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Multi-Satellite Detection of Long-Range Transport and Transformation of Atmospheric Emissions from the Hunga Tonga-Hunga Ha’apai Volcano
No full textLarge volumes of atmospheric pollutants injected into the troposphere and stratosphere
from volcanic eruptions can exert significant influence on global climate. Through utilizing multisatellite
observations, we present a large-scale insight into the long-range transport and transformation
of sulfur dioxide (SO2) emissions from the Hunga Tonga-Hunga Ha’apai eruption on
15 January 2022. We found that the transport of volcanic emissions, along with the transformation
from SO2 to sulfate aerosols, lasted for two months after the Tongan eruption. The emitted volume
of SO2 from the volcano eruption was approximately 183 kilotons (kt). Both satellite observation
and numerical simulation results show that the SO2 and volcanic ash plumes moved westward at
a rate of one thousand kilometers per day across the Pacific and Atlantic Ocean regions and that
SO2 transformation in the atmosphere lasted for half a month. The transport and enhancement of
aerosols is related to the conversion of SO2 to sulfate. CALIPSO lidar observations show that SO2
reached an altitude of 25–30 km and transformed into sulfate in the stratosphere after 29 January.
Sulfate aerosols in the stratosphere deceased gradually with transport and fell back to the background
level after two months. Our study shows that satellite observations give a good characterization of
volcanic emissions, transport, and SO2-sulfate conversion, which can provide an essential constraint
for climate modeling.Published2661OSA2: Evoluzione climatica: effetti e loro mitigazioneJCR Journa
Present-day seismicity of the Matese Massif (central-southern Apennines, Italy): new constraints on the seismotectonic setting of the central and southern sides
No full textWe investigated the 2009-2020 instrumental seismicity of the Matese Massif. With the
exception of two relevant seismic sequences (2013-2014 and 2016-2017, MMAX = 4.9), the
background seismicity consists of low magnitude seismic swarms (MMAX = 3.3) located at
the borders of the massif, and sparse single events (MMAX = 3.5). The focal mechanisms
of the single events located near the NW and west edges of the massif suggest that this
seismicity occurs on SW dipping, ca. NW-SE striking normal fault segments, in accordance
with the kinematics of the Aquae Iuliae Fault. The focal mechanisms of two low magnitude
seismic swarms located in the morphological depression, separating the Matese Massif
from the Sannio Mountains, provide seismological evidence, never previously observed
in this area, of the existence of an active east-western fault segment with dextral strikeslip kinematics. To the west of this area, there is no seismological evidence of strike-slip
kinematics, whereas such evidence is found to the east. This area could represent the
westernmost expression of the active strike-slip regime that characterises the Apulian
foreland. Along the faults situated on the southern side, the very rare detected seismicity
could be related to the high emission of CO2-bearing gas vents located near these faults.
Considering the time elapsed from the last destructive earthquake (1349), the possible
sources of the poorly known 346 and 1293 earthquakes, and the rare seismicity detected
in the last 25 years, we speculate that the south-western side of the Matese may be
affected by large earthquakes in the future.Published113-134JCR Journa
Seismic source mapping by surface wave time reversal: application to the great 2004 Sumatra earthquake
No full textThis article has been accepted for publication in Geophysical Journal International ©:The Author(s) 2023. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Uploaded in accordance with the publisher's self-archiving policy.
