Oceanography Chapters 5-8 Review – Flashcards
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Photic Zone
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Thin film of lighted water at and just below the ocean surface. 100-600 meters
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Pycnocline
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Zone in which density increases with increasing depth, 18% of ocean water
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Deep Zone
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80% of ocean water, 3rd zone
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Halocline
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In some regions, especially in shallow water near rivers, a pycnocline may develop in which the density increase with depth is due to vertical variations in salinity. In this case, the pycnocline is a halocline.
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Thermocline
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The rapid density increase in the pycnocline is mainly due to a decrease in temperature with depth in this area
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Hurricane of 1921
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Tarpon springs; category 3 at landfall; storm surge in tampa; 10 to 15 ft of water destroying much of downtown and ybor; extensive destruction in Clearwater, palm harbor, and tarpon springs, formed hurricane pass and split hog island (now caladesi and honeymoon)
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Great Gale of 1848
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First reorded hurricane in tampa bay area. sept 23, 1848 category 3; landfall near Sarasota and southern pinallas county; overwashed Egmont key and formed John's Pass.
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Hurricane Katrina
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passed over Fl as category 1; grew to category 5 in gulf of mexico; made landfall as a category 3-4; storm surge in New Orleans 8.5 miles and Mississippi coast. Water came in but couldn't go out; death toll between 1300 and 4000. Coastal development took away some of the "shock absorbers" ( barrier islands, coastal, wetlands, delta lands, all absorb a storm's energy) Levee are made of peat ( a very weak earthen material)
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Hurricane Sandy
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Extra tropical cyclone combined with hurricane to form a "superstorm". Made landfall at spring tide ( highest of high tides); widespread destruction at barrier island communities in New Jersey to New York; flooding of subways in NYC
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Storm Surge
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A mass of water that is driven by the storm
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Tropical Cyclone
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Great masses of warm, humid, rotating air. Occur in all tropical oceans; forms within in ONE humid air mass; may have different names according to where they form. Counter-clockwise flow (N. Hemisphere), appear as circular spirals, 74mph is hurricane strength, can last from 3hrs-3weeks, storm surge.
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Names of Tropical Cyclones outside the Atlantic Ocean Basin
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Atlantic Ocean - Hurricane E. Pacific Ocean - Typhoons Australia - Willi- Willis Indian ocean - Tropical cyclone
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Extratropical Cyclone
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form at the boundary between both, polar cells and ferrell cells (Polar front between TWO air masses); mainly in winter; causes twisting of the atmosphere that circulates counter-clockwise; moves from west to east; also called Nor easters
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Salinity
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The measure of total inorganic solids in water; 35 ppt (parts per thousand)/psu (Practical salinity units)
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Foraminifera
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amoeba like creatures with calcium carbonate shells (calcium carbonate is CaCO3)
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Diatoms
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algae with silica shell; makes siliceous ooze
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Radiolaria
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amoeba like silica shell; makes salicious ooze
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Pteropods
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calcareous algae, slow drifting mollusks
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Calcareous ooze
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Calcium rich; from shells of foraminfero; pteropods, coccolithophires (calcareous algae), only forms to a certain depth, below that depth you'll only find siliceous ooze
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Siliceous ooze
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formed by organisms such as diatoms, that contain silica in their shells; "silica - rich"; formed by radiolarians, diatoms; slow to dissolve at depth
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Neretic sediment
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primarily terrigenous sediments located on continental margins. "of the shore or coast", distributed by currents, orderly sorting of sediments, some biological component(small), can become sedimentary rocks by lithification
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Pelagic sediment
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fine sediments that are mainly biogenic in origin; located on continental slope, continental rise, and deep ocean basins. "of the open ocean", types: turbidites (deposits caused by turbidity), clays (fine, easily transported, terrigenous), oozes (remains of marine organisms)
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Cosmogenous sediment
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extra-terrestrial origin; interplanetary dust, asteroids, meteors, comets. *Microtektites- sediment that changed once heated, falling from space? drop shape, turns to glass
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Hydrogenous sediment
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inorganic, precipated directly from sea water; submerged rocks, hydrothermal vents, manganese modules; no biogenic material
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Terrigenous sediment
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inorganic, from land (continents, islands, volcanoes, blowndust) most end up on continental margins, slow process; 45%
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Biogenous sediment
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organic, from the remains of living organisms or the activity of organisms; most abundant of marine sediments; made of calceous and siliceous compounds
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Manganese nodules
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Chemical precipitate; high mineral content
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Hurricane
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A tropical cyclone that occurs in the atlantic ocean
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Upwelling
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The upward motion of water. Cool water from the bottom that is nutrient rich is brought towards the surface; bring lots of fish because of nutrients brought up. Occurs when wind is moving surface water away, cold water is pushed up to fill that space
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Downwelling
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Downward motion of water. Opposite of upwelling, supplies the deeper ocean with nutrients and dissolved gases
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Weather
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the current state of conditions in a certain area
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Climate
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the average long term state of weather in an area
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Hadley Cell
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cell in the tropics, one on each side of the ITCZ
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Ferrel Cell
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mid-Latitude cells, westerlies (surface winds of the ferrell cells)
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Polar Cell
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at high latitudes, near the poles
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ITCZ (Doldrums)
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Intertropical Convergence zone; calm equatorial area where the surface winds of the converging Hadley cells meet,rising warm air
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Subtropical High (Horse Latitudes)
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area of high atmospheric pressure and little surface wind near 30 degree n/s; most major deserts lie in this zone. between hadley and ferrell cells. (sometimes the sailors would have to throw their horses overboard)
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Antarctic Bottom Water
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Most dense, coldest, migrates north along sea floor
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Front
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boundary between air masses of different densities; colder air mass sinks below warmer air mass. (polar front- area between Ferrell and Polar cells at 60 degrees N/S)
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Current
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****
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Lithification
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converging of sediments into sedimentary rocks
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Monsoon
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pattern of wind circulation that is seasonal, causes lots of rain. Areas with monsoons usually have wet summers and dry winters.
