I was just browsing about looking at seismograms - (It really would be nice if Southern California had one or two - or anything like that online - considering the number of instruments down here you' think one or two could be online.....)

Anyway - I was looking at the Mammoth Sismogram and noticed that daily around 7:15-8:15 it gets really noisy and then drops off about 4:15pm (sometimes later for night skiing?)

I figure its either wind or skiers - and going back in time seeing the same pattern over and over - I surmise that its probably all those snow-boarders.

Any thoughts?

Canie

• Mammoth Summit Seismogram