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170 Cards in this Set
- Front
- Back
Who were the first regular ocean traders? |
The Phoenicians |
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What was the Library of Alexandria? |
-History's greatest accumulation of ancient writings (3rd century BCE) -Founded by Alexander the Great in Egypt -1st university -scrolls and charts from ships were taken and kept here |
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What is a chart? |
Graphic representations of water and water- related information |
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Cartographer |
"Chart maker", The first were mariners that wrote information down during voyages |
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Eratosthenes of Cyrene |
-2nd librarian at Alexandria -First to correctly calculate the circumference of the Earth -Developed longitude and latitude |
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Prime meridian |
0 degrees longitude Greenwich, England |
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Latitude |
Lines running parallel to the equator |
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Longitude
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Lines running from pole to pole; perpendicular to equator
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Polynesians |
Spread to New Guinea, Phillipines, Central Polynesia, then Hawaii Used stick charts to navigate |
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What was the first voyage solely for science? |
HMS Challenger (1872-1876) |
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Captain James Cook |
-Member of Royal Navy -first to use scientific investigation |
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Stick Charts |
A bamboo grid that showed wind and wave patterns and used shells to represent locations of islands. |
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Reverse Tribute |
Chinese navigators traveled to other lands with gifts to demonstrate their wealth and power. -1400s -300 ships |
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Chinese inventions |
-compass -central rudder -watertight compartments -multiple mast sails -sail battens |
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Sail Battens |
Bamboo inserted into pockets on the sail to prevent luffing, the vibration of the sail. |
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Renaissance |
In the European Age of Discovery, when Europeans really began exploring the sea. |
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Henry the Navigator |
Had explorers detail charts and explore the west coast of Africa. Mid-1400s, established a center at Sagres for marine science and navigation. |
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Christopher Columbus |
Wanted to travel from England to India, so went West, hit North America, and thought it was India. His stories inspired others to follow. |
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Ferdinand Magellan |
Led an expedition that was the first to circumnavigate the globe. He died in the Phillipines. Only 18 of 260 sailors returned from the 3 year trip. |
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US Exploring Expedition |
Launched in 1838, was a naval and scientific expedition. |
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HMS Beagle |
Ship on which Charles Darwin served as a naturalist. Traveled to South America and some Pacific Islands. |
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John Harrison |
Designed and built a clock that was accurate enough to determine longitude. |
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Ben Franklin |
Charted the first ocean current, the Gulf Stream, with his cousin, Tom Falger. |
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Matthew Maury |
Father of physical oceanography; sensed a worldwide pattern of surface winds and published information on how to sail. |
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Thomson and Murray |
Proposed the Challenger expedition, which took measurements on currents, meteorology, distribution of sediments, locations of coral reefs, and discovered 4717 new species. |
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Polar Expedition |
Explorers reached the north and south poles by the 20th century |
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Meteor Expedition |
First expedition to use modern optical and electronic equipment for oceanographic investigation; used echosounder |
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Atlantis |
Vessel whose expeditions confirmed the Mid- Atlantic Ridge |
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Trieste |
Blimp-like bathyscaphe that descended into the Challenger Deep area of the Mariana Trench |
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Glomar Challenger |
Drilling ship where samples obtained by scientists provided confirming evidence of seafloor spreading and plate tectonics |
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Echosounder |
Used to sense contours of the seafloor by beaming sound waves and measuring the time required for the waves to bounce back. |
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Three most prominent marine institutions in the United States |
1. Woods Hole Oceanographic Institution 2. Scripps Institution of Oceanography 3. Lamont-Doherty Earth Observatory of Columbia University |
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HROV Nereus |
Autonomic robotic device that carries out tasks programmed previously; deepest diving vehicle in operation |
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Topex/Poseidon |
Satellite that provides 95% coverage of the Earth |
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Jason-1 |
Satellite that monitors global climate interactions between the ocean and atmosphere |
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Aqua |
Project to collect a large amount of information about the Earth's water cycle |
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Alfred Wegener |
German meteorologist and polar explorer; proposed continental drift. Said continents fit together and were once Pangaea and have been drifting apart |
