OK here's an image of the event after its been put into the analysis program

and have done some FFT lowpass 6 pole filtering with a cutoff at 5Hz to cut out a lot of the manmade and other higher freq noise

now for some other info....

There are 4 wave arrivals nother on the seismogram

P = The P wave is the fastest travelling, ~ 7 - 8km/sec. It is a compressional wave like a sound wave. Their frequency avg's around 1 - 5 Hz, give or take a little

S = S wave it travels a bit slower ~ 5 - 6 km/sec. It is a shear wave ... ground motion is perpendicular to the direction of propagation. Their frequency avg's around .1 - 1Hz, give or take a little

The LQ and LR are the surface waves, they dont penetrate into the earth to any great distance, a few 10's or so of km. They are the slowest travelling at ~ 3 - 4 km/sec

and are complex styles of shear waves.

LQ = Love waves, LR = Rayleigh waves

It is the surface waves that do the damage to buildings and other structures. Their very low frequency from ~ 10 to ~ 200 seconds/cycle. are, along with various ground types allow structures vibrate at their resonant freqs and demolish themselves.

( I will add to that ... there is also the initial hi acceleration pulse that can do initial damage to weaker structures.)

OK there's seismology 101

cheers

Dave