Insights into the dynamic processes of the 2007 Stromboli eruption and possible meteorological influences on the magmatic system

Abstract

The unrest of Stromboli volcano leading to the February 27–April 2, 2007 eruptive period and to the March 15 paroxysm is constrained by combining broad‐band seismic data and 1‐Hz GPS (High Rate GPS – hereinafter HRGPS) measurements. During the pre‐eruptive stage, the simultaneous examination of seismic and HRGPS data, together with weather parameters, suggests the possible influence of external perturbations on the magmatic system, which evolved toward a critical state after January 2007. Some days after the onset of the eruption, a sudden change of the seismic and eruptive behaviour was recognized, while ground deformation began to show a deflation. The March 15 paroxysm was preceded, about two days before, by a peak of the HRGPS spectral power densities (a small inflation) and by the occurrence of a few VT earthquakes located at depths down to 3.5 km b.s.l. These findings constrain, for the first time at Stromboli volcano, the deep origin of a fast rising magma batch, rich in gas, that led to a strong explosive event.

Statistical analysis of the volcano seismicity during the 2007 crisis of Stromboli, Italy

“…The four signals are characterized by frequencies in specific ratios and with a clear radial polarization, supporting the results of previous works revealing the presence of P waves [see, e.g., Falsaperla et al , 1998, 2002; De Lauro et al , 2008]. The lowest band (0.1–0.5 Hz) with a characteristic peak close to 0.3 Hz contains the best polarized signal, sometimes masked by contributes coming from oceanic microseismic noise [ De Lauro et al , 2005, 2006; Patanè et al , 2007], whereas scattering prevails at higher frequencies.…”

Stromboli 2007 eruption: Deflation modeling to infer shallow‐intermediate plumbing system

“…The modelled source would represent the connection between the deeper LP magma source and the shallower HP magma source. It is worth noting that the depressurizing source is located above the hypocenters of the volcano‐tectonic earthquakes that preceded, about two days before, the major 15 March explosion, in coincidence with the small inflation detected by the GPS network [ Patanè et al , 2007].…”

Eos, Transactions, American Geophysical Union Volume 89, Number 30, 22 July 2008

“…Beginning on 27 February 2007, Stromboli volcano again underwent an eruption. On 15 March 2007, a major explosion occurred, heralded about 2 days prior by signifi cant variations in high-rate (1 hertz) GPS spectral power densities and the occurrence of shallow volcanotectonic earthquakes [Patanè et al, 2007]. Although still preliminary, the tomographic images obtained provide a fi rst innovative view of the P velocity structure of Stromboli volcano, which will be very useful for the precise localization of the seismicity affecting this volcano.…”