oceanography ii notes giant wave mrs. burkey earth...
TRANSCRIPT
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OCEANOGRAPHY II NOTESMRS. BURKEY
EARTH SPACE SCIENCE – CY CREEK HS
TIDES
• THE RISE AND FALL IN SEA LEVEL IS CALLED A TIDE.
•CAUSED BY A GIANT WAVE.
•AVERAGE LOW-TIDE/HIGH-TIDE CYCLE TAKES ABOUT 12 HRS AND 25 MIN.
TIDAL RANGE
• IS THE DIFFERNCE IN OCEAN LEVEL BETWEEN HIGH AND LOW TIDE.
• EX: HIGH TIDE= 25FT LOW TIDE= 20FT TIDAL RANGE= 5FT
HIGH TIDE= 20FT LOW TIDE= 7 FT TIDAL RANGE= 13FT
HIGH TIDE= 30FT LOW TIDE=20FT TIDAL RANGE= 10FT
GRAVITATIONAL EFFECT OF THE MOON
• TWO BIG BULGES OF WATER FORM ON
THE EARTH:
•ONE DIRECTLY UNDER THE MOON
•ANOTHER ON THE EXACT OPPOSITE SIDE
•AS THE EARTH SPINS, THE BULGES
FOLLOW THE MOON.
GRAVITATIONAL EFFECT OF THE SUN
1. SPRING TIDES
• EARTH, MOON, AND SUN ARE LINED
UP
•HIGH TIDES ARE HIGHER AND LOW
TIDES ARE LOWER THAN NORMAL
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GRAVITATIONAL EFFECT OF THE SUN
2. NEAP TIDES
• EARTH, MOON, AND SUN FORM
RIGHT ANGLES
•HIGH TIDES ARE LOWER AND LOW
TIDES ARE HIGHER THAN NORMAL
TIDAL PATTERNS• DIURNAL
• ONE HIGH AND ONE LOW TIDE EACH (LUNAR) DAY
• SEMIDIURNAL
• TWO HIGH AND TWO LOW TIDES OF ABOUT THE SAME HEIGHT DAILY
• MIXED
• CHARACTERISTICS OF BOTH DIURNAL AND SEMIDIURNAL WITH SUCCESSIVE HIGH AND/OR LOW TIDES HAVING SIGNIFICANTLY DIFFERENT HEIGHTS
Variations in tidal form world wide
VARIABLE TIDES
DATUM - A REFERENCE
FROM WHICH MEASUREMENTS ARE MADE.
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MONTHLY TIDAL CURVES
Figure 9-16
Bay of Fundy
High tide
Low tide(6 hours later)
Video Clip:http://www.youtube.com/watch?v=qfhNjpu_IU4
BATHYMETRY“BATHY” = DEEP/DEPTH“METRY” = TO MEASURE
THE STUDY OF UNDERWATER DEPTH
FEATURES ON THE OCEAN FLOOR
http://www.ngdc.noaa.gov/mgg/image/2minrelief.html
SONAR• SOUND NAVIGATION AND RANGING
• TECHNIQUE THAT USES SOUND PROPAGATION TO NAVIGATE, COMMUNICATE WITH OR DETECT OBJECTS ON OR UNDER THE SURFACE OF THE WATER.
• PROVIDES A QUICK WAY OF LOOKING THROUGH WATER TO IDENTIFY FEATURES IN AND UNDER THE WATER (FISH, SANDBARS, ETC.)
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Gravitation Detection - local direction of gravitybased on attraction to underwater mountains.
HTTP://MARINE.USGS.GOV/FACT-SHEETS/FS172-97/MAPPING.HTML
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1. CONTINENTAL SHELF
• SUBMERGED EDGE OF CONTINENT
• GENTLE SLOPE AWAY FROM SHORE
• RESOURCES!
(GAS, OIL, GRAVEL, FISHING!)
2. CONTINENTAL SLOPE
• STEEP!
• TRANSITION FROM SHELF TO DEEP
OCEAN FLOOR
3. CONTINENTAL RISE
• MEDIUM STEEP...
• SEDIMENT THAT COLLECTS AT
BOTTOM OF SLOPE
Continental Margin
SUBMARINE CANYONS• CUT INTO CONTINENTAL SHELF & SLOPE!