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Coriolis Effect
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The observed deflection of a moving object. Caused by the moving frame of reference on the spinning earth. As air warms, expands and rises at the equator, it moves toward the pole. Not a straight path of travel, air is deflected eastward. N. Hemisphere (deflection to the right, clockwise) S. Hemisphere (deflection to the left, counter-clockwise)
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Calcium Carbonate Compensation Depth
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the rate at which the calcareous ooze coming in matches the rate of it dissolving. no calcareous ooze below this depth
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El Nino
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exceptions to normal wind and current flow. During an el nino year, opposite happens from a non-el nino year. Downwelling occurs, rain in areas that don't normally get rain. Elevated sea level in the Ease Pacific (Peru), elevated water temp., elevated rain/coastal storms, downwelling (disrupts fishing). Generally thought we have less storms during el nino.
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Aphotic Zone
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dark water beneath the photic zone, total darkness except for light generated by organisms (bio-luminescent)
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Average salinity of the ocean
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35ppt (parts per thousand)
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Wavelengths of light that penetrate the deepest and shallowest in the ocean. [Colors of the spectrum and how deep they go]
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blue goes deeper than red.
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How do temperature and salinity affect density?
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Density increases with: increase salinity, increase pressure, decrease temp. Density decreases with: decrease salinity, decrease pressure, increase temp.
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Know the currents of the North Atlantic Gyre
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canary, gulf, atlantic, north equatorial
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Characteristics of Eastern and Western Boundary Currents
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Eastern Boundary Currents- broad, shallow, cold, w/ poorly defined lines. Western Boundary Currents- narrow, warm, deep
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Characteristics of liquid water vs. ice (bond angle, crystal lattice)
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bond angle increases from 105 to 109 degrees between oxygen and hydrogen. Hydrogen bonds form a crystal lattice (ice). 24 H2O molecules in the space that 27 fit into as liquid. ice (solid) floats on water (liquid)
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Factors affecting Storm Surge
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1) intensity of storm 2) forward speed 3) size of the storm (bigger storm-more wind, more storm surge, smaller storm-less wind, less storm surge) 4) angle of approach (perpendicular=more storm surge, parallel=less storm surge) 5) width and slope of continental shelf (wide gentle slope=more storm surge, narrow sharp slope=less storm surge)(Tampa Bay area)
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What do rubber ducks and Nike shoes have to do with currents?
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Two different times a shipment boat accidentally dropped a ton of rubber ducks/ Nike shoes into the ocean and they tracked where they ended up around the world. Gave oceanographers a new view on the circulation of ocean currents.
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Elements (ions) most abundant in water
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oxygen, nitrogen, carbon dioxide
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Gases most abundant in the atmosphere
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nitrogen, oxygen, and water vapor
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How is oil and natural gas formed?
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the barrel of microscopic organisms over time are heated and compressed.
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Surface Currents
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wind driven movements of water at or near the oceans surface, water piles up in the direction that the wind bows, gravity pulls the water down slope but the coriolis effect deflects the water, gyre, eddies, transfer heat from tropical to polar regions, influence weather and climate, distribute nutrients and scatter organisms.
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Transverse Currents
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flow from east to west, and west to east in a gyre. (N. Equatorial current, N. Atlantic current)
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North Atlantic Deep Water
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Origins in the Arctic but landlocked to the North. Must "escape" via deep channels near Greenland, Scotland, and Iceland. Flows south along the seafloor.
