TINGKAT DAN KARAKTER DERAU SEISMIK DI PULAU BANGKA BERDASARKAN REKAMAN SEISMOMETER BROADBAND TIGA KOMPONEN; SEISMIC NOISE LEVELS AND CHARACTERS IN THE BANGKA ISLAND RECORDED BY THREE COMPONENTS BROADBAND SEISMIOMETER

UTARI, MELFA, Wiwit Suryanto

2016 | Disertasi | FMIPA

The purpose of the reaserch have been done to calculate the seismic noise levels, to evaluate the characters of the seismic noise sources, and to calculate seismic noise levels to daily variations, seasonal variations, and spatial variations in the Bangka Island. The result of this research are expected to contribute on the performance of each seismic station in the Bangka Island. The data used in this research is data by recorded three components broadband seismometer in 10 stations, 8 stations in the Bangka Island and 2 stations in the South Sumatera. Seismic noise levels in the Bangka Island is calculated by using the Power Spectral Density (PSD). Futhermore, the probability of PSD variation is calculated using the Probability Density Fuction (PDF). Through PDF appearance will be easier to analyze the quality of available data and to evaluate the characters of the seismic noise sources at certain periods in each component stations. Based of the analysis result showed that seismic noise levels for all components in short periods (0.1 – 1 second) located between new low noise model (NLNM) and new high noise model (NHNM), that shows a good condition of all stations in short periods, except SLN station located in top NHNM. Seismic noise levels in short periods associated with cultural noise caused by human activities and increased during the day. While seismic noise levels in microseismic periods ( 4 – 16 second) and long periods (> 20 second) located above NHNM. This is caused by frequency response of the seismometer only up to 0.5 Hz or only up to 5 second so seismic noise levels in microseismic period and long periods can not be interpreted properly.

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