[Steve Van Doorn]

Couple places of interest in Sothern Utah :
http://www.quake.utah.edu/helicorder/icu_webi.htm
This one seems to have a lot of background noise which seems to vary from day to day which is odd…
but even if you disregard the noise look at the area between 10 and 12:00 MST.
http://www.quake.utah.edu/helicorder/msu_webi_3d.htm

[winoneforthegipper]

That MSU was from the 11th?

However there was regional harmonics as the times on the other recorders are exact!

Good catch!