Oceanography Notes Midterm Corrections
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density and salinity remain mostly unchanged in deep ocean temperature-salinity diagram: identify deep water masses by temperature, salinity, and density. isothermal water column makes for easier up and down welling. Antarctic bottom water: formed under sea ice in s subpolar lats in Antarctic continental margins. Sink down Antarctica continental slope. Densest water in open ocean. spreads into all ocean basins. returns to surface in 1000yrs. North Atlantic Deep Water: from: Irminger Sea, Labrador Sea, Med Sea, Norwegian sea. moves to all ocean basins. less dense; sits on top of Antarctic bottom water no sinking at subtrop convergences arctic convergences: mass sinking occurs antartic intermeiate water: formed sinking at Antarctic convergence. ;east studied water mass. no vertical mixing at low lat, much vertical much at high lat ocean common waters: mix of antarctic bottom water and north atlantic deep water. lines basins of Indian and pacific oceans because no access to N hemis deep water. surface water of pac to salin to sink, Indian too warm to sink difficult to identify where verticle flow to surface occurs. every liter water that sinks much rise supposedly greater in low lat areas also, deep water moving along rugged topography produces upwelling most intense deep water flow along western side due to coriolis and bathymetric features conveyer belt circulation: model combing deep and surface currents cold water dissolve more oxygen than warm water. in past, warm water probably was more a part of deep water conveyer belt circulation initiated in Atlantic. Chapter 7 Online Wrong
Chapter 8
Chapter 8 Wrong
Chapter 9 tides: periodic raising and lower of avg sea lvl. 450 BC Hertodotus observe tides in writing. Issac Newton 1642-1727 universal law gravitation
gravity pulls all water on earth to moon and sun tides generated by forces imposed on earth generated by combination of gravity and motion among earth, moon and sun
if mass increases, gravitational force increases if distance increases, gravitational force greatly decreases the greater the mass of objects and the closer they are, the greater they attract zenith: pt closest to moon, greatest grav attraction nadir: pt furthest from moon, weakest grav attraction at angles. causing grav attraction b/w each particle and moon be slightly different centripetal force: required to keep planets in orbit. inward center-seeking force. provided by grav attraction b/w planets and sun broken string, ball flies tangent to orbital pattern gravity supplies centripetal force particles identical mass rotate in identical sized paths due to E moon rot sys each req identical centrip force to maintain circular path
red arrow to black area at pt of beginning avg 1 million the magn E grav if res force vertical; at nadir and zenith arrow outward, and along “equator” N and S arrows downward. no tide effect tide-generating forces: if resultant force significant horizontal to E surface: produce tidal bulges. small forces, but max at 45deg relative to NS “equator” gravitational attraction inversely proportionate to the square of the distance between two masses. tide-gen force inversely proporationate to the ccube of the distance between each point on earth and center of moon or sun distance more highly weighed variable for tide-gen force tide-gen force pushes water into bulges oat zenith and nadir [Lunar bulges] side facing moon bulge is because grav force>centripetal. side away from moon is because centripetal>grav force. bulges are equal. all pts on earth experience 2 tides per day except the poles
there is tide in glass of water tidal period: time b/w each tide [2 per day] 12 hours ideally at equator lunar day: 24hr 50m, moon overhead to overhead solar day: 24hr, sun overhead to overhead moon rises 50min later each day, high tides occur 50 mins later each consecutive day. solar bulges: caused by sun; at closest and furthest distance from thereof sun 27mx bigger than moon sun tidal attract is less than moon because sun is 390x farther from earth solar bulges 46% of lunar bulges flood tide: tides appear move toward shore ebb tide: away shore but; earth’s rotation carries various location into and out of the tidal bulges, which are fixed relative to sun and moon monthly tidal cycle 29.5 days; this is how long it take moon to orbit earth
very large at new and full moons spring tide: max tidal range. 2x per month syzygy: call the moon during full and new. at quarter moon, lunar/solar tide working at right angles neap tide: small tidal range; destructive interference quadrature: call the moon at quarter moon time b/w spring tides or neap tides is ½ monthly lundar cycle: 2 weeks time b/w spring and neap tides is ¼ monthly lunar cycle: 1 week
moon has synchronous rotation: identical periods of rotation “blue moon” once every 2.72 years.
