The 2012 Ferrara seismic sequence: from a 1D reliable crustal structure for moment tensor solutions to strong implications for seismic hazard

On May 20 2012, an event of Ml 5.9 (Mw 5.6) stuck the southem edge of the Po river plain (Pianura Padana). The earthquake was preceded by a foreshock of Ml 4.1 (Mw 3.8), less than 3 hours before the Mw 5.6 main. Hypocentral depths were 6.3 km for both events. Centroid depths were 5 and 6 km, respectively. The activated fault was a reverse one, dipping to the south. Then a complex seismic sequence started, in which more than six earthquakes with Ml greater than 5 stuck the area, the last one on June 3, 2012. Aftershocks delineated a 50 km long and 10-15 km wide zone, approximately elongated in the WE direction. More than 2100 events were located between May 19 and June 25 2012 by the INGV National Seismic Network, 80 of them with Ml greater than 3.5. The damage due to the Ml 5+ earthquakes was widespread, as they severely hit historical towns and industrial infrastructures. However, a striking inconsistency exists between the relatively small moment magnitudes and the corrisponding high level of damage. In order to define a velocity structure for the crust beneath the Pianura Padana, to be used for waveform inversion of moment tensors, we gathered all the geophysical and geological information available for the area. The model is characterized by very thick and shallow Quaternary sediments, to be used for the inversion of broadband waveforms for moment tensor (MT) solutions, in the frequency band between 0.02-0.1 Hz. We calculated moment tensors for 20 events down to Mw~3.2. We demonstrate how surface waves dominate the seismograms in the region, which may have played a major role in enhancing the damage to industrial structures observed in the epicentral area. Synthetic seismograms computed using the developed model well reproduced the anomalous durations of the ground motion observed in Pianura Padana, also highlighting important implications for the seismic hazard in the entire area. The present seismic hazard assessment as well as the size of the historical earthquakes in the region (and so their recurrence times), may need to be re-evaluated in the light of this new results

Crustal permeability changes inferred from seismic attenuation: Impacts on multi-mainshock sequences

We use amplitude ratios from narrowband-filtered earthquake seismograms to measure variations of seismic attenuation over time, providing unique insights into the dynamic state of stress in the Earth’s crust at depth. Our dataset from earthquakes of the 2016–2017 Central Apennines sequence allows us to obtain high-resolution time histories of seismic attenuation (frequency band: 0.5–30 Hz) characterized by strong earthquake dilatation-induced fluctuations at seismogenic depths, caused by the cumulative elastic stress drop after the sequence, as well as damage-induced ones at shallow depths caused by energetic surface waves. Cumulative stress drop causes negative dilatation, reduced permeability, and seismic attenuation, whereas strong-motion surface waves produce an increase in crack density, and so in permeability and seismic attenuation. In the aftermath of the main shocks of the sequence, we show that the M ≥ 3.5 earthquake occurrence vs. time and distance is consistent with fluid diffusion: diffusion signatures are associated with changes in seismic attenuation during the first days of the Amatrice, Visso-Norcia, and Capitignano sub-sequences. We hypothesize that coseismic permeability changes create fluid diffusion pathways that are at least partly responsible for triggering multi-mainshock seismic sequences. Here we show that anelastic seismic attenuation fluctuates coherently with our hypothesis

Investigating the possible causal role of coffee consumption with prostate cancer risk and progression using Mendelian randomization analysis.

