Hello Roger,

I would like to have your opinion on what I believe to be clusters of great quakes, 8+ and up. I have looked at this before. There "seems" to be a major super cluster of 8 mag quakes at the turn of the last century. 1897 to about 1906 and further. If you look at the NEIC data for quakes, global, up to 1994, some years have 4 and 5 great quakes. 1906 has 5, and I don't think San Fransisco is one of them. Another super cluster would be from 1957 to 1965. Since 2000, we have had some 16 great quakes. Roger, what is the statistical average, timewise, for great quakes to occur? 1 every year, or?

Appreciate your work, thanks!
Glen

PDE 2000 06 04 162826.17 -4.72 102.09 33 8.30 MeGS 6CFM ......S
PDE 2000 06 18 144413.31 -13.80 97.45 10 8.00 MeGS .F M .T.....
PDE 2000 11 16 045456.74 -3.98 152.17 33 8.20 Ms GS .C M STS...S
PDE 2000 11 17 210156.49 -5.50 151.78 33 8.20 MSBRK .F M .......
PDE 2001 01 26 031640.50 23.42 70.23 16 8.00 Ms GS .CFM .......
PDE 2001 06 23 203314.13 -16.26 -73.64 33 8.40 MwHRV 8CFM .T....S
PDE 2001 11 14 092610.01 35.95 90.54 10 8.00 Ms GS .D M .......
PDE 2002 11 03 221241 63.52 -147.44 4 8.50 Ms GS 9CFM F.S...M
PDE 2003 09 25 195006.36 41.81 143.91 27 8.30 MwHRV 8CFM .T....S
PDE 2004 12 23 145904.41 -49.31 161.35 10 8.10 MwHRV .FFM .T.....
PDE 2004 12 26 005853.45 3.30 95.98 30 9.00 MwHRV 9C M STS...M
PDE 2005 03 28 160936.53 2.09 97.11 30 8.60 MwHRV 8C M 3TS....
PDE-W 2006 11 15 111413.57 46.59 153.27 10 8.30 MwHRV 2C M .T.....
PDE-W 2007 01 13 042321.16 46.24 154.52 10 8.20 Ms GS 6F M .T.....
PDE-W 2007 04 01 203956.38 -8.46 157.04 10 8.10 MwGCMT .C M UT....S
PDE-Q 2007 08 15 234057.95 -13.35 -76.51 39 8.00 MwGCMT .. M .......