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Evidence for Pangaea |
-Continents fit together -Alignment of mountain ranges on different continents -fossil tropical plants in Antarctica |
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Continental Crust |
Outermost layer of Earth on land composed of granite; density = 2.7 g/cm3 |
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Oceanic Crust |
Outermost layer of Earth beneath ocean composed of basalt; density = 2.9 g/cm3 |
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Mantle |
Middle layer composed of silicon, oxygen, iron, and magnesium. Density = 4.5 g/cm3 |
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Core |
Innermost layers with liquid outer core layer and solid innermost core layer composed mainly of iron. Density = 13 g/cm3 |
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Lithosphere |
Cool, rigid, outer layer of Earth |
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Asthenosphere |
Hot, partially melted layer that flows slowly |
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Mantle |
Denser and more slowly flowing than asthenosphere |
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Outer Core |
Dense, viscous liquid layer, extremely hot |
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Inner Core |
Solid, very dense and extremely hot |
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Buoyancy |
Floats by displacing a volume of water equal to it's weight |
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Isostatic Equilibrium |
Balanced support of lighter material in a heavier, displaced supporting matrix; analogous to buoyancy in a liquid |
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Pacific Ring of Fire |
A circle of violent geological activity surrounding much of the Pacific Ocean |
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Radiometric dating |
Dates rocks by measuring the amounts of different elements in rocks. Radioactive decay is that elements lose particles from nuclei, are unstable, and change into new stable forms. Can measure the half-life, time it takes for half of the element to decay. |
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Echo sounder |
Devices that measure the depth by bouncing high-frequency sound waves off the bottom and measure the time until they are received. |
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Theory of Plate Tectonics |
Developed primarily by John Tuzo Wilson. Integration of continental drift and seafloor spreading. The lithosphere consists of many plates that are floating on the asthenosphere. |
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Radioactive Decay |
Decay of unstable nuclei into other stable forms. Creates heat in the core. Ex. Ur238 to Pb206 |
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Convection Currents |
Form when warm mantle rises and cool, dense mantle sinks down. Powered by gravity and temperature. |
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Archipelago |
Chain of islands that form because of hotspots. Ex. Hawaiian islands |
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Transform Boundaries |
Areas where plates move laterally adjacent to one another. Crust is conserved. Earthquake potential is high. |
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Convergent Boundaries |
Where plates move into one another; crust is destroyed. The denser crust is subducted under the lighter and destroyed. Creates volcanoes. |
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Divergent Boundaries |
These are constructive boundaries where plates are moving away from each other, leaving a gap where new crust is formed. |
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Terranes |
Oceanic plateaus formed by uplifting and mountain building as they strike a continent. |
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Bathymetry |
The study of the contours of the ocean floor. |
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Echo sounding |
Measures depth of ocean from a boat by emitting sound pulses and measuring the time it takes for the pulses to be reflected back to the boat after hitting bottom. |
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Multibeam System |
Uses many beams, up to 121, to investigate the contours of the sea floor in more detail |
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Satellite Altimetry |
Use satellites that are not moving in orbit and send radar beams down to measure changes in sea surface which reflects ocean floor. Gravitational pull causes water to pile up over large peaks. |
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Didson |
Dual-beam sonar with high resolution to enable you to tell the difference between fishes. |
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Continental Margin |
Classification of sea floor. The submerged outer edge of a continent. |
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Ocean Basin |
Classification of sea floor. The deep sea floor beyond a continental margin. |
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Passive Margins |
Continental margins that face the edges of diverging plates. Have little activity and wide shelves. |
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Active Margins |
Continental margins that face edges of converging plates, resulting in a lot of activity and narrow shelves. |
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Continental Shelf |
Shallow, submerged edge of a continent. Wider among passive margins, narrow along active. |
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Continental Slope |
Transition between continental shelf and deep ocean floor. Formed by sediments that reach the edge of the shelf and spill over the side. Slopes are steeper at active margins than passive. |
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Shelf Break |
Abrupt transition from shelf to slope. |
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Continental Rise |
Present at passive margins. Crust at the base of the slope is covered by an accumulation of sediment. |
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Turbidity Current |
