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TIDE & TIDE DIAMOND. TIDE Vertical rise and fall of the surface of a body of water caused primarily by the differences in gravitational attraction of the moon, and to a lesser extent of the sun, upon different parts of the earth.
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TIDE & TIDE DIAMOND
TIDE Vertical rise and fall of the surface of a body of water caused primarily by the differences in gravitational attraction of the moon, and to a lesser extent of the sun, upon different parts of the earth. Moon is many times closer to the earth than the sun therefore gravitational pull is 2 1/4 times more pronounced
What Causes Tides Strong gravitational pull of the moon on the side of the earth nearest the sun, Strong outward centrifugal force generated by the earth-moon system on the opposite side of the earth, Cause the water on the earth’s surface to bulge out in the form of high tides on both sides. The same phenomenon occurs between the sun and the earth but on a much smaller scale. • The moon revolves around the earth once each month. • Lunar or Tidal day - 24 hrs and 50 min • Earth rotates beneath it in the same direction. • Most locations on earth experience four tides per day. • Each successive high and low tide constitutes one tide cycle. • Tide patterns are distorted from the normal 4-tide pattern because of the effects of landmasses, constrained waterways, friction, the Coriolis effect, and other effects.
Large High Tide Small High Tide X Declination of The Moon Y
DOKUZ EYLUL UNIVERSITYSCHOOL OF MARITIME BUSINESS AND MANAGEMENTDEPARTMENT OF DECK SELÇUK NAS AIR DRAFT WATER LEVEL DRAFT CHART DATUM ( LATW ) CHART ELEVATION MHWS MHWS MHWN High of Tide (HOT) MLWN MLWS CHARTED DEPTH BOTTOM Selçuk Nas
TIDE CURRENT • Current = the horizontal movement of a body of water. • Causes: • Gravitational effects of sun and moon • Heating and cooling of Earth’s atmosphere • Winds blowing across the ocean’s surface • Changes in salinity due to rain and evaporation • The Coriolis effect Set - the direction of the currents motion Drift - the velocity of the current Set & Drift represent the vector added to ship’s motion by the current
1410 DR 1400 DR 7th Feb. 1010 HW LW BA TIDE DIAMOND SET : 2650 Drift : 2,6 Knot For Spring Tide 1,3 Knot Neap Tide
1410 DR 1400 DR 7th Feb. HW LW BA TIDE DIAMOND SET : 2650 Drift : 2,6 Knot For Spring Tide 1,3 Knot Neap Tide We will check Mean Rangeand Actual Rangefor Actual Drift OK
1410 DR 1400 DR 7th Feb. BA TIDE DIAMOND SET : 2650 Drift : 2,6 Knot For Spring Tide 1,3 Knot Neap Tide MEAN RANGES Springs = 6 m Neaps = 3,2 m ACTUAL RANGE = 5,5 m We will compare ranges and make a interpolation
1410 DR 1400 DR 7th Feb. 2,8 m 1,3 Knot 0,5 m Y BA TIDE DIAMOND MEAN RANGES Springs = 6 m Neaps = 3,2 m SET : 2650 Drift : 2,6 Knot For Spring Tide 1,3 Knot Neap Tide ACTUAL RANGE = 5,5 m Springs = 6 m 2,6 Knot Neaps = 3,2 m 1,3 Knot Z ACTUAL RANGE = 5,5 m Z = 2,6 – 0,23 Z = 2,37 = 2,4 Knot Y = ( 0,5 x 1,3 ) / 2,8 Y = 0,23
SET : 2650 Drift : 2,4 1410 DR 1400 DR 7th Feb. BA TIDE DIAMOND
HW LW ACTUAL RANGE = HW – LW 6,5 – 1 5,5 m