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CSES-01 Electron Density Background Characterisation and Preliminary Investigation of Possible Ne Increase before Global Seismicity
No full textIn this paper, we provide a characterisation of the ionosphere from April 2018 to September 2022 for 48 investigated months. We used the data of the China Seismo Electromagnetic Satellite (CSES-01), which is a sun-synchronous satellite with five days of revisit time and fixed local time of about 2 a.m. and 2 p.m. The unique orbit of CSES-01 permitted us to produce a monthly background of the ionosphere for night- and daytime with median values acquired during geomagnetic quiet time in equatorial and mid-latitude regions (i.e., between 50° S and 50° N of geographical latitude). We compared the obtained CSES-01 monthly median values with the solar activity in terms of sunspot numbers, and we found a high correlation of 0.89 for nighttime and 0.85 for daytime between the mean sunspot number and the maximum of the characterised CSES-01 Ne map values. In addition, we extracted all the anomalous positive increases in CSES-01 electron density and compared them with the Worldwide M5.5+ shallow earthquakes. We tested two different definitions of anomaly based on median and interquartile range or (mild) outliers. We tried two relationships between anomalies inside Dobrovolsky’s area before the earthquake and the magnitude of the same seismic events: one which considers distance in space and time and a second which only uses the anticipation time of the anomaly before the earthquake. Using both anomaly definitions, we searched the best coefficients for these two laws for mid-latitude and equational regions. We found that the best coefficients are independent of the anomaly definition, but better accuracy (greater than 80%) is obtained for the outlier definition. Finally, using receiving operating characteristic (ROC) curves, we show that CSES-01 increases seem statistically correlated to the incoming seismic activity.Published1527OST4 Descrizione in tempo reale del terremoto, del maremoto, loro predicibilità e impattoOSA3: Climatologia e meteorologia spazialeJCR Journa
Electron Signal Induced by GRB 221009A on Charged Particle Telescopes of POES and MetOp Satellites
No full textGRB 221009A is a long gamma-ray burst among the most energetic and nearest (z = 0.151) detected so far. The energy fluence of the burst was so large to cause ionization of the upper layers of Earth's atmosphere and also observable signals in satellite-borne particle detectors. Electron signals, with the same GRB time development, can arise from the interaction of energetic photons with the particle detector and support structures. This effect was previously reported for the HEPP-L on board the China Seismo-Electromagnetic Satellite. We searched for the same effect on the particle detectors on board five POES and MetOp satellites. Electron signals in coincidence with the gamma-ray emission of the burst were found in three satellites, which were well illuminated by the GRB. The properties of the found electron signals are reported and discussed.Published159OSA3: Climatologia e meteorologia spazialeJCR Journa
The Influence of Cumulative Intensity on Macroseismic Source Parameters: The Case of 2016–2017 and 1703 Seismic Sequences (Central Italy)
No full textThe macroseismic source parameters of earthquakes occurring within a sequence are strongly influenced by cumulative damage effects. When we deal with historical seismic sequences, in addition to the cumulative intensities, other intrinsic uncertainties due to the scarcity and indeterminacy of sources come into play. These issues imply that the parameterizations of the single earthquakes within a historical seismic sequence are not univocal and that all the uncertainties that are addressed when assessing macroseismic intensity should be carefully considered in the parameter estimation. In the light of these considerations, we performed some tests on the 2016–2017 and 1703 seismic sequences, which occurred in the same area in central Italy, to compute the macroseismic source parameters by means of two independent methods. Results show that the cumulative effects arising from multiple damaging earthquakes can cause biases in the intensity assessments, which affect the computed magnitude and epicentral locations. To reduce bias in macroseismic intensities due to cumulative damage, we illustrate a simple procedure, called cumulative intensity subtraction (CIS), which consists in discarding the localities strongly damaged by the early earthquakes of a sequence from the intensity distributions used for computing the macroseismic source parameters of the subsequent earthquakes. The outcomes show that, for the 2016 seismic sequence, the CIS approach provides locations in agreement with the instrumental epicenters and with the causative faults. For the 1703 sequence, the CIS approach along with explicit accounting for the indeterminacy in intensity assignments give a range of equally plausible solutions. The CIS represents an exploration of a simple strategy that stems from an attempt to give significance to macroseismic intensity in the presence of cumulative damage.Published759–774OST4 Descrizione in tempo reale del terremoto, del maremoto, loro predicibilità e impattoJCR Journa
Forcing and impact of the Northern Hemisphere continental snow cover in 1979–2014