Turbulence mixes sediments into water above a sloping bottom. The sediment-filled water is denser so it runs down slopes at high speeds and can create submarine canyons. |
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Submarine Canyon |
These canyons cut into shelves and slopes and terminate on the deep-sea floor in a fan-shaped wedge of sediment. Ex. Hudson Canyon east of NJ |
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Oceanic Ridges |
Mountainous chains of young basaltic rock at active spreading centers |
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Hydrothermal Vents |
Cold water descends into the crust where it is heated as it descends toward magma while picking up Fe, S, Cu, Zn, etc. The heated water returns to the surface carrying the elements and discharges through fissures or vents on the floor. |
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Who discovered hydrothemal vents? |
Robert Ballard discovered them while he was on the submersible called Alvin |
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Abyssal Plains |
Flat areas of sediment covered floor between continental margins and oceanic ridges found on the periphery of all oceans (less in Pacific). Sediment can exceed 1000 m thick |
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Abyssal Hills |
Extinct volcanoes or rock intrusions near oceanic ridges that form when newly formed crust moves away from the center of a ridge. |
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Seamount |
Volcanic projections from the floor that don't rise above sea level and are formed at spreading centers |
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Guyots |
Flat-topped seamounts that have been eroded by waves and carried away from a spreading center. |
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Coral Atoll |
Coral grows around an oceanic island. The island subsides as the coral continues to grow until the island is completely underwater. This leaves a circle of coral and a lagoon in the middle. |
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Trench |
Arc-shaped depressions in the floor that are caused by subduction of a converging oceanic plate. Most are on edges of active Pacific and are the deepest places in Earth's crust |
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Sediment |
Particles of organic or inorganic materials that accumulate in loose, unconsolidated forms |
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Terrigenous sediment |
Sediment originating on land. Erosion of mountains by water and wind carries sediment to the sea, it gets deposited on the sea floor, and travels with the plate. |
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Biogenous sediment |
Sediment of biological origin. Can either be siliceous or calcareous elements in the shells or skeletons of small animals. |
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Hydrogenous sediment |
Minerals that have precipitated directly from seawater from submerged rock, leaching from crust, hydrothermal vents, and river runoff. Most common are manganese and phosphorite nodules. |
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Cosmogenous sediment |
Sediment of extraterrestrial origin. From interplanetary dust that falls on the atmosphere and rare impacts by large asteroids and comets |
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Microtektites |
Translucent oblong particles of glass that form as asteroid impacts melt some of the crustal material of Earth, splashes it into space, and the material melts again as it rushes through the atmosphere. |
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Neritic sediment |
Sediment on the continental shelf that consists primarily of terrigenous material. |
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Pelagic sediment |
Sediments of the slope, rise, and deep-ocean floor. These are finer and mostly biogenous. |
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Lithification |
Neritic sediments are converted into sedimentary rock by pressure-induced compaction or by cementation |
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Turbidites |
The deposits from turbidity currents when they stop. These are graded layers of terrigenous sand interbedded with finer pelagic sediments typical of the deep-sea floor. |
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Ooze |
Deep-ocean sediment containing at least 30% biogenous material. Small, single-celled, drifting, plantlike organisms and the organisms that feed on them contribute to oozes. |
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Siliceous Ooze |
The shells of the small animals of oozes are made of silica. Radiolarians and diatoms |
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Calcareous Ooze |
The shells of the small animals of oozes are made of calcium carbonate. Foraminifera, pteropods, and coccolithophores. |
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Calcium carbonate compensation depth (CCD) |
The depth where the rate at which calcareous sediments are supplied to the seabed equals the rate at which those sediments dissolve. Below this depth, the skeletons dissolve leaving no ooze. |
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Manganese nodules |
Discovered on the HMS Challenger, consist primarily of manganese and iron oxides.They grow very slowly and often form around nuclei such as teeth, bone, and skeletons. Bacterial activity may play a role in development |
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Evaporites |
Hydrogenous deposits of salts. These salts precipitate as water evaporates from isolated arms of the ocean or from landlocked seas or lakes. |
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Oolite sands |
Molecules of calcium carbonate may precipitate around shell fragments or other particles to form white, rounded grains. |
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Deep Sea Drilling Project (DSDP) |
Oceanic drilling project from 1968-1983. Provided crucial data to support seafloor spreading and the theory of plate tectonics. |
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GLOMAR Challenger |
