Term
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Definition
| is a composite science that studies oceans and oceanic phenomena |
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Term
| Why is oceanography called a composite science? |
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Definition
| It draws on the methods and knowledge of biology, chemistry, physics, and geology to study all aspects of the world ocean. |
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Term
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Definition
-largest ocean/ geographic feature on planet
-covers half ocean surface on Earth
-deepest (3940 meters average) |
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Definition
-1/2 the size of Pacific and not as deep
-relatively narrow
-bounded by almost parallel continental margins |
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Definition
-slightly smaller than Atlantic Ocean but has dame average depth.
-largely Southern Hemisphere ocean |
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Definition
-7% of the size of the Pacific
-Only a little more than 1/4 as deep as the rest of the oceans |
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Term
| What is salinity and the average salinity of the oceans? |
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Definition
the total amount of solid material dissolved in water
average salinity is 3.5% or 35% |
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Term
| What are the main sources for the dissolved materials that are measured by salinity? |
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Definition
-chemical weathering of rocks on the continents (delivered by streams at estimated rate of more than 2.5 billion tons anually)
-Earth's interior or outgassing |
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Term
| Describe salinity changes with latitude and with depth? |
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Definition
The amount of evaporation and precipitation both effect salinity.
Dry subtropics- more evaporation occurs removing water increases salinity.
Equatorial regions or wet ares- more water added and decreases salinity. |
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Term
| Describe how seawater temperature changes with latitude and depth. (low-latitudes) |
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Definition
| high temps at surface, but temp decreases rapidly with depth because the Sun's rays can not penetrate vary far into the Ocean. |
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Term
| Describe how seawater temperature changes with latitude and depth. (high-latitudes) |
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Definition
| surface temps. are colder temp, is similar to that are the surface a few degrees above freezing with depth. |
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Term
| How is the density of seawater related to the temperature of seawater? |
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Definition
| Increase in temp. causes water to expand and decrease seawater density |
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Term
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Definition
| a layer of water in which there is a rapid change in temperature in the vertical dimension |
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Term
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Definition
| a layer of water in which there is a rapid change of density with depth. |
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Term
| Describe the layered nature of the ocean. |
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Definition
-ocean layers are driven by density
-surface mixed zone
-transition zone
-deep zone |
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Term
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Definition
2%
mixing of these waters by waves as well as turbulence from currents and tides created a rapid vertical heat transfer, and this area is nearly uniform in temps. |
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Term
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Definition
18%
-separates the warm surface layer from the deep zone of cold water below |
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Term
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Definition
80%
- water temp a few degrees above freezing
density remains constant/high |
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Term
| Why does the three-layered structure not exist in high latitudes (close to the pole)? |
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Definition
| the water column is iothermal and iopycnal which means that ther is no rapid change in temp. or density with depth. Consequently, good vertical mixing between surface and deep waters can occur in high-latitude regions. |
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Term
| How is the ocean basin mapped with sound? |
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Definition
Echo sounders- transmit a sound wave in to the water in order to produce an echo when it bounces off any object
-a receiver intercepts the echo reflected from the bottom and a clock precisely measures the time traveled
-depth can be calculated using the speed of sound waves in water ans the time required for the energy pulse to reach the ocean floor and return |
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Term
| What are the different methods of mapping using sound waves? |
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Definition
| Echosounding and acoustic doppler (sonar and multibeam) |
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Term
| How is the ocean mapped using radar altimetry by satellites? |
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Definition
They are able to measure elevated areas by bouncing microwaves off the sea surface.
