how do tides work?
Tides are caused by the gravitational attraction of the earth to the moon and to the sun. Although the moon is a lot smaller than the sun, it is a lot closer to the earth; so the moon’s gravitational effect on the tides is about three times that of the sun. The highest tides ocur when the sun, the earth and the moon are all in line, and the gravitational attraction of the sun and the moon is aligned. These are called ‘spring tides’, and they happen during new moon (when the sun and the moon are on the same side of the Earth), and full moon (when the sun and the moon are opposite each other). When the sun and the moon are at right angles, relative to the earth (during half moon), the tides are at their weakest, called ‘neap tides’. Also, during its orbit around the sun, the earth is closer to the sun at times; and during these times, the spring tides are at their highest; called ‘king tides’, ot technically ‘perogee syzygy’ tides – meaning ‘closest in line’.
Tides are caused mainly by the moons gravitational pull on the ocean.The time it takes the moon to reappear at the same place in the sky each day is 24 hours and 50 minutes . Most areas in the world have two high tides and two low tides a day, so the tide clock has been specially designed to rotate twice each lunar day (every 12 hours and 25 minutes) giving you a quick and easy indication of high and low water. The Quartz tide clock will always stay synchronized to the moon. There are other influences on sea levels that effect exact tide times. Therefore the tide clock should only ever be used as a guide, and is not intended for navigational use. • The suns own gravitational pull, when lined up with the moon (full moon and new moon) creates higher and lower tides. This can alter tide times by up to an hour. • Changing atmospheric pressure. • Strong on-shore and off-shore winds. • Changing volume of river flows.
