A64. By using the arithmetic or graphical average during the 2-minute observation
period.
A65. It would be less than the actual wind speed.
A66. A rapid fluctuation in wind speed with a variation between peaks and lulls of 10
knots or more observed in the lo-minute period prior to the actual time of
observation.
A67. A sudden increase in wind speed of 16 knots or more and the sustained increase
must be 22 knots or more for at least 1 minute.
A68. The vertical distance from the crest to the trough of the wave.
A69. The wind speed, the length of time the wind has been blowing, and the size of the
fetch area.
A70. 8 to 13 feet.
A71. The time it takes for a complete wave cycle to pass a given point.
A72. Wavedirection is the direction the majority of waves in a group are coming from.
A73. The average height of the highest 1/3 of all the waves present,
A 74. Swell waves are sea waves that have moved out of the area of formation and are
more smooth and regular in appearance.
A75. By using the average height of all the swell waves present.
A76. 14°F .
A 77. The source of the ice accretion, the thickness of the ice, and a determination of the
rate of accumulation or melt-off.
A 78. It is due to the salinity of seawater and the density changes in seawater caused by
salinity. In addition, thefreezingofseawater is slowed because of waves, currents,
and tides.
A 79. March.
A80. Sea ice that is frozen solidly to the shores of islands or land masses.
A81. Rafting ice indicates that the ice is closing rapidly.
A82. It normally drifts to the right (about 30°) of the wind direction.
A83. Antarctica and Greenland.
A84. The prevailing sea current at the icebergs submerged depth.
1-69
