Post on 17-Jan-2018
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Unit 3 Oceanography Section 3: Currents, Waves, and Tides
Earth Science Mr. Margetan Ocean Currents Surface Currents Movement
of water on the surface, primarily caused by winds Ocean Currents
Longshore Currents Currents which run parallel to the shoreline due
to energy released from waves Ocean Currents Upwelling Currents
Occur when wind moves seawater at the surface and new water from
below replaces it Critical Thinking #1 How might upwelling currents
be beneficial to life in the ocean?Explain. Ocean Currents Deep
Currents Move slowly beneath surface, primarily caused by differing
water densities Critical Thinking #2 What processes might cause
changes in density that form deep ocean currents? Ocean Currents
Global Conveyor Belt A connected deep ocean current that circles
the entire planet Waves Waves Up and down, circular movement of
energy in water
Caused primarily by wind Also, disturbances in the ocean,
earthquakes Critical Thinking #3 How are ocean waves similar to
seismic waves?How are they different? Factors Influencing Wave
Size
Strength of Wind Speed wind is blowing Fetch Distance wind is
blowing Duration Length wind is blowing Parts of a Wave Crest
Highest point on a wave
Trough Lowestpoint on a wave Wavelength Horizontal distancefrom
crest to crest Wave Height Vertical distance fromcrest to trough
How do Waves Break? Waves begin to change shape at a depth its
wavelength Waves break at adepth of 1.3x itswave height Critical
Thinking #4 Considering how waves break, how might the shape of the
ocean floor influence the shape of waves? Types of Breakers Surging
Breakers Waves roll into the shore, occurs at steep beaches
Plunging Breakers Wavescurl and break, occurs atmoderate slope
beaches Spilling Breakers Wavesbreak far from shore, occursat
gentle slope beaches Tides Tides Daily changes in the level of the
ocean surface
2 high tides and 2 low tides each day caused by gravitational pull
of primarily themoon, but also the sun High Tides and Low
Tides
High (Flood) Tides Occur on side of Earth facing and opposite the
moon, due to both gravity facing and centrifugal force opposite Low
(Ebb) Tides Occur on sides halfway between the moon Spring Tides
and Neap Tides
Spring Tides = Highest and lowest tides, when moon and sun align
Neap Tides= Small tidal range, when moon and sun are perpendicular
Critical Thinking #5 Why are spring tides stronger than neap
tides?Explain.