Chapter 16 - Marine and Coastal Systems and Resources Flashcards
continental shelf
the gently sloping underwater edge of a continent, varying in width from 100 m (330 ft) to 1300 km (800 mi), with an average slope of 1.9 m/km (10 ft/mi)
current
the flow of a liquid or gas in a certain direction
upwelling
in the ocean, the flow of cold, deep water toward the surface. Upwelling occurs in areas where surface currents diverge.
thermohaline circulation
a worldwide system of ocean currents in which warmer, fresher water moves along the surface and colder, saltier water (which is denser) moves deep beneath the surface
el Nino-southern oscillation (ENSO)
a systematic shift in atmospheric temperature, and ocean circulation in the tropical pacific ocean. ENSO cycles give rise to el nino and la nina conditions
el Nino
the exceptionally strong warming of the eastern pacific ocean that occurs every 2 to 7 years and depresses local fish and bird populations by altering the marine food web in the area. Originally, the name that Spanish speaking fishermen gave to an unusually warm surface current that sometimes arrived near the pacific coast of south America around Christmas time
downwelling
in the ocean, the flow of warm surface water toward the ocean floor. Downwelling occurs where surface currents converge
ocean acidification
the process by which today’s oceans are becoming more acidic (attaining a lower pH) as a result of increased carbon dioxide concentrations in the atmosphere. Ocean acidification occurs as ocean water absorbs CO2 from the air and forms carbonic acid. this impairs the ability of corals and other organisms to build exoskeletons of calcium carbonate, imperiling coral reefs and the many organisms that depend on them
la Nina
the exceptionally strong cooling of the surface water in the equatorial pacific ocean that occurs every 2 to 7 years and has widespread climatic consequences.
photic zone
in the ocean or a freshwater body, the well-lit top layer of water where photosynthesis occurs
mangrove
a tree with a unique type of roots that curve upwards to attain oxygen, which is lacking in the mud in which they grow, and that serves as stilts to support the tree in changing water levels. mangroves grow in tropics, costliness, and subtropics
estuary
an area where a river flows into the ocean, mixing fresh water with salt water
coral reef
a mass of calcium carbonate composed of the skeletons of tiny coral marine organisms called corals
salt marsh
flat land that is intermittently flooded by the ocean where the tide reaches inland. salt marshes occur along temperate costliness and are thickly vegetated with grasses, rushes, shrubs and other herbaceous plants
tide
the periodic rise and fall of the ocean’s height at a given location, caused by the gravitational pull by the sun and the moon
