bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary analysis of surface temperature anomalies that preceded the two major Emilia 2012 earthquakes (Italy)
Authors: Kai Qin  , Lixin X. Wu  , Angelo De Santis  , Gianfranco Cianchini
Published: June 2021

In the 1980's, from an analysis of satellite images, Russian scientists reported on a short-term thermal infrared radiation enhancement that occurred before some medium-to-large earthquakes in central Asia [Gorny et al. 1988]. Since then, many researchers have been studying earthquake thermal anomalies with satellite remote sensing data [Qiang et al. 1991, Tronin 1996, Tramutoli et al. 2001, Ouzounov and Freund 2004, Saraf and Choudhury 2004, Aliano et al. 2008, Blackett et al. 2011]. Recently, abnormal surface latent heat flux [Dey and Singh 2003, Cervone et al. 2005, Qin et al. 2009, Qin et al. 2011, Qin et al. 2012], outgoing long-wave radiation [Ouzounov et al. 2007] and microwave radiation [Takashi and Tadashi 2010] have also been shown to precede earthquakes. To investigate the possible physical mechanisms of such satellite thermal anomalies, some studies conducted a series of detecting experiments on rock loaded to fracturing [Wu et al. 2000, Freund 2002, Wu et al. 2002, Wu et al. 2006a, Wu et al. 2006b, Freund et al. 2007], and some hypotheses have been proposed. These have included: leaking of pore-gas, and hence the resulting greenhouse effect [Qiang et al. 1995]; activating and recombining of p-holes during rock deformation [Freund 2002]; release of latent heat due to near-surface air ionization [Pulinets et al. 2006], and stress-induced thermal effects due to friction and fluids [Wu and Liu 2009]. […] In this study, the long-term temperature data from both satellite and ground (with greater emphasis on the satellite data) have been used to determine whether there were thermal anomalies associated with this Emilia 2012 seismic sequence. In particular, the next section will be dedicated to describing both the data and the method of analysis. In Section 3, we provide the more significant results, which we discuss in Section 4, together with the main conclusions. […]
Effects on the groundwater levels of the May-June 2012 Emilia seismic sequence
Authors: Marco Marcaccio  , Giovanni Martinelli
Published: June 2021

A variety of phenomena were observed in the groundwaters in concomitance with the May-June 2012 seismic sequence that occurred in the Emilia Romagna area. In particular, phreatic wells close to the epicentral area were affected by a sudden increase in water level of up to 4 m. In some cases, the sands of aquifers were ejected outside wells, and >700 liquefaction phenomena were recorded [Bertolini and Fioroni 2012, this volume]. Some automatic stations of the regional well network recorded variations in well levels. These data can be considered useful to understand the relationships between seismic events and the local groundwaters [see also Italiano et al. 2012, this volume]. […] In 1976, a regional network composed of 330 wells was set up with the purpose of monitoring the groundwater levels using manual techniques. These data have been used for environmental purposes and for water management. In recent years, the monitoring network managed by Agenzia Regionale Prevenzione e Ambiente (ARPA) has increased the number of wells (to about 600), and chemical analyses are also periodically carried out for environmental monitoring activities. In the past three years, an automatic monitoring network composed of 40 stations was set up and this has allowed the monitoring of the water levels and the temperatures, at a rate of one measure per hour, and to broadcast the data to the host center located in Bologna. […]
Rapid scenarios and observed intensities
Authors: Franco Pettenati  , Livio Sirovich
Published: June 2021

After a destructive earthquake, national Governments need to know the approximate amount of damage, the number of casualties, and the financial losses as soon as possible. Rapid scenarios are also used to inform the general public; see the widely used Shakemap package [Wald et al. 1999, 2006] of the US Geological Survey (USGS) and the one modified by the Istituto Nazionale di Geofisica e Vulcanologia (INGV; National Institute of Geophysics and Volcanology), which is reproduced for Figure 1. The general matter of the use of intensities in damage scenarios was discussed in a special session at the 2008 Annual Meeting of the Seismological Society of America (http://www.seismosoc.org/meetings/2008/specialsessions.html), and was also discussed in the NIS-1 session of the European Congress in Moscow, in August 2012 (http://www.esc2012-moscow.org/esc_thematicareas.html). The purposes of the present report are to: (i) compare different types of intensities; (ii) check two rapid scenarios of intensity; and (iii) understand whether the KF formula [Sirovich 1996, Sirovich et al. 2009] can be used as a new 'attenuation' relationship to improve rapid scenarios. […]
Vertical slip rates of active faults of southern Albania inferred from river terraces
Authors: Oswaldo Guzmán  , Jean-Louis Mugnier  , Riccardo Vassallo  , Rexhep Koçi  , François Jouanne
Published: June 2021