Drilled all over the world, discovered salt domes and oil there. Drilled 17 holes at 10 different locations along the Mid-Atlantic ridge. Verified young age of ocean floor. |
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Clamshell sampler |
Tool to take relatively undisturbed sediment samples |
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Piston corer |
A cylinder of sediment is taken to determine the age, density, strength, molecular composition, and radioactivity of the material |
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Palynology |
Study of plant pollen, spores, and certain microscopic planktonic organisms (palynomorphs) in living and fossil forms |
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Palynostratigraphy |
Utilizing palynology to observe differences in pollen, spores, etc. in different fossil layers. This can indicate changes in water and over land |
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Polar molecule |
Has both a positive and negative side |
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Hydrogen bonds |
Hold water molecules together; positive end of one water molecule bonds to the negative end of another |
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Cohesion |
Ability of water molecules to stick together, creating surface tension |
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Adhesion |
The tendency of water molecules to stick to other surfaces/substances |
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Heat |
Energy produced by the random vibration of atoms or molecules |
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Heat Capacity |
A measure of the heat required to raise the temperature of 1gram of a substance by 1 degree C. |
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Latent heat of vaporization |
The amount of energy required to break the bonds. This is heat input that does not cause a temperature change but does produce a change in state. |
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Latent heat of fusion |
The amount of heat energy that must be removed per gram of pure water at 0 decrees C to form ice. 80 calories of heat for water |
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Thermal Inertia |
Tendency of a substance to resist a change in temperature with the gain or loss of heat energy |
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Surface zone |
Top layer with the lowest density and 2% of all ocean water. Temp and salinity are constant with depth due to current and wave action |
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Pycnocline |
Zone in which density increases with increasing depth. 18% of all ocean water. Isolates surface water from dense deep water |
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Deep zone |
Little change in density with depth. Makes up 80% of ocean water |
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Thermocline |
Zone in which temperature changes rapidly with depth. Same layer as the pycnocline |
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Halocline |
Zone of rapid salinity increase with depth. Zone often coincides with the thermocline to produce a pronounced pycnocline. |
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Refraction |
The bending of waves when they travel from one medium to another |
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Refractive index |
A ratio that expresses the degree to which light is refracted from one medium to another. |
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Absorption |
Light's electromagnetic energy is converted to heat |
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Scattering |
When light bounces between air or water molecules, dust, water droplets, or other objects before being absorbed |
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Photic zone |
Thin film of lighted water at the surface zone. 600m in clear water, 100m in most |
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Aphotic zone |
Dark water that lies in blackness. The only light in this zone is light of biological origin |
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Twilight zone |
Area of rapidly decreasing light |
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Active sonar |
The projection and return through water of short pulses of high-frequency sound to search for objects in the ocean |
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Side-scan sonar |
Sound pulses leave the submerged towed array, bounce off the bottom, return to the device, and the computer processes the pulses into images |
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Ionic bonds |
Electrostatic attraction that exists between ions that have the opposite charge. Between Na and Cl |
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Salinity |
The total quantity of dissolved inorganic solids in water |
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Forchhammer's principle |
The ratio of major salts is constant in samples of seawater from various locations. The ocean is always in constant proportions; the ocean is at chemical equilibrium because ions are added and removed at the same rate |
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Residence time |
Average length of time an element spends in the ocean |
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Mixing time |
How often the ocean is overturned; about 1600 years |
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Conservative constituents |
These constituents occur in constant proportions, have long residence times, and are the most abundant dissolved materials in the ocean. Ex. Na and Cl |
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Nonconservative constituents |
These have short residence times and are associated with seasonal, biological, or short geological cycles. Ex. Ca, Si, Fe |
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Coriolis Effect |
Deflection of air or water away from it's initial course due to east rotation of Earth. N hem turn to right, S hem turn to left. Due to spherical shape of Earth so equator moves faster than northern locations because must cover a larger distance in the same time. |
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Currents |
Mass flow of water |
