Terms

Question 1

The harbor entrance should, if possible, be located on _____of the harbor.

Answer 1

lee side

Question 2

A every long standing wave on a large but limited body of water generally occurring when a storm dies down after producing a wind tide is called:

Answer 2

Seiche

Question 3

Waves generated by storms, which occur outside area of observation.

Answer 3

Swells

Question 4

An instrument use to measure the intensity of wind

Answer 4

Beuforts scale

Question 5

A wave generated in deep water, when reaching
shoaling waters, changes not only in its height but also in its length but the period will ____

Answer 5

Remain constant

Question 6

An open water navigable depth is called:

Answer 6

Fairway

Question 7

Waves are formed by frictional drag of wind across the water surface. This is a process of transferring energy from wind to water. Water particles are moved from their position by the wind, and then returned to the original position by gravity, which is restoring force. These waves
are called:

Answer 7

Gravity waves

Question 8

The pressure against a vertical wall due to waves called:

Answer 8

Clapotis

Question 9

A change in the dissection of travel of the wave with change in depth of water which distributes wave energy
along the seashore unevenly is called:

Answer 9

Wave refraction

Question 10

Waves generated by wind that are acting on the sea surface bordering on the port site.

Answer 10

Wind waves

Question 11

Wind generated waves which are created in the deep ocean at some distance from the port site and the wind what created them may too distant to be felt in the port or
may have stopped blowing or changed, its direction by time
when wave reach the port.

Answer 11

Swell waves

Question 12

Waves of this type have very long periods, typically from 30 sec. up to the tidal period of 12 hr. 25 min. and are mostly found in enclosed or semi-enclosed basins such as
artificial port basins or bays.

Answer 12

Seiching waves

Question 13

Waves created by large, sudden impacts, such as earthquakes, volcanoes or landslide that ends up in the ocean.

Answer 13

Tsunamis

Question 14

Waves in which the ratio of water depth to the wave length is less than 0.50 but greater than 0.40.

Answer 14

Intermediate water waves

Question 15

The distance that the wind blows over the sea in generating the waves is known as:

Answer 15

Fetch

Question 16

The arithmetical mean value of the highest, one-third of the waves for a stated interval.

Answer 16

Significant wave height

Question 17

An abnormal rise of the sea level that occurs when typhoon passes by. This rise above normal level on this open coast is due to atmospheric pressure reduction as well as due to wind stress.

Answer 17

Storm surge

Question 18

Waves with an extremely long period that mainly occur when there is a sudden large scale sea floor movements associated severe, shallow focus earthquake.

Answer 18

Tsunamis

Question 19

The horizontal extension of the generating area in the
direction of the wind is called:

Answer 19

Fetch

Question 20

The difference in height between the mean higher high
water and the mean lower low water is called:

Answer 20

Diurnal range

Question 21

The highest tides which occur at intervals of half a lunar
month is called:

Answer 21

Spring tides

Question 22

The datum line of design of port facilities in accordance
with charts, which is being used by the Phil. Ports Authority
(PPA).

Answer 22

MLLW

Question 23

The type of tide which will occur at nor near the time
when the moon is new or full that is when the sun, moon and earth fall in line and the tide generating forces of the
moon and sun are additive.

Answer 23

Spring tide

Question 24

When the lines connecting the earth with the sun and
the moon form a right angle, that is the moon is in her
quarters, then the actions of the moon and sun are
subtractive, and the lowest tides of the month occur, this is
called:

Answer 24

Neap tide

Question 25

Owing to retardation of the tidal wave in the ocean by frictional force, as the earth resolves daily around its axis and as the tide tends to follow the direction of the moon, the highest tide for each location is not coincident with conjunction and opposition but occurs at some constant time after new and full moon. This interval which may amount to as much as two and a half days is known as:

Answer 25

Age of the tide

Question 26

In many parts of the world, the high waters reach their greatest height and the low waters at the least height, soon after the time of full and new moon. These tides are called:

Answer 26

Spring tides

Question 27

The difference in height between high water and low water at a tidal station is called:

Answer 27

Tidal range

Question 28

When the daily high waters are usually at their least height and the daily low waters their greatest height soon after the moon is in quandrature. This tides are called:

Answer 28

Neap tides

Question 29

Waves formed by earthquake disturbances.

Answer 29

Tsunamis

Question 30

Waves formed by gravitational attraction of the moon and sun.

Answer 30

Tides

Question 31

The spread of energy along a wave crest is called:

Answer 31

Diffraction

Question 32

The bending of waves as they slow down.

Answer 32

Refraction

Question 33

Waves under the influence of the winds that generated them are called:

Answer 33

Sea

Question 34

The distance that a wind blows across the water is called:

Answer 34

Fetch

Question 35

The time that a wind blows across the water is called:

Answer 35

Duration

Question 36

The average of the highest one-third of the waves are called:

Answer 36

Significant wave height

Question 37

The highest tide which occurs at intervals of half a lunar month when the sun, moon and earth fall in line.