Fluvial terraces of Shkumbin, Devoll, Osum and Vjosa rivers (southern Albania and northwestern Greece) are studied in order to quantify the vertical slip rates of the large active faults of the Dinaric-Albanic-Hellenic Alpine fold belt. The spatial and temporal variations of the incision rates along these rivers were estimated from the geomorphological mapping of the Quaternary sediments, the geometry and the dating of the terraces. Eleven terraces levels were identified in Albania from 68 geochronological ages already published or acquired for this work. The five lower terraces of the four studied rivers are well dated (10 new and 23 already published ages). These terraces are younger than 30 ka and their remnants are numerous. Their restoration allows estimating the regional trend of incision rate and the identification of local shifts. We argue that these shifts are linked to the active tectonics when they coincide with the faults already mapped by previous authors. Vertical slip rates for eight active faults in southern Albania are thus estimated for the last 19 ka and vary from ~0.1 to ~2 mm/a. The Lushnje Tepelene Thrust, that extends more than 120 kilometers, has a throw rate that varies from 0.2 to 0.8 mm/a, whereas the active faults of the extensional domain are segmented but are very active, with throw rates reaching locally 2 mm/a.
An interhemispheric comparison of GPS phase scintillation with auroral emission observed at the South Pole and from the DMSP satellite
Authors: Paul Prikryl  , Yongliang Zhang  , Yusuke Ebihara  , Reza Ghoddousi-Fard  , Periyadan T. Jayachandran  , Joe Kinrade  , Cathryn N. Mitchell  , Allan T. Weatherwax  , Gary Bust  , Pierre J. Cilliers  , Luca Spogli  , Lucilla Alfonsi  , Vincenzo Romano  , Baiqi Ning  , Guozhu Li  , Martin J. Jarvis  , Donald W. Danskin  , Emma Spanswick  , Eric Donovan  , Mike Terkildsen
Published: June 2021

The global positioning system (GPS) phase scintillation caused by high-latitude ionospheric irregularities during an intense high-speed stream (HSS) of the solar wind from April 29 to May 5, 2011, was observed using arrays of GPS ionospheric scintillation and total electron content monitors in the Arctic and Antarctica. The one-minute phase-scintillation index derived from the data sampled at 50 Hz was complemented by a proxy index (delta phase rate) obtained from 1-Hz GPS data. The scintillation occurrence coincided with the aurora borealis and aurora australis observed by an all-sky imager at the South Pole, and by special sensor ultraviolet scanning imagers on board satellites of the Defense Meteorological Satellites Program. The South Pole (SP) station is approximately conjugate with two Canadian High Arctic Ionospheric Network stations on Baffin Island, Canada, which provided the opportunity to study magnetic conjugacy of scintillation with support of riometers and magnetometers. The GPS ionospheric pierce points were mapped at their actual or conjugate locations, along with the auroral emission over the South Pole, assuming an altitude of 120 km. As the aurora brightened and/or drifted across the field of view of the all-sky imager, sequences of scintillation events were observed that indicated conjugate auroras as a locator of simultaneous or delayed bipolar scintillation events. In spite of the greater scintillation intensity in the auroral oval, where phase scintillation sometimes exceeded 1 radian during the auroral break-up and substorms, the percentage occurrence of moderate scintillation was highest in the cusp. Interhemispheric comparisons of bipolar scintillation maps show that the scintillation occurrence is significantly higher in the southern cusp and polar cap.
Combined geophysical techniques for detailed groundwater flow investigation in tectonically deformed fractured rocks
Authors: John Alexopoulos  , Emmanuel Vassilakis  , Spyridon Dilalos
Published: June 2021

In this paper we present a combination of several near surface geophysical investigation techniques with high resolution remote sensing image interpretations, in order to define the groundwater flow paths and whether they can be affected by future seismic events. A seasonal spring (Amvrakia) located at the foot of Meteora pillars near the village of Kastraki (Greece) was chosen as a test site. The Meteora conglomeratic formations crop out throughout the study area and are characterized by large discontinuities caused by post Miocene till present tectonic deformation [Ferriere et al. 2011, Royden and Papanikolaou 2011]. A network of groundwater pathways has been developed above the impermeable marls underlying the conglomeratic strata. Our research aims to define these water pathways in order to investigate and understand the exact mechanism of the spring by mapping the exposed discontinuity network with classic field mapping and remote sensing image interpretation and define their underground continuity with the contribution of near surface geophysical techniques. Five Very Low Frequency (VLF) profiles were conducted with different directions around the spring aiming to detect possible conductive zones in the conglomeratic formations that the study area consists of. Moreover, two Electrical Resistivity Tomography (ERT) sections of a total length of 140m were carried out parallel to the VLF profiles for cross-checking and verifying the geophysical information. Both techniques revealed important conductive zones (<200 Ohm m) within the conglomerate strata, which we interpret as discontinuities filled with water supplying the spring, which are quite vulnerable to displacements as the hydraulic connections between them might be easily disturbed after a future seismic event.
The IDIPOS project: is a multidisciplinary data infrastructure for weather and space weather feasible?
Authors: Vincenzo Romano  , Luca Spogli  , Alberto Salvati  , Claudio Rafanelli  , Lili Cafarella
Published: June 2021

