Ports and Harbors Flashcards
The maximum current velocity through the harbor entrance should not exceed ___.
1.5 m/s or 3 knots
The stopping distance of a loaded ship is _____.
7 to 8 times the ship’s length
AN instrument used to measure the intensity of wind.
Beuforts Scale
The ratio of the wave length to its height for ocean waves is between
17 and 33
An open water of navigable depth is called __
Fairway
Waves generated by storms, which occurs outside area of observation.
Swells
Waves generated by wind that are acting on the sea surface bordering on the port site.
Wind wave
Waves in which the ratio of water depth to the wave length is greater than 0.5
Deep water waves
Waves in which the ratio of water depth to the wave length is less than 0.5 but greater than 0.4
Intermediate water waves
Waves in which the ratio of water depth to the wave length is less than or equal to 0.4
Shallow water wave
The arithmetical mean value of the highest, one third of the waves for a stated interval.
Significant wave height
An abnormal rise of the sea level that occurs when a typhoon passes by.
Storm surge
The distance that the wind blows over the sea in generating the waves is known as:
Fetch
The ratio of the wave height to its wave length is called:
steepness
The falling tide
Ebb Tide
Waves with an extremely long period that mainly occur when there is a sudden large scale se floor movements associated severe, shallow focus earthquake.
Tsunamis
The difference in height between the mean higher high water and mean lower low water.
Diurnal Range
The highest tides which occur at intervals of half a lunar month is called
Spring Tides
The difference in height between high water and low water at a tidal station is called ___.
Tidal Range
Waves formed by moving ship or boats are called _____
Wakes
Waves formed by earthquake disturbances.
Tsunamis
Waves formed by gravitational attraction of the moon and sun
Tides
The spread of energy along a wave crest is called ____
Diffraction
The bending of waves as they slow down.
Refraction
Waves under the influence of the winds that generated them are called ___
Sea
The periodic rise and fall of the ocean waters produced by the attraction of the moon and sun
Tides
The average of the high water over a 19 year period is known as ____
Mean High Water
Tides which occurs only one high tide a day is called ____
Diurnal Tides
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 ____
Mixed Diurnal Tides
The average height of the higher high waters over a 19 year period
Mean higher high water
The average of the low water over a 19 year period is known as ____
Mean low water
The higher of the two high waters of any diurnal tide day
Higher High water.
The lower of the two low waters of any diurnal tide day.
Lower low water
The lowest height of water of spring tides.
Lowest low water
The height of the mean high water above the mean low water
Mean Range
The mean of the height of mean high water above the mean low water is referred to as:
Mean Sea Level
A maximum wave height and wave period of the maximum wave height in wave train.
Highest Wave
The height between the trough and the crest of a wave is called _____
Amplitude
Highest point of the wave
Wave crest
The lowest point of the wave
Wave trough
The distance between the highest point and the lowest point of the wave.
Wave height
The process of widening, enlarging, cleaning, or deepening of channels in harbors, rivers and canals.
Dredging
The flow of seawater in the horizontal direction that accompanies a tidal variation of sea level and is thus periodic.
Seiche
The return current toward the sea is called
Ebb current
The period during which the current is negligible while it is changing directions is called ________
Slack Water
