Struttura crostale e subcrostale della penisola italiana dalla interpretazione congiunta di immagini tomografiche e profile DSS

Questo studio rappresenta la conclusione di una serie di analisi precedentemente proposte e volte alla migliore comprensione della struttura profonda della penisola italiana. Tale serie, iniziata con il confronto tra la sismicità crostale e le interpretazioni dei profili DSS (Cassinis e Solarino, 2004; Cassinis e Solarino, 2006), si era successivamente estesa alla struttura litosferica (Solarino e Cassinis, 2005; Solarino e Cassinis, 2007). In ambedue le occasioni lo studio era stato condotto avendo cura di utilizzare le più recenti elaborazioni dei profili e selezionando gli ipocentri con criteri molto restrittivi. Nello spirito dei precedenti lavori, anche in questo caso si è eseguita una analisi congiunta di dati ottenuti con diverse tecniche sovrapponendo alle interpretazioni già esistenti le informazioni ricavate da un recente studio tomografico (Scafidi et al., 2008) effettuato con la tecnica della inversione di terremoti locali (Thurber, 1983)

An automatically generated high-resolution earthquake catalogue for the 2016–2017 Central Italy seismic sequence, including P and S phase arrival times

The 2016–2017 central Italy earthquake sequence began with the first main shock near the town of Amatrice on August 24 (Mw 6.0), and was followed by two subsequent large events near Visso on October 26 (Mw 5.9) and Norcia on October 30 (Mw 6.5), plus a cluster of four events with Mw > 5.0 within few hours on 18 January 2017. The affected area had been monitored before the sequence started by the permanent Italian National Seismic Network (RSNC), and was enhanced during the sequence by temporary stations deployed by the National Institute of Geophysics and Volcanology and the British Geological Survey. By the middle of September, there was a dense network of 155 stations, with a mean separation in the epicentral area of 6–10 km, comparable to the most likely earthquake depth range in the region. This network configuration was kept stable for an entire year, producing 2.5 TB of continuous waveform recordings. Here we describe how this data was used to develop a large and comprehensive earthquake catalogue using the Complete Automatic Seismic Processor (CASP) procedure. This procedure detected more than 450 000 events in the year following the first main shock, and determined their phase arrival times through an advanced picker engine (RSNI-Picker2), producing a set of about 7 million P- and 10 million S-wave arrival times. These were then used to locate the events using a non-linear location (NLL) algorithm, a 1-D velocity model calibrated for the area, and station corrections and then to compute their local magnitudes (ML). The procedure was validated by comparison of the derived data for phase picks and earthquake parameters with a handpicked reference catalogue (hereinafter referred to as ‘RefCat’). The automated procedure takes less than 12 hr on an Intel Core-i7 workstation to analyse the primary waveform data and to detect and locate 3000 events on the most seismically active day of the sequence. This proves the concept that the CASP algorithm can provide effectively real-time data for input into daily operational earthquake forecasts, The results show that there have been significant improvements compared to RefCat obtained in the same period using manual phase picks. The number of detected and located events is higher (from 84 401 to 450 000), the magnitude of completeness is lower (from ML 1.4 to 0.6), and also the number of phase picks is greater with an average number of 72 picked arrival for a ML = 1.4 compared with 30 phases for RefCat using manual phase picking. These propagate into formal uncertainties of ±0.9 km in epicentral location and ±1.5 km in depth for the enhanced catalogue for the vast majority of the events. Together, these provide a significant improvement in the resolution of fine structures such as local planar structures and clusters, in particular the identification of shallow events occurring in parts of the crust previously thought to be inactive. The lower completeness magnitude provides a rich data set for development and testing of analysis techniques of seismic sequences evolution, including real-time, operational monitoring of b-value, time-dependent hazard evaluation and aftershock forecasting

Evaluation of liquefaction triggering potential in Italy: a seismic-hazard-based approach