All rights reserved.Different approaches to map seismic rupture in space and time often lead to incoherent results for the same event. Building on earlier work by our team, we ‘time-reverse’ and ‘backpropagate’ seismic surface wave recordings to study the focusing of the time-reversed field at the seismic source. Currently used source-imaging methods relying on seismic recordings neglect the information carried by surface waves, and mostly focus on the P-wave arrival alone. Our new method combines seismic time reversal approach with a surface wave ray-tracing algorithm based on a generalized spherical-harmonic parametrization of surface wave phase velocity, accounting for azimuthal anisotropy. It is applied to surface wave signal filtered within narrow-frequency bands, so that the inherently 3-D problem of simulating surface wave propagation is separated into a suite of 2-D problems, each of relatively limited computational cost. We validate our method through a number of synthetic tests, then apply it to the great 2004 Sumatra–Andaman earthquake, characterized by the extremely large extent of the ruptured fault. Many studies have estimated its rupture characteristics from seismological data (e.g. Lomax, Ni et al., Guilbert et al., Ishii et al., Krüger & Ohrnberger, Jaffe et al.) and geodetic data (e.g. Banerjee et al., Catherine et al., Vigny et al., Hashimoto et al., Bletery et al.). Applying our technique to recordings from only 89 stations of the Global Seismographic Network (GSN) and bandpass filtering the corresponding surface wave signal around 80-to-120, 50-to-110 and 40-to-90 s, we reproduce the findings of earlier studies, including in particular the northward direction of rupture propagation, its approximate spatial extent and duration, and the locations of the areas where most energy appears to be released.Published1018-10351T. Struttura della Terra3T. Fisica dei terremoti e Sorgente SismicaJCR Journa
Magnitude Distribution and Clustering Properties of the 3D Seismicity in Central Apennines (Italy)
No full textIn this paper we deal with statistical features of earthquakes, seeking possible
correlations between the G-R magnitude distribution and the short-term clustering in an
area of the Central Apennines, Italy, where significant seismicity with earthquakes
exceeding magnitude 6.0 has been repeatedly observed from 1990 to the present. For
this purpose, a recently developed version of the ETAS model, incorporating a threedimensional
spatial triggering kernel, has been adopted. Our analysis has been carried
out representing the b-value and the probability of independence of events on six vertical
cross-sections suitably related to the seismic structures that are considered responsible
of the seismicity observed in the study area.
The results of the statistical analysis of the seismicity in the study area have shown a
clear distinction between the western normal low-angle fault system, characterized by
eastward dip, and the eastern normal fault systems, with westward dip. In the former
(Etrurian Fault System; EFS) we found seismicity with a high b-value and high probability
of independence, i.e., a scarce capacity of producing clusters and strong aftershock
sequences. The eastern fault systems of our study area are distinguishable in two main
distinct systems, which generated two strong seismic sequences in 1997 and 2016-2017.
In the former (Colfiorito) sequence the seismicity showed a very low b-value and a
modest probability of independence, while in the latter (Central Italy) sequence the bvalue
was significantly higher and the probability of independence had extremely low
values (manifesting a high level of clustering). The much higher b-value of the EFS than
the other extensional sources could be caused by its peculiar seismotectonic role of
discontinuity at the base of the normal active faulting, and its reduced capacity of
accumulating stress. This circumstance may be interpreted by a difference in the
rheological properties of these fault systems, possibly also in relation to their present
status in the earthquake cycle and the presence of strong aftershock sequences.Published2004–20202T. Deformazione crostale attivaJCR Journa
Multi-scale response of the high-latitude topside ionosphere to geospace forcing
No full textWe investigate the response of the topside ionosphere, auroral and polar sectors, to the forcing of the geospace during September
2017. Specifically, we aim at characterizing such a response in terms of the involved spatial scales and of their intensification during
the different auroral and polar cap activity conditions experienced in the selected month, that is characterized by severe geomagnetic
storm conditions. For our purposes, we leverage on and compare various in situ plasma density data products provided by the Swarm
constellation of the European Space Agency (ESA). The spatio-temporal variability of the involved scales in the plasma density observation
is featured through the application of the Fast Iterative Filtering (FIF) signal decomposition technique and, for the first time in
the ionospheric field, of a FIF-derived dynamical spectrum called ‘‘IMFogram”. The instantaneous time-frequency representation provided
through the IMFogram illustrates the time development of the multi-scale processes with spatial and temporal resolutions higher
than those obtained with traditional signal processing techniques. To demonstrate this, the IMFogram is tested against Fast Fourier and
Continuous Wavelet Transforms. With our fine characterization, we highlight how scale cascading and intensification processes in the
