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