Shallow velocity model in the area of Pozzo Pitarrone, Mt. Etna, from single station, array methods and borehole data

Abstract

<p>Seismic noise recorded by a temporary array installed around Pozzo Pitarrone, NE flank of Mt. Etna, have been analysed with several techniques. Single station HVSR method and SPAC array method have been applied to stationary seismic noise to investigate the local shallow structure. The inversion of dispersion curves produced a shear wave velocity model of the area reliable down to depth of about 130 m. A comparison of such model with the stratigraphic information available for the investigated area shows a good qualitative agreement. Taking advantage of a borehole station installed at 130 m depth, we could estimate also the P-wave velocity by comparing the borehole recordings of local earthquakes with the same event recorded at surface. Further insight on the P-wave velocity in the upper 130 m layer comes from the surface reflected wave observable in some cases at the borehole station. From this analysis we obtained an average P-wave velocity of about 1.2 km/s, compatible with the shear wave velocity found from the analysis of seismic noise.</p>

Performance of a Rotational Sensor to Decipher Volcano Seismic Signals on Etna, Italy

“…found shear velocities below 400-450 m/s for depths down to 60 m and around 600-700 m/s at depths between 60 and 130 m for a halfspace and a vp/vs ratio of 2. The velocities resolved byZuccarello et al (2016) are lower than the ones byBean et al (2014) and consistent with the here estimated seismic wave velocities for LP events.…”

“…Zuccarello et al. (2016) found shear velocities below 400–450 m/s for depths down to 60 m and around 600–700 m/s at depths between 60 and 130 m for a halfspace and a vp/vs ratio of 2. The velocities resolved by Zuccarello et al.…”

“…Scattering in the wavefield of VT events might result from small-scale structures, which have stronger impact on high frequencies (Yuan et al, 2020) and are likely to be present at a volcano. Zuccarello et al (2016) for example, reported that the mechanical properties of the uppermost few hundred meters of rock in volcanic environments such as Mount Etna vary strongly. The sensors were installed in a plane area near Pizzi Deneri filled with unconsolidated pyroclastic material.…”

“…reported values of 1,000 m/s on Etna Bean et al (2014). mentioned P-wave velocities of 1.8 km/s in the top 800 m, which results in Rayleigh wave velocities of 855 m/s Zuccarello et al (2016). found shear velocities below 400-450 m/s for depths down to 60 m and around 600-700 m/s at depths between 60 and 130 m for a halfspace and a vp/vs ratio of 2.…”

Shallow Magma Storage Beneath Mt. Etna: Evidence From New Attenuation Tomography and Existing Velocity Models

“…This is confirmed by previous shallow velocity models of Mt. Etna performed based on correlations of ambient seismic noise using a dense seismic array and a borehole (Zuccarello et al., 2016). This type of analysis is common in volcanic areas where the use of seismic arrays is available (e.g., Luzón et al., 2011).…”