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Element mobility during basalt-water-CO2 interaction: observations in natural systems vs. laboratory experiments and implication for carbon storage
No full textToday, carbon dioxide removal from the atmosphere is the most ambitious challenge to mitigate climate changes. Basalt rocks are abundant on the Earth's surface (≈ 10%) and very abundant in the ocean floors and subaerial environments. Glassy matrix and minerals constituting these rocks contain metals (Ca2+, Mg2+, Fe2+) that can react with carbonic acid to form metal carbonates (CaCO3, MgO3 and FeCO3). Here, we present a data compilation of the chemical composition of waters circulating in basalt aquifers worldwide and the results of simple basalt-water-CO2 experiments. Induced or naturally occurring weathering of basalts rocks release elements in waters and elemental concentration is closely dependent on water CO2 concentration (and hence on water pH). We also performed two series of experiments where basaltic rock powder interacts with CO2-charged waters for one month at room temperature. Laboratory experiments evidenced that in the first stages of water-rock interaction, the high content of CO2 dissolved in water accelerates the basalt weathering process, releasing in the water not only elements that can form carbonate minerals but also other elements, which depending on their concentration can be essential or toxic for life. Relative mobility of elements such as Fe and Al, together with rare earth elements, increases at low pH conditions, while it decreases notably at neutral pH conditions. The comparison between experimental findings and natural evidence allowed to better understand the geochemical processes in basaltic aquifers hosted in active and inactive volcanic systems and to discuss these findings in light of the potential environmental impact of CO2 storage in mafic and ultramafic rocks.Published4JCR Journa
Schools-tailored actvities communicate seismic risk
No full textRisk communication is a crucial element in the management of risks: it has a great potential to raise awareness, increase preparedness, and promote legislative interventions.
Uncertainty, lack of scientific knowledge, misunderstanding, misinformation, cognitive bias, distrust in authorities are among the major threats of effective risk communication. Nonetheless recent studies have highlighted that seismic risk communication practices have been increasing during the last decades although still more work needs to be done.
There are different models of risk communication: the majority refer to the public understanding paradigm, in which information are given in a “one-way” direction to the public, and to the public engagement paradigm, in which stakeholders are meant to participate in the building process of knowledge. In preparing a risk communication campaign, the school target has revealed as one of the most important to address, given its high potential to influence a risk-resilient society.
In this paper, activities to communicate seismic risk communication specifically designed to engage middle school students are presented. Science communication with teen audiences has a unique challenge: there is a fundamental need to design a communication that can help them feel involved.
The work presents the framework within which the activity is done. It describes the communication goals, learning methodology and present some of the activities that have been included in a format suitable for open-door outreach events. The activities discussed in this work were tested within two open-doors that were held at the Milano division of the National Institute for Geophysics and Volcanology in the year 2023.PublishedFerraraOS: Terza mission
The formation and growth mechanisms of young back-arc spreading ridges from high-resolution bathymetry: The Marsili Seamount (Tyrrhenian Sea, Italy)
No full textThe formation and growth mechanisms of Mid-Ocean Ridges (MOR) are relatively well known, whereas
those of back-arc spreading ridges are comparatively less known because geophysical, geochemical, and
morphological data are scarce and of low density. Here we present a high-resolution bathymetry of the
Marsili Seamount (MS; 1Ma 3 ka), which represents the inflated spreading ridge of the 2Ma old Marsili
back-arc basin associated to the subduction of the Ionian Sea below the Calabrian Arc and Tyrrhenian Sea.
MS is 70 km long, 30 km wide, and its height reaches about 3000 m from surrounding seafloor. Our new
digital bathymetric model has a 5 m grid cell size resolution and covers the MS bathymetry from 1670
mbsl to the top at 491 mbsl. We conduct morphometric and morphological analyses of the bathymetry
and recognize landforms due to volcanic, tectonic, hydrothermal and gravity processes. MS consists of
volcanoes related to fissural and central-type activity, this latter located at the northern and southern tips
of the main dike swarms. Dike swarms represent the surface expression of different ridge segments
whose strikes are controlled by the larger scale back-arc spreading processes and by the local occurrence
of an active hydrothermal field. This latter develops in a flat area between two partly overlapping ridge
segments where historical volcanism and extensional processes concentrate. Such ridges represent the
embryonic stage of the formation of transform-like faults. Central volcanoes, the northern of which is
characterized by a caldera, form at the tips of MS because the decrease in width of the major volcanic
fissures promotes vent localization associated with the formation of sill-like reservoirs from which
central-type vents may develop. Gravity processes affecting the MS flanks are due to shallow seafloor
sliding. Caldera collapses affecting the northernmost central-type polygenic volcano must be included
in the evaluation of the hazard related to potential tsunami. Inward dipping faults characterize the MS
eastern flank suggesting a moderately asymmetric growth of the spreading ridge possibly associated with
the eastward opening of the Marsili back-arc.