The Italian National Antarctic Programme (PNRA) has long supported scientific and technological activities addressed to the implementation, upgrade and maintenance of infrastructure and instruments supporting geosciences and physical sciences in the polar region. This report describes the first results of the Italian Database Infrastructure for Polar Observation Sciences (IDIPOS) project, which was recently approved by the PNRA. The project aims to study the feasibility of the hardware and software infrastructure for the construction of relational databases of acquisitions from past and current experiments in the polar areas. The study is based on the fundamental characteristics of the infrastructure: its implementation in Italy, with locations across the country, and its integration into the existing and future telematics infrastructure that will be available at the Italian bases. The project proposes a modern and high-tech infrastructure dedicated to data treatment, accessibility and archiving, in line with international standards. This infrastructure will allow modern, rapid and reliable treatment of the acquired data. The IDIPOS infrastructure is crucial during the planning phase of scientific and monitoring activities of the PNRA, especially of those included in the Scientific Committee on Scientific Research (SCAR) projects, the International Polar Year, and the framework of international cooperation. In the first phase of the project, the observations are related to research projects in different PNRA sectors. The infrastructure will be potentially extendable to other observational activities. In this report, the infrastructure is introduced, while highlighting its usefulness for weather and space-weather forecasting for the scientific community and in the framework of Global Navigation Satellite System (GNSS) Research and Application for Polar Environment (GRAPE) in particular.
Fluid transfer and vein thickness distribution in high and low temperature hydrothermal systems at shallow crustal level in southern Tuscany (Italy)
Authors: Francesco Mazzarini  , Giovanni Ruggieri  , Ilaria Isola  , Chiara Boschi  , Andrea Dini  , Giovanni Musumeci  , Sergio Rocchi
Published: June 2021

Geometric analysis of vein systems hosted in upper crustal rocks and developed in high and low temperature hydrothermal systems is presented. The high temperature hydrothermal system consists of tourmaline-rich veins hosted within the contact aureole of the upper Miocene Porto Azzurro pluton in the eastern Elba Island. The low temperature hydrothermal system consists of calcite-rich veins hosted within the Oligocene sandstones of the Tuscan Nappe, exposed along the coast in southern Tuscany. Vein thickness distribution is here used as proxy for inferring some hydraulic properties (transmissivity) of the fluid circulation at the time of veins’ formation. We derive estimations of average thickness of veins by using the observed distributions. In the case of power law thickness distributions, the lower the scaling exponent of the distribution the higher the overall transmissivity. Indeed, power law distributions characterised by high scaling exponents have transmissivity three order of magnitude lower than negative exponential thickness distribution. Simple observations of vein thickness may thus provides some clues on the transmissivity in hydrothermal systems.
Preface
Authors: Paola De Michelis  , Gerald Duma
Published: June 2021

Repeat station measurements are designed specifically to represent and model the geomagnetic field and its secular variations on a regional scale with a level of detail that would not be achievable using only data from permanent geomagnetic observatories. Although geomagnetic repeat station surveys have a long tradition in many European countries, they were carried out independently in the individual countries. For this reason, it has been difficult for a long time to use the data efficiently for studies of geomagnetic secular variations of the whole European continent. […]
Sensing the upper and lower levels of the atmosphere during the 2009 equinoxes using GPS measurements
Authors: Wayan Suparta
Published: June 2021

