Data Services Newsletter

Volume 6 : No 3 : December 2004

GSN Station Noise Computation

In early 2003, the two Global Seismic Network operators conducted a study of current noise levels at GSN stations to aid the community in its effort to create appropriate specifications for the next generation of GSN instrumentation and to evaluate the need for STS1 sensors at locations where background noise levels are comparatively high. Initial results from this work suggested that the prevailing model of global seismic noise published by Jon Peterson of the USGS in 1993 was badly in need of revision. A vast wealth of high quality, digital data had been collected since Peterson’s time, so a much more robust statistical analysis of prevailing noise levels could be undertaken.

This study is now complete and the results, including a new noise model, will appear shortly in The Journal of Geophysical Research. The data set covers a wider frequency band than was considered in 2003 and incorporates all GSN stations operating during the time period of the 2003 study. For future reference, plots of the background noise at individual GSN stations as well as a pre-print of the paper can be found at:

http://ida.ucsd.edu/Noise_Study/noisestudy.html

GSN 1st-percentile noise plotted by sensor
Figure 1: GSN 1st-percentile noise plotted by sensor. (Reproduced from the JGR article)

References

Berger, J., Davis, P., and Ekström, G. (2004) Ambient Earth noise: A survey of the Global Seismographic Network, J. Geophys. Research, 109, B11307, doi:10.1029/2004JB003408.
Peterson, J. (1993) Observations and Modeling of Seismic Background Noise, USGS Open-File Report 93-322, U. S. Geological Survey, Albuquerque, New Mexico.

by Pete Davis (IRIS/IDA)

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