scholarly journals Seismological constraints for the dyke emplacement of the July-August 2001 lateral eruption at Mt. Etna volcano, Italy

2013 ◽  
Vol 46 (4) ◽  
Author(s):  
Domenico Patanè ◽  
Eugenio Privitera ◽  
Stefano Gresta ◽  
Aybige Akinci ◽  
Salvatore Arpalone ◽  
...  
Keyword(s):  
Local Stress ◽  
Focal Mechanisms ◽  
Fracture System ◽  
Etna Volcano ◽  
Upward Migration ◽  
Mt Etna ◽  
Seismic Swarms ◽  
Earthquake Distribution ◽  
Volcanic Pile ◽  
Summit Region

In this paper we report seismological evidence regarding the emplacement of the dike that fed the July 18 - August 9, 2001 lateral eruption at Mt. Etna volcano. The shallow intrusion and the opening of the eruptive fracture system, which mostly occurred during July 12, and July 18, were accompanied by one of the most intense seismic swarms of the last 20 years. A total of 2694 earthquakes (1 £ Md £ 3.9) were recorded from the beginning of the swarm (July 12) to the end of the eruption (August 9). Seismicity shows the upward migration of the dike from the basement to the relatively thin volcanic pile. A clear hypocentral migration was observed, well constraining the upwards propagation of a near-vertical dike, oriented roughly N-S, and located a few kilometers south of the summit region. Earthquake distribution and orientation of the P-axes from focal mechanisms indicate that the swarm was caused by the local stress source related to the dike intrusion.

scholarly journals The geodynamics of Mt. Etna volcano during and after the 1984 eruption

1999 ◽  
Vol 42 (3) ◽  
Author(s):  
S. La Delfa ◽  
G. Patanè ◽  
C. Centamore
Keyword(s):  
Complex Stress ◽  
Focal Mechanisms ◽  
Combined Effects ◽  
Etna Volcano ◽  
Locking Mechanism ◽  
Mt Etna ◽  
Complex Stress Field ◽  
Seismic Networks ◽  
Tectonic Forces ◽  
The University

Data concerning M > 2.5 earthquakes that occurred at Mt. Etna volcano (Sicily, Italy) during the period April 15th - October 29th, 1984 are here presented and discussed. Only those events with reliable focal mechanisms (at least eight polarities) have been considered. Instrumental information comes from local seismic networks run by the University of Catania and the CNRS (Grenoble, France). The results obtained support the hypothesis that the seismicity and the volcanic activity at Mt. Etna are related to a complex stress field, due to the combined effects of the tectonics associated with the interaction between the African and Eurasian plates and the movement of magma into the crust. In particular, we hypothesize that the tectonic forces caused the end of the 1984 eruption, by means of a "locking mechanism".

scholarly journals Stress tensor computation from earthquake fault-plane solutions: an application to seismic swarms at Mt. Etna volcano (Italy)

1997 ◽  
Vol 40 (5) ◽  
Author(s):  
S. Gresta ◽  
C. Musumeci
Keyword(s):  
Stress Tensor ◽  
Fault Plane ◽  
Local Stress ◽  
Depth Range ◽  
Etna Volcano ◽  
Exact Methods ◽  
Fault Plane Solutions ◽  
Stress Regime ◽  
Mt Etna ◽  
Regional Tectonic

Fault-plane solutions of some tens of local earthquakes which occurred at Mt. Etna volcano during 1983-1986 have been inverted for stress tensor parameters by the algorithm of Gephart and Forsyth (1984). Three seismic sequences were focused on which respectively occurred during a flank eruption (June 1983), just after the end of a subterminal eruption (October 1984) and during an inter-eruptive period (May 1986). The application to the three sets of data of both the "approximate" and the "exact" methods evidenced the stability of results, and the stress directions are well defined in spite of the small number of events used for the inversion. The s1 obtained agrees with the regional tectonic framework, nearly horizontal and oriented N-S, only in the shallow crust, and just after the 1984 eruption. This supports the hypothesis of a tectonic control on the end of the eruptive activities at Mt. Etna. Conversely, results concerning the depth range 10-30 km are in apparent disagreement with other investigations (Cocina et al., 1997), as well as with the regional tectonics. The stress was here found homogeneous, but with s1 respectively trending ENE-WSW (June 1983) and E-W (May 1986). We suggest that the stress field could be temporarily modified by a local stress regime driven by the intrusion of uprising magma.