This short-term work characterized the upper and lower levels of the atmosphere through Global Positioning System (GPS) measurements. The observations were conducted during the 2009 equinoxes from two pairs of conjugate polar observing stations: Husafell, Iceland (HUSA) and Resolute in Nunavut, Canada (RESO) and their conjugate pairs at Scott Base (SBA) and Syowa (SYOG) in Antarctica, respectively. The total electron content (TEC), an indicator of the upper atmosphere, and the precipitable water vapor (PWV), which served as the lower atmospheric response, were retrieved and analyzed. The results reveal a good relationship between TEC and PWV at each station during the onset day of the equinoxes, whereas an asymmetrical response was observed in the beginning of and after the equinoxes. In addition, the conjugate pairs were only consistent during the autumnal equinox. Thus, the high correlation was observed following the seasonal pattern for the onset day, while strong and moderate correlations were found only for the vernal equinox in Antarctica and the Arctic, respectively. This relationship reflects the fact that the intensity of solar activity during the solar minimum incident on the lower atmosphere through the conjugate points is associated with the variation of the Sun’s seasonal cycle, whereas the TEC and PWV showed an opposite relationship.
XCO2 retrieved from IASI using KLIMA algorithm
Authors: Samuele Del Bianco  , Bruno Carli  , Marco Gai  , Lucia Maria Laurenza  , Ugo Cortesi
Published: June 2021

Carbon dioxide (CO2) is the main greenhouse gas released into the Earth’s atmosphere by human activities. The concentration of CO2 in the atmosphere depends on the balance of natural sources and sinks, which are being perturbed by anthropogenic forcing due to fossil fuel burning, uncontrolled urban development, deforestation and other land use changes. An improvement in our understanding of processes responsible for absorption of CO2 is urgently needed both for a reliable estimate of future CO2 levels, and for the enforcement of effective international agreements for its containment. [...]
Validation of minor species of the MIPAS2D database
Authors: Enzo Papandrea  , Stefano Casadio  , Enrico Arnone  , Massimo Carlotti  , Elisa Castelli  , Marta De Laurentis  , Bianca Maria Dinelli
Published: June 2021

The MIPAS2D [Dinelli et al., 2010] database has been developed applying the tomographic analysis technique GMTR [Carlotti et al., 2001] to measurements acquired in the nominal observation mode of the complete MIPAS (Michelson Interferometer for Passive Atmosphere Sounding) [Fischer et al., 2008] mission. […]
Geology and geophysics at the archeological park of Vulci (central Italy)
Authors: Marco Marchetti  , Vincenzo Sapia  , Adriano Garello  , Donatella De Rita  , Alessandra Venuti
Published: June 2021

The Vulci archeological site was object of interest by the Soprintendenza ai beni culturali dell’Etruria meridionale (Italian government department responsible for southern Etruria’s cultural heritage) since the beginning of the 20th century. In 2001, the Ministero dei Beni Culturali (Italian ministry of cultural heritage) along with the local authorities, opened a natural-archeological park. In this area, it lies most of the ancient Etruscan city of Velch (today known by its Latin name, Vulci) including the Osteria Necropolis that is the object of this study. Recently, new archaeological excavations were made and the local authorities needed major geological information about the volcanic lithotypes where the Etruscans used to build their necropolis. The aim of this study is to define the geological and geophysical characteristics of the rock lithotypes present in the Vulci park. For this purpose, a geological map of the area (1:10000) has been realized. Moreover, two different geophysical methods were applied: measurements of magnetic susceptibility and electrical resistivity tomography. Magnetic susceptibility analyses clearly identify magnetic contrasts between different lithotypes; the characteristics of the pyroclastic flow that originated the Sorano unit 2 and its vertical facies variations are well recorded by this parameter that along with lithostratigraphic observations provides information about the depositional conditions. Two electrical resistivity tomographies were performed, which show the Sorano unit 2 thickness to be of c. 7 m with resistivity values ranging from 200 to 400 Ω·m. This kind of multidisciplinary approach resulted to be suitable to study this type of archaeological sites, revealing that areas characterized by a relevant thickness and wide areal extension of volcanic lithotypes can be a potential site where Etruscans might have excavated their necropolis.
Determination of the complex frequencies for the normal modes below 1mHz after the 2010 Maule and 2011 Tohoku earthquakes
Authors: Hao Ding  , Wen-Bin Shen
Published: June 2021

Based upon SG (superconducting gravimeter) records, the autoregressive method proposed by Chao and Gilbert [1980] is used to determine the frequencies of the singlets of seven spheroidal modes (0S2, 2S1, 0S3, 0S4, 1S2, 0S0, and 3S1) and the degenerate frequencies of three toroidal modes (0T2, 0T3, and 0T4) below 1 mHz after two recent huge earthquakes, the 2010 Mw8.8 Maule earthquake and the 2011 Mw9.1 Tohoku earthquake. The corresponding quality factor Qs are also determined for those modes, of which the Qs of the five singlets of 1S2 and the five singlets (m=0, m=±2, and m=±3) of 0S4 are estimated for the first time using the SG observations. The singlet m=0 of 3S1 is clearly observed from the power spectra of the SG time series without using other special spectral analysis methods or special time series from pole station records. In addition, the splitting width ratio R of 3S1 is 0.99, and consequently we conclude that 3S1 is normally split. The frequencies and Qs of the modes below 1mHz may contribute to refining the 3D density and attenuation models of the Earth.
Anomalous secular sea-level acceleration in the Baltic Sea caused by isostatic adjustment
Authors: Giorgio Spada  , Marco Olivieri  , Gaia Galassi
Published: June 2021

