Tides

Question 1

What are tides?

Answer 1

rise and **fall **of the water around the edge of the land

Question 2

How are tides generated?

Answer 2

gravatational attraction and centrifugal attraction between Earth, Sun and moon

Question 3

What waves are tides?

Answer 3

standing waves

Question 4

How are standing waves created?

Answer 4

progressive wave **directly reflected **back on itself produces a **standing **wave.

Question 5

Why are standing waves developed?

Answer 5

2 waves (original and reflected) are moving at** same speed** but different directions

Question 6

What is the relationship between wave height and tidal range?

Answer 6

they are** equal** to each other

Question 7

What tide does the crest indicate?

Answer 7

high tide

Question 8

What tide does the trough indicate?

Answer 8

Low tide

Question 9

Why are tides considered shallow waters?

Answer 9

wavelength is 1/2 the** circumfrence **of earth but the depth is less than 1/20 the wavelength?

Question 10

What is flow?

Answer 10

When tides come in

Question 11

What is ebb?

Answer 11

When the tide goes out

Question 12

What is the relationship between the average distance between the moon and Earth?

Answer 12

their relationship is constant

Question 13

How does the relationship in distance of moon and Earth stay constant?

Answer 13

Gravity and Inertia

Question 14

What is gravity?

Answer 14

masses are attracted to one another

Question 15

What is inertia?

Answer 15

tendency of **objects **to continue moving in a straight line

Question 16

What parts of gravitational and centrifugal forces are constant?

Answer 16

inertia is constant, but the influence of gravity isn’t

Question 17

What is the relationship between gravity force and inertia on the moon side?

Answer 17

gravity is more than** inertia**

Question 18

What is the relationship between gravity force and inertia on the sun side?

Answer 18

Inertia is more than gravity

Question 19

What are the assumptions of the equilibrium model?

Answer 19

1. Earth is covered in H20
2. Tide **waves **are progressive
3. **Water **is in **equilibrium **with generating forces

Question 20

How long is Lunar orbit?

Answer 20

about 27 days

Question 21

What happens when a rotating moon causes a tidal day?

Answer 21

the moon moves while Earth rotates

Question 22

How long is a full tidal cycle?

Answer 22

24 hours and 50 minutes for full tidal cycle

Question 23

What is a sun tide?

Answer 23

Sun** produces** its **own tidal **wave

Question 24

How long does it take for Earth to revolve on its axis with respect to the Sun?

Answer 24

about 24 hours

Question 25

How do tides in sun tides produced by the Moon continuously?

Answer 25

**eastward **relative **to **the **tide** wave **produced **by the **Sun**

Question 26

What is a spring tide?

Answer 26

**tides **are **higher **than the **moon** and is **aligned** with the **sun**

Question 27

What are neap tides?

Answer 27

**tides** are **lower ** **moon** and **sun** are **perpendicular**

Question 28

What is the tidal range?

Answer 28

the **difference height** between **consecutive high** and **low waters**

Question 29

What is the tidal wave amplitude?

Answer 29

1/2 of the tidal range?

Question 30

What is a king tide?

Answer 30

the greatest tidal effect of a year.

Question 31

How are king tides created?

Answer 31

when the **orbits **and **alignment **of the **Earth, moon, and sun** **combine**

Question 32

What is declination?

Answer 32

**Angle** where the **moon** or **sun orbits** are **offset** from **the equator** due to **elliptical orbital paths** and** tilt **of the **Earth**

Question 33

What determines the number of magnitude of tides?

Answer 33

**location** of **Earth** due to **declination**

Question 34

What are tidal patterns?

Answer 34

tides behave differently in different places.

Question 35

What is a diurnal tide?

Answer 35

1 high water and 1 low water each tidal day

Question 36

What is a semi-dirurnal tide?

Answer 36

**two high waters **and **two low waters **each tidal day.

Question 37

How long is a semi dururnal tidal period?

Answer 37

12hours and 25minutes

Question 38

How long is a diurnal tide period?

Answer 38

24 hours and 50 minutes

Question 39

What is a mixed semi-diurnal tide?

Answer 39

**tides **reach **different heights** and **low tides** drop to **different levels**

Question 40

What influences tidal range?

Answer 40

**constructive **and **destructive **wave **interference**

Question 41

What does tidal theory doesn't explain?

Answer 41

**Earth** turns **eastward faster** than **tide** moves **freely westward.** **Friction displaces tide crest **to the **east** of **expected position** **under moon**

Question 42

What are standing rotary waves?

Answer 42

**tide** that **results **in **standing wave** **moving **around **central node** of a **basin**

Question 43

What does tidal theory not explain (2)?

Answer 43

* **Continents separate the oceans, the tide wave is discontinuous. * Wave is contained within the ocean basins and oscillates in the basin as a standing wave. * Reflected from continents. * Refracted by changes in water depth. * Diffracted as it passes through gaps/channels.

Question 44

How do tides and currents turn in the North Hemisphere?

Answer 44

current:clockwise tide:counterclockwise

Question 45

How do tides and currents turn in the South Hemisphere?

Answer 45

currents: counterclockwise tide:clockwise

Question 46

What happens during the horizontal component of motion?

Answer 46

Because the horizontal time is long (0.5 period) Coriolis becomes important. NH deflected Right and SH deflected left. Current has clockwise rotation in NH and counter in SH.

Question 47

Wat is the angle of declination?

Answer 47

28.5