Tides

Tides are defined as the periodic rise and fall in sea levels that occur as a result of gravitational forces of the sun and moon. The moon is the primary factor in controlling temporal rhythm and heights of tides because of its close proximity and regular rotation around the earth. The predictability of tides is dependent on the moons orbit around the earth which takes twenty four hours and fifty minutes per rotation. During this time there are generally two low tides and two high tides that rise and fall on the shoreline, depending on the geography of the shoreline. The highest tides recorded on earth occur along the Bay of Fundy, a body of water that lies between Nova Scotia and New Brunswick provinces in Canada.   In this region you may observe tidal variations of up to forty two feet high in a twelve hour period.  

The influence of the Sun’s gravity on the tides is less than that of the moon because although the diameter of the sun is 400 times that of the moon, it is far, far further away from the Earth. If the moon did not exist there would still be high and low tides because of the sun, however they would only be half the size compared to their lunar counterparts.

 

Without the combined influence of the sun and the moon there also would be no neap tides or spring tides, which occur when the sun and the moon are either pulling in the same direction or in opposition to each other.   A neap tide occurs ever quarter moon when the sun and the moon are at a right angle with each other and as a result create lower tides compared to the rest of the month. Spring tides occur when the sun and the moon are in line with each other so that the combined gravitational pull is much stronger, thus creating higher high tides and lower low tides. Also, without the moon the four definitive seasons of summer, autumn, winter and spring would be different and there would be no twelve month calendar, as these are dependent on the revolutions of the moon. It is also thought by scientists that the moon stabilises the tilt of the earth’s rotation and without the tilt, sun rays would penetrate the earth’s surface at a fixed angle continually and the rays would remain perpendicular to the ground all year round.

previousPrevious - Climate Change Research
Next - Effects and Usenext
Back to Tides