Hello Mike,

I had Roger run perihelion/ahelion for gravity purposes, and because these events are so close to
solstace that I intended to use the finding for inclinational purposes also. Northern tides are greater at solstace, and perihelion. I am talking about all tides---liquid, solid crustal and plasticity in the upper mantle. So I needed some kind of breakdown of the quakes time wise over the earths orbit. I won't even go into wobble, which I think is 1 degree or something. Polaris is not exactly in line with the Earths axis. I also needed hemispherics for comparitive analysis. To date, I have not seen a study on hemispheric differences in seismicity, or any rates or ratios compared to overall global background. It will be generalized, simply because the lithosphere is not a homogeneous structure. Throw in magma plumes and hot spots, things get very complicated.

I use the term strike for direction of the fault. I usually use general terms such as northwest or northeast. Some are west-east. When I look at focal mechanisms I also look at the dip vector or rake of slip. 0 to 180 degrees is pure strike slip. 90 degrees is pure dip slip reverse. -90
is pure normal or hangwall dropping perpendicular to right hand reference strike. Of course there are other angles for oblique and over thrusts are +30, +20 or below if I remember.

I have a general understanding of the isotropic dipoles in Mx, y, z. When they start doing inversions and CLVD--compensated linear vector dipole, then it gets a bit hairy for me. I know they are looking for the best double couple and fit based in part on Greens functions. The more I learn, the more interesting it becomes. So that makes me a non "ist" also.

Hope that helps a little bit. The kind of data that Roger has found can lead in a ton of directions. We may find something significant. I'll have more... Thanks to Roger, also.

Response appreciated,
Glen

P.S. If you come across anything on this paper wise, please let me know. don't want to break any well constructed wheels.