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Home  Education  Tides and Water Levels  Tidal Variations - The Influence of Position and Distance
  << Back The elliptical orbits  of the moon around the Earth and the Earth around the sun have a  substantial effect on the the Earth’s tides. Once a month, at perigee,  when the moon is closest to the Earth, tide-generating forces are  higher than usual, producing above average ranges in the tides. About  two weeks later, at apogee, when the moon is farthest from the Earth,  the lunar tide-raising force is smaller, and the tidal ranges are less  than average. When the Earth is closest to the sun (perihelion), around  January 2 of the calendar year, tidal ranges are enhanced. At aphelion,  when the Earth is furthest from the sun, around July 2, tidal ranges  are reduced (Sumich, J.L., 1996; Thurman, H.V., 1994).


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