Answer 37

Spring tides

Question 38

The lowest tide of the month when the lines connecting the earth with the sun and the moon form a right triangle, that is when the moon is in its quarters are called:

Answer 38

Neap tides

Question 39

Tides that occur twice its lunar day is called:

Answer 39

Semi-diurnal tides

Question 40

High crested waves caused by the rush of flood tide up a river or by meeting of tides are called:

Answer 40

Tidal bores

Question 41

The circulation of masses of air more or less parallel to the earth's surface.

Answer 41

Wind

Question 42

The side of a structure facing the direction from which the wind comes.

Answer 42

Windward side

Question 43

Prevailing winds which are seasonal blowing in one direction over part of the year and in the opposite direction the remainder of the year.

Answer 43

Monsoon

Question 44

The opposite side of a structure facing the direction from which the wind comes.

Answer 44

Leeward side

Question 45

The graphical representation of the direction, frequency and intensity of winds at a particular location over a period of time is known as:

Answer 45

Wind rose

Question 46

The periodic rise and fall of the ocean waters produced by the attraction of the moon and sun.

Answer 46

Tides

Question 47

Tides which occurs only one high tide a day is called:

Answer 47

Diurnal tides

Question 48

If one of the two daily tide is incomplete, that is it does not reach the height of the previous tide, then the tides are referred to as:

Answer 48

Mixed diurnal tides

Question 49

The highest tides in the world where a rise of 100 ft. has been recorded occur in __

Answer 49

Bay of Funday

Question 50

The average of the high water over a 19-year period is known as:

Answer 50

Mean high water

Question 51

The average height of the higher high waters over a 19- year period.

Answer 51

Mean higher high water

Question 52

Average of the low water over a 19-year period

Answer 52

Mean low water

Question 53

The higher of the two high waters of any diurnal tide day.

Answer 53

Higher high water

Question 54

The lower of the two low waters of any diurnal tide day.

Answer 54

Lower low water

Question 55

The average height of the lower low waters over a 19- year period.

Answer 55

Lower low water

Question 56

The highest height of water of spring tides.

Answer 56

Highest high water

Question 57

The lowest height of water of spring tides.

Answer 57

Lowest low water

Question 58

The height of the mean high water above mean low water.

Answer 58

Mean range

Question 59

The mean of the height of mean high water above the mean low water is referred to as:

Answer 59

Mean sea level

Question 60

The difference in height between the mean higher high water and the mean lower low water.

Answer 60

Diurnal range

Question 61

Regular occurrence at certain locations are high crested single or solitary type of wave caused by the rush of flood tide up in the river or by the meeting of tides as in the Bay of Funday where the highest tide of 100 ft. is recorded in the world is referred to as:

Answer 61

Tidal bore

Question 62

A wave at a point where the water depth is equal to ½ of the wavelength or greater to be expressed in terms of the parameters of significant wave.

Answer 62

Deep water wave

Question 63

A hypothetical wave having a wave height and period equal respectively to average values of the wave height and period of the largest 1/3 of all waves in the train as counted in the order of greater wave height.

Answer 63

Significant wave

Question 64

A maximum wave height and wave period of the maximum wave height in wave train.

Answer 64

Highest wave

Question 65

Waves which occur in water having a depth less than one half of the wave length and the influence of the bottom changes the form or orbital motion from circular to elliptical or near-elliptical.

Answer 65

Shallow water wave

Question 66

Waves break under the following conditions: I. When the forward velocity of the crest particles exceeds the velocity of the propagation of the wave itself. II. When the wave height exceeds (1/7) of the wave length in deep water III. When the wave reaches shallow water where the depth is equal to about one and one quarter of its height.

Answer 66

All of the above

Question 67

The length between two consecutive crests is called:

Answer 67

wave length

Question 68

The height between the trough and the crest of a wave is called:

Answer 68

amplitude

Question 69

The wave form travels over the water surface and the time for two consecutive crests to pass a point is called:

Answer 69

wave period

Question 70

The speed of the wave form which travels over the water surface for a certain wave period.

Answer 70

Velocity of wave propagation

Question 71

The water level that guarantees about 98% of tide is safe to ships seems to be suitable from the expression of the technical resolution of the International Water Wave Congress. Such water level, which is 0.15 m. ~ 0.4 m. below MLLW should be used for design of ports

Answer 71

Design Low Tide (DLT)

Question 72

Shape of the wave and wave speeds are governed by the displacement of water particles and the functions of the following variables. I. Wave length II. Water depth III. Wave motion IV. Wave shoals

Answer 72

I and II only

Question 73

The elevation of the crest above the through of the wave.

Answer 73

Wave height

Question 74

The interval of time for two wave crests to pass the same position in space.

