Hi Barry, I'm a little south of you...   I also
have increased noise.  Whenever I see this kind of noise, I check with
Berkeley at:

http://quake.geo.berkeley.edu/bdsn/make_seismogram.html



If you just create plot without setting time, it will create todays
seismogram for CMB... I use 4 for compression to get an hour per line; 
and pixels at 25 to get a little separation.  Sorry if I am sharing old
info...   if so, maybe it will help others? 



If you check the following ocean weather link you will see why... 
there are 20 to 25 foot waves off the NW USA coast.   Earlier, they
were showing up to 30 foot waves. You can click on any box to see the
conditions in the box...  I click on the box that shows Alaska to below
Baja...   and yes, the energy is apparently coming from 200 to 400
miles away:

http://www.oceanweather.com/data/



At one time I had my gain so high that noise like this would set off my
alarm, (I have a separate alarm, which I built before I had a computer
and recording capability).

  Stephen

  PSN Station #55

  38.828N  120.979W

  near Pilot Hill Calif   



Barry Lotz wrote:

  

    

      

        


To all

Related to instrument quality- maybe. I have noticed a lot more
microseismic activity the last few days. The background noise on my
vertical is around +/- 300 counts @  8.7 sec  and 6.6 sec  (two narrow
peaks). I don't remember this magnitude in years past. I'm sure it is
weather related. I live about 200 miles east of the west coast of
northern California. Anyone else noticed an increase in background
lately? Every time I look at the output I think I'm looking at surface
waves after an event.

Barry