Preliminary Result of Rayleigh Wave Tomography beneath Jailolo Volcanic Complex, North Moluccas, Indonesia using Ambient Noise
Aprilia Nur Vita(a*)(c), Zulfakriza(b), Andri Dian Nugraha(b) Agustya Adi Martha(c), Supriyanto Rohadi(c), Nova Heryandoko(c), Claus Milkerreit(d)

(a)Master Program of Earth Sciences, Faculty of Earth Sciences and Technology, Institut Teknologi Bandung, Bandung, Indonesia.
*aprilia.nurvita[at]gmail.com
(b)Global Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Bandung, Indonesia.
(c)Agency of Meteorology, Climatology, and Geophysics (BMKG), Jakarta, Indonesia.
(d)German Research Centre for Geoscience (GFZ), Postdam, German.

Abstract

Abstract. In November 2015 to February 2016, seismic swarm activity occurred around Jailolo volcano, a long dormant and few studied of volcano that located on Halmahera Island, North Moluccas, Indonesia. We perform seismic ambient noise tomography method to delineate the sub surface seismic structure beneath Jailolo volcanic complex. We use vertical component of seismogram data retrieved from 29 temporary short-period seismic stations of 7G Seismic Network in January to March 2017 observation. The 7G Seismic Network was collaboration research between Indonesia Agency of Meteorology, Climatology and Geophysics (BMKG), Indonesia and German Research Centre for Geoscience (GFZ). We cross correlated vertical component of pair stations to estimated Green^s function of Rayleigh wave. More than 350 of group velocity were estimated. We measure the dispersion characteristic of Rayleigh wave group velocity by applied frequency time analysis (FTAN) technique. We compare Green Function and the dispersion curve by applied different bandpass filter. The Green Function of Rayleigh wave is clearly seen in causal and/or acausal part by applied 0.01-0.5 Hz band-pass filter and then dispersion curve is picked within 2-10 s. The Rayleigh group velocities average is 0.6-0.9 km/s

Keywords: Jailolo, Halmahera, Indonesia, swarm earthquake, Rayleigh wave, ambient noise tomography

Topic: Earth and Planetary Sciences