Plans to build electricity generating windturbines in the immediate vicinity of our observatory have led us to evaluate the influence of windturbines on seismic background noise levels. The poster (Postscript, 83 Mb), compressed poster (bzip2, 19 Mb), or the PDF poster (2.1 Mb) (presented at the annual meeting of the German geophysical society in Berlin in March 2004) summarizes our findings.
Signal attenuation with increasing distance from the windmill is shown in figure 7 of the poster. For selected frequencies with high coherency the fall-off is shown in fig. 8: vertical component at 12 Hz (fig. 8a, 170kB PostScript) , radial component at 9.5 Hz (fig. 8b, 170kB PostScript) , radial component at 2.5 Hz (fig 8c, 170kB PostScript) , transverse component at 2.5 Hz (fig 8d, 170kB PostScript) .
The observation, that already now, we are limited in our ability to detect high-frequency teleseismic signals by industrial noise from the nearby industry (4.7 Mb pdf) is an important piece of evidence in our line of arguments (note the reduced noise levels during lunch break from 11-12 UT or 12:00 - 13:00 local time). The same figure with a figure caption in German is here (119 MB compressed PostScript).
Three component sonogram of industrial noise recorded with the STS-2 at BFO is here (349 kB PostScript).
Signal decay with separation from a wind turbine is inspected here (168 kB PostScript).