Ken Ring at PredictWeather.com who claims over 5000 subscribers including farmers, corporations and government agencies, uses in his own words, "trends and cycles of Moon orbits to predict the weather", scored some notoriety lately for having tweeted a Valentine's Day prediction for a Christchurch, New Zealand earthquake between February 15 and 25.
Damn that was a convoluted sentence.
Be reminded here of the devastating magnitude 6.3 earthquake the hit Christchurch February 21, 2011.
Earthquakes correlate with kingtides - they are a function of the kingtide in the land deep under the ground.
The whole 2/3 of the planet that is beneath the Earth's surface has a moving egg-shaped bulge that, as the earth daily rotates, is always pointing to the moon, just as when a magnet is moved above a plate of iron filings and the area under the magnet is always more responsive.
The perigee (day that the moon is closest to earth each month) is in control of the timing of the kingtide. Sometimes new moon accompanies perigee (as on 4 Sept 2010), sometmes full moon (22 Feb 2011), so kingtide occurs around these dates as well.
Before new year kingtide days were new moon-related. From February onwards full moon has accompanied perigee, so kingtides were full moon-related.
It does not mean all full moons (or new moons) bring the biggest earthquakes.
Perigee (closest approach to the Earth) is also a factor.
I can find no other use of the phrase kingtide anywhere (I know you believe me when I say that I looked) that correlates in any way to Mr. Rings.
He predicts an second earthquake March 20, 2011 in Christchurch based on the astronomy of that day, namely the "Supermoon" on March 19, and the Jupiter, Saturn opposition which is exact on March 28, 2011, but is within a few degrees from mid March until mid April 2011.
Click on the below sketch of the Jupiter, Saturn opposition for a radically different way to look at both the world and the universe around you.
Remembering as always ..... head ..... swivel.