Location of seismic events and eruptive fissures on the Piton de la Fournaise volcano using seismic amplitudes

Abstract

[1] We present a method for locating the source of seismic events on Piton de la Fournaise. The method is based on seismic amplitudes corrected for station site effects using coda site amplification factors. Once corrected, the spatial distribution of amplitudes shows smooth and simple contours for many types of events, including rockfalls, long-period events and eruption tremor. On the basis of the simplicity of these distributions we develop inversion methods for locating their origins. To achieve this, the decrease of the amplitude as a function of the distance to the source is approximated by the decay either of surface or body waves in a homogeneous medium. The method is effective for locating rockfalls, longperiod events, and eruption tremor sources. The sources of eruption tremor are usually found to be located at shallow depth and close to the eruptive fissures. Because of this, our method is a useful tool for locating fissures at the beginning of eruptions. Citation: Battaglia, J., and K. Aki, Location of seismic events and eruptive fissures on the Piton de la Fournaise volcano using seismic amplitudes,

Site effect determination using seismic noise from Tungurahua volcano (Ecuador): implications for seismo-acoustic analysis

“…12). The best locations were obtained with Q = 40.6 (0.4-4.0 Hz), which is comparable to Q values used in other volcanic regions, for instance Q = 50 (3 and 7.5 Hz) for Piton de la Fournaise volcano (Battaglia & Aki 2003), Q = 60 (5-12 Hz) for Cotopaxi and Tungurahua volcanoes (Kumagai et al 2010), and Q = 60 (7-12 Hz) for Taal volcano (Kumagai et al 2013). The cluster appears beneath the north-western flank, but the locations might be influenced by the lack of azimuthal coverage of the July-August 2006 seismic network.…”

“…Based on this interpretation Kumagai et al (2010), studying Cotopaxi and Tungurahua volcanoes, justifies the use of frequencies 5-12 Hz to get better seismic source locations. Similarly, Battaglia & Aki (2003) studying Piton de la Fournaise volcano, found that the best source locations were obtained by filtering the signals in 5-10 Hz. Although scattering is one of the physical processes expected in a heterogeneous medium, we propose a complementary physical interpretation.…”

“…Therefore, our site correction applies across a broad frequency range, minimizing site effects and taking into account several physical processes. It is worth noting that Battaglia & Aki (2003) and Kumagai et al (2010) used a common frequency band for all stations to obtain the source locations. However, we use non common bands, because we interpret each one as a site property that defines each site FRF.…”

Distinguishing high surf from volcanic long‐period earthquakes

“…seismic and infrasound amplitudes across the local network provide a metric to compare activity levels through time and obtain some information about source locations [e.g., Battaglia and Aki, 2003]. In order to compare the amount of LP energy from the swarm across the network to preswarm and postswarm values, we calculate the root-mean-square (RMS) spectral energy in 20 min, nonoverlapping windows for the entire month of October 2013.…”

The Q-factor of the crust of the central Baikal Rift Zone, according to the stations' Huramsha "and" Fofonovo "

“…Согласно модели, предложенной Battaglia и Aki [4], интенсивность сейсмической волны, распространяющейся в геологической среде, уменьшается с расстоянием по закону…”