plasma density observations follow the ionospheric currents activity, as depicted through the auroral activity and polar cap indices, and
through the field-aligned currents data product provided by Swarm.Published5490-5502OSA3: Climatologia e meteorologia spazialeJCR Journa
ERMES report INT-20221109_0000046 v1
No full textIstituto Nazionale di Geofisica e VulcanologiaUnpublished5T. Sismologia, geofisica e geologia per l'ingegneria sismic
The Cretaceous volcanism of the Songliao Basin: Mantle sources, magma evolution processes and implications for the NE China geodynamics - A review
No full textContinental rifts result from the simultaneous action of shallow processes such as the thinning of the lithosphere,
and deeper processes related to the dynamics of the mantle. The role of these deeper processes may change over
time as a function of the type of rifting, e.g., subduction-related rift vs plume-related rifts, and the pre-rift
geodynamics. During the Cretaceous, the Songliao Basin (NE China) was affected by continental rifting
accompanied by discontinuous stages of volcanism. The relative role of the asthenospheric and lithospheric
mantle associated with the Songliao Basin rift volcanism, its evolution with time, and the origin of the felsic rocks
are still debated problems due to the lack of comprehensive studies. Here, we present a critical review of the
available geochronological and geochemical data (major, trace elements, and Sr-Nd isotopes) and show that the
Songliao rift Cretaceous volcanism developed between 133 Ma and 102 Ma in five main stages: Stage I (133–129
Ma), Stage II (124–118 Ma), Stage III (117–113 Ma), Stage IV (115–106 Ma), and Stage V (105–102 Ma). While
magmas with an alkaline, intraplate affinity characterize all the Stages, magmas with a subalkaline (calc-alkaline)
signature erupted in Stages II and III. Mafic and intermediate rocks are always present, whereas felsic
magmas have been found in the last three Stages. Based on the major, trace elements and Nd-Sr isotopic compositions,
the general evolution of volcanism is dominated by crystal fractionation processes. Evidence of
assimilation of upper crust material is restricted to the more evolved rocks (SiO2 > 57 wt%). The alkaline mafic
rocks derived from a veined asthenospheric mantle modified by melts deriving from the sediments of the Paleo-
Pacific slab or associated with pre-rifting, Jurassic, collisional subduction processes related to the closing of the
Mongol–Okhotsk Ocean. The source of the Songliao rift subalkaline rocks is the sub-continental lithospheric
mantle metasomatized by fluids released from the dehydration of the subducting Paleo-Pacific slab. The release
of fluids from the sediments subducted during the Jurassic Mongol–Okhotsk collision may also have played a
role. The Songliao Basin Cretaceous rift may be classified as a subduction-related rift caused by the eastward rollback
of the west-dipping Paleo-Pacific slab, a process initiated after the Jurassic collisional phase in NE China.
Within the wider geodynamic frame of the eastern Asian block, the 133–102 Ma volcanism of the Songliao rift
suggests a transition from a lithospheric mantle responsible for the pre-140 Ma NE China, Mongolia, and Russia
volcanism to an asthenospheric mantle source of the post-107 Ma magmatism. This is also suggested by the fact
that the Songliao rift magmatism shows compositional features consistent with the contribution of both the
lithospheric and asthenospheric mantle. The Songliao rift volcanism would be therefore associated with a passive
rifting process, where the progressive removal of the lithosphere below East Asia, which is due to eastward
rollback of the Pacific oceanic plate, caused an upwelling of asthenospheric material, finally involved in the post-
102 Ma magmatism in the NE China block.Published104294OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
Modeling the Trajectories of Ballistics in the Summit Area of Mt. Etna (Italy) during the 2020–2022 Sequence of Lava Fountains
No full textBetween 2020 and 2022, more than sixty lava fountains occurred at Mt. Etna (Italy), which formed high eruption columns rising up to 15 km above sea level (a.s.l.). During those events, several ballistics fell around the summit craters, sometimes reaching touristic areas. The rather frequent activity poses questions on how the impact associated with the fallout of those particles, can be estimated. In this work, we present field data collected soon after the lava fountain on 21 February 2022. This event produced a volcanic plume of about 10 km a.s.l. which was directed toward the southeast. Several ballistics fell in the area of the Barbagallo Craters (just southeast of the summit area at around 2900 m a.s.l.), which is one of the most popular touristic areas on Etna. Hence, we collected several samples and performed laboratory analyses in order to retrieve their size, shape and density. Those values together with a quantitative analysis of the lava fountain were compared with results obtained by a free-available calculator of ballistic trajectories named the ‘Eject!’. A similar approach was hence applied to other lava fountains of the 2020–2022 sequence for which the fallout of large clasts was reported. This work is a first step to identifying in near real-time the area affected by the fallout of ballistics during Etna lava fountains and quantifying their hazard.Published145OSV3: Sviluppo di nuovi sistemi osservazionali e di analisi ad alta sensibilitàJCR Journa
Geofluids as a possible unconventional tool for seismic hazard assessment