Coffee consumption has been shown in some studies to be associated with lower risk of prostate cancer. However, it is unclear if this association is causal or due to confounding or reverse causality. We conducted a Mendelian randomisation analysis to investigate the causal effects of coffee consumption on prostate cancer risk and progression. We used two genetic variants robustly associated with caffeine intake (rs4410790 and rs2472297) as proxies for coffee consumption in a sample of 46,687 men of European ancestry from 25 studies in the PRACTICAL consortium. Associations between genetic variants and prostate cancer case status, stage and grade were assessed by logistic regression and with all-cause and prostate cancer-specific mortality using Cox proportional hazards regression. There was no clear evidence that a genetic risk score combining rs4410790 and rs2472297 was associated with prostate cancer risk (OR per additional coffee increasing allele: 1.01, 95% CI: 0.98,1.03) or having high-grade compared to low-grade disease (OR: 1.01, 95% CI: 0.97,1.04). There was some evidence that the genetic risk score was associated with higher odds of having nonlocalised compared to localised stage disease (OR: 1.03, 95% CI: 1.01, 1.06). Amongst men with prostate cancer, there was no clear association between the genetic risk score and all-cause mortality (HR: 1.00, 95% CI: 0.97,1.04) or prostate cancer-specific mortality (HR: 1.03, 95% CI: 0.98,1.08). These results, which should have less bias from confounding than observational estimates, are not consistent with a substantial effect of coffee consumption on reducing prostate cancer incidence or progression.British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, and the National Institute for Health Research, under the auspices of the UK Clinical Research Collaboration Cancer Research UK. Grant Number: C18281/A19169 RMM and Caroline Relton (Integrative Cancer Epidemiology Programme) Canadian Institutes of Health Research the European Commission's Seventh Framework Programme. Grant Numbers: 223175, HEALTH-F2-2009-223175 Cancer Research UK. Grant Numbers: C5047/A7357, C1287/A10118, C5047/A3354, C5047/A10692, C16913/A6135 National Institute of Health (NIH) Cancer Post-Cancer GWAS. Grant Number: 1 U19 CA 148537-01 the GAME-ON initiative the European Community's Seventh Framework Programme. Grant Numbers: 223175, HEALTH-F2-2009-223175 Cancer Research UK. Grant Numbers: C1287/A10118, C1287/A 10710, C12292/A11174, C1281/A12014, C5047/A8384, C5047/A15007, C5047/A10692 the National Institutes of Health. Grant Number: CA128978 Post-Cancer GWAS initiative. Grant Numbers: 1U19 CA148537, 1U19 CA148065, 1U19 CA148112 the GAME-ON initiative the Department of Defence. Grant Number: W81XWH-10-1-0341 the Canadian Institutes of Health Research (CIHR) CIHR Team in Familial Risks of Breast Cancer Komen Foundation for the Cure Breast Cancer Research Foundation. Grant Number: Ovarian Cancer Research Fund VicHealth and Cancer Council Victoria Australian NHMRC. Grant Numbers: 209057, 251553, 504711 Cancer Council Victoria Australian Institute of Health and Welfare (AIHW) National Death Index and the Australian Cancer Database U.K. Health Technology Assessment (HTA) Programme of the NIH Research. Grant Numbers: HTA 96/20/99, ISRCTN20141297 Prodigal study and the ProMPT (Prostate Mechanisms of Progression and Treatment) National Cancer Research Institute (NCRI) Department of Health, the Medical Research Council and Cancer Research UK. Grant Number: G0500966/75466 Cancer Research UK. Grant Number: C5047/A7357 NIHR Biomedical Research Centre at The Institute of Cancer Research and Royal Marsden NHS Foundation Trust National Institute for Health Research Bristol Nutrition Biomedical Research Unit based at University Hospitals Bristol NHS Foundation Trust and the University of Bristol FCH, DEN and JLD are NIHR Senior Investigators MRC and the University of Bristol. Grant Numbers: G0600705, MC_UU_12013/6This is the final version of the article. It first appeared from Wiley via https://doi.org/10.1002/ijc.3046

On the Relationship betweenMwandMLfor Small Earthquakes

Estimating the moment magnitudes (Mw) of a small earthquake is a challenging task. One viable option to measure its size is to calculate its local magnitude (ML) and convert it to the physically basedMw. Unfortunately, to correctly perform such a conversion is not easy; moreover, even though many studies demonstrate that the equivalence betweenML andMw is incorrect for small events, these two parameters are sometimes thought to be strictly equivalent, regardless of the earthquake’s size. Using random vibration theory, we show that, below Mw ∼ 4, the ML of a small earthquake is proportional to the logarithm of its seismic moment, and the following relationship holds: EQ-TARGET;temp:intralink-;;55;536 MwSMALL 2 3 MLSMALL C′: We test our findings on a high-quality data set in the Upper Tiber Valley (northern Apennines, Italy), composed of events in the range of 0 ≤ ML ≤ 3:8, for which we compute accurate estimates of ML and Mw. Online Material: Details of the processing procedure, figures of the empirical regional attenuation functional, and source terms of 1191 events from the Alto Tiberina fault (ATF) data set and earthquake catalog.Published2402-24082T. Sorgente SismicaJCR Journa

