Seismic noise analysis of broadband stations in the Eastern Ghat Mobile Belt of India using power spectral density

摘要

ABSTRACT The seismic background noise is studied at newly constructed sites of the Eastern Ghat Mobile Belts (EGMB), in Orissa. Ten broadband stations have been deployed along two profiles. The area has not been previously attempted for any broadband experiment. To assess the performance of the stations, we investigate the characteristics of different types of noises dominated at those sites. The power spectral densities of ambient background noise for each site are calculated and compared with the global noise model. The results suggest that the noise levels at all stations that belong to profile-1 are within the global high and low bounds. Along profile-2, the station PATN stabilizes after some time post-deployment while noise levels at other two stations are within the proposed limits. Results show that profile-1 is predominated by cultural noise, and the microseismic noise levels are observed to be low in both the profiles. Assessment of the temporal and seasonal variation of the noise has also been done, along with the calculation of the power spectral densities in the East and North components of the seismometer for this station. Overall, our observations suggest that installation of the seismometers have been successful in all the sites.