Observations from the global array of tide gauges show that global sea-level has been rising at an average rate of 1.5-2 mm/yr during the last ~150 years [Douglas 1991, Spada and Galassi 2012]. Although a global sea-level acceleration was initially ruled out [Douglas 1992], subsequent studies [Douglas 1997, Church and White 2006, Jevrejeva et al. 2008, Church and White 2011] have coherently proposed values of ~1 mm/year/century [Olivieri and Spada 2013]. More complex non-linear trends and abrupt sea-level variations have now also been recognized. Globally, these could manifest a regime shift between the late Holocene and the current rhythms of sea-level rise [Gehrels and Woodworth 2013], while locally they result from ocean circulation anomalies, steric effects and wind stress [Bromirski et al. 2011, Merrifield 2011]. Although isostatic readjustment affects the local rates of secular sea-level change [Milne and Mitrovica 1998, Peltier 2004], a possible impact on regional acceleration has been so far discounted [Douglas 1992, Jevrejeva et al. 2008, Woodworth et al. 2009] since the process evolves on a millennium time scale [Turcotte and Schubert 2002]. Here we report a previously unnoticed anomaly in the long-term sea-level acceleration of the Baltic Sea tide gauge records, and we explain it by the classical post-glacial rebound theory and numerical modeling of glacial isostasy. Contrary to previous assumptions, our findings demonstrate that isostatic compensation plays a role in the regional secular sea-level acceleration.
Origin of the gases released from the Acqua Passante and Ermeta wells (Mt. Amiata, central Italy) and possible environmental implications for their closure
Authors: Barbara Nisi  , Orlando Vaselli  , Franco Tassi  , Javier de Elio  , Marcelo Ortega  , Juan Caballero  , Daniele Rappuoli  , Luis Felipe Mazadiego
Published: June 2021

The Mt. Amiata volcano (Tuscany, central Italy) hosts the second largest geothermal field of Italy. Its SW and NE sectors are characterized by the presence of several CO2-rich (>95% by vol.) gas discharges. An intense Hg mining activity had taken place from the 19th century up to the end of the ’70s, particularly close to Abbadia San Salvatore, during which two drillings (Acqua Passante and Ermeta) intercepted a CO2-rich gas fertile horizon. The related gases are emitted in the atmosphere since 1938 and 1959, respectively, causing severe concerns for the local air quality. In this work the results of a geochemical and isotopic survey carried out on these gas emissions from March 2009 to January 2014 are presented. CO2 fluxes from both the two wells and soil from an area of about 653,500 m2 located between them were measured. The two wells are emitting up to 15,000, 92 and 8 tons y-1 of CO2, CH4 and H2S, respectively, while the computed soil CO2 output was estimated at 4,311 ton y-1. The spatial distribution of the CO2 soil flux suggests the presence of preferential patterns, indicating sites of higher permeability. Since the local municipality is evaluating the possibility to plug the Ermeta vent, a temporarily closure should first be carried out to test the possible influence of this operation on the diffuse soil degassing of deep-originated CO2 in the surrounding area. This implies that diffuse soil gases should carefully be monitored before proceeding with its definitive closure.
Improvements on Near Real Time Detection of Volcanic Ash Emissions for Emergency Monitoring with Limited Satellite Bands
Authors: Torge Steensen  , Peter Webley  , Jon Dehn
Published: June 2021

Quantifying volcanic ash emissions syneruptively is an important task for the global aviation community. However, due to the near real time nature of volcano monitoring, many parameters important for accurate ash mass estimates cannot be obtained easily. Even when using the best possible estimates of those parameters, uncertainties associated with the ash masses remain high, especially if the satellite data is only available in the traditional 10.8 and 12.0 μm bands. To counteract this limitation, we developed a quantitative comparison between the ash extents in satellite and model data. The focus is the manual cloud edge definition based on the available satellite reverse absorption (RA) data as well as other knowledge like pilot reports or ground-based observations followed by an application of the Volcanic Ash Retrieval on the defined subset with an RA threshold of 0 K. This manual aspect, although subjective to the experience of the observer, can show a significant improvement as it provides the ability to highlight ash that otherwise would be obscured by meteorological clouds or, by passing over different surfaces with unaccounted temperatures, might be lost entirely and thus remains undetectable for an automated satellite approach. We show comparisons to Volcanic Ash Transport and Dispersion models and outline a quantitative match as well as percentages of overestimates based on satellite or dispersion model data which can be converted into a level of reliability for near real time volcano monitoring. 
Data insertion in volcanic ash cloud forecasting
Authors: Kate Louise Wilkins  , Shona Mackie  , Matthew Watson  , Helen N. Webster  , David J. Thomson  , Helen F. Dacre
Published: June 2021

