9 January 2013

King Tide Is Holding Court

Posted by Dan Satterfield

Unusually high tides will occur this week because Earth will be nearer to the Sun and Moon simultaneously (during a New Moon). Image from NOAA.

The World’s oceans will rise up considerably higher than usual this week due to an effect called “King TIdes”.  The tides are a result of the gravitational forces of the Sun and the Moon of course but when the Moon is full or new we are “lined up” and the gravity from both act in concert with each other. It may seem that a full moon would act opposite but in fact the tides are reinforced in both situations. This “lining up” of the Sun,Earth and Moon has an astronomical name called SYZYGY.

However, you need the two P’s for the King of Tides to hold court. Perigee and Perihelion  When the Moon is closest to Earth it is said to be at Perigee and when the Earth is closest to the Sun we are at Perihelion  When both of these events happen at the same time as a Full or New Moon we get the highest of Astronomical tides. In places where the tidal range is naturally high like the English Channel, Northern Australia, or the Bay of Fundy in Canada, there can be some very high water levels.

Click the image to see how you can help document the high tide levels for science.

The Maryland Department of Natural Resources is asking the public to take photos of the high tides this week so we can better understand what the water will cover at certain tide levels. Info on how you and your camera can help is here. California, Canada and Australia are also asking for help from those who live near the water and the MDNR site has links to those sites as well.

While none seems likely this week, a strong coastal storm could produce much more damage than it otherwise would, if it happened during this period.