Dynamics of the 1989 fracture system and relations with the Etna eruptive activity of the last 30 years

2020 ◽  
Author(s):  
Salvatore Gambino ◽  
Giampiero Aiesi ◽  
Alessandro Bonforte ◽  
Giuseppe Brandi ◽  
Francesco Calvagna ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Potential Hazard ◽  
Fracture System ◽  
Monitoring Networks ◽  
Tectonic Structures ◽  
Distance Measurements ◽  
Effusive Activity ◽  
Mt Etna ◽  
Fracture Reactivation ◽  
Summit Region

<p>On September 11, 1989, after four months of Strombolian activity at the summit craters, effusive activity began on Mt. Etna and lasted about a month.</p><p>The 1989 eruption of Mt. Etna was characterized by the formation of two fracture systems, striking NE-SW and NNW-SSE, and both starting from the SE Crater on September, 24.</p><p>The NE-SW system was followed by effusive activity while the NNW-SSE fractures opened for a length of 7 km without eruptive phenomena. Between September, 27 and October, 3 the fracture system propagated until it reached and cut the SP 92 provincial road (Zafferana - Rifugio Sapienza), near the 1792 effusive mouth, and continued southward for another 700 m.</p><p>We investigated the fracture southern branch dynamics through 30 years of ground deformation data collected by the discrete and continuous INGV monitoring networks. We considered levelling, GPS, EDM, and extensometers data. EDM and levelling measurements began in the 80s; on 2003 EDM measurements have been replaced by GPS.</p><p>During the 1989 eruption, EDM measurements showed variations of tens of centimeters on the lines close to the fracture.</p><p>Precise levelling discrete measurements revealed, in the period 4-16 October 1989 and during the 1991-1993 eruption a subsidence of some centimeters on benchmarks close to fracture.</p><p>A network of rod extensometers evidenced the fracture activation during the 2001 intrusion phases (12-17 July) measuring several centimeters of left lateral slip. Distance measurements and InSAR show signs of the fracture reactivation during the 2002 and 2018 eruptions.</p><p>Several authors show as the 1989 fracture zone connects the summit region of the volcano with the tectonic structures of the lower SE flank considering it as well part of the NNW-SSE oriented structure.</p><p>The dynamics of these last 30 years suggests that the 1989 fracture play an important role on the flank dynamics and strain distribution. It also represents a potential hazard to population because it represents a possible way of ascending magma also testified by cones aligned along the structure.</p>

scholarly journals Finite element analysis of ground deformation due to dike intrusion with applications to Mt. Etna volcano

2009 ◽  
Vol 47 (5) ◽  
Author(s):  
A. Occhipinti Amato ◽  
M. Elia ◽  
A. Bonaccorso ◽  
G. La Rosa
Keyword(s):  
Ground Deformation ◽  
Near Field ◽  
Elastic Half Space ◽  
Etna Volcano ◽  
Element Analysis ◽  
Dike Intrusion ◽  
Dislocation Models ◽  
Mt Etna ◽  
Realistic Topography ◽  
2001 Eruption

A 2D finite elements study was carried out to analyse the effects caused by dike intrusion inside a heterogeneous medium and with a realistic topography of Mt. Etna volcano. Firstly, the method (dimension domain, elements type) was calibrated using plane strain models in elastic half-spaces; the results were compared with those obtained from analytical dislocation models. Then the effects caused both by the topographic variations and the presence of multi-layered medium on the surface, were studied. In particular, an application was then considered to Mt. Etna by taking into account the real topography and the stratification deduced from seismic tomography. In these conditions, the effects expected by the dike, employed to model the 2001 eruption under simple elastic half-space medium conditions, were computed, showing that topography is extremely important, at least in the near field.

scholarly journals Relationship between seismicity and eruptive activity at Mt. Etna volcano (Italy) as inferred from historical record analysis: the 1883 and 1971 case histories

1996 ◽  
Vol 39 (2) ◽  
Author(s):  
R. Azzaro ◽  
M. S. Barbano
Keyword(s):  
Seismic Activity ◽  
Historical Record ◽  
Effusion Rate ◽  
Etna Volcano ◽  
Case Histories ◽  
Seismic Behaviour ◽  
Volcanic System ◽  
Prolonged Duration ◽  
Mt Etna ◽  
A Minor

In this paper historical and recent seismological data are analysed in order to investigate the relationship between seismicity and eruptive phenomena at Mt. Etna volcano. The 1883 and 1971 case histories have been proposed because they are significant events in the recent history of the volcano regarding volcanic hazard and show very different evolutions of associated seismic activity and eruption dynamics. The first (1883) represents flank eruptions characterised by high seismic release, short duration and moderate effusion rate whereas the second (1971) can be ascribed to eruptions starting as summit or subterminal events and thereafter developing on the flanks with a minor level of seismicity, higher effusion rate and prolonged duration. The pattern of seismic activity during 1883 and 1971, as inferred from historical record analysis, and the different associated type of eruption may be a result of diverse stress conditions acting on the volcanic system. The interpretation of the seismic behaviour by considering historical eruptions in a systematic fashion will contribute to a clearer understanding of volcanic phenomena at Mt. Etna.