Measurement variations as small as few centimeters |
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Term
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Definition
Occur where oceanic lithosphere is being subducted beneath the edge of a continent
-narrow to no continental shelf
-continental slope extends abrup[tly into a deep-ocean trench
-landward wall and continental s;p[e are essentially the same feature. |
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Term
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Definition
NOT associated with plate boundaries and experiences little volcanism and few earthquakes
-comprising of continental shelf, -continental slope and
-continental rise |
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Term
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Definition
| a seaward extension of a valley that was cut on the continental shelf during a time when sea level was lower or a canyon curved into the outer Continental shelf, slope, and rise by turbidity currents |
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Term
| How are submarine canyons relate to turbidity currents? |
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Definition
| Turbidity currents are thought to be the major force int he excavation of most submarine canyons. |
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Term
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Definition
| deep and incredibly flat features of the deep-ocean floor, usually living at the foot of the continental floor. |
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Term
| How are mid-ocean ridges and deep ocean trenches related to Plate Tectonics? |
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Definition
| Trenches are sites of plate convergence where slabs of oceanic lithosphere subduct and plunge back to the mantel. This creates earthquakes and volcanic activity. Thus trenches are often paralleled by volcanic island arcs. Continental volcanic arcs are also located parallel to trenches the lie adjacent to continental margins. |
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Term
| What are the three types of ocean sediment? |
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Definition
-Terrigenous
-Biogenous
-Hydrogenous |
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Term
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Definition
derived from land
-consist primarily of mineral grains that were weathered from continental rocks and transported to the ocena
-larger particles settle rapidly near shore whereas small particles take years to settle and travel thousands of kiolmeters |
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Term
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Definition
derived from organisms
-sediment consists of shells and skeletons of marine animals and algae
-produced mostly by microscopic organisms living in the sun lit waters near ocean surface
-Once it dies, their hard tests (shell) continually "rain" down and accumulate on the seafloor. |
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Term
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Definition
derived from water
-consists of minerals that crystallize directly from sea water through various chemical reactions |
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Term
| How does the composition of deep ocean sediments change at 15,000 feet and what causes the change in composition of the sediments? |
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Definition
| Below a certain depth (500 m) carbonate will dissolve due to pressure, temperature, and dissolved CO2 content. This depth is called the Carbonate Compensation Depth (CCD). Below this point, pelagic sediments are primarily composed of silica (SiO2). |
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Term
| How do seafloor sediments provide information about past climates of the Earth? |
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Definition
-often contain the remains of organisms that once lived near the sea surface
-The numbers and types of these organisms change as the climate changes and the remains in seafloor sediments record these changes. |
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Term
| Beaches are different because they are either _____ or ______ and the continental margin is _____ |
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Definition
- emergent
-submergent
-different |
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Term
| Beaches are different because they are either _____ or ______ and the continental margin is _____ |
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Definition
- emergent
-submergent
-different |
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Term
| Florida is an example of what? |
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Definition
passive margin
-broad, sandy beaches,
-barrier islands,
-broad, gentle continental shelf with slope and rise |
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Term
Deep basin is underlain by _____
Abyssal plain, mid-oceanic ridge, extinct volcanoes form ____ and ____ |
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Definition
-oceanic curst
-seamounts and guyots |
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Term
Hydrogenous sediments are economically very important now and in the future. ____ and ____ around oceanic ridges may be mined in the future
____, ___, ____ as well as ____ are used every day form ancient ocean deposits. |
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Definition
manganese nodules, sulfides
salt, gypsum, limestone and metal |
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Term
| Active Margins are associated with |
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Definition
| comtinetal shelf, slope, and rise, canyons, turbidity currents and deep sea fans |
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Term
| What is the driving force for surface currents? |
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Definition
| Global Winds or the friction between the ocean and the wind that blows |
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Term
| How does the Coriolis Effect influence the surface currents? |
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Definition
| Earth's rotation , currents are deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. As a consequent, gyres flow in opposite directions in the 2 different hemispheres |
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Term
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Definition
| the large, circular surface current pattern found in each ocean. |
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Term
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Definition
| Movements of ocean water caused by density difference brought about by variations in temperature and salinity. |
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Term
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Definition
| the rising of cold water from deeper layers to replace warmer surface water that has been moved away. |
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Term
| Why is a lot of marine life found in areas of upwelling? |
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Definition
| upwelling brings greater concentrations of dissolved nutrients, such as nitrates and phosphates to the ocean surface. This promotes microscopic plankton growth, which supports extensive populations of fish. |
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Term
| List three factors that determine the size of a wave |
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Definition
-wind speed
-length of time the wind has blown
- fetch, distance that wind has traveled across open water |
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Term
| How do waves cause erosion? |
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Definition
| wave erosion is caused by wave impact pressure and abrasion,the sawing and grinding action of water armed with rock fragments. |
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Term
| How does wave refraction straighten a coast? |
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Definition
-wave approach shore nearly parallel
-wave energy then concentrated against the sides and ends of headlands
-B/C waves reach shallow water in fromt of headland sooner, they bend more nearly parallel to the protruding land and strike all 3 sides.
