The background seismic noise in Venezuela has been studied using broadband stations of the Red Sismológica Satelital Nacional (RSSN) (Netcode VE), including stations AS117 and AS118 of the auxiliary network of the IMS. To calculate the most representative values of noise at a given period, the method proposed by McNamara and Buland (2004) has been applied.
For periods lower than 1 s, the AS118 station shows values of -131.5 dB, while AS117 shows values of -121.5 dB. This 10 dB difference is attributed to the continuous discharge of water from the dam where AS117 is installed. For periods longer than 30 s, the vertical component of AS117 presents noise values close to the NLNM proposed by Peterson (1993), while the horizontal components present a sharp increase in noise values. The exact opposite behavior occurs in station AS118.
An interpolation of the noise values was generated in the range 4 - 8 s (double frequency peak) where high noise values were observed in basins and low values in mountain ranges.
The results obtained are important for studying the behaviour of the stations and detecting equipment failures. In addition, we show the behaviour of noise sources in Venezuela.
The results obtained in this study are important to understand the behavior of the IMS seismic stations in Venezuela. This study uncovers important information for the analysis of background noise collected by this auxiliary sensors.