along the floor of the major oceans

Rift Valley

a long, narrow valley that forms as tectonic plates separate

Seamount

a submerged mountain on the ocean floor that is at least 1,000 m high and that has a volcanic origin

Ocean Trench

a long, narrow, and steep depression on the ocean floor that forms when one tectonic plate subducts beneath another plate; trenches run parallel to volcanic island chains or to the coastlines of continents; also called a trench or a deep-ocean trench

Sonar

SOund Navigation And Ranging.This technology is based on the echo-ranging behavior of bats. Scientists use this to determine the ocean's depth by sending sound pulses from a ship down into the ocean. The sound moves through the water, bounces off the ocea

Plankton

the mass of mostly microscopic organisms that float or drift freely in freshwater and marine environments

Nekton

all organisms that swim actively in open water, independent of currents

Benthos

organisms that live at the bottom of oceans or bodies of fresh water

Benthic Environment

the region near the bottom of a pond, lake, or ocean

Pelagic Environment

in the ocean, the zone near the surface or at middle depths, beyond the sublittoral zone and above the abyssal zone

Desalination

a process of removing salt from ocean water