In the present study, we analyze ground-motion hazard maps and hazard disaggregation in order to define areas in Italy where liquefaction triggering due to seismic activity can not be excluded. To this end, we refer to the triggering criteria (not to be confused with liquefaction susceptibility criteria, which essentially take into account soil type and depth to groundwater) proposed by the Italian Guidelines for Seismic Microzonation, which are described in the main body of the paper. However, the study can be replicated in other countries that adopt different criteria. The final goal is the definition of a screening map for all of Italy that classifies sites in terms of liquefaction triggering potential according to their seismic hazard level. The map, which is referred to with the Italian acronym MILQ – Mappa del potenziale d'Innesco della LiQuefazione (i.e., map of liquefaction triggering potential), and the associated data are freely accessible at the following web address: https://distav.unige.it/rsni/milq.php (last access: 28 April 2023). Our results can be useful to guide land-use planners in deciding whether liquefaction is a hazard that needs to be considered within the planning processes or not. Furthermore, they can serve as a guide for recommending geological and geotechnical investigations aimed at the evaluation of liquefaction hazards or, conversely, rule out further studies with consequent savings in efforts and money.</p

Cigarette smoke increases BLT2 receptor functions in bronchial epithelial cells: in vitro and ex vivo evidence

Leukotriene B4 (LTB4) is a neutrophil chemotactic molecule with important involvement in the inflammatory responses of chronic obstructive pulmonary disease (COPD). Airway epithelium is emerging as a regulator of innate immune responses to a variety of insults including cigarette smoke, the major risk factor for COPD. In this study we have explored whether cigarette smoke extracts (CSE) or soluble mediators present in distal lung fluid samples (mini-bronchoalveolar lavages) from smokers alter the expression of the LTB4 receptor 2 (BLT2) and peroxisome proliferator- activated receptor-a (PPAR-a) in bronchial epithelial cells. We also evaluated the effects of CSE on the expression of intercellular adhesion molecule 1 (ICAM-1) and on the binding of signal transducer and activator of transcription 1 (STAT-1) to ICAM-1 promoter as well as the adhesiveness of neutrophils to bronchial epithelial cells. CSE and minibronchoalveolar lavages from smokers increased BLT2 and ICAM-1 expression as well as the adhesiveness of neutrophils to bronchial epithelial cells and decreased PPAR-a expression. CSE induced the activation of STAT-1 and its binding to ICAM-1 promoter. These findings suggest that, in bronchial epithelial cells, CSE promote a prevalent induction of pro-inflammatory BLT2 receptors and activate mechanisms leading to increased neutrophil adhesion, a mechanism that contributes to airway neutrophilia and to tissue damage

Seismotectonic analysis of a complex fault system in Italy: the "Garfagnana-North" (Northern Tuscany) line

We present the results obtained combining different techniques to determine the seismotectonic character of the Garfagnana region (northern Tuscany). There, the existence of a rather complex fault system is acknowledged and somewhat mapped, but apart from the geological evidences, very little is known about its extension with depth and the regime. The seismic potential of the system is also well known. The area was characterized, in the past, by destructive earthquakes; in particular a major event (Ms=6.4) struck the Lunigiana-Garfagnana area in September 1920, but many others have been reported. Therefore, the seismicity is under constant monitoring by the national seismic network (RSNC – National Central Seismic Network) and a pool of local stations, belonging to a regional network (RSLG – Regional Seimic network of Lunigiana and Garfagnana). These additional stations account for the lower magnitude seismicity. Such a concentration of seismic stations, and the consequent availability of several seismograms, makes likely to record and localize earthquakes down to a very low magnitude threshold (inferior to Ml = 2.0) with extremely narrow hypocentral parameter errors . Making use of the resulting databases, several analyses were conducted to determine the shape, size, extension with depth of the fault and the associated seismicity. The methodology consists in seismic tomography (1D and 3D velocity models), precise location algorithms NonLinLoc and HypoDD (very constrained and reliable locations) and computation of focal mechanisms (fault orientation and source), all combined with the constraints provided by the geology. The main findings of the study are that the concentration of the recent seismic activity is close to the likely location of the most relevant historical events. In particular the earthquakes are distributed along a plane in the range 0 – 20 km depth dipping 30° NE. All focal mechanisms show a transtensive character