scholarly journals Isochronal maps at Mt. Etna volcano (Italy): a simple and reliable tool for investigating large-scale heterogeneities

1997 ◽  
Vol 40 (5) ◽  
Author(s):  
G. Patanè ◽  
C. Centamore ◽  
S. La Delfa
Keyword(s):  
Large Scale ◽  
Volcanic Edifice ◽  
P Wave ◽  
Etna Volcano ◽  
Low Velocity ◽  
Seismic Stations ◽  
Arrival Times ◽  
Mt Etna ◽  
Wave Arrival ◽  
Feeding Systems

This paper analyses twelve etnean earthquakes which occurred at various depths and recorded at least by eleven stations. The seismic stations span a wide part of the volcanic edifice; therefore each set of direct P-wave arrival times at these stations can be considered appropriate for tracing isochronal curves. Using this simple methodology and the results obtained by previous studies the authors make a reconstruction of the geometry of the bodies inside the crust beneath Mt. Etna. These bodies are interpreted as a set of cooled magmatic masses, delimited by low-velocity discontinuities which can be considered, at present, the major feeding systems of the volcano.

A reappraisal of seismic Q evaluated at Mt. Etna volcano. Receipt for the application to risk analysis

2014 ◽  
Vol 19 (1) ◽  
pp. 105-119 ◽  
Author(s):  
Edoardo Del Pezzo ◽  
Francesca Bianco ◽  
Elisabetta Giampiccolo ◽  
Giuseppina Tusa ◽  
Tiziana Tuvé
Keyword(s):  
Risk Analysis ◽  
Etna Volcano ◽  
Mt Etna

Deploying and operating an Absolute Quantum Gravimeter on the summit of Mount Etna volcano

2021 ◽  
Author(s):  
Daniele Carbone ◽  
Laura Antoni-Micollier ◽  
Filippo Greco ◽  
Jean Lautier-Gaud ◽  
Danilo Contrafatto ◽  
...  
Keyword(s):  
Gravity Data ◽  
Volcanic Tremor ◽  
Mount Etna ◽  
Quality Data ◽  
Etna Volcano ◽  
High Quality ◽  
Absolute Gravimetry ◽  
Superconducting Gravimeters ◽  
Mt Etna ◽  
Absolute Quantum

<p>The NEWTON-g project [1] proposes a paradigm shift in terrain gravimetry to overcome the limitations imposed by currently available instrumentation. The project targets the development of an innovative gravity imager and the field-test of the new instrumentation through the deployment at Mount Etna volcano (Italy). The gravity imager consists in an array of MEMS-based relative gravimeters anchored on an Absolute Quantum Gravimeter [2].<br>The Absolute Quantum Gravimeter (AQG) is an industry-grade gravimeter measuring g with laser-cooled atoms [3]. Within the NEWTON-g project, an enhanced version of the AQG (AQGB03) has been developed, which is able to produce high-quality data against strong volcanic tremor at the installation site.<br>After reviewing the key principles of the AQG, we present the deployment of the AQGB03 at the Pizzi Deneri (PDN) Volcanological Observatory (North flank of Mt. Etna; 2800 m elevation; 2.5 km from the summit active craters), which was completed in summer 2020. We then show the demonstrated measurement performances of the AQG, in terms of sensitivity and stability. In particular, we report on a reproducible sensitivity to gravity at a level of 1 μGal, even during intense volcanic activity.<br>We also discuss how the time series acquired by AQGB03 at PDN compares with measurements from superconducting gravimeters already installed at Mount Etna. In particular, the significant  correlation with gravity data collected at sites 5 to 9 km away from PDN proves that effects due to bulk mass sources, likely related to volcanic processes, are predominant over possible local and/or instrumental artifacts.<br>This work demonstrates the feasibility to operate a free-falling quantum gravimeter in the field, both as a transportable turn-key device and as a drift-free monitoring device, able to provide high-quality continuous measurements under harsh environmental conditions. It paves the way to a wider use of absolute gravimetry for geophysical monitoring.</p><p>[1] www.newton-g.com</p><p>[2] D. Carbone et al., “The NEWTON-g Gravity Imager: Toward New Paradigms for Terrain Gravimetry”, Front. Earth Sci. 8:573396 (2020)</p><p>[3] V. Ménoret et al., "Gravity measurements below 10−9 g with a transportable absolute quantum gravimeter", Nature Scientific Reports, vol. 8, 12300 (2018)</p>

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