Tides - Bowditch Flashcards
1
Q
Tides - main tide generating body
A
- Moon
2
Q
Tides - Sun’s effect vs. Moon’s
A
- Sun’s effect is 46% of the Moon’s due to its greater distance from the Earth
3
Q
Tides - semidiurnal tide
A
- two high and two low waters each tidal day with small differences in the respective highs and lows
- ie. the US Atlantic Coast
4
Q
Tides - diurnal tide
A
- only single high and single low water each tidal day
- ie. northern shore of Gulf of Mexico
5
Q
Tides - mixed tide
A
- diurnal and semidiurnal oscillations make a large inequality in high waters, low waters, or both
- usually two high and two waters a day, but sometimes becomes diurnal
- ie. US Pacific Coast
6
Q
Tides - spring tides
A
- greater range tides
- full or new Moon
- tractive forces are in line
- semidiurnal variation
7
Q
Tides - neap tides
A
- lesser range tides
- first and third quarter Moon
- tractive forces at right angles
- semidiurnal variation
8
Q
Tides - priming tides
A
- Moon between new and first quarter
- Moon between full and third quarter
- high tide occurs after Moon transit
- semidiurnal variation
9
Q
Tides - lagging tides
A
- Moon between first quarter and full
- Moon between third quarter and new
- high tide occurs before Moon transit
- semidiurnal variation
10
Q
Tides - perigean tides
A
- Moon nearest Earth in its orbit
- semidiurnal range is increased
11
Q
Tides - apogean tides
A
- Moon is farthest point from Earth in its orbit
- semidiurnal range is decreased
12
Q
Tides - diurnal variations in ranges occur as…
A
- the Moon and Sun change declination
13
Q
Tides - tropic tides
A
- Moon is at its max semi-monthly declination
- either North or South
- diurnal tides are at their max
14
Q
Tides - equatorial tides
A
- when the Moon crosses the Equator
- diurnal effect is a minimum