During the eruption of Eyjafjallajökull in April and May 2010, the London Volcanic Ash Advisory Centre demonstrated the importance of infrared (IR) satellite imagery for monitoring volcanic ash and validating the Met Office operational model, NAME. This model is used to forecast ash dispersion and forms much of the basis of the advice given to civil aviation. NAME requires a source term describing the properties of the eruption plume at the volcanic source. Elements of the source term are often highly uncertain and significant effort has therefore been invested into the use of satellite observations of ash clouds to constrain them. This paper presents a data insertion method, where satellite observations of downwind ash clouds are used to create effective ‘virtual sources’ far from the vent. Uncertainty in the model output is known to increase over the duration of a model run, as inaccuracies in the source term, meteorological data and the parameterizations of the modelled processes accumulate. This new technique, where the dis- persion model (DM) is ‘reinitialized’ part-way through a run, could go some way to addressing this. 
On-site early-warning system for Bishkek (Kyrgyzstan)
Authors: Dino Bindi  , Tobias Boxberger  , Sagynbek Orunbaev  , Marco Pilz  , Jacek Stankiewicz  , Massimiliano Pittore  , Iunio Iervolino  , Enrico Ellguth  , Stefano Parolai
Published: June 2021

In this work, the development of an on-site early warning system for Bishkek (Kyrgyzstan) is outlined. Several low cost sensors equipped with MEMS accelerometers are installed in eight buildings distributed within the urban area. The different sensing units communicate each other via wireless links and the seismic data are streamed in real-time to the data center using internet. Since each single sensing unit has computing capabilities, software for data processing can be installed to perform decentralized actions. In particular, each sensing unit can perform event detection task and run software for on-site early warning. If a description for the vulnerability of the building is uploaded in the sensing unit, this piece of information can be exploited to introduce the expected probability of damage in the early-warning protocol customized for a specific structure.
A summary of hazard datasets and guidelines supported by the Global Earthquake Model during the first implementation phase
Authors: Marco Pagani  , Julio Garcia  , Damiano Monelli  , Graeme Weatherill  , Anselm Smolka
Published: June 2021

The Global Earthquake Model (GEM) initiative promotes open, transparent and collaborative science aimed at the assessment of earthquake risk and its reduction worldwide. During the first implementation phase (2009-2014) GEM sponsored five projects aimed at the creation of global datasets and guidelines toward the creation of open, transparent and, as far as possible, homogeneous hazard input models. These projects concentrated on the following global databases and models: an instrumental catalogue, a historical earthquake archive and catalogue, a geodetic strain rate model, a database of active faults, and set of ground motion prediction equations. This paper describes the main outcomes of these projects illustrating some initial applications as well as challenges in the creation of hazard models.
Central Asia earthquake catalogue from ancient time to 2009
Authors: Natalya N. Mikhailova  , Aidyn S. Mukambayev  , Irina L. Aristova  , Galina Kulikova  , Shahid Ullah  , Marco Pilz  , Dino Bindi
Published: June 2021

In this work, we present the seismic catalogue compiled for Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan and Turkmenistan) in the framework of the Earthquake Model Central Asia (EMCA) project. The catalogue from 2000 B.C. to 2009 A.D. is composed by 33,034 earthquakes in the MLH magnitude (magnitude by surface waves on horizontal components widely used in practice of the former USSR countries) range from 1.5 to 8.3. The catalogue includes both macroseimic and instrumental constrained data, with about 32,793 earthquake after 1900 A.D. The main sources and procedure used to compile the catalogues are discussed, and the comparison with the ISC-GEM catalogue presented. Magnitude of completeness analysis shows that the catalogue is complete down to magnitude 4 from 1959 and to magnitude 7 from 1873, whereas the obtained regional b value is 0.805.
Paleomagnetic dating of tectonically influenced Plio-Quaternary fan-system deposits from the Apennines (Italy)
Authors: Michele Saroli  , Marco Moro  , Fabio Florindo  , Michele Lancia  , Pontus C. Lurcock
Published: June 2021

