Stephen --

I'm seeing the same thing in Southern California, and it has increased
substantially this afternoon.  See
http://www.keckec.com/images/current.kc1.gif

The amplitude is quite large too.  There are two storm systems off Baja
California (one off northern Baja and the other southwest of the tip) that
I suspect are responsible.  Tropical storms and hurricanes (usually later
in the season) are often responsible for large background noise, even when
they are 1500 miles away.

Karl Cunningham



--On Thursday, May 30, 2002 09:08 -0700 Stephen & Kathy 
wrote:

> FYI,,   I noticed a strangeness in the background noise today as I was
> checking my traces, so I did an FFT and discovered that they had a period
> of about 8 seconds,,   as compared to the normal 4.5 to 5.5 that I've
> noticed over the years for Northern California!    Anyone have any idea
> why????    Could this be caused by the hurricane,, or is something else
> going on???   I verified that it was not my machine by checking with the
> Berkeley "make your own seismogram" link!!
> 
> http://quake.geo.berkeley.edu/bdsn/make_seismogram.html
> 
> I haven't noticed such long period microseisms before,,,   perhaps I just
> wasn't looking??

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