mt etna
Recently Published Documents


TOTAL DOCUMENTS

803
(FIVE YEARS 154)

H-INDEX

57
(FIVE YEARS 6)

Geosciences ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 9
Author(s):  
Fabio L. Bonali ◽  
Elena Russo ◽  
Fabio Vitello ◽  
Varvara Antoniou ◽  
Fabio Marchese ◽  
...  

Immersive virtual reality can potentially open up interesting geological sites to students, academics and others who may not have had the opportunity to visit such sites previously. We study how users perceive the usefulness of an immersive virtual reality approach applied to Earth Sciences teaching and communication. During nine immersive virtual reality-based events held in 2018 and 2019 in various locations (Vienna in Austria, Milan and Catania in Italy, Santorini in Greece), a large number of visitors had the opportunity to navigate, in immersive mode, across geological landscapes reconstructed by cutting-edge, unmanned aerial system-based photogrammetry techniques. The reconstructed virtual geological environments are specifically chosen virtual geosites, from Santorini (Greece), the North Volcanic Zone (Iceland), and Mt. Etna (Italy). Following the user experiences, we collected 459 questionnaires, with a large spread in participant age and cultural background. We find that the majority of respondents would be willing to repeat the immersive virtual reality experience, and importantly, most of the students and Earth Science academics who took part in the navigation confirmed the usefulness of this approach for geo-education purposes.


2021 ◽  
Author(s):  
John Murray

The influence of faulting on the eruptive mechanisms of Mt Etna has been intensively studied, especially regarding the importance of regional tectonics, magma pressure, gravitational spreading and east flank instability. Here we examine the influence of an additional process: the wholesale sliding of the Etna massif along its sloping basement. Using laboratory analogue experiments, we create a series of model volcanoes on sloping basements, with obstructions to represent the mountains and hills surrounding Etna, and an unconstrained downslope edge to represent the unbuttressed seaward slopes. We find that analogues of all the Etna fault systems can be produced in the same model. Furthermore, we find that the relative velocities of transcurrent faulting and extension of each model flank fault system match those of Mt Etna in every case. We also find convincing evidence that gravitational spreading of the summit cone, combined with downslope sliding, controls the position of future eruptive vents around the summit, by creating faults and fractures that form paths of least resistance for magma intrusions. The intruding magma in turn augments fracture opening by an order of magnitude, in a feedback process that dominates within the summit graben. We conclude that gravitational spreading and sliding are the dominant processes in creating faults at Etna, and that these two processes, augmented by magma pressure, are responsible for the rapid seaward movement of the eastern slopes, tectonically cut off from the stable western flanks. The influence of regional tectonism is up to two orders of magnitude lower. The conceptual model derived here could make an important contribution to the investigation and monitoring of eruptive, seismic and landslide hazards, by providing a unified mechanical system that can be used to understand deformation.


2021 ◽  
Author(s):  
Francesco Sortino ◽  
Salvatore Giammanco ◽  
Pietro Bonfanti ◽  
Carla Bottari

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1624
Author(s):  
Emilio Badalamenti ◽  
Valentina Catania ◽  
Serena Sofia ◽  
Maria Teresa Sardina ◽  
Giovanna Sala ◽  
...  

Betula aetnensis is an endemic tree of high conservation value, which thrives on the nutrient-poor volcanic soils of Mount Etna. Since plant–microbe interactions could play a crucial role in plant growth, resource uptake, and resistance to abiotic stresses, we aimed to characterize the root and rhizosphere microbial communities. Individuals from natural habitat (NAT) and forest nursery (NURS) were surveyed through microscopy observations and molecular tools: bacterial and fungal automated ribosomal intergenic spacer analysis (ARISA), fungal denaturing gradient gel electrophoresis (DGGE). B. aetnensis was found to be simultaneously colonized by arbuscular (AM), ectomycorrhizal (ECM), ericoid (ERM) fungi, and dark septate endophytes (DSE). A high diversity of the bacterial community was observed whilst the root fungal assemblage of NAT plants was richer than that of NURS. Root and rhizosphere fungal communities from NAT plants were characterized by Illumina MiSeq sequencing. Most of the identified sequences were affiliated to Helotiales, Pezizales, and Malasseziales. Ascomycota and Basidiomycota dominated roots and rhizosphere but differed in community structure and composition. ECM in the roots mainly belonged to Tylospora and Leccinum, while Rhizopogon was abundant in the rhizosphere. The Helotiales, including ERM (mostly Oidiodendron) and DSE (mostly Phialocephala), appeared the dominant component of the fungal community. B. aetnensis harbors an extraordinarily wide array of root-associated soil microorganisms, which are likely to be involved in the adaptation and resistance mechanisms to the extreme environmental conditions in volcano Etna. We argue that nursery-produced seedlings could lack the necessary microbiota for growth and development in natural conditions.


2021 ◽  
Vol 64 (Vol. 64 (2021)) ◽  
Author(s):  
Tiziana Sgroi ◽  
Graziella Barberi ◽  
Alessandro Marchetti

