Marine Physics

1
Marine Physics

• Chapters 8, 9, 10
• JUST COPY WHAT IS UNDERLINED!!!!!!

2
Influence of Currents on Climate

• Pgs 9-20 to 9-21

3

• Currents play a critical role in how oceans
  affect weather and climate by transporting heat
  from warm areas to cool areas.
• Currents moderate climates- without the currents
  moving heat, the worlds climates would be more
  extreme.

4
Gulf Stream

• One of the deepest
• surface currents-
• carries heat
• Powerful, warm, swift
• Starts at the Gulf of Mexico, crosses the
  Atlantic Ocean
• Influences the east coast of N. America and the
  west coast of Europe
• Moves warm air from
• over the Gulf Stream inland
• Florida and N. Europe-
• milder winters

5
California Current

• S. California- mild climate due to the moderating
  effects of the Pacific Ocean
• The southerly current along the Calif. coast
  brings cool water from the north, keeping it
  cooler than it normally would be in the summer

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Factors that Affect Direction and Patterns of
Major Ocean Surface Currents

• Pgs 9-3 to 9-5

7

• 1 Wind
• Transfers energy to the water it blows across by
  the force of friction on the waters surface
• Causes both surface currents and waves
• Ekman Transport/Spiral Current moves to the
  right of the Wind at a 45 degree angle
• Major wind belts
• Trade winds
• Westerlies
• Polar Easterlies

8

• 2 Land Masses
• interrupt the flow of ocean currents creating
  closed circular current systems called gyres.
• Forces currents to turn

9

• 3 Coriolis Effect
• influences the wind by giving it a circular flow
  pattern
• the air deflects toward the right in the Northern
  Hemisphere and toward the left in the Southern
  Hemisphere- same with currents
• Christopher Columbus reached the new world thanks
  to the Coriolis effect
• Note If the Earth did not rotate and remained
  stationary, the atmosphere would circulate
  between the poles (high pressure areas) and the
  equator (a low pressure area) in a simple
  back-and-forth pattern. But because the Earth
  rotates, circulating air is deflected.

10
4 Temperature

• Convection currents
• Vertical movement of currents caused by
  temperature differences
• Temperature divides layers of water
• Deep sea vs. surface currents

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Cause of the Coriolis Effect

• Earths rotation- adds an apparent sideways
  motion to objects moving over the Earths surface.

Pilots need to correct their flight path based on
the earth rotating under the airplane, which is
the Coriolis effect.
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In the inertial frame of reference (upper part of
the picture), the black object moves in a
straight line. However, the observer (red dot)
who is standing in the rotating frame of
reference (lower part of the picture) sees the
object as following a curved path.
14
Tides

• Pgs 10-3 to 10-24

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What are Tides?

• Daily variations in the oceans level
• The mean average tide occurs later each day by 50
  min
• High?Low 6 hours 13 min.
• High?High12 hours 25 min.
• most noticeable at the shore, but affect the
  entire ocean.

16
Cause of Tides

• Result from the gravitational pull of the moon,
  and, to a lesser degree, the sun
• Earth is not a perfect sphere
• Time of the month
• Shape of the ocean basin
• Large, wide basins have smaller tidal ranges
• Narrow, shallow basins have larger tidal ranges
• Season
• Coriolis effect

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Spring and Neap Tides

• Spring tides occur during the full moon and new
  moon (they do not have anything to do with the
  season Spring)
• occur when the Earth, the Sun, and the Moon are
  in a line- every 2 weeks
• high tides are very high and the low tides are
  very low
• especially strong tides

Spring Tide
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• Neap tides occur during quarter moon phases
• occur when the gravitational forces of the Moon
  and the Sun are perpendicular to one another
  (with respect to the Earth).
• results in a smaller difference between high and
  low tides
• especially weak tides

Neap Tide
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Tidal Patterns Currents

• pgs 10-21 to 10-24

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Tidal Pattern

• Diurnal tide
• Single high and low tide daily
• Location Gulf of Mexico
• Semidiurnal Tide
• Two equal high and low tides
• Location east coast of U.S.
• Mixed Tide
• Two unequal high and low tides
• Location Pacific coast of U.S.

23
Waves
24
Parts of a Wave (draw figure)
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Movement of Water in a Wave

• A wave is the transmission of energy through
  matter.

• As the wave approaches, individual particles of
  water move in circular patterns as the waves
  energy moves through the water
• Orbital motion

26
Tsunamis

• Sometimes reaching heights of 40 meters (120 ft.)
  or more, tsunamis are the most dramatic and
  destructive of waves.

27
Cause of Tsunamis

• A tsunami results from sudden water displacement
  caused by
• Landslide
• Iceberg falling into the sea from a glacier
• Undersea volcanoes
• Earthquake
• Also called tidal waves
• Shallow water waves, fast moving