No full textThe main drivers of the continental Northern Hemisphere snow cover are investigated in the 1979–2014 period. Four observational datasets are used as are two large multi-model ensembles of atmosphere-only simulations with prescribed sea surface temperature (SST) and sea ice concentration (SIC). A first ensemble uses observed interannually varying SST and SIC conditions for 1979–2014, while a second ensemble is identical except for SIC with a repeated climatological cycle used. SST and external forcing typically explain 10 % to 25 % of the snow cover variance in model simulations, with a dominant forcing from the tropical and North Pacific SST during this period. In terms of the climate influence of the snow cover anomalies, both observations and models show no robust links between the November and April snow cover variability and the atmospheric circulation 1 month later. On the other hand, the first mode of Eurasian snow cover variability in January, with more extended snow over western Eurasia, is found to precede an atmospheric circulation pattern by 1 month, similar to a negative Arctic oscillation (AO). A decomposition of the variability in the model simulations shows that this relationship is mainly due to internal climate variability. Detailed outputs from one of the models indicate that the western Eurasia snow cover anomalies are preceded by a negative AO phase accompanied by a Ural blocking pattern and a stratospheric polar vortex weakening. The link between the AO and the snow cover variability is strongly related to the concomitant role of the stratospheric polar vortex, with the Eurasian snow cover acting as a positive feedback for the AO variability in winter. No robust influence of the SIC variability is found, as the sea ice loss in these simulations only drives an insignificant fraction of the snow cover anomalies, with few agreements among models.Published2157–2184OSA2: Evoluzione climatica: effetti e loro mitigazioneJCR Journa
Co-Creating GIS-Based Dashboards to Democratize Knowledge on Urban Resilience Strategies: Experience with Camerino Municipality
No full textNatural hazards are increasingly threatening our communities; hence it is imperative to provide communities with reliable information on possible impacts of such disasters, and on resilience measures that can be adopted to recover from disasters. To increase the engagement of various stakeholders in decision-making processes related to resilience to natural hazards, problem-specific information needs to be presented to them in a language understandable to non-experts in the field. To this end, this paper illustrates experimentation with low-code platforms for fast digitalization of resilience reports, incorporating the perspectives of various stakeholders in the analysis, thus making informed decision-making practicable. We present a co-creation-based approach to develop GIS-based user-friendly dashboards in support to the identification of resilience strategies against natural hazards; this approach has been developed within the framework of the European project ARCH. Urban areas are regarded as complex social-ecological systems whose various dimensions should be considered in this resilience endeavor, during all phases of the Disaster Risk Reduction and Climate Change Adaptation cycle. The work presented in this paper specifically targets the possible impacts and risks that might affect the cultural heritage subsystems of our cities, generally underrepresented in the international literature related to urban resilience assessment. We describe how we applied our approach to the Camerino municipality, a historic Italian town exposed to seismic risk, which was struck by a severe earthquake sequence in 2016–2017 and discuss the results of our experience.The research activities have been funded by the project “ARCH—Advancing Resilience of historic areas against Climate-related and other Hazards” funded by Horizon 2020—European Union Research and Innovation Program under grant agreement No. 820999. The sole responsibility for the content of this publication lies with the authors. It does not necessarily represent the opinion of the European Union. Neither the EASME, nor REA, nor the European Commission is responsible for any use that may be made of the information contained therein. The work is also funded by Project 1.7 “Technologies for the efficient penetration of the electric vector in the final uses” within the “Electrical System Research” PTR 22–24.Published65OST4 Descrizione in tempo reale del terremoto, del maremoto, loro predicibilità e impattoJCR Journa
A novel infrastructure for the continuous monitoring of soil CO2 emissions: a case study at the alto Tiberina near fault observatory in Italy
No full textStatic and dynamic stress, along with earthquakes, can trigger the emission and migration of crustal fluids, as frequently observed on the surface and within the upper crust of tectonically active areas such as the northern Apennines of Italy. To investigate the origin of these fluids and their interconnection with the seismogenic process, we complemented The Alto Tiberina Near Fault Observatory (TABOO-NFO), a multidisciplinary monitoring infrastructure composed of a dense array of seismic, geodetic, strain, and radon sensors, with a proper geochemical network grounded on four soil CO2 flux monitoring stations and weather sensors, placed near the main vents of the superficial manifestations. The TABOO-NFO is a state-of-the-art monitoring infrastructure, which allows for studying various geophysical parameters connected to the deformation processes active along a crustal fault system dominated by the Alto Tiberina fault (ATF), which is a 60 km long normal fault dipping at a low angle (<15°–20°). The region is favourable for conducting geochemical studies, as it is characterised by the presence of over-pressurised fluids trapped at certain depths and superficial manifestations associated with the emission of large quantities of fluids. After describing the theoretical framework and the technological aspects based on which we developed the geochemical monitoring network, we described the data recorded in the first months. Over the studied period, the results showed that soil CO2 flux was primarily influenced by environmental parameters, and that the selected sites received a regular supply of deep-origin CO2.Published11726437T. Variazioni delle caratteristiche crostali e "precursori"9T. Geochimica dei fluidi applicata allo studio e al monitoraggio di aree sismiche1IT. Reti di monitoraggio e sorveglianzaJCR Journa
