Analysis of Frequency Spectrum, Waveform Cross Correlation and Polarization to Mount Sinabung Tremor during October-November 2013 Qori Fajar Hermawan (a*), Sukir Maryanto (b), Hendra Gunawan (c)
(a) Faculty of Mathematics and Natural Sciences, Mulawarman University
Jalan Barong Tongkok No. 04, Kampus Gunung Kelua, Samarinda, East Kalimantan, 75123
*qorifajarhermawan[at]fmipa.unmul.ac.id
(b) Faculty of Mathematics and Natural Sciences, Brawijaya University
Jalan Veteran, Malang, East Java, 65145
(c) Center for Volcanology and Geological Hazard Mitigation (CVGHM)
Jalan Diponegoro No. 57, Bandung, West Java, 40122
Abstract
Mount Sinabung is an active volcano in North Sumatra Province and showed the eruption activity in 2013. The activity of this volcano could be observed by the seismometers surrounding it. The tremor signal could be observed in the October to November 2013 and it has not been studied before. This study was conducted to analysis the characteristic of Mount Sinabung tremor in the period from October to November 2013 based on the analysis of the frequency spectrum, waveform cross-correlation and polarization. We found 260 data of Mount Sinabung tremor during October to November 2013. The result of frequency spectrum analysis indicated that Mount Sinabung tremors had a wide frequency value, with a value of 0 to 25 Hz and dominant frequency is 1 to 3 Hz. Based on the shape of the frequency spectrum, Mount Sinabung tremor could be distinguished into two types namely, harmonic and nonharmonic tremor. The result of waveform cross correlation analysis showed correlation coefficient values were good enough, from 0.5 to 0.9. The highest correlation value of waveform cross correlation analysis showed the eruption activity on 8 November 2013. Based on the analysis of polarization, tremor source was in the South crater or East-Southeast or 90 degrees to 120 degrees from Station Mardingding. The depth of the tremor source is ranging 0.5 below sea level to 2.4 km above sea level.
Keywords: tremor, Mount Sinabung, frequency spectrum, waveform cross-correlation, polarization