The Western Ionian Sea is characterised by an active and diffuse seismicity, directly related to the convergence of the European and African Plates and by gravitational sinking and rollback of the  oceanic lithosphere. In this area, the location of earthquakes is characterised by considerable uncertainties due to large azimuthal gaps, resulting in notable location errors. This problem was  partially overcome with the use of data recorded by NEMO-SN1 seafloor observatory (October 2002 February 2003; June 2012 - May 2013). We relocated 1130 crustal and sub-crustal earthquakes  using land network and NEMO-SN1 data. As most events occurred on Mt. Etna, we focused on 358  earthquakes in the offshore area and near the coasts of Sicily and Calabria. The use of the combined  land-marine networks has improved the earthquake locations in terms of azimuthal GAP, as well as  in horizontal and vertical errors. The comparison between locations performed with and without NEMO-SN1 data shows that differences in latitude, longitude and depths are more evident in the Western Ionian Sea and in the coast of Sicily, where values of the differences over 5 km correspond  to structural heterogeneities. The increased number of seismic stations deployed on land from 2003  to 2012 did not influence the location of events occurring offshore, where NEMO-SN1 continued to be the distinctive tool in the location process. Moreover, the new 73 focal mechanisms computed with  P-wave polarities from NEMO-SN1 and land stations are in agreement with the regional structural   model, showing a prevalent normal, normal/oblique, and strike-slip kinematics. The similarity of two   new focal solutions with the mechanisms of the main shock and aftershock of the 1990 earthquake  demonstrates that the seismic structures are still active and potentially dangerous. The P-wave travel- time residual analysis confirms the activity along the main structural alignments.  A single point of observation in the Ionian Sea can significantly improve the quality of locations, giving an opportunity to focus on the seismogenic structures responsible for the occurrence of  medium-to-high magnitude earthquakes.


2021 ◽  
Vol 9 ◽  
Author(s):  
Katie Males ◽  
Jo Gottsmann

Magma reservoir recharge is widely recognised as a precursor of eruptive activity. However, the causative relationships between reservoir rejuvenation and surface observables such as gravitational potential field changes and ground deformation are still poorly understood. At intermediate and silicic intra-plate volcanoes where crustal mechanical heterogeneity combined with high-prominence are expected to fundamentally affect the crustal stress and strain relationship, protracted period of repose and absence of monitoring data raise questions about the detectability of magma recharge. Here we report results from integrated geodetic forward modelling of ground displacements and gravity changes from reservoir recharge at Erciyes Dağ, a large prominence (∼2,800 m), yet poorly studied, stratovolcano of the Central Anatolian Volcanic Province in Turkey. The most recent eruption at ∼7000 BC, close proximity to the Kayseri Metropolitan Area and absence of dedicated volcano monitoring set a precedent to explore stealth magmatic processes at the volcano. Using finite element analysis we systematically explore the influence of subsurface mechanical heterogeneities and topography on surface deformation and gravity changes from magmatic recharge of Erciyes Dağ’s reservoir. We show that whilst crustal heterogeneity amplifies ground displacements and gravity variations, the volcano’s substantial prominence has the opposite effect. For generic reservoir pressure and density changes of 10 MPa and 10 kg m−3 predicted vertical displacements vary by a factor of 5 while residual gravity changes vary by a factor of 12 between models ignoring topography or mechanical heterogeneity and those that do not. We deduce reservoir volume and mass changes of order 10–3 km3 and 1010 kg, respectively, at the detectability limit of conventional surveying techniques at the volcano. Though dependent on model assumptions, all results indicate that magma recharge at Erciyes Dağ may go undetected at fluxes 1) sufficient to maintain an active reservoir containing eruptable magma and 2) similar to those reported for intermediate/silicic volcanoes with repose times of 100–1,000s of years (e.g., Parinacota) and persistently active mafic volcanoes such as Mt. Etna and Stromboli. Our findings may be utilised to inform integrated geodetic and gravimetric monitoring at Erciyes Dağ and other large prominence silicic volcanoes and could provide early insights into reservoir rejuvenation with implications for the development of disaster risk reduction initiatives.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Pasquale De Gori ◽  
Elisabetta Giampiccolo ◽  
Ornella Cocina ◽  
Stefano Branca ◽  
Carlo Doglioni ◽  
...  

AbstractIdentifying and monitoring the presence of pressurized magma beneath volcanoes allows for improved understanding of internal dynamics and prediction of eruptions. Here we show with time-repeated tomography clear evidence that fresh melts accumulate since 2019 in three reservoirs located at different depths in the central feeding system. In these three volumes, we observe a significant reduction of seismic wave velocity, an anomaly that has endured for almost two years. Reservoir re-pressurization induced seismicity clusters around the pressurized volumes within high fluid pressure compartments. This indicated a sharp change in volcano behavior, with re-pressurization of the central system replacing two-decade-long, flank collapse-dominated dynamics. The volume where the velocities are altered is remarkable in size, suggesting the injection of new melt, and that erupted lava represents only a small percentage. Our findings suggest that ongoing volcanic recrudescence can persist.


2021 ◽  
Vol 176 (11) ◽  
Author(s):  
P. P. Giacomoni ◽  
F. Casetta ◽  
V. Valenti ◽  
C. Ferlito ◽  
G. Lanzafame ◽  
...  

AbstractThe petrological study of volcanic products emitted during the paroxysmal events of December 2015 from the summit craters of Mount Etna allow us to constrain T-P-XH2O phase stability, crystallization conditions, and mixing processes along the main open-conduit feeding system. In this study, we discuss new geochemical, thermo-barometric data and related Rhyolite-MELTS modelling of the eruptive activity that involved the concomitant activation of all summit craters. The results, in comparison with the previous paroxysmal events of the 2011–2012, reinforce the model of a vertically extended feeding system and highlight that the activity at the New South-East Crater was fed by magma residing at a significantly shallower depth with respect to the Central Craters (CC) and North-East Crater (NEC), even if all conduits were fed by a common deep (P = 530–440 MPa) basic magmatic input. Plagioclase dissolution, resorption textures, and the Rhyolite-MELTS stability model corroborate its dependence on H2O content; thus, suggesting that further studies on the effect that flushing from fluids with different H2O/CO2 ratio are needed to understand the eruption-triggering mechanisms for high energetic strombolian paroxysmal episodes.


Sign in / Sign up

Export Citation Format

Share Document