Continuous dynamic response along a pre-existing structural discontinuity induced by the 2001 eruption at Mt. Etna

Gambino, Salvatore

doi:10.1186/bf03352497

Cited by 17 publications

(11 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In particular, high V p anomaly in the velocity structure (Patanè et al 2002), low Q p (Martinez-Arevalo et al 2005) and negative gravity anomaly (Carbone et al 2003) have been observed in the sector Z2. Moreover, ground deformations observed by GPS (Bonforte et al 2004) show a pattern compatible with a dyke intrusion, and extensometer data (Gambino 2004) collected slightly east of Z2, highlight ground movements that are in agreement with the mechanism proposed here.…”

Section: R E S U Lt S a N D Discussionsupporting

confidence: 87%

“…Etna volcano. The main feeding mechanism just described is consistent with almost all the observations made, but seismic activity (Patanè et al 2002;Musumeci et al 2004), gravity observations (Carbone et al 2003), GPS measurements (Bonforte et al 2004) and extensometer data (Gambino 2004) highlight a complex behaviour that cannot be explained by one simple intrusion mechanism, because all the geophysical information also points to important phenomena in a volume located 2-3 km SE from the eruptive scenario.…”

Section: Introductionsupporting

confidence: 79%

See 1 more Smart Citation

The dynamics of the 2001 Etna eruption as seen by full moment tensor analysis

Saraò

Cocina

Privitera

et al. 2010

Geophysical Journal International

View full text Add to dashboard Cite

The Mt. Etna eruption of July 2001 was announced by severe seismic activity and by the opening of a 7-km-long zone of densely distributed fractures. The large amount of data collected gave a unique opportunity to study the magma migration process and to infer the position and geometry of the uprising dyke. Results from multidisciplinary approaches suggest that the observed phenomenology was the result of the rapid intrusion of a vertical dyke, oriented roughly N–S and located a few km south of the summit region.\ud To add new constraints to the dynamics of the eruption process, in this study we determine the full seismic moment tensors of 61 earthquakes, selected among those occurring between July 12 and July 18 (Md ≥ 2.2), located in a depth ranging from 1 km above sea level (a.s.l.) to 3 km below sea level (b.s.l.).\ud At the beginning of the seismic swarm, the dominant component of the seismic source tensor is double-couple percentage (around 65 per cent on average) statistical significant at 95 per cent confidence level and in the following hours the non-double-couple components increase at the expenses of the double-couple. Such observations are related well with the system of fractures formed just before the eruption, whereas the increasing non-double-couple components can be explained as the response of the confining rocks to the rising magma and degassing processes.\ud The type of focal mechanisms retrieved are predominantly of normal fault type (44 per cent), strike slip (30 per cent) and thrust mechanisms (9 per cent), and outline a scenario that concurs with the stress regime induced by a dyke injection.\ud The space–time analysis of seismic source locations and source moment tensors (1) confirms the evidence of a vertical dyke emplacement that fed the 2001 lateral eruption and (2) adds new insights to support the hypothesis of the injection of a second aborted dyke, 2 km SE from the fractures zone

show abstract

Section: R E S U Lt S a N D Discussionsupporting

confidence: 87%

Section: Introductionsupporting

confidence: 79%

The dynamics of the 2001 Etna eruption as seen by full moment tensor analysis

Saraò

Cocina

Privitera

et al. 2010

Geophysical Journal International

View full text Add to dashboard Cite

show abstract

“…Later on (in terms of weeks or months) the cumulated stress was released, and the ground deformation propagated to the eastern periphery of the volcano. The propagation started from the upper southeastern flank, along a NNW‐SSE fault near the intrusive dike, as already detected early during the intrusion [ Gambino , 2004] and during the first days of the eruption by Bonforte et al [2004].…”