Brain energy metabolism: A roadmap for future research

Although we have learned much about how the brain fuels its functions over the last decades, there remains much still to discover in an organ that is so complex. This article lays out major gaps in our knowledge of interrelationships between brain metabolism and brain function, including biochemical, cellular, and subcellular aspects of functional metabolism and its imaging in adult brain, as well as during development, aging, and disease. The focus is on unknowns in metabolism of major brain substrates and associated transporters, the roles of insulin and of lipid droplets, the emerging role of metabolism in microglia, mysteries about the major brain cofactor and signaling molecule NAD+, as well as unsolved problems underlying brain metabolism in pathologies such as traumatic brain injury, epilepsy, and metabolic downregulation during hibernation. It describes our current level of understanding of these facets of brain energy metabolism as well as a roadmap for future research

Il terremoto del 21 giugno 2013 in Lunigiana. Le attività del coordinamento Sismiko

Il 21 giugno 2013 alle ore 10.33 UTC è stato registrato dalla Rete Sismica Nazionale (RSN) [Amato e Mele, 2008; Delladio, 2011] dell’Istituto Nazionale di Geofisica e Vulcanologia (INGV) un terremoto di magnitudo (ML) 5.2 nel distretto sismico1 denominato “Alpi Apuane” tra i comuni di Minucciano in provincia di Lucca e Fivizzano e Casola in provincia di Massa e Carrara, zona conosciuta come “Lunigiana”. L’evento sismico, localizzato dai sismologi in turno presso la sala di sorveglianza sismica di Roma [Basili, 2011] con coordinate 44.153°N e 10.135° E e una profondità di circa 5 km è stato ben risentito in tutta la penisola centro-settentrionale ed è stato seguito in poche ore da numerosi eventi anche di ML ≥ 3.0 (16 nelle prime 72 ore). Storicamente l’area oggetto della sequenza sismica è stata interessata da numerosi terremoti di magnitudo superiore a 5.0 il più grande dei quali quello avvenuto nel 1920 nella zona della Garfagnana (fonte dati: Catalogo Parametrico dei Terremoti Italiani - CPTI11 [Rovida et al., 2011]), ad una distanza di circa 12 km dal mainshock odierno, interessata anch’essa da una piccola sequenza sismica a gennaio del 2013. In considerazione dell’entità dell’evento e seguendo le procedure definite per le situazioni di emergenza internamente all’INGV anche in accordo con l’Allegato A2 della Convenzione vigente 2012- 20203 fra l’ente e il Dipartimento di Protezione Civile (DPC), è stata attivata la Rete Sismica Mobile della sede INGV di Roma (Re.Mo. [Moretti et al., 2010]). Nell’arco di tempo di poco più un’ora dall’accadimento del mainshock è stata disposta l’installazione di una rete sismica temporanea costituita da sei stazioni a integrazione delle reti sismiche permanenti già presenti in area epicentrale (RSN e Regional Seismic network of North-Western Italy – RSNI [Ferretti et al., 2008; 2010; Eva et al., 2010; Pasta et al., 2011]). Nel contempo sono stati consultati tramite e-mail i referenti delle unità di rete sismica mobile delle altre sedi INGV che nell’ambito del coordinamento “Sismiko” [Moretti et al., 2012] negli ultimi due anni hanno dato la propria disponibilità, in termini di personale e strumentazione, ad intervenire in caso di emergenza sismica; sono stati inoltre contattati i colleghi del Dipartimento di Scienze della Terra, dell’Ambiente e della Vita, dell’Università degli Studi di Genova (DISTAV) i più vicini all’area epicentrale e gestori della RSNI che hanno comunicato loro stessi l’intenzione di installare due stazioni temporanee, una in real-time e una in configurazione stand-alone. In questo lavoro viene descritta l’attività compiuta dalla Rete Sismica Mobile INGV, la tempistica dell’intervento effettuato in sinergia con i colleghi dell’Università di Genova, i dettagli circa l'installazione e la gestione delle stazioni sismiche temporanee nel primo mese di attività e una valutazione del dataset acquisito

The Grosmarin experiment

The GROSMARIN (which stands for GrandROSMARIN) cruise is proposed by UMR Géosciences Azur (with fellow french and italian research groups). Its goals are to better characterize active structures along this zone and to assess the resulting seismic hazard in a sort of continuation with respect to the MALISAR experiment, which has already surveyed some active structures through shallow observations. The GROSMARIN cruise is in fact the necessary counterpart to characterize them at depth