# Oceanography Chapers 9-11

Topics: Tide, Moon, Tidal power Pages: 10 (2689 words) Published: June 10, 2012
Chapter 9

Review Questions

Explain why the Sun's influence on Earth's tides is only 46% that of the Moon's, even though the Sun is so much more massive than the Moon.
although the sun is much larger than the moon and has much more gravitational power, the distance between the earth and the moon is extremely further than the distance between the earth and moon. so much that it greatly dampens the effect of the suns gravity.

Why is a lunar day 24 hours and 50 minutes long, while a solar day is 24 hours long?
This happens because the moon revolves around the Earth in the same direction that the Earth is rotating on its axis. Therefore, it takes the Earth an extra 50 minutes to catch up to the moon.

Which is more technically correct: The tide comes in and goes out: or Earth rotates in and out of tidal bulges. Why?

Explain why the maximum tidal range (spring tide) occurs during new moon and full moon phases and the minimum tidal range (neap tide) at first-quarter and third-quarter moons.

If Earth did not have the Moon orbiting it, would there still be tides? Why or why not?
yes, because the sun is also a factor in tides.

What is declination? Discuss the degree of declination of the Moon and Sun relative to Earth's Equator. What are the effects of declination of the Moon and Sun on the tides?
declination is the angular distance of the sun or moon above or below earth's equatorial plain.

Are tides considered deep-water waves anywhere in the ocean? Why or why not?
A deepwater wave is where the ocean depth is at least half of the wavelength. Since the wavelength of tides is about 15,000 kilometers, it is impossible for the tides to be deepwater waves.

Describe the number of high and low tides in a lunar day, the period, and any inequality of the following tidal patters: diurnal, semidiurnal, and mixed.
a lunar day is the period of time it takes for the Earth to complete one full rotation on its axis with respect to the moon. In this period most places experience two high tides and two low tides. This pattern is called semi diurnal. Some places experience only one high tide and 1 low tide. This is called diurnal. Some places experience two highs and two lows but one of the high tides is significantly higher than the other and one of the low tides is lower than the other. This is called mixed.

Discuss factors that help produce the world's greatest tidal range in the Bay of Fundy. the bay of fundy, splits into two narrow passageways. the bay also narrows and shoals, along with the coriolis effect adding to the tides extreme range.

Discuss the difference between rotary and reversing tidal currents.
A rotary current is a tidal current that is observed in the open ocean and makes one complete rotation during a tidal period, and a reversing tidal current occurs at the margins of landmasses. the water flows in and out for equal periods of time seperated by slack water where the water is still at high and low tidal extremes.

Of flood current, ebb current, high slack water, and low slack water, when is the best time to enter a bay by boat? When is the best time to navigate in a shallow, rocky bay?
the best time to enter a bay by boat is during a flood tide, so larger boats can enter due to the enlarged depth, and the best time to navigate in a shallow rocky bay is during high tide.

Describe the spawning cycle of grunion, indicating the relationship between tidal phenomena, where grunion lay their eggs, and the movement of sand on the beach.
during the summer months for 3 or 4 days after the highest spring tides, grunion deposit their eggs on sandy beaches. the successively lower high tides during the approaching neap tides conditions won't wash the eggs from the sand until they are ready to hatch 10 days later. as the next spring tide is approached, successively, higher high tides whash the eggs free and allow them to hatch. the spawning cycle begins a few days later...