Hi Randy- A comment on Trains:
I record back-ground noise to compute Shear wave velocities with the Ref=
raction Microtremor method-ReMi, MASW is another popular method used by =
geotechnical engineers to do the same.

As you know we have RR tracks running thru Las Vegas and I find the trai=
ns produce Surface waves (Mostly Rayleigh which has a large vertical com=
ponent) better than any other man made Seismic Noise


Jim O'Donnell BC-Geophysics =

Geophysical Consultant/Contractor
Geotechnical/Geothermal/Oil & Gas/Mining Applications
Seismic Surveys- Surface Waves, Refraction, & Reflection
Ground Penetrating Radar, Resistivity, Magnetic, & VLF-EM Surveys
Geophysics@..........  702.293.5664  702.281.9081 cell   =

Boulder City, NV


---------- Original Message ----------
From: "Randall Pratt" 
To: 
Subject: Re: Human Seismic Activity
Date: Thu, 3 Feb 2011 08:53:09 -0600

Hi,
 =

I would suspect railroad traffic sequenced along a track.  During the ni=
ght when other traffic is quiet you may see the railroad from farther di=
stance.  In my location the noise builds and then decays over several mi=
nutes.  I don=92t see one every hour but there is a daily schedule that =
shows up and when the wind is right I hear the whistle to verify.  =

 =

Randy
Hi Randy- A comment on Trains:
I record back-g=
round noise to compute Shear wave velocities with the Refraction Microtr=
emor method-ReMi, MASW is another popular method used by geotechnical en=
gineers to do the same.

As you know we have RR tracks running thr=
u Las Vegas and I find the trains produce Surface waves (Mostly Rayleigh=
 which has a large vertical component) better than any other man made Se=
ismic Noise


Jim O'Donnell BC-Geophysics 
=
Geophysical Consultant/Contractor
Geotechnical/Geothermal/Oil & G=
as/Mining Applications
Seismic Surveys- Surface Waves, Refraction, &a=
mp; Reflection
Ground Penetrating Radar, Resistivity, Magnetic, &=
 VLF-EM Surveys
Geophysics@..........  702.293.5664  702.28=
1.9081 cell   
Boulder City, NV


---------- Origi=
nal Message ----------
From: "Randall Pratt" <rpratt@..............
>
To: <psnlist@..............>
Subject: Re: Human Seismic=
 Activity
Date: Thu, 3 Feb 2011 08:53:09 -0600



Hi,
 
I would suspect railroad traffic sequenced =
along a track.  During the night when other traffic is quiet you ma=
y see the railroad from farther distance.  In my location the noise=
 builds and then decays over several minutes.  I don=92t see one ev=
ery hour but there is a daily schedule that shows up and when the wind i=
s right I hear the whistle to verify.  
 
Randy