-By contrast, refraction in teh bays cause waves to diverge and expend less enregy
-in these zones of weakened wave activity sediments can accumulate and form sandy beaches.
-over time erosion of headlands and deposition in the bays will straighten an irregular shoreline. |
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Term
| What are erosional features? |
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Definition
Wave-cut cliffs
Wave-cut platform
Marine terrace
sea arch
sea stack |
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Term
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Definition
| a seawater-facing cliff along a steep shoreline formed by wave erosion at its bade and mass wasting |
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Term
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Definition
| a bench or shelf in the bedrock at sea level,cut by wave erosion |
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Term
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Definition
| a wave-cut platform that has been exposed above sea level |
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Term
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Definition
| an arch formed by wave erosion when caves on opposite sides of a headland unite |
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Term
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Definition
| an isolated mass of rock standing just offshore, produced by wave erosion of a headland. |
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Term
| What are depositional features? |
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Definition
Spit
baymouth bar
tombolo
barrier islands |
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Term
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Definition
| an elongated ridge of sand that projects from the land into the mouth of an adjacent bay |
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Term
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Definition
| a sandbar that completely crosses a bay, sealing if off from the open ocean |
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Term
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Definition
| a ridge of sand that connects an island to the mainland or to another idland |
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Term
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Definition
| a low elongated ridge of sand that parallels the coast |
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Term
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Definition
| any form of artificial structure built to protect a cost or to prevent the movement of sand along a beach |
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Term
| What structures are used in hard stabilization? |
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Definition
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Term
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Definition
a barrier built at a right angle tot he beach to trap sand that is moving parallel to the shore
helps to maintain or widen beaches losing sand |
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Term
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Definition
| a structure protecting a nearshore area from breaking waves |
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Term
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Definition
| a barrier construct to prevent waves from reaching the area behind the wall. Its purpose is to defend property from the force of breaking waves. |
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Term
| What are alternative to hard stabolization? |
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Definition
| Are beach nourishment and relocation |
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Term
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Definition
| a cost where land that was formerly below sea level has been exposed either b/c of crustal uplift of a drop in sea level or both |
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Term
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Definition
| a cost with a form that is largely the result of the partial drowning of a former land surface either b/c of a rise of sea level or subsidence of crust or both |
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Term
| What is the origin of tides? |
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Definition
| caused by the gravitational attraction of the Moon and to a lesser extent the Sun |
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Term
| Why does the Moon have a greater infulence on the tides then the Sun? |
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Definition
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Term
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Definition
| occur 2xs a month when the Moon-Earth-Sun are aligned |
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Term
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Definition
| occur 2xs a month during the first and third quarters of the Moon, the gravitational forces of Moon and Sun act on Earth at right angle and each partially offsets the influence of the other. |
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Term
Diurnal tidal pattern
Semidiurnal tidal pattern
Mixed tidal patteren |
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Definition
-characterized by a single high tide and a single low tide each tidal day
-exhibits two high tides and two low tides each tidal day, with each high/ low about the same height
-normally 2 high/ 2 low tides each tidal day, with high and low tides of different heights |
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Term
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Definition
| tidal currents that advance into the coastal zone as the tide rises |
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Term
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Definition
| as tide falls, seaward moving water |
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Term
| Surface currents moderate the climate by _____ _____. Cold currents can cause Coastal _____ form |
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Definition
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Term
| Erosional Coasts tend to be associated with |
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Definition
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Term
| Depositional coasts tend to be associated with |
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Definition
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Term
| Barrier islands parallel depositonal or submergent coasts and move constantly due to wave erosion, over wash and rising sea level.Many of our coastal communities here in Florida are built on barriers such as ____ Beach |
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Definition
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Term
| Sea level is rising so how successful will any of these measures be in the long term? |
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Definition
| They will not be very successful in the future. |
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Term
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Definition
| a description of aggregate weather conditions, the sum of all statistical weather information that helps describe a place or region. |
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Term
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Definition
| the state of the atmosphere at a given time |
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Term
| What are the major gases in the atmosphere? |
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Definition
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Term
| Why is water vapor important to our atmosphere? |
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Definition
| it is the source of all cloud and precipitation and like carbon dioxide, it is also a heat absorber. |
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Term
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Definition
| the movements of the atmosphere are sufficient to keep a large quantity of solid and liquid particles suspended with in it |
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Term
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Definition
absorbs potentially harmful UV radiation from the Sun.