The Marsili back-arc spreading rate is similar to those of MOR slow spreading ridges. However, the MS
morphology resembles that of fast spreading ridges. These two features also characterize more extended
back-arc spreading ridges (e.g. the Mariana in Western Pacific). We conclude that, independently from
the spatial scale, the increase in the ridge accretion rate is related to the progressive addition of a
subduction-related component to a pure spreading mantle source.Published101723OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
Developing hazard scenarios from monitoring data, historical chronicles, and expert elicitation: a case study of Sangay volcano, Ecuador
No full textSangay volcano is considered as one of the most active volcanoes worldwide. Nevertheless, due to its remote location and low-impact eruptions, its eruptive history and hazard scenarios are poorly constrained. In this work, we address this issue by combining an analysis of monitoring data and historical chronicles with expert elicitation. During the last 400 years, we recognize periods of quiescence, weak, and enhanced eruptive activity, lasting from several months to several years, punctuated by eruptive pulses, lasting from a few hours to a few days. Sangay volcano has been mainly active since the seventeenth century, with weak eruptive activity as the most common regime, although there have also been several periods of quiescence. During this period, eruptive pulses with VEI 1–3 occurred mainly during enhanced eruptive activity and produced far-reaching impacts due to ash fallout to the west and long-runout lahars to the south-east. Four eruptive pulse scenarios are considered in the expert elicitation: strong ash venting (SAV, VEI 1–2), violent Strombolian (VS, VEI 2–3), sub-Plinian (SPL, VEI 3–4), and Plinian (PL, VEI 4–5). SAV is identified as the most likely scenario, while PL has the smallest probability of occurrence. The elicitation results show high uncertainty about the probability of occurrence of VS and SPL. Large uncertainties are also observed for eruption duration and bulk fallout volume for all eruptive scenarios, while average column height is better characterized, particularly for SAV and VS. We interpret these results as a consequence of the lack of volcano-physical data, which could be reduced with further field studies. This study shows how historical reconstruction and expert elicitation can help to develop hazard scenarios with uncertainty assessment for poorly known volcanoes, representing a first step towards the elaboration of appropriate hazard maps and subsequent planning.Published68OSV1: Verso la previsione dei fenomeni vulcanici pericolosiJCR Journa
GPR investigations at San Nicolò Church: a case-study from the 1669 eruption in the old settlement of Misterbianco (Etna, Sicily)
No full textMisterbianco, located on the southern slope of Mt. Etna (eastern Sicily), was destroyed in the past by two catastrophic events that raised the old town to the ground. The first was the great eruption of 1669, whose lava front buried dozens of villages encountered along its path, entirely destroying the architectural heritage of Etna's southern flank. The second event was the disastrous 1693 Val di Noto earthquake, which caused major destruction throughout south-eastern Sicily, also damaging the few still standing buildings in the town. The GPR survey performed at this site, 350 years after the eruption, allowed a first attempt of planimetric reconstruction of the San Nicolò Church. Starting from the site history, we present the results of an integrated approach that involves history, volcanology and geophysics aimed at addressing future archaeological excavations for the protection of archaeological and monumental assets in a difficult setting as this volcanic environment.Published42-50JCR Journa
Testing the Predictive Power of b Value for Italian Seismicity
No full textA very efficient method for estimating the completeness magnitude mc and the scaling parameter b of earthquake magnitude distribution has been thoroughly tested using synthetic seismic catalogues. Subsequently, the method was employed to assess the capability of the b-value in differentiating between foreshocks and aftershocks, confirming previous findings regarding the Amatrice-Norcia earthquake sequence. However, a blind algorithm reveals that the discriminative ability of the b-value necessitates a meticulous selection of the catalogue, thereby reducing the predictability of large events occurring subsequent to a prior major earthquake.Published1084N/A or not JC
Seismo-Stratigraphic Data of Wave-Cut Marine Terraces in the Licosa Promontory (Southern Tyrrhenian Sea, Italy)
No full textSome seismo-stratigraphic evidence on the occurrence of wave-cut marine terraces in the
Licosa promontory (Southern Tyrrhenian Sea, Italy) based on Sub-bottom Chirp seismic sections is
herein presented. Such evidence is provided by marine terraced surfaces situated at various water
depths below sea level and etched into the rocky acoustic basement, which are extensively extending
in the seaward extension of the Licosa promontory. It is possible that the isotopic stratigraphy and
the terraced marine surfaces are connected, so they can be attributed and dated indirectly. The
geologic study of seismic profiles has pointed to the prominence of the acoustic basement, extending
to the seabed close to the coast and subsiding seawards under the Quaternary marine succession.
