The name Supermoon was coined by astrologer Richard Nolle in 1979 , arbit rarily defined as :
Anew or full moon which occures wuth the moon at or near (within 90% of ) its closest approach to Earth in a given orbit.
In short , Earth , moon and son are all in a line , with moon in its nearest approach to Earth .
when the moon is either new or full , the combined effect of the sun and moon on the Earth’s oceans , the tide , is greatest.
It has been claimed that the supermoon of March 19 , 2011 was responsible for the grounding of five ships in the Solent in the UK but such claims are not supported by any evidence .
There has been speculation that natural disasters , such as earthquake and tsunami and 2004 Indian ocean earthquake and tsunami and the 2011 Tohoku earthquake and tsunami , are causally related and linked with 1-2 weeks period surrounding a supermoon .
no evidence has been found of any correlation between supermoon with major earthquakes .
The moon distance varies each month between approximately 357000 Kilometers and 406,000 Km , a full moon at perigee is up to 14 % larger and 30 % brighter than one at its farthest point .