Odd. I was just thinking the same thing. I've never seen them proffer such an explanation on one particular "medium sized" quake before! It's as though USGS is trying to reassure everyone in So Cal that there's "nothing to worry about - the tone of the press release seems to imply "that it's just some little anomalous quake that means little or nothing" - although at 6.4 how "little & meaningless" it is certainly is subject to debate.

As Shakespeare said "Me Thinks the lady doth protest too much!"

I wonder what they REALLY know or suspect strongly that they're now trying to cover up? Something is going on and it's far more than just this one quake that USGS is trying so hard to "blow off" as though it is nothing.

Any ideas?