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Surface currents |
Wind-driven flow of water near the surface of the ocean |
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Thermohaline currents |
Deep, slow currents that affect seawater beneath the pycnocline |
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Gyre |
Circular currents formed by surface winds, the sun's heat, the Coriolis effect, and gravity Clockwise in N hem, counter clockwise S hem |
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What are the 4 currents that make up the North Atlantic gyre? |
Gulf stream North Atlantic current Canary current North equatorial current |
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Ekman transport |
Surface water moves 45 deg right of wind direction. The lower layer moves to the right of the surface and so on. The net movement of water is 90 deg right of wind direction |
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Geostrophic gyres |
Gyres in balance between the pressure gradient and the Coriolis effect N. At, S. At, N. Pac, S. Pac, Indian |
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Antarctic Circumpolar current |
Flows endlessly eastward around Antarctica driven by westerly winds |
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Western boundary currents |
Narrow, deep, fast currents found at western boundaries of ocean basins |
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Eastern boundary currents |
cold, shallow, broad with poorly defined boundaries |
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Atmospheric circulation cell |
A large ciruit of air |
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Hadley cells |
Tropical cells found on each side of the equator. Air warms as it flows south near the surface, rises and cools as it moves north until it condenses and falls. This can go south to complete the cycle or north. |
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Ferrel cells |
Cells at mid-latitudes. Falling northward air from Hadley cells generate current flowing north across the surface that is warm and rises. This air can go south, cool, condense and fall to complete the cycle or go north |
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Polar cells |
Cells located near the poles. Northward air from the Ferrel cells continue at high altitudes towards the poles, eventually condensing and falling. That air moves southward across the surface and warms until it rises and either goes north to complete the cycle or south into the Ferrel cells |
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Doldrums |
Calm equatorial areas between Hadley cells. Strong heating causes surface air to rise, creating a lot of rain in the area |
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Horse latitudes |
Areas between Hadley and Ferrel cells where cool, dry air is falling. Evaporation is higher than precipitation in these areas |
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Trade winds |
Surface winds of the Hadley cells. In N. hem: northeasterly trade winds, S. hem: southeasterly trade winds |
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Westerlies |
Surface winds of the Ferrel cells. |
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Intertropical Convergence Zone (ITCZ) |
Same as doldrums. Where winds on either side of the equator converge. Position changes seasonally: most north in July and most south in January due to thermostatic effects of water |
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Monsoon |
A pattern of wind circulation that changes with the season. These areas have wet summers and dry winters. Because of differential heating of land and ocean. |
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Sea Breeze |
In the afternoon when land heats more than the ocean so warm air over land rises and cool air over ocean moves shoreward to replace it. |
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Land Breeze |
At night when the land cools more than the ocean so warm air over the ocean rises and cool air from land moves offshore to replace it |
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Storms |
Regional atmospheric disturbances |
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Cyclones |
Huge rotating masses of low pressure air in which winds converge and ascend |
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Tropical Cyclones |
Cyclones in tropical areas that form in one air mass. Spin counter clockwise in the N hem and clockwise in S hem |
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Extratropical Cyclones |
At the boundary of the Ferrel and Polar cells in winter. Temperature difference across the polar front is large and winds go in different directions, enlarging the waves. Eventually, a twist will form and the cold dense air slides beneath the warmer air and eventually forms a cyclone |
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Meanders (eddies) |
Isolated pockets of warmer water that pinch off after sharp meanders in the current. The force of the water will cut across the curved path and pinch off the meander, creating an eddy. |
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Westward Intensification |
Water at the northern boundary of a gyre feels the Coriolis effect more and turns to the right (southward) sooner than westward water turns to the north. Causes western boundary currents to be faster, deeper, and more concentrated. |
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Upwelling |
Vertical movement of water upwards due to wind. |
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Downwelling |
Vertical movement of water downwards due to wind |
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El Nino |
Trade winds diminish and warm water pool moves eastward, creating precipitation and downwelling at the east coast and dry conditions and upwelling of warm surface water in the west. Causes crashes in fisheries. |
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La Nina |
Overcompensation for El Nino. Trade winds return strongly and moves the warm water back to the west allowing the east to cool off and creates massive upwelling of cool, nutrient-rich water in the east. |