Previous analysis has emphasized regions of specific interest, relying almost completely on a visual inspection of the data for trends. We present a global statistical analysis of the stress indicators to quantify trends in the data with a wavelength of at least several hundred kilometers. We analyze two types of information contained within the stress indicator dataset. Second, the Rayleigh test, a standard statistical method in the analysis of directional data, is applied to the SHmax orientations within the bins to test the null hypothesis that the orientations are random. These analyzes quantify and extend a number of important conclusions drawn from visual inspection of the World Stress Map, including the existence of broad regions of compression and uniform directional trends throughout much of the continental plate interiors.
Trends tend to be much weaker in the slowest moving continental plates.
This provides further evidence to support the conclusion that the intraplate stress field is strongly influenced by the ridge push force. The SHmax orientations within 5 x 5 degree bins which pass the Rayleigh test, plotted on a base of average topography.