Insights into magma dynamics at Etna (Sicily) from SO2 and HCl fluxes during the 2008–2009 eruption
No full textMagma convection, where low-viscosity, gas-rich magma ascends, degasses, and crystallizes before sinking down the same conduit in either annular or side-by-side flows, has been proposed for active basaltic volcanoes, where excess gas fluxes relative to erupted lava volume can be observed. Experimental studies show that convection is produced by buoyant ascending gas-rich magma and descending degassed magmas following density difference contrast, while geophysical studies point to the endogenous growth of active volcanoes through magma accumulation in plutons. However, many aspects of the convection process remain unclear, in particular, the depth to which magma ascends before overturning. Models have been proposed where overturn occurs near the surface and also at depths greater than 2 km from the top of the magma-filled conduit. The long-term monitoring of volcanic gas compositions may reveal new insights into the convection process, as each gas has a unique solubility-pressure profile. We report measurements of SO2 and HCl gas fluxes from Etna between October 2007 and May 2011, in which an ~90% collapse in halogen flux was observed together with an effusive eruption. This observation indicates that the halogen fluxes, during quiescent periods on Etna, require both magma supply to the shallowest levels and a period of residence. The lava effusion has the effect of reducing the shallow residence time, drastically reducing the halogen flux. These results provide a new interpretative framework for the degassing process and gas composition monitoring to explain subtle variations in magma supply and residence times in basaltic volcanism.Published419-423JCR Journa
Tracking a Pyroclastic Density Current With Seismic Signals at Mt. Etna (Italy)
No full textPyroclastic density currents (PDCs) are dangerous flows of volcanic rock and gas that are the
most deadly proximal volcano hazard. There is significant interest in better understanding PDC dynamics,
however, they are challenging to study due to their extreme hazard, unpredictable occurrence, and because
complex internal dynamics are obscured by visually opaque clouds of ash. PDCs exert forces on Earth's surface
and generate seismic waves. Here, we use seismic data recorded by the permanent monitoring network at Mt.
Etna (Italy) to track the 11 February 2014 PDC at second-scale temporal resolution and calculate a maximum
velocity of 76 m/s (274 km/hr). We identify multiple pulses and show that the late-stage source locations
correspond with the mapped coarse-grained PDC deposits. High temporal and spatial resolution measurements
of PDC movement from seismic data can be used to inform numerical modeling of PDC dynamics and aid
in hazard assessment by improving our understanding of PDC flow paths. This work illustrates how seismic
signals can be used to track surficial mass movements in real-time.Publishede2022JB0261145V. Processi eruttivi e post-eruttiviJCR Journa
Urban Seismic Networks: A Worldwide Review
No full textSeismic networks in urban areas today represent key infrastructure to better address the tasks of earthquake preparation and mitigation in the pre-event phase, and are an important knowledge tool supporting disaster risk management during seismic crises and post-disaster recovery. In the last fifteen years, a decrease in instrumentation costs and the development of new low-cost devices have enhanced the deployment of several monitoring and experimental networks worldwide. This paper conducts a review of scientific work that refer to the deployment of Urban Seismic Networks (USN) in order to define the current state of the art. We collected a list of more than one hundred USNs worldwide that were operative within the period from 1994–2023. For each USN, we report the locations and objectives along with information about the timing, coverage, geometry, and technical characteristics (sensors and transmission). By reviewing all these aspects, this paper offers important insights to provide guidelines for new implementations, bearing in mind that the interest in monitoring urban areas is expected to continue to increase in the near future driven by population growth in urbanized areas.Published13165OST5 Verso un nuovo MonitoraggioJCR Journa
Correlation between small earthquakes and CO2 anomalies in spring waters: a statistical experiment on the probability of seismic occurrence
No full textWe correlated carbon dioxide (CO2) time series detected at the Gallicano site in Tuscany, Italy, with low-magnitude earthquakes occurred in the surrounding area between 2017 and 2021. The CO2 irregular component distribution was analyzed by a Pearson type VII fit, and its cumulate probability by the Gauss’s hypergeometric function, to statistically evidence anomalous fluctuations. We calculated the Matthews correlation between gas concentrations and low-magnitude earthquakes by defining a binary occurrence of CO2 anomalies and seismic events. A positive correlation was highlighted by a time lag between the digital series, which resulted in CO2 anomaly detections ahead of the earthquake time of two days. The correlated earthquakes were mainshocks of local magnitude 1.2 to 3.6, with epicenters within 40 km from the Gallicano site. Correlations among rainfalls, CO2 concentrations and earthquakes were also considered, showing that only few rainfall events were followed by a CO2 anomaly, mostly a day late.Published1128949OST5 Verso un nuovo MonitoraggioJCR Journa