I have followed your discussion of noise. I, too, have notice a =
cycling from quiet to "busy"; with some intervals of seemingly quiet =
conditions during times that you expect quiet and vice versa. As =
everyone has said, what you call noise comes from two sources natural =
and man-made. I found that some of this noise can be explained with =
experience and time; bad storms like Katrina hitting New Orleans(at six =
hundred miles), the demolishing of old buildings with wrecking balls =
(about 4 miles away), maybe even tornadoes (ten miles), the microcisms =
proceeding the first cold front in the Fall, bad local storms with wind =
and lightning(as far as 100 miles away), a local train that goes within =
about a mile of this location about twice a week about 9:30 pm local =
time and even local truck traffic like the trash pickup truck each week. =
 One that really had me fooled for about a week or so was a geologic =
team in the area using a machine to test soil liquifaction. It created =
"little" quakes which seemed to move -- and they did move, well anyway, =
the truck moved!! If you limit you observations to just earthquakes you =
will miss many interesting events and hopelessly stagnate and become a =







 
I have followed your discussion of noise. I, =
too, have=20
  notice a cycling from quiet to "busy"; with some intervals of =
seemingly=20
  quiet conditions during times that you expect quiet and vice =
versa. As=20
  everyone has said, what you call noise comes from two sources natural =
and=20
  man-made. I found that some of this noise can be explained with =
experience and=20
  time; bad storms like Katrina hitting New Orleans(at six hundred =
miles), the=20
  demolishing of old buildings with wrecking balls (about 4 miles away), =
maybe=20
  even tornadoes (ten miles), the microcisms proceeding the first =
cold=20
  front in the Fall, bad local storms with wind and lightning(as far as =
100=20
  miles away), a local train that goes within about a mile of this =
location=20
  about twice a week about 9:30 pm local time and even local truck =
traffic like=20
  the trash pickup truck each week.  One that really had me fooled =
for=20
  about a week or so was a geologic team in the area using a machine to =
test=20
  soil liquifaction. It created "little" quakes which seemed to move -- =
and they=20
  did move, well anyway, the truck moved!! If you limit you observations =
to just=20
  earthquakes you will miss many interesting events and hopelessly =
stagnate and=20
  become a dull little boy -- and that is NOT what we want out of =
seismology is=20
  it?