No full textIn recent decades, phenomenological methods known as Recognition of
Earthquake-Prone Areas (REPA) were set up for identifying potential sites of
powerful earthquakes. The information on potential earthquake sources
provided by the REPA method is an essential part of seismic hazard
assessment methodology. For the first time, we have combined global-scale
information on the geographic occurrence of geofluids with global-scale
information on earthquake occurrence, heat flow distribution, and S-wave
dispersion, to gain insights into the evolution of local stress-strain fields. We
focused on areas characterized by the occurrence of thermal waters and/or by the
release of deep-seated gases, as traced by the isotope composition of associated
helium. We noticed that the geographic distribution of these geofluids could serve
as an indirect indicator of crustal permeability anomalies generated by crustal
deformation procedures. This study proposes adding geofluids to the list of
fundamental geological parameters to be considered in hazard assessment
research.Published1286817JCR Journa
The Belìce Valley as a Territorial Laboratory: from Public Policy Experimentation to a Large-area Administration Strategy
No full textThe emerging field of research concerning the geography of dissatisfaction
focuses on explaining the formation of political inclinations and behaviors
through a geographic location perspective (Iammarino et alii, 2019; Stroppe,
2023). Such dynamics are the subject of public debate, particularly with regard
to rural and disadvantaged areas that seem to fuel, more than others, attitudes
of political resentment, as in the case of abstentionism or protest voting (Rodríguez-
Pose, 2017). Central to the research on these «less fortunate» or more marginal
areas is the model that argues how citizens residing in areas relatively distant
from service-providing hubs perceive inequality in access to economic and social
resources (Petino, Scrofani, 2020). This perception contributes to the feeling of
being ignored in the broader context of global «long networks» (Dematteis, 2021),
where original local socio-cultural specificities tend to disappear, of national economic
development or on the part of political elites in general (Cramer, 2016;
Stroppe, 2023). Conversely, since every geographic system is marked by a vastness of tangible and intangible resources, normally affected by a dynamic process
of local accumulation, it has the potential to generate territorial heritage. Such
heritage, if made available to the local community and investors, could succeed
in influencing the entire set of connections, both formal and informal, that participants
have developed over time to manage it. The goal of asset creation and
management will be the compensatory measure to reduce spatial disparities and
should normally be supported by appropriate policy interventions. Activating
these dynamics represents a strategic challenge and is both complex and the subject
of European cohesion policies. While we may believe that (territorial) cohesion
policies are a well-established objective on the part of the European Union
(CEC, 2008), it is equally clear that is obviously a mistake to continue to pursue
this objective in the simple application of the same models and practices of development
for all, both for regions and for EU countries, with the risk of homologation
of intervention and its lack of effectiveness. Therefore, it is necessary that
(territorial) cohesion should be achieved by protecting and, even more, promoting
the diversity of territories in order to ensure real and lasting well-being for
local populations (Prezioso, 2020; Petino, Scrofani, 2020). See in this sense the
report by Barca (2009) entitled «An Agenda for a reformed Cohesion Policy. A
place-based approach to meeting European Union challenges and expectations»
to observe how development models that incentivize processes of valorization
of territorialized resources according to place-based or place evidence-based
approaches, can be considered paradigmatic in the approach to «places» to their
understanding and to the possible implementation of cohesion policies aimed
at local specificities and for this reason, at least on paper, more effective. It is in
this scenario that our observation finds its ease, in a phase that moreover sees
the issue of energy transition becoming a central element of European policy, to
facilitate which transition support tools, such as energy communities, have been
introduced for local communities. The area of observation is the Belìce Valley in
Sicily, which will be discussed in the second section. In particular, our focus is on
that part that was affected by the 1968 earthquake, already the subject of reconstruction
intervention in the past decades and more recently of the community
policy that, in the 2014-2020 seven-year period, allowed for the establishment of
a new governance entity called the Local Action Group (LAG) Valle del Belìce.
New opportunities could arise from the constituting energy communities and
from the hypothesis of a candidature as a project area in the National Strategy
for Inner Areas, which we will discuss in more detail in the third paragraph. The
aim of this work is to reconstruct the territorial mosaic in order to identify some
characteristics and possible development trajectories by offering an interpretation,
a guiding thread and a possible way out of typical dynamics of stagnation
that have been keeping an area of great interest on the margins for just over fifty
years (Messina, 2019; Mattia et alii, 2021).Published129-152OS: Terza missioneN/A or not JC