The Roveto Valley is a narrow, elongated, NW-trending depression filled with continental Plio-Quaternary deposits that outcrop at different topographic elevations. A morpho-lithostratigraphic succession of the continental deposits has been defined in order to reconstruct the geological Quaternary evolution of the area. These deposits do not contain materials suitable for biostratigraphic dating; therefore, in order to determine their chronology, three different units were sampled for magnetostratigraphic investigations. Paleomagnetic results demonstrated that standard demagnetization techniques are effective in removing secondary remanence components and in isolating the characteristic remanent magnetization, allowing us to determine, for each cycle, whether it was deposited before or after the Brunhes-Matuyama geomagnetic reversal at 781 ka. Preliminary rock magnetic analyses indicated that magnetite is the main magnetic carrier and that hematite, which gives the pink colour to the matrix, is in the superparamagnetic grain-size range and thus does not retain any paleomagnetic remanence.
Annex 2 to: Trace elements mobility in soils from the hydrothermal area of Nisyros (Greece)
Authors: Kyriaki Daskalopoulou  , Sergio Calabrese  , Silvia Milazzo  , Lorenzo Brusca  , Sergio Bellomo  , Walter D'Alessandro  , Kostantinos Kyriakopoulos  , Franco Tassi  , Francesco Parello
Published: June 2021

A.1 Analytical Tecniques

All soil samples were air dried, thoroughly mixed and split into subsamples for analysis. Particular care was taken using a Riffle-type sample splitter to ensure that representative subsamples were obtained. All analyses were made after sieving the soil samples through a 2-mm sieve and, except for pH determination, ground with an agate mortar. [...]
Application of ionospheric tomography for high frequency oblique incidence ray tracing
Authors: Sandip Nandi  , Bijoy Bandyopadhyay
Published: June 2021

Recognizing the applicability of tomographic imaging in the ionosphere, the reconstruction method has been applied to generate more realistic low latitude ionospheric background based on the Ionex TEC data and also direct measurement TEC data over West Bengal, India. Using these backgrounds, ray tracing of high frequency waves has been performed. Influence of Earth’s magnetic field and also the existence of horizontal gradient of electron concentration in the ionosphere are considered separately for analyzing the ray tracing algorithm. Evaluation of ray tracing parameters and maximum usable frequency for different ground range ensures the possibility of application of ionospheric tomography technique for accurate ray tracing. The analysis shows accurate ray tracing for HF waves, thus defeating the restriction of choice of ionospheric model for analytical ray tracing methods. Performance analysis of the ray tracing technique presented in this paper ensures the consistency of speed with the other methods.
An analytical expression for early electromagnetic signals generated by impulsive line-currents in conductive Earth crust, with numerical examples
Authors: Ken'ichi Yamazaki
Published: June 2021

Changes in the electromagnetic (EM) field after an earthquake rupture but before the arrival of seismic waves (“early EM signals”) have sometimes been reported. Quantitative evaluations are necessary to clarify whether the observed phenomena are accounted for by known theories and to assess whether the phenomenon can be applied to earthquake early warning. Therefore, analytical expressions for the magnetic field generated by an impulsive line-current are derived for a conductive half-space model, and for a two-layer model; the somewhat simpler situation of a conductive whole-space is also considered. By analyzing the expressions obtained for the generated EM field, some expected features of the early EM signals are discussed. First, I verify that an early EM signal arrives before the seismic waves unless conductivity is relatively high. Second, I show that early EM signals are well approximated by the whole-space model when the source is near the ground surface, but not when it is at depth. Third, I show that the expected amplitudes of early EM signals are within the detection limits of commonly used EM sensors, provided that ground conductivity is not very high and that the source current is sufficiently intense. However, this does not mean that the EM signals are easily distinguishable, because detector sensitivity does not account for additive noise or false positive detections.
Assessing ‘alarm-based CN’ earthquake predictions in Italy
Authors: Matteo Taroni  , Warner Marzocchi  , Pamela Roselli
Published: June 2021

The quantitative assessment of the performance of earthquake prediction and/or forecast models is essential for evaluating their applicability for risk reduction purposes. Here we assess the earthquake prediction performance of the CN model applied to the Italian territory. This model has been widely publicized in Italian news media, but a careful assessment of its prediction performance is still lacking. In this paper we evaluate the results obtained so far from the CN algorithm applied to the Italian territory, by adopting widely used testing procedures and under development in the Collaboratory for the Study of Earthquake Predictability (CSEP) network. Our results show that the CN prediction performance is comparable to the prediction performance of the stationary Poisson model, that is, CN predictions do not add more to what may be expected from random chance.
Exploring the submarine Graham Bank in the Sicily Channel
Authors: Mauro Coltelli  , Danilo Cavallaro  , Giuseppe D’Anna  , Antonino D’Alessandro  , Fausto Grassa  , Giorgio Mangano  , Domenico Patanè  , Stefano Gresta
Published: June 2021