max declination of sun relative to Earth’s equator is 23.5 plane of moon’s orbit tilted 5deg with respect to ecliptic so, max declination of moons orbit relative to Earths equator= 28.5 changes dec from N to S during the miltiple lunar cycles within 1 year so, tidal bulges are rarely aligned with the equator [as is ideal] earth 92.2million miles from sun during N hemis winter. 94.5 million miles during summer distance b/w E and sun varies 2.5% over course of year perihelion: earth nearest to sun. tidal ranges large. January aphelion: earth furthest from sun. tidal ranges small greatest tidal ranges in Jan each year moon around earth elliptical, E-M distance varies 8%
moon cycle: perigee, apogee, back to perigee every 27.5 days proxigean: spring tide coincide with perigee. especially high tides. storms heavy dmg now. also, spring tide graeter range during N hemis winter max spring tide once every 1600 yrs declination of moon determines position of tidal bulges neither the 2 high or 2 low tides of same H b/c of declination of moon and sun tidal moves more as forced waves with their speed determined by ocean depth 435mph avg. bulges don’t exists, because they’re too slow cells: what ocean tides break up into instead amphidromic point: near center of each cell, around which crests and trophs of tide wave rotate. no tidal range here cotidal lines: radiate from amphidromic point: connects point where high tide occurs simultaneously. tide wave rotates CCW in N hemis, CW in S hemis wave complete 1 rotation during tidal period [12 lunar hours] limits size of cells. low occurs 6 hrs after high in amph cell high on “10” cotidal line, low must be occurring on “4” cotidal line of cell inc turbulence and mixing strongly affect tides. tidal waves breaking conts produces internal waves over 150 factors affect tides at given coast effect: high tide rarely occurs when moon at apogee. vary place to place mathematical model beyond limits of scientists
common in shallow inland seas semidiurnal tidal pattern: 2 high and low tides each luner day. H of successive H and L tides approx the same, NEVER exactly. tidal period: 12hr, 25m common along atlantic coasts of us mixed tidal pattern: character of both above. successive H and L very different H [condition called diurnal inequality]. Tidal period typically 12hr 25m, but can exhibit diurnal period too. most common type; pac coast N America bay of Fundy: largest tidal range rotary current: produced by current rotation CCW in N hemis basin. In open portion of basin reversing current: moves into and out of restricted passages along coast. caused by increased friction in nearshore shoaling waters. once a rotary current. rotary currents less .6mph. reversing currents up to 28mph in restricted channels. rev currents in mouths of bays
during these times, no currents occur more some minutes reversing currents cause navigational hazards, but prevent sed build-up and replenish bay nutrients tidal current significant even at depths whirlpool/vortex: rapidly spinning body of water. cause by rev currents. most common in shallow passages connecting 2 large bodies water with difference tidal patterns/cycles up to 10 mph Maelstrom off N coast Norway is strongest in world Datum: MLLW; avg of 2 low slack waters tidal bore: wall of water that moves up low-lying rivers due to incoming tide. to 5m high/14 mph. develop where large tidal range, loww-lying river exists. due to resistance of river flow. Chientang River [China] has the largest bore.
no neap tide during solar eclipse open ocean tidal current rotary strongest gravitational force=highest tide go collecting during spring tide [great tidal range] ideal high tide interval; 12hr 25m force of gravity not related to velocity plane of solar system= eclictic plane moon over equator will not describe tropical tides tidal waves are thousands of kilometers, and are deep water waves centripetal force act perpendicular to the solar gravitational force side of earth closest to sun, high tides not form due to gravitational forces tidal forces not greatest at sygyzy semidiurnal tides result in 2 predicatable lows every day Chapter 10 US 80% pop coastal waves crash on most coasts 10k per day
shore and coast greatly vary coastline: boundary between shore and coast backshore: above high tide shoreline-> water covered only during storms foreshore: submerged at high tide, exposed at low tide. shoreline: water’s edge. follows tide nearshore: seaward from low tide shoreline to low tide breaker line -never exposed. affected by waves offshore zone: beyond low-tide breakers. waves rarely affect bottom beach: a deposit of the shore area wave-cut bench: flat, wave-eroded surface bench is the entire active area of coast that experience changes due to breaking waves recreational beach: area of beach above shoreline berm; dry, gently sloping region at foot of coastal cliffs or dunes. beach face: wet, sloping surface extend from berm to shoreline more exposed low tide. also called low tide terrace longshore bars: beyond beach face: 1 or more; sand bars parallel coast. these “trip” water longshore troph: separate longshore bar from beachface. notch: between coastline and berm. order: coastline-notch-berm-high tide shoreline-beach face-low tide shoreline-wace cut bench-longshore troph-longshore bar-low tide breaker line beach sediment finer from rivers that drain lowland areas than highland areas mud coasts: Suriname, SW India beaches: material in transit along shoreline movement parallel and perpendicular to coast swash: water from broken wave running up beach face. soaks in. backwash: drains back. picking up sed whichever is dominant dictates deposition or erosion light wave activity – more swash. wide, developed beach heavy wave activity-less swash, more backwash. New wave swash on top of old wave backwash. removed sand creates bars Chapter 10 wrong a beach on low relief tropical island made mostly of calcium carbonate isostatic rebound CANNOT produce global sea lvl rise barrier flat is the woodland above the salt marshes, which are closest to lagoon shore includes from low tide line to notch COPYRIGHT 2007 BY LITERAL, INC. Directory: indie indie -> And we need your turnover indie -> Name Family Name Date/Place of birth Current Address Past Addresses Web site Professional profile Working History Download 177.02 Kb. Share with your friends:
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