Oceanography Chapter 9

The most important factor that causes ocean tides on Earth is the __________.
moon
If the side of Earth that faces the Moon experiences a tidal bulge (high tide), then the opposite side of Earth will experience a __________.
tidal bulge or high tide
A lunar day is __________ in duration.
24 hrs and 50 min
It is Thursday and an angler is planning a fishing trip in two days on Saturday. The angler knows from experience that the fishing is best at a particular location at the beginning of high tide. He does not have a tide table, but the angler noted that the high tide on Thursday was at 12:15 PM. At what time on Saturday should he plan to arrive to start fishing, assuming that this location has a diurnal tide type?
1:55
The low and high tides experienced on Earth are the result of __________.
tidal bulges
The Moon’s influence on Earth’s tides is __________ the influence of the Sun.
greater than
The weakest gravitational force caused by the Moon is called the __________, which is found at the point on Earth farthest from the Moon.
nadir
On the side of Earth closest to the Moon, gravitational forces __________ the centripetal forces.
exceed
Resultant forces result in __________ tidal bulge(s) on Earth.
two
A centrifugal force is one that is directed _____ and a centripetal force is one that is directed _____.
outward; inward
Tides occur on Earth because of an imbalance between gravity and __________.
centripetal force
Tidal forces cause deformation of our planet because __________.
the supplied gravitational forces at various points within the planet differ from the centripetal force required to maintain the orbital relationship between the Sun, Earth, and Moon
Measurable tidal bulges occur in __________.
the ocean, the atmosphere, and earth’s crust
Select the best ending to the following statement: The tides are considered an example of shallow-water waves because the tidal bulges have a wavelength that is on the order of __________.
thousands of kilometers
Of the following statements about the force of gravity between two bodies, which is/are true?
The force of gravity between two bodies increases with an increase in mass.
The force of gravity between two bodies decreases as distance increases.
The force of gravity between two bodies is most affected by a change in distance.
Of the following statements about the tides, which is/are true?
There are two tidal bulges on Earth caused by the Moon: one facing the Moon, and the other facing away from the Moon.
Although we observe the tides coming in and going out, in reality Earth is rotating into and out of various tidal bulges, which produces changing tides.
Both Earth and the Moon orbit around their common center of mass, called the barycenter.
The tides are caused by an imbalance between the centripetal force and the gravitational force of the Moon and the Sun.
Of the following statements about the location of the barycenter of the Earth–Moon system, which is/are true?
It is located at a point beneath Earth’s surface within the mantle.
It is located at the center of mass of the Earth-Moon system.
Of the following statements about the contribution of the Sun and the Moon to Earth’s tides, which is/are true?
The lunar tidal bulges are about twice the size of the solar tidal bulges.
The Sun’s contribution to the tides is less than that of the Moon.
The Moon exerts over twice the gravitational pull of the Sun on Earth’s tides because of its proximity to Earth.
What do we call the tide that occurs when constructive interference between lunar and solar bulges produces a large tidal range?
spring tide
What are tides?
regular daily rises and falls of sea level caused by the gravitational attraction of the moon and sun
Why are high tides found simultaneously on opposite sides of Earth?
tidal bulges occur on both sides of earth that are aligned with the tide-generating body
Why does the Moon generate larger tidal forces than the Sun?
although the sun is much bigger, the moon is much closer
What do we call the tide that occurs when destructive interference between lunar and solar bulges produces a small tidal range?
neap tide
How many spring and neap tides will a tide-recording station experience in a given month?
2 spring; 2 neap
It is Wednesday, and you are planning a fishing trip for this coming Saturday. You have heard that fishing is best at your chosen spot when the ebb current begins to flow, so you wish to start fishing at high tide. You do not have a tide table, but you have noted that today’s high tide was at 1:10 p.m. At what time on Saturday should you plan to arrive and start fishing?
3:40 PM
A proxigean tide occurs when __________.
the Moon is at perigee at a time of syzygy
Of the following statements about forces and tidal bulges, which is/are true?
-on the side of earth closest to the moon, a tidal bulge will form as a result of an excess of gravitational force
-on the side of earth facing away from the sun, a tidal bulge will form due to an excess of centripetal force
-tidal bulges are produced on both sides of earth from the moon and the sun
Of the following statements about the monthly tidal cycle, which is/are true?
The full moon and the new moon affect the tides about the same.
The full moon is associated with spring tide conditions.
Spring tides occur twice a month.
Neap tides occur twice a month.
Of the following statements about lunar phases, which is/are true?
Over the few days of a waxing crescent moon, the tidal range decreases.
Over the few days of a waxing gibbous moon, the tidal range increases.
Of the following statements about tides in a simple tidal bulge model, which is/are true?
Tides are greatest when the Moon is at perigee and Earth is at perihelion.
Neap tides result from destructive interference between the solar and lunar tidal bulges.
Spring tides result from constructive interference between the solar and lunar tidal bulges.
A lunar or solar eclipse can occur only when the Moon is in syzygy.
A relatively small tidal range could be expected __________.
at an amphidromic point
What are Earth’s three different tidal patterns called?
diurnal, semidiurnal, and mixed
What do we call the time that passes between two high tides?
tidal period
How many diurnal tides would you expect during one tidal period?
two tides
How many semidiurnal tides would you expect during one tidal period?
four tides
How is a semidiurnal period related to a tidal day?
the semidiurnal period is half of the tidal day
What pattern of tides would you expect to see for a mixed tidal system?
four tides of different heights
Some of the tide height numbers in your tide table are preceded by minus signs (or in some cases printed in red). This tells you that __________.
spring tides are occurring
You have just arrived for a vacation on the Oregon coast, and you wish to explore some tide pools while you are there. You hear the local weatherman say that there will be a minus tide at 7 a.m. tomorrow. You should __________.
set your alarm to wake you early; this may be your best chance for tidepooling
Of the following statements about tidal patterns and tidal charts, which is/are true?
-the tidal range is the difference in height between a high tide and a low tide
-a mixed tidal pattern has 2 lows of unequal height and 2 highs of unequal height every tidal day
-a tidal day is 24 hrs and 50 min long
-a semidiurnal tidal pattern has 2 low tides every tidal day
A boat is most likely to be carried out to sea from a harbor by a(n) __________.
ebb current
A grunion “run” would be expected within a few nights after __________.
a new or full moon
Disadvantages of tidal power plants relative to conventional thermal plants include higher initial plant costs, periodicity of tidal currents, and __________.
impacts on the marine environment