Moment magnitude and local magnitude of small earthquakes nucleating along a low angle normal fault in the Upper Tiber Valley (Italy)

The computation of the moment magnitude of small earthquakes (MW < 3) allows the investigation of key aspects of the physics of the seismic source, like the scaling properties of earthquakes. In order to do that, we analyse the crustal propagation of seismic waves in the Upper Tiber Valley (Northern Apennines, Italy) using 38,000 high-resolution broadband seismograms from 1192 well-located micro-earthquakes that occurred between 2010 and 2014, in the local magnitude range -1.0 ≤ ML ≤ 3.8. Because we use weak-motion data, we maximize the signal-to-noise ratios by applying a complex technique based on Random Vibration Theory (RVT). Our analysis of the data produced two main results: i) we are able to calculate the seismic moment (and moment magnitude) for very small events, down to at least MW = -1.5. ii) we determined a relationship between MW and ML , and use RVT to show that ML ~ log10 (M0) for small earthquakes.PublishedSan Francisco2T. Sorgente Sismic

Residential Buildings’ Real Estate Values Linked to Summer Surface Thermal Anomaly Patterns and Urban Features : A Florence (Italy) Case Study

Climate-change-related extreme events impact ecosystems, people, economy, and infrastructures, with important consequences on the real estate market as well. This study aims to investigate the variation of residential buildings’ real estate values in a historic Italian city in relation to the summer surface thermal anomaly pattern and urban features surrounding buildings. Open data from remote sensing products and the national database of the Revenue Agency of Italy were used. Real estate values of residential buildings were spatially analyzed in four urban belts, and the association with daytime summer surface hot- and cool-spot zones was studied through odds ratio (OR) statistic. Urban features (impervious area, tree cover, grassland area, and water body) surrounding residential buildings with different real estate values were also analyzed. Considering the whole Florentine municipality, 13.0% of residential buildings fell into hot-spot zones (only 0.6% into cool-spot ones), characterized by very low tree cover surfaces (generally <1%), most of which were in the central belt (37% of all buildings in central belt). Almost 10% of these buildings belonged to the highest market value class revealing a positive association (OR = 1.53) with hot-spot zones. This study provides useful information to plan targeted building interventions to avoid a probable decrease of the value of residential properties in high heat-related risk areas

Source characteristic of 2000 small earthquakes nucleating on the Alto Tiberina fault system (Central Italy)

The Alto Tiberina Fault (ATF) is a 60 km long east-dipping low-angle normal fault, located in a sector of the Northern Apennines (Italy) undergoing active extension since the Quaternary (Chiaraluce et al. 2007). The ATF has been imaged by analyzing the active source seismic reflection profiles, and the instrumentally recorded persistent background seismicity. The present study is an attempt to separate the contributions of source, site, and crustal attenuation, in order to focus on the mechanics of the ATF, as well as the syn- and antithetic structrure related on the ATF hanging-wall (i.e. Gubbio fault and Umbria Valley fault). In order to compute source spectra, we perform a set of regression over the seismograms of ~ 400 small earthquakes (0.5 < ML < 3.0) recorded between 2010 and 2014 at 50 permanent seismic stations deployed in the framework of the Alto Tiberina Near Fault Observatory project (TABOO; Chiaraluce et al., 2014), three of which located in shallow boreholes. Because we deal with some very small earthquakes, we maximize the signal to noise ratio (SNR) with a technique based on the analysis of peak values of bandpass-filtered time histories, in addition to the same processing performed on Fourier amplitudes. We rely on Random Vibration Theory (RVT, Cartwright and Longuet-Higgins, 1956) to completely switch from peak values in the time domain to Fourier spectral amplitudes. So far, highly accurate, stable source spectra have been used to compute moment magnitudes (Mw) of all the events in the present data set, whereas in future developments the same data will be used to gain insights into the underlying mechanics of faulting and the earthquake processes.UnpublishedSan Francisco2T. Sorgente Sismic

Time Variability of crustal attenuation during the Amatrice-Visso-Norcia earthquake sequence in the Central Apennines (Italy)

