NAVIGATION

Partim 4

Prof. Capt. M. Dauwe

Student’s Workbook

Table of Contents

Click on an item coloured blue to see its content and further

Cover

Course Objectives ….. 2

Training Objective ….. 3

1. BASICS OF TIDES

1.1. Introduction ….. 4
1.2. Physics in tides ….. 6

1.2.1 Forces ….. 6

a. Introduction ….. 6
b. Gravity ….. 7
c. Coriolis effect ….. 8
d. Revolution (centrifugal) ….. 9
e. Combined action at-a-distance forces, equilibrum between masses ….. 9
f.  Frictional force ….. 10

1.2.2 Waves ….. 12

a. Standing wave ….. 12
b. Resonance ….. 14

1.3. Theoritic model ….. 15

1.3.1. Equilibrium of tides ….. 15

1.3.1.1. Tractive forces ….. 15
1.3.1.2. Tidal forces ….. 19

1.3.1.2.1. Elementary approach ….. 19
1.3.1.2.2. Tidal forces at a distinctive point on earth ….. 20
1.3.1.2.3. Tidal forces at an arbitrary point on earth ….. 24

1.3.2. Ratio moon/sun ….. 25
1.3.3. Composite effect of the moon and the sun ….. 26
1.3.4. Tidal frequencies ….. 26
1.3.5. Impact of declination ….. 33

1.4. Dynamic model ….. 34

1.4.1. Dynamic theory of tide ….. 34
1.4.2. Water depth ….. 34
1.4.3. Tidal bassins ….. 35
1.4.4. Co-tidal charts ….. 38
1.4.5. Tidal stream ….. 40
1.4.6. Disturbances and influences on tides ….. 44

Storm surges ….. 45
Seiches ….. 45
Edge Waves ….. 46
Shape of shorelines ….. 47
The shape of bays and estuaries ….. 47
Tidal variations due to earth rotation and polar actions ….. 48
Tsunamis ….. 48
Bores ….. 48
Tide rip ….. 49
Reversing falls ….. 49

2. ANALYSIS OF TIDES – simplified harmonic analysis

2.1. History ….. 50
2.2. Basics ….. 50

3. TIDE GAUGING ….. 57

4. PRACTICAL TIDE ANALYSIS (exercises)

4.1. Introduction ….. 65
4.2. The graphical method ….. 68
4.3  The calculated method ….. 79