MOTION IN THE OCEAN

Earth Science-CCCC-5.4.6.G.1 and 5.4.6.G.29/29/14Do Now: What is the term for Death of a body of fresh water and what are the steps of this process? Eutrophication

Objective: SWBAT to understand the composition, circulation and distribution of the OceanWaves, Tides, and CurrentsMOTION IN THE OCEANWavesA disturbance which moves through or over the surface of a fluid Ocean Wave is the movement of energy over a body of water Mostly caused by winds (Also earthquakes, volcanoes, grav. Pull)

Form of great energy

Wave CharacteristicsParts of a WaveCrest = high point

Trough = low point

Height = vertical distance from crest to trough

Wavelength = Horizontal distance between crest to crest or trough to trough

WavesWater moves back to the ocean under the waves in a current called an undertow.Waves hitting the shore at an angle cause a current along the shoreline called a longshore current.

WavesThere are two types of waves in the open ocean:As waves approach the shore, they increase in height and eventually crash as breakers or whitecapsSwells are rolling waves that move steadily across the ocean.

Deadly Rip CurrentRip current- A rush of water that flows rapidly back to sea through a narrow opening

RIP CURRENT- Caused by converging longshore currents- Very dangerous ; Red Flag- DO NOT fight rip current; swim parallel to shore to get out of channel

Size of Wind Generated WavesDepends on 3 things:Wind SpeedWind Duration (length of time wind blows)Fetch Extent of open water across which the wind can blow

Water Motion in WavesWater travels in vertical circular orbits

Wave moves, particles dont! (a little demonstration with the cork and the aquarium filled with water)

Importance of WavesShaping CoastlinesErode cliffsGrind rock into sand

EcologyReturns O2 to waterStir up food for filter feeders

Caused by undersea quake or volcano Wavelength = ~150 mi. Wave height = 6 1Can NOT perceive in boat Speed > 500 mphSlows down to ~25 mph at shore; water builds up to ~65+ ftTSUNAMI -TIDAL WAVETsunami Waves

Creation of a Tsunami

10/2/14Do Now: What are the few ways a Tsunami can start

Objective: SWBAT understand the composition, circulation and distribution of the Ocean

TidesThe daily rhythmic rise and fall of the oceans water along coastlines

High tide = rising, incoming tide, flowLow tide = receding, outgoing tide, ebb Slack tide = vertical movement stopsTides are very long, slow wavesHigh tides occurs every- 12 hours 25 minAnd Low tides occur every 12 hours 25minSo how much time between a high and low tide?6 hours 12mins

Tidal day is 24 hours 50 min

NJ has 2 high and 2 low tides daily

1. Gravitational pull of sun & moon on EarthWhat Causes Tides?

Moon closer, therefore > effect Like magnet, pulls water away from surface = TIDAL BULGE2. Centrifugal Forces Produced by motions of Earth, sun, & moon Bulge on opposite side because centr. force > pull of moon

Types of Tides2xs/monthSpring Tide - Moon and sun are in direct line with one another

- Results in unusually high tidal range Tidal Range = vertical distance between high & low tides

It occurs in the beginningof the 1st and 3rd week of a month at the New/ Full Moon-

10/3/14Do Now: When do Neap/Spring tides occur? And which have an unusually high tides and unusually low tides?Spring Tides- Occur in the beginningof the 1st and 3rd week of a month at the New/ Full Moon, unusually high tides and Neap Tide- Occur 2nd and 4th week of a month at the 1st quarter and 3rd quarter moon Objective: SWBAT understand the composition, circulation and distribution of the Ocean

Neap Tidesun and moon are at right angles

Pulls cancel each other out causes a weak pull

unusually low tidal range

2 xs / month

Spring vs. Neap TidesDistance bet. Moon & Earth Perigee TidesMoon closest to earth, very high tides (causes flooding)Apogee TidesMoon farthest away from earth, very low tides

Types of Tides ContinuedDiurnal Tides1 high & 1 low / dayParts of Gulf of Mexico and Asia

Semi-Diurnal Tides2 high & 2 low / dayAtlantic coasts of North America and Europe

Mixed2 high & 2 low / day (height varies)Pacific coastTIDES10/7/14Do Now: What are the two things that cause tides?1. Gravitational pull of sun & moon on Earth 2. Centrifugal Forces- Produced by motions of Earth, Sun, & Moon

Objective: SWBAT to describe the, circulation and distribution of the Ocean Importance of TidesFishing Circulate water in bays & estuaries Tidal Energy Circulates food, wastes, etc

Currents What are currents?A large stream of moving water that flows through the ocean

Causes- Wind- Rotating Earth- Density Changes

10/8/14Do Now: What causes ocean currents?

Objective: SWBAT describe the circulation and distribution of the Ocean

Surface Ocean Currents

Broad, slow drifts; never cross equator Wind generated; circular gyresRed is warm currentBlue is a cold current Coriolis Effect- The effect of Earths rotation on the direction of winds and currents- N. Hemis clockwise; RightS. Hemis counterclockwise; Left

Coriolis Effect

Gulf Stream- Brings warm water from equator north along east coast of N. A. - N. Atlantic

Sometimes form eddies circulating water that pinches off from the current

IMPORTANCE OF SURF. CURRENTS

MIGRATIONNAVIGATIONWEATHER

Localized Surface CurrentsLongshore Current.

Flows parallel to shore; move sediment

Deep Ocean CurrentsSeparated from surface currents by boundary called a Thermohaline (diff in densities)

Flow beneath surface; cross equator

Move North to South

10/10/14Do Now: In the Coriolis effect which way does the water/wind move in the Northern and Southern Hemisphere ?

Objective: SWBAT describe the circulation and distribution of the Ocean

Importance Of Deep CurrentsUpwellingBrings deep water to surf.Circulates nutrients upMoves plankton & larvae

OCEANS