Without it our planet would be inhabitable for most life as we know it. |
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Term
Ozone is composed of ____ oxygen atoms.
It forms and reforms in atmosphere and ____ interfere with formation |
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Definition
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Term
| Decrease in Ozone threatens people because |
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Definition
- increases risk of skin cancer
- UV rays impairs immune system
-promotes cataracts, which could lead to blindness |
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Term
| _____ is the weight of the air above us and it changes as does temperature with distance from the Earth's surface |
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Definition
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Term
| Four Layers of atmosphere and related temp changes |
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Definition
-Troposphere- temp. drops with height
-stratosphere- remains contant to about 12 miles then continues to increase to 31 miles above Earth surface
-mesosphere- temp. decreases with height
-thermosphere- temps. increase with height |
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Term
| Describe what causes the seasons |
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Definition
the tilt of the Earth's axis controls seasons.
-North hemisphere towards Sun, summer
-North hemisphere away Sun, Winter |
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Term
| What is the difference between heat and temperature? |
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Definition
Heat- quantity of energy present
temperature - the intensity, or the degree of hotness |
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Term
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Definition
transfer of heat through matter by molecular activity.
-metal spoon in hot pan |
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Term
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Definition
transfer of heat by mass movement or circulation within a substance
-boiling water |
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Term
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Definition
| heat-transfer mechanism by which solar energy reaches our planet |
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Term
| Earth materials and gases in the atmosphere _____ the Sun's radiation and re-radiate heat. |
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Definition
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Term
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Definition
| measures reflectivity of radiation |
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Term
| How is the Earth's atmosphere heated? |
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Definition
% soloar energy srrkes the top of the atmosphere reaches Earth's surface ans is absorbed.
Earth releases the adsorbed radiation in the form of long wave radiation.
The absorption of terrestrial radiation, primarily water vapor and carbon dioxide, is responsible for heating the atmosphere. |
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Term
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Definition
| the transmission of short-wave solar radiation by the atmosphere coupled with the selective absorption of longer, wavelength terrestrial radiation especially by water vapor and carbon dioxide. |
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Term
| Why has CO2 risen in out atmosphere over the past 150 years? |
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Definition
It is due to:
-use of coal and other fuels
-deforestation b/c CO2 is released from burning and decaying vegetation. |
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Term
| What are three possible consequences of rising global temperatures? |
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Definition
1. shifts in temp and rainfall patterns
2. a gradual rise in sea level
3. changing storm tracks and higher frequency and greater intensity of hurricanes
4. an increase in the frequency and intensity of heat waves and droughts |
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Term
| How can geographic position be considered a control of temperature? |
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Definition
Temperatures change with distance from the ocean because the oceans slowly absorb and release heat.
Temperature also changes with elevation. |
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Term
| ____ heats and cools slowly and resists temperature change. The oceans moderate air temperature, for this reason, and moderate coastal climates. |
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Definition
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