Section: Discussionmentioning

confidence: 84%

Dynamics of Mount Etna before, during, and after the July–August 2001 eruption inferred from GPS and differential synthetic aperture radar interferometry data

et al. 2008

View full text Add to dashboard Cite

Ground deformation data from GPS and differential synthetic aperture radar interferometry (DInSAR) techniques are analyzed to study the July–August 2001 Mount Etna eruption as well as the dynamics preceding and following this event. Five GPS surveys were carried out on the entire Mount Etna network or on its southeastern part, from July 2000 to October 2001. Five ERS-2 ascending passes and three descending ones are used to form five interferograms spanning periods from a month to 1 year, before and encompassing the eruption. Numerical and analytical inversions of the GPS and DInSAR data were performed to obtain analytical models for preeruptive, syneruptive and posteruptive periods. The deformation sources obtained were from the Mogi model: (1) pressure sources located beneath the upper western flank of the volcano, inflating before the eruption onset and deflating afterward; (2) tensile dislocations to model the intrusion of a N-S dike in the central part of the volcano; and (3) two sliding and two normal dislocations to model the eastern and southern flank dynamics. This study confirms that the lower vents of the eruption were fed by a magma stored at depth ranging from 9 to 4 km below sea level, as proposed from petrochemical and geophysical researches. The rising of the magma through the shallow crust started months before the eruption onset but accelerated on the last day; this study suggests that in the volcanic pile the path of the rising magma was driven by the volcano topography. The eastern sliding plane and the interaction between dike intrusion and flank instability have been better defined with respect to previous studies. The sliding motion abruptly accelerated with the dike intrusion, and this continued after the end of the eruption. The acceleration was accompanied by the propagation of the strain field toward the eastern periphery of the volcano

show abstract

“…Effusive activity started in the late evening of 17 July due to the intrusion of a vertical dike [e.g., Acocella and Neri , 2003; Behncke and Neri , 2003]. Field measurements [ Billi et al , 2003; Lanzafame et al , 2003] along with ground deformation and seismic data [e.g., Gambino , 2004] documented the dynamic response of the NNW–SSE system during the final stage of the dike intrusion.…”

Section: Introductionmentioning

confidence: 99%

Effects of the 1989 fracture system in the dynamics of the upper SE flank of Etna revealed by volcanic tremor data: The missing link?

et al. 2010

View full text Add to dashboard Cite

[1] Fracture reactivation is a widespread process in nature even though evidence of magma-induced reactivation is less documented. Here we provide evidence of the reactivation of a fracture system on the upper flank of the Mt. Etna volcano and consider its possible implications in understanding the recent volcanic and tectonic activity. A NNW-SSE trending fracture, partly accompanied by magma emplacement in the form of a laterally propagating dike, formed in 1989 on the upper SE flank of Etna. Lava effusions in 1991-1993, 2001, and 2006 were associated with volcano-tectonic (VT) seismicity and ground deformations on the upper part of the volcano, which document the seismogenetic involvement of the 1989 fractures, although without eruptive phenomena along the discontinuity. In addition to the aforementioned episodes of VT seismicity, differences in the characteristics of the background seismic radiation (volcanic tremor) were measured at stations close to these fractures during the eruptive activity on 24 November 2006, for which more detailed volcanological and seismological time histories are available. Moving on from these findings, we analyze volcanic tremor data recorded close to the summit and along the S flank of the volcano to highlight the interactions between seismic radiation and the 1989 fracture system. Centroid location of volcanic tremor and wave field characteristics at stations of the permanent local seismic network of Etna highlight the guidance role played by the 1989 fractures during the eruptive activity on 24 November 2006. In addition, the collected data shed light on hitherto unknown structural features, which appear to connect the volcano summit to the lower SE slope and also play an important role in controlling the instability of the E flank. More generally, this study shows how (1) using an integrated approach, it is possible to link apparently different features to a common structure, showing uniform and distinct dynamics relevant at the volcano scale, and (2) fracture reactivation can also occur by means of magma intrusion, playing an important role in the transfer of magma within a volcanic edifice.Citation: Falsaperla, S., F. Cara, A. Rovelli, M. Neri, B. Behncke, and V. Acocella (2010), Effects of the 1989 fracture system in the dynamics of the upper SE flank of Etna revealed by volcanic tremor data: The missing link?,

show abstract

Continuous dynamic response along a pre-existing structural discontinuity induced by the 2001 eruption at Mt. Etna

Cited by 17 publications

References 25 publications

The dynamics of the 2001 Etna eruption as seen by full moment tensor analysis

The dynamics of the 2001 Etna eruption as seen by full moment tensor analysis

Dynamics of Mount Etna before, during, and after the July–August 2001 eruption inferred from GPS and differential synthetic aperture radar interferometry data

Effects of the 1989 fracture system in the dynamics of the upper SE flank of Etna revealed by volcanic tremor data: The missing link?

Contact Info

Product

Resources

About