Download MS1R_EXRT_ExamReviewMarine1RegularAnswers_V01

Exam Review Marine 1 Regular
1.
What factors are responsible for the prevailing wind patterns of the earth?

The factors responsible for prevailing wind patterns are differential solar heating of the
earth’s surface as a function of latitude (more heat at low latitudes and less heat at higher
latitudes) and the earth’s rotation.
2.
. What combination of factors produces neap tides?
a.
Neap tides result from the earth being at a right (90°) angle from the moon and the sun.
Solar tides result from the gravitational attraction between the earth and the sun, and
lunar are produced by the gravitational attraction between the earth and the moon. Even
though the sun has a much larger mass than the moon, the moon is much closer to Earth
and therefore exerts a stronger force on the earth’s surface. When the sun, earth, and
moon are at a 90-degree angle, the high tide is lower and the low tide is higher than
when the sun, earth, and moon are aligned in a straight line (180° angle).
3.
Describe how winds are produced.
a.
The earth’s surface winds are a result of differential solar heating on the earth’s surface,
forming convection cells (warm air rising and cool air falling) at regular intervals
(latitudes). Air falls at the equator and rises at 30° N and S. Air falls at 60° N and S and
rises at the poles (90° N and S). Latitudes at which air falls are characterized by
precipitation in contrast to latitudes where the air rises (dry). If the earth did not rotate,
winds would move toward the falling air masses. Due to the earth’s rotation and the
Coriolis force, surface winds are deflected to the right (clockwise) in the Northern
Hemisphere and to the left (counterclockwise) in the Southern Hemisphere.
4.
Explain how waves are formed.
a.
Waves are generated when a disturbing force is applied to the ocean surface. The
disturbing force that produces capillary and wind waves is the wind. The disturbing
force that generates a tsunami is a tectonic event, such as an earthquake or volcanic
activity on the ocean floor. The disturbing force that produces a seiche is a change in
atmospheric pressure over an enclosed body of water, such as a bay or large lake. The
gravitation interaction of the earth, moon, and sun produces the tides (a type of wave).
5.
Describe how upwellings occur.
a.
Upwelling occurs when atmospheric winds cause surface ocean water to diverge. Cold,
nutrient-rich water moves up from the bottom to replace the displaced surface water.
Upwelling occurs in coastal areas where the winds blow surface water off-shore, and
cold nutrient and oxygen-rich bottom water surfaces. This also occurs along the equator
in the eastern Pacific Ocean where wind patterns cause surface waters to diverge.
6.
What is the biological importance of upwelling and downwelling zones?
a.
Upwelling causes nutrient and oxygen-rich bottom water to surface. An increase in
nutrients produces increased algal and zooplankton populations in upwelling areas.
Increased primary production means more food for animals; upwelling zones are the
most productive areas of the ocean. In contrast, downwelling moves oxygen and
nutrient-depleted surface water to the ocean bottom. Low nutrient levels and
comparatively lower dissolved oxygen concentrations inhibit biological activity.
Downwelling zones are areas of low primary productivity.
7.
What are gyres and how are they formed?
a.
Gyres are large circular surface ocean patterns that carry warm water from the tropics to
the poles and cool water from higher latitudes toward the tropics. The Coriolis force
deflects the surface current in predictable patterns in both hemispheres.
b.
The different direction of prevailing wind belts (trade winds, Westerlies, polar Easterlies)
interacting with the earth’s rotation causes surface ocean water to circulate in a clockwise
pattern in the Northern Hemisphere gyres and counterclockwise in the Southern
Hemisphere
8.
List three different processes that circulate water in the oceans.
a.
Surface currents (gyres),
b.
upwelling and downwelling,
c.
density-driven (thermohaline) vertical water movement circulate water within the
oceans.