The Proxigean Tide occurs when the Moon is at its closest point in its orbit
to the Earth and in its New or Full Moon phase. At this time, its tidal effect
on the Earth is maximum. Tidal gravitational forces vary as the third power of
the distance between Earth and Moon, so even a small difference in distance can
translate into a big effect. The orbit of the moon varies from a distance of
356,500 to 406,700 kilometers with an average distance near 380,000 kilometers.
The variation between the maximum and minimum distances results in tidal force
changes of a factor of 1.2 times the average tidal forces.
Visit the Lunar
perigee and apogee calculator to calculate these distances yourself!
The times when this will happen often coincide with major coastal flooding
events. Between 1997 and 2020 there will be 102 times when this will happen.
You can see the list by looking at Fergus J. Wood's book Tidal Dynamics
published in 1978 by D. Reidel Publishing company, Dordrecht Holland. There are
tables computed by van Flandern at the U.S. Naval Observatory. Here is a short
list of the most extreme events based on the time between perigee and syzygy
being less than 5 hours: New Moon is pretty bad because both the Sun and the Moon are on the same
side of the Earth, and with the Moon near its closest point to the Earth, the
tide- making potential is highest. I will probably not plan to be on the beach
on the above dates! Return to Dr. Odenwald's FAQ page at the Astronomy Cafe Blog.
Date Phase
3/11/2003 New
1/10/2005 New
2/28/2006 New
12/12/2008 Full
1/30/2010 Full
3/19/2011 Full
5/6/2012 Full
6/23/2013 Full
8/10/2014 Full
9/28/2015 Full
11/14/2016 Full
5/25/2017 New
1/2/2018 Full
7/13/2018 New
8/30/2019 New
10/16/2020 New
12/4/2021 New
1/21/2023 New