Major NZ Earthquakes and the Moon

Major NZ Earthquakes and the Moon

Are major earthquakes related to the position of the Moon? Does the gravitational field of the Moon (and Sun) influence earthquakes on Earth? Recent (N.Z.) media reports have given widespread coverage to local predictions of large earthquakes based on the position and phase of the Moon. Is there a correlation?

16 major (mag. > 6.9) earthquakes in and around New Zealand have been accurately recorded since 1848. Two elements of the Moon are investigated.

If the Moon strongly influenced (by its gravitational field) the occurence of major earthquakes then we should expect to see a greater number of major earthquakes near New Moon and when the Moon is at it's nearest approach to Earth.

NZ Earthquakes mag. > 6.9

New Zealand Earthquakes of mag. > 6.9. 16 events have been recorded since 1848. Plotted is fractional illumination of the Moon (x axis) versus Moon Distance from Earth (in units of Earth radii). The latest earthquake, 21 August 2001 (the data point at X=0.03, Y=57.2) is shown at the bottom, left part of the plot.

The earthquake events display a scatter diagram.

Conclusion: Whilst 16 events is not a large sample size, there is no strong statistical evidence for the Moons position or illumination influencing New Zealands major (mag. >6.9) earthquakes.

Glen Mackie

Glen Mackie is Senior Research Fellow, in the School of Physical and Chemical Sciences, Victoria University of Wellington.

Related Web links:

IGNS Earthquakes

Last updated Sept 1., 2001