Answer 74

period

Question 75

Large waves (long period) can be generated only when the fetch (distance over which the wind blows) is large. Waves continue to grow after they reach a velocity of _ of the wind speed, but at a decreasing rate.

Answer 75

1/3

Question 76

The flow of energy along the wave crest in a direction at right angles to the direction of wave travel is called:

Answer 76

diffraction

Question 77

A type of wave where the depth is less than ½ of wave length but greater than 1/25 of the wave length.

Answer 77

Transitional water wave

Question 78

A type of wave where the depth is less than 1/25 of wave length.

Answer 78

Shallow water wave

Question 79

The highest point of the wave is called:

Answer 79

wave crest

Question 80

The lowest point of the wave.

Answer 80

wave trough

Question 81

The distance between the highest point and the lowest point of the wave.

Answer 81

wave height

Question 82

The vertical distance of the wave crest and the wave trough.

Answer 82

wave height

Question 83

From the Sine wave curve shown, what do you call the value of "L"?

Answer 83

Wave length

Question 84

From the Sine wave curve shown, what is the value of h?

Answer 84

Amplitude

Question 85

From the Sine wave curve shown, what do you call the region x?

Answer 85

Crest length region

Question 86

From the Sine wave curve shown, what do you call the region y?

Answer 86

Trough length region

Question 87

From the wave behavior, indicate what zone is covered by the distance x.

Answer 87

Shoaling zone

Question 88

What zone is covered by the distance "y"?

Answer 88

Transition zone

Question 89

What zone is covered by the distance "z"?

Answer 89

Shallow zone

Question 90

The average height of the sea for all stages of the tide obtained from systematic observations of sea level at equal intervals over a long period of time along a given coastline is called:

Answer 90

Mean sea level

Question 91

The process of widening, enlarging, cleaning, or deepening of channels in harbors, rivers and canals to maintain the idea depth of berthing areas due to fast siltation rate is known as:

Answer 91

Dredging

Question 92

The periodic rise and fall of sea level in response to the gravitational attraction of the sun and moon as modified by the earth's rotation.

Answer 92

Astronomical tide

Question 93

A phenomenon involving abnormal oscillations of the water level with a period of approximately a few minutes to a few tens of minutes. It occurs when small fluctuations of the water level are generated by micro scale variations of the atmospheric pressure by an air front or a low pressure in the outer sea and the components of those oscillations whose period is the same as a natural period of the harbor are amplified through resonance.

Answer 93

Seiche

Question 94

The flow of seawater in the horizontal direction that accompanies a tidal variation of sea level and is thus periodic.

Answer 94

Seiche

Question 95

The time of rotation of the earth with respect to the moon and the planets, which is approximately 24 hours and 50 minutes.

Answer 95

Astronomical tidal day

Question 96

The chart datum for harbor works is generally the:

Answer 96

Lowest astronomical tide

Question 97

The rise of sea level due to the greenhouse effect between years 2000 and 2050 is assumed to be about:

Answer 97

0.25 m to 0.30 m

Question 98

The rise and fall of the water level due to change in the atmospheric pressure is approximately equal to:

Answer 98

0.9 cm rise or fall of the water level for 1 m bar fall or rise in atmospheric pressure

Question 99

Wind generated waves but are created in the deep ocean at some distance from the port site and the wind that created them may be too distance to be felt in the port and may have changed its direction by the time the waves reach the port.

Answer 99

Swell

Question 100

Waves, which have a very long period, typically from 30 sec up to the tidal period of 12 hr and 24 min. and are mostly found in enclosed or semi-enclosed basins such as bays or port basins.

Answer 100

Seiching

Question 101

The regular periodic rise and fall of the surface of the seas, observable along their shores is called:

Answer 101

Tide

Question 102

The average height of all low waters at any place over a sufficiently extended period of time is called:

Answer 102

Mean low water

Question 103

The tidal current setting into the bays and estuaries along the coast is called:

Answer 103

Flood current

Question 104

The return current toward the sea is called:

Answer 104

Ebb current

Question 105

The period during which the current is negligible while it is changing directions is called _. It is the period during which the current is less than 1/10 of a knot or less than 0.169 fps.

Answer 105

Slack water

Question 106

The average time interval, in solar hours and minutes from a lunar transit to the next succeeding high water at a given place as determined by an extended set of observations is called:

Answer 106

High water lunitidal interval of the place

Question 107

The maximum height reached by each rising tide is called:

Answer 107

High water

Question 108

The maximum depression of the falling tide is called:

Answer 108

Low water

Question 109

The straight-line stretch of open water available for wave growth without the interruption of land is called:

Answer 109

Fetch

Question 110

The interval of time between successive crests of the water waves passing a stationary point of reference is called:

Answer 110

Wave period

Question 111

What is the worst condition which should be considered in relation to the design of coastal defense works?

Answer 111

Combination of unusually high sea level with severe wave action

Question 112

It is the single most important environmental factor in the broad field of coastal engineering?

Answer 112

Coastal erosion