Over the last decade our work has been mostly about reducing uncertainties over spectral measurements in seismology (e.g. Malagnini and Munafò, 2018; Malagnini and Dreger, 2016; Munafò et al., 2016; Akinci et al., 2014). Here we measure time-domain peak values from narrow bandpass-filtered time histories and transform them into spectral estimates by using the theoretical results of Random Vibration Theory (Cartwright and Longuet-Higgins, 1956) and the Parseval Theorem. We develop a novel approach to quantify time domain fluctuations of highfrequency seismic attenuation and apply it to a massive data set of seismic waveforms from the Central Apennines in Italy, which includes recordings spanning the recent earthquake sequence of Amatrice-Visso-Norcia (2016-2017). Our observations show that the crustal seismic wave propagation in the region is strongly affected by transients triggered by the main events. The time varying attenuation is probably due to the associated migration of crustal fluids, in addition to seasonal oscillations related to precipitation-induced variations of crustal stresses. We also observe oscillation periods in the attenuation time series corresponding to solid Earth tides. Sensitivity to tides is stronger in the aftermath of the mainshocks, indicating an important role played by rock damage.SubmittedWashington7T. Variazioni delle caratteristiche crostali e precursori sismic

The 2012 Ferrara seismic sequence: from a 1D reliable crustal structure for moment tensor solutions to strong implications for seismic hazard

On May 20 2012, an event of Ml 5.9 (Mw 5.6) stuck the southem edge of the Po river plain (Pianura Padana). The earthquake was preceded by a foreshock of Ml 4.1 (Mw 3.8), less than 3 hours before the Mw 5.6 main. Hypocentral depths were 6.3 km for both events. Centroid depths were 5 and 6 km, respectively. The activated fault was a reverse one, dipping to the south. Then a complex seismic sequence started, in which more than six earthquakes with Ml greater than 5 stuck the area, the last one on June 3, 2012. Aftershocks delineated a 50 km long and 10-15 km wide zone, approximately elongated in the WE direction. More than 2100 events were located between May 19 and June 25 2012 by the INGV National Seismic Network, 80 of them with Ml greater than 3.5. The damage due to the Ml 5+ earthquakes was widespread, as they severely hit historical towns and industrial infrastructures. However, a striking inconsistency exists between the relatively small moment magnitudes and the corrisponding high level of damage. In order to define a velocity structure for the crust beneath the Pianura Padana, to be used for waveform inversion of moment tensors, we gathered all the geophysical and geological information available for the area. The model is characterized by very thick and shallow Quaternary sediments, to be used for the inversion of broadband waveforms for moment tensor (MT) solutions, in the frequency band between 0.02-0.1 Hz. We calculated moment tensors for 20 events down to Mw~3.2. We demonstrate how surface waves dominate the seismograms in the region, which may have played a major role in enhancing the damage to industrial structures observed in the epicentral area. Synthetic seismograms computed using the developed model well reproduced the anomalous durations of the ground motion observed in Pianura Padana, also highlighting important implications for the seismic hazard in the entire area. The present seismic hazard assessment as well as the size of the historical earthquakes in the region (and so their recurrence times), may need to be re-evaluated in the light of this new results.PublishedRoma3T. Pericolosità sismica e contributo alla definizione del rischioope

A Spectral-Lagrangian Boltzmann Solver for a Multi-Energy Level Gas

In this paper a spectral-Lagrangian method for the Boltzmann equation for a multi-energy level gas is proposed. Internal energy levels are treated as separate species and inelastic collisions (leading to internal energy excitation and relaxation) are accounted for. The formulation developed can also be used for the case of a mixture of monatomic gases without internal energy (where only elastic collisions occur). The advantage of the spectral-Lagrangian method lies in the generality of the algorithm in use for the evaluation of the elastic and inelastic collision operators. The computational procedure is based on the Fourier transform of the partial elastic and inelastic collision operators and exploits the fact that these can be written as weighted convolutions in Fourier space with no restriction on the crosssection model. The conservation of mass, momentum and energy during collisions is enforced through the solution of constrained optimization problems. Numerical solutions are obtained for both space homogeneous and space inhomogeneous problems. Computational results are compared with those obtained by means of the DSMC method in order to assess the accuracy of the proposed spectral-Lagrangian method