What are the “Perigean Spring Tides”? Do they cause coastal flooding?
The question of “Perigean Spring Tides” has been one that our office has been required to answer on numerous occasions over the years. The whole issue of coastal flooding during the “perigean spring tides” stems from a misunderstanding of the information presented in a book by Fergus J. Wood, published in 1978. The moon is the primary source of the gravitational forces which cause the tides. The proximity of the moon in relation to the earth does have an effect on the range of the tides at any given time. In each of its 28-day elliptical orbits, the moon reaches a “perigee,” its closest point of approach to the earth. During these periods, there will be a slight increase in the average range of tides. The increases in the range of the tides is seen by a slightly higher than average high tide, as well as a slightly lower than average low tide.