Ancient remains of marine terraces, found at a range of water depths between 5 m and 50 m, have
documented the major morphological changes of the acoustic basement during the Late Quaternary.Published392–418OSA4: Ambiente marino, fascia costiera ed Oceanografia operativaN/A or not JC
Feedback responses between endogenous and exogenous processes at Campi Flegrei caldera dynamics, Italy
No full textThe Campi Flegrei caldera is characterized by the phenomenon of bradyseism, as evidenced by stratigraphic records of alternate oceanic and continental sediments dating back over a thousand years. Since 2005, the caldera has been in a phase of unrest, which is increasing volcanic deformations and associated seismicity around the region, resulting in a growing
concern over the dense population in the inhabitation. Recent studies have highlighted that the caldera dynamics are driven by a combination of endogenous processes and modulation phenomena induced by exogenous processes, e.g., rainfall, atmospheric pressure, and tidal loading. Although the complex feedback mechanisms of both endogenous and exogenous processes are still under debate, the present study is focused on the increased potential of modulation due to exogenous processes with the increase or evolution in the degree of inflation of the magma chamber. Specifically, Campi Flegrei volcanic system shows sensitivity to seasonal hydrological cycles during slower rates of inflation and to short-period tidal modulations during higher rates of inflation. The observed seasonal modulations of seismic activity are explained in terms of water infiltration into the shallow aquifers, basins, and vent depression system of the caldera. The rainfall-induced pore pressure build-up also favours the instability of the brittle cap rock, promoting seismicity. In addition, this study suggests that the tidal loadings provide horizontal NS extensions to the mostly NW–SE, NE–SW, and EW-oriented scattered fractures and further contribute towards fracture propagation. During this process, a cyclic opening and sealing of fractures by volatile outgassing and silicate settling may, respectively, produce the episodic behaviour of the seismicity. The seismicity in relation to exogenous processes imposed by seasonal rainfall and tidal loadings shows that the degree of correlation depends on the different rates of inflation. The long-period seasonal modulations and short-period tidal modulations during the evolution of the degree of inflation are finally interpreted in the framework of the fault resonance destabilization model, under rateand- state dependant frictional formalism.Published22OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
Subsurface 3D modeling of Pantelleria island (Italy) using gravity data
No full textPantelleria is a 84 km2 extended volcanic island located in the Mediterranenan Sea between Sicily
(Italy) and Tunisia. Previous studies described that in Pantelleria island both tectonic structures
and the volcano-tectonic features had a common tectonic origin controlled by a NW-SE directed
extension in accordance with the regional trend of the Sicily Channel arising interest for
multiapproach investigations.
Indeed, in the last decades this area has been field of widespread analysis useful for the
investigation of the volcano-tectonic and tectonic activity, as well as for geodetic study and
resources exploration.
Our approach focused on the gravimetric analysis of Pantelleria island and in particular we
provided a 3D inverted model of the area, starting from in-situ gravity measurements. The 250 m
model resolution has been endorsed by the presence of a total of 290 measurement stations,
distributed both onshore and offshore and acquired during some field surveys up to 2006; 236 of
them were already published and inverted in past using 2.5D modelling. Input data consisted of a
database containing Bouguer anomaly data reduced using a density of 2500 kg/m3 and referred
to the Geodetic Reference System 1980 (GRS80) Ellipsoid.
As a result, the 3D modelling allowed exploring density differences through the about 4 km depth,
emphasizing interesting geological structures.
Such results would help any drilling program in the island (e.g. for geothermal purposes), lead to
more successful drilling programs, and serve as well-constrained geologic input to improve the
accuracy of future numerical (e.g. reservoir) models.UnpublishedVienna, AustriaOST5 Verso un nuovo MonitoraggioOSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciOSV3: Sviluppo di nuovi sistemi osservazionali e di analisi ad alta sensibilit
Holocene relative sea-level changes along the Caribbean and Pacific coasts of northwestern South America
No full textAll Rights ReservedPredicting coastal change depends upon our knowledge of postglacial relative sea-level variability, partly controlled by glacio-isostatic responses to ice-sheet melting. Here, we reconstruct the postglacial relative sea-level changes along the Caribbean and Pacific coasts of northwestern South America by numerically solving the sea-level equation with two scenarios of mantle viscosity: global standard average and high viscosity. Our results with the standard model (applicable to the Pacific coast) agree with earlier studies by indicating a mid-Northgrippian high stand of ~2 m. The high-viscosity simulation (relevant to the Caribbean coast) shows that the transition from far- to intermediate-field influence of the Laurentide Ice Sheet occurs between Manzanillo del Mar and the Gulf of Morrosquillo. South of this location, the Colombian Caribbean coast has exhibited a still stand with a nearly constant Holocene relative sea level. By analyzing our simulations considering sea-level indicators, we argue that tectonics is more prominent than previously assumed, especially along the Caribbean coast. This influence prevents a simplified view of regional relative sea-level changes on the northwestern South American coast.Published28-43OSA4: Ambiente marino, fascia costiera ed Oceanografia operativaJCR Journa