Chapter 9: Tides
Know the sequence of the daily tide
A high tide to low tide sequence repeated twice a day, termed a semidiurnal tide.
What is a whirlpool?
A rapidly rotating mass of water in a river or sea into which objects may be drawn, typically caused by the meeting of conflicting currents.
Describe Tidal Bulges
Created on opposite sides of the Earth due to the moon's gravitational force and inertias counterbalance
Which pattern would we observe along the west coast, east coast and Gulf of Mexico?
Diurnal tidal
Describe the three tidal patterns
Diurnal: cycle with only one high and low tide each lunar day Semidiurnal: when the two highs and the two lows are about the same heigh Mixed: high and low tides differ in height
Explain the difference between Flood and Ebb currents
Flood: when it is coming from the sea to the shore (tide is coming in, or high tide is ensuing) Ebb: when it is coming from shore and returning to the sea (low tide ensuing)
Describe Solar Bulges
Half the size of those caused by the Moon. Like the Moon, gravitational attraction to the Sun creates one bulge towards the Sun and one away from it
Describe Lunar Bulges
Moon's gravitational pull
What causes these bulges?
On opposite sides of the Earth due to the moon's gravitational force and inertias counterbalance.
What are spring and neap tides?
Spring tides: occur when the sun and moon are directly in line with the earth and their gravitational pulls reinforce each other to make the highest tides. Neap tides: occur when the sun, earth, and moon form a right angle and the sun's gravitational pull counteracts the moon's pull making a weaker high tide.
What causes tides?
The gravitational pull of the moon
Why does the moon have a higher tide generating effect than the Sun?
The moon is closer to the earth so that its gravitational gradient is stronger than that of the sun
What happens when the tide's mass is decreased/increased?
Tides around the equator are higher during both a new moon and a full moon
What is the monthly tidal cycle?
Twice a month, around new moon and full moon when the Sun, Moon, and Earth form a line (syzygy)
