Unit 18- Earths Ocean

Front 1

aphotic zone

Back 1

the portion of a lake or ocean where there is little or no sunlight.

Front 2

biomass

Back 2

the total mass of organisms in a given area or volume.

Front 3

intertidal zone

Back 3

the area that is above water at low tide and under water at high tide

Front 4

neritic zone

Back 4

where the water is never so deep as to take it out of the photic zone.

Front 5

oceanic zone

Back 5

begins in the area off shore where the water measures 200 meters (656 feet) deep or deeper.

Front 6

photic zone

Back 6

the depth of the water in a lake or ocean that is exposed to such intensity of sunlight.

Front 7

salinity

Back 7

the concentration of dissolved salts in water etc., usually expressed in parts per thousand by weight.

Front 8

water column

Back 8

a conceptual column of water from the surface of a sea, river or lake to the bottom sediments.

Front 9

Coriolis effect

Back 9

an effect whereby a mass moving in a rotating system experiences a force (the Coriolis force ) acting perpendicular to the direction of motion and to the axis of rotation.

Front 10

downwelling

Back 10

the downward movement of fluid, especially in the sea, the atmosphere, or deep in the earth.

Front 11

gyre

Back 11

a spiral; a vortex

Front 12

high tide

Back 12

the state of the tide when at its highest level.

Front 13

longshore current

Back 13

is an ocean current that moves parallel to shore.

Front 14

low tide

Back 14

the state of the tide when at its lowest level.

Front 15

neap tide

Back 15

a tide just after the first or third quarters of the moon when there is the least difference between high and low water.

Front 16

rip current

Back 16

a relatively strong, narrow current flowing outward from the beach through the surf zone and presenting a hazard to swimmers.

Front 17

spring tide

Back 17

a tide just after a new or full moon, when there is the greatest difference between high and low water.

Front 18

storm surge

Back 18

a rising of the sea as a result of atmospheric pressure changes and wind associated with a storm.

Front 19

surface current

Back 19

The water at the oceansurface is moved primarily by winds that blow in certain patterns because of the Earth's spin and the Coriolis Effect.

Front 20

thermohaline circulation

Back 20

part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes.

Front 21

tidal range

Back 21

he vertical difference between the high tide and the succeeding low tide

Front 22

tide

Back 22

the alternate rising and falling of the sea, usually twice in each lunar day at a particular place, due to the attraction of the moon and sun.

Front 23

upwelling

Back 23

a rising of seawater, magma, or other liquid.

Front 24

wave

Back 24

a long body of water curling into an arched form and breaking on the shore.

Front 25

bottom trawling

Back 25

trawling (towing a trawl, which is a fishing net) along the sea floor.

Front 26

manganese nodule

Back 26

a small concretion consisting of manganese and iron oxides, occurring in large numbers in ocean-floor sediment.

Front 27

chemosynthesis

Back 27

the synthesis of organic compounds by bacteria or other living organisms using energy derived from reactions involving inorganic chemicals, typically in the absence of sunlight.

Front 28

hydrothermal vent

Back 28

an opening in the sea floor out of which heated mineral-rich water flows.

Front 29

invertebrate

Back 29

an animal lacking a backbone, such as an arthropod, mollusk, annelid, coelenterate, etc. The invertebrates constitute an artificial division of the animal kingdom, comprising 95 percent of animal species and about 30 different phyla.

Front 30

phytoplankton

Back 30

plankton consisting of microscopic plants.

Front 31

plankton

Back 31

the small and microscopic organisms drifting or floating in the sea or fresh water, consisting chiefly of diatoms, protozoans, small crustaceans, and the eggs and larval stages of larger animals. Many animals are adapted to feed on plankton, especially by filtering the water.

Front 32

primary productivity

Back 32

he rate at which energy is converted by photosynthetic and chemosynthetic autotrophs to organic substances.

Front 33

reef

Back 33

a ridge of jagged rock, coral, or sand just above or below the surface of the sea.

Front 34

vertebrate

Back 34

an animal of a large group distinguished by the possession of a backbone or spinal column, including mammals, birds, reptiles, amphibians, and fishes.

Front 35

zooplankton

Back 35

plankton consisting of small animals and the immature stages of larger animals.