• MOST CAUSED BY EARTHQUAKES
http://oceanexplorer.noaa.gov/explorations/deepeast01/background/dumping/media/dumping1.html
OCEAN BASIN FLOOR
1. DEEP-OCEAN TRENCHES• SUBDUCTION ZONES
• SUPER DEEP! (>10,000M)
2. ABYSSAL PLAINS• FLATTEST PLACES ON EARTH!
• COVERED IN SEDIMENT
3. SEAMOUNTS• SUBMERGED VOLCANOES
4. GUYOTS• INACTIVE SEAMOUNTS
• FLAT TOP FROM EROSION
5. ISLAND• ABOVE GROUND SEAMOUNT
SeamountIsland
GuyotAbyssal Plains
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OCEAN RIDGES• DIVERGENT PLATE BOUNDARY
• MOUNTAINOUS CHAIN OF YOUNG VOLCANIC
ROCK
• SITE OF HYDROTHERMAL VENTS
ATOLLS
• RING-SHAPED ISLANDS OF
CORAL REEFS
• FORM ON SUBMERGED INACTIVE
VOLCANOES
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OCEAN – ATMOSPHERE CIRCULATION (REVIEW SECTION)
• SOLAR RADIATION HEATS THE SURFACE CAUSING DIFFERENTIAL
HEATING.
• HIGH AND LOW PRESSURE AREAS FORM.
• AIR WILL RISE & SINK CAUSING CONVECTION CURRENTS IN THE
ATMOSPHERE.
• DIFFERENCES IN PRESSURES CAUSE WINDS TO BLOW.
• SEA SURFACE WINDS CAUSE SURFACE CURRENTS ON THE OCEAN.
• SALINITY AND TEMPERATURE CAUSE THE DEEP OCEAN CURRENTS.
OCEAN – ATMOSPHERE CIRCULATION
SEA SURFACE TEMPERATURE
http://www.ldeo.columbia.edu/dees/ees/climate/slides/sst_march.gif
OCEAN SALINITY
http://www.ldeo.columbia.edu/dees/ees/climate/slides/sal_march.gif
•http://ingrid.ldgo.columbia.edu/
El NinoLa Nina
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EL NINO? (WARM)
• TRADE WINDS WEAKEN
• THERMOCLINE DROPS
• UPWELLING IS CUT OFF
• SST RISES IN E.PACIFIC
• HIGH & LOW PRESSURE AREAS
IN PACIFIC REVERSE
• DISRUPTS FISH/BIRD
POPULATIONS IN E.PACIFIC
• OCCUR EVERY 2-7 YEARS
• LASTS 12-18 MONTHS
LA NINA (COLD)
• TRADE WINDS
STRENGTHEN
• SST DECREASE IN E.PACIFIC
• UPWELLING INCREASES
• OCCURS EVERY 3-5 YEARS
• LASTS 9-12 MONTHS
• PRENTICE HALL TEXTBOOK ANIMATION LINK • PRENTICE HALL TEXTBOOK ANIMATION LINK
• PRENTICE HALL TEXTBOOK ANIMATION LINK • PRENTICE HALL TEXTBOOK ANIMATION LINK
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SST- (SEA SURFACE TEMPERATURE) DIFFERENCES BETWEEN EL NINO AND LA NINA
A
B
C
QUIZ! WHICH IS WHICH…NORMAL, EL NINO, LA NINA?
WERE YOU’RE PREDICTIONS CORRECT?
WHAT ARE THE EFFECTS OF EL NINO?
BRUSH FIRES CAUSED BY DROUGHTINCREASED TROPICAL STORMS
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DEVASTATING FLOODSHURRICANES
• EL NIÑO CONTRIBUTES TO MORE EASTERN PACIFIC HURRICANES AND FEWER ATLANTIC HURRICANES.
• LA NIÑA CONTRIBUTES TO FEWER EASTERN PACIFIC HURRICANES AND MORE ATLANTIC HURRICANES.
US hurricane damage
TORNADO ACTIVITY
DEPENDS ON THE LOCATION OF THE POLAR JET STREAM
• EL NINO: MORE TO THE SOUTH
• LA NINA: MORE TO THE NORTH
MEASUREMENTS!
How can we predict an El Nino or La Nina event?
BUOYS
MEASURES...
• TEMPERATURE
• CURRENTS
• WINDS
RADIOSONDE
• WEATHER BALLOON
• MONITORS GLOBAL
WEATHER AND CLIMATE
PATTERNS
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SATELLITESPROVIDE DATA ON:
• RAINFALL
• WIND
• OCEAN TEMP.
• SEA SURFACE
HEIGHT
• OCEAN COLOR
• SURFACE CURRENTS
TOPEX/POSEIDON (T/P)