In the Sicily Channel, volcanic activity has been concentrated mainly on the Pantelleria and Linosa islands, while minor submarine volcanism took place in the Adventure, Graham and Nameless banks. The volcanic activity spanned mostly during Plio-Pleistocene, however, historical submarine eruptions occurred in 1831 on the Graham Bank and in 1891 offshore Pantelleria Island. On the Graham Bank, 25 miles SW of Sciacca, the 1831 eruption formed the short-lived Ferdinandea Island that represents the only Italian volcano active in historical times currently almost completely unknown and not yet monitored. Moreover, most of the Sicily Channel seismicity is concentrated along a broad NS belt extending from the Graham Bank to Lampedusa Island. In 2012, the Istituto Nazionale di Geofisica e Vulcanologia (INGV) carried out a multidisciplinary oceanographic cruise, named “Ferdinandea 2012”, the preliminary results of which represent the aim of this paper. The cruise goal was the mapping of the morpho-structural features of some submarine volcanic centres located in the northwestern side of the Sicily Channel and the temporary recording of their seismic and degassing activity. During the cruise, three OBS/Hs (ocean bottom seismometer with hydrophone) were deployed near the Graham, Nerita and Terribile submarine banks. During the following 9 months they have recorded several seismo-acoustic signals produced by both tectonic and volcanic sources. A high-resolution bathymetric survey was achieved on the Graham Bank and on the surrounding submarine volcanic centres. A widespread and voluminous gas bubbles emission was observed by both multibeam sonar echoes and a ROV (remotely operated vehicle) along the NW side of the Graham Bank, where gas and seafloor samples were also collected.
First deep underground observation of rotational signals from an earthquake at teleseismic distance using a large ring laser gyroscope
Authors: Andreino Simonelli  , Jacopo Belﬁ  , Nicolò Beverini  , Giorgio Carelli  , Angela Di Virgilio  , Enrico Maccioni  , Gaetano De Luca  , Gilberto Saccorotti
Published: June 2021

Recent advances in large ring laser gyroscopes (RLG) technologies opened the possibility to observe rotations of the ground with sensitivities up to 10−11 rad/sec over the frequency band of seismological interest (0.01-1Hz), thus opening the way to a new geophysical discipline, i.e. rotational seismology. A measure of rotations in seismology is of fundamental interest for (a) the determination of all the six degrees of freedom that characterize a rigid body’s motion, and (b) the quantitative estimate of the rotational motions contaminating ground translation measurements obtained from standard seismometers. Within this framework, this paper presents and describes GINGERino, a new large observatory-class RLG located in Gran Sasso underground laboratory (LNGS), one national laboratories of the INFN (Istituto Nazionale di Fisica Nucleare). We also report unprecedented observations and analyses of the roto-translational signals from a tele-seismic event observed in such a deep underground environment.
The use of the empirical mode decomposition for the identification of mean field aligned reference frames
Authors: Mauro Regi  , Alfredo Del Corpo  , Marcello De Lauretis
Published: June 2021

The magnetic field satellite data are usually referred to geocentric coordinate reference frame. Conversely, the magnetohydrodynamic waves modes in magnetized plasma depend on the ambient magnetic field, and is then useful to rotate the magnetic field measurements into the mean field aligned (MFA) coordinate system. This reference frame is useful to study the ultra low frequency magnetic field variations along the direction of the mean field and perpendicularly to it. In order to identify the mean magnetic field the classical moving average (MAVG) approach is usually adopted but, under particular conditions, this procedure induces undesired features, such as spectral alteration in the rotated components. We discuss these aspects promoting an alternative and more efficient method for mean field aligned projection, based on the empirical mode decomposition (EMD).
The August 24th 2016 Accumoli earthquake: surface faulting and Deep-Seated Gravitational Slope Deformation (DSGSD) in the Monte Vettore area
Authors: Domenico Aringoli  , Piero Farabollini  , Marco Giacopetti  , Marco Materazzi  , Silvia Paggi  , Gilberto Pambianchi  , Pietro Paolo Pierantoni  , Eugenio Pistolesi  , Alan Pitts  , Emanuele Tondi
Published: June 2021

On August 24th 2016 a Mw=6.0 earthquake hit central Italy, with the epicenter located at the boundaries between Lazio, Marche, Abruzzi and Umbria regions, near the village of Accumoli (Rieti, Lazio). Immediately after the mainshock, this geological survey has been focused on the earthquake environmental effects related to the tectonic reactivation of the previously mapped active fault (i.e. primary), as well as secondary effects mostly related to the seismic shaking (e.g. landslides and fracturing in soil and rock).This paper brings data on superficial effects and some preliminary considerations about the interaction and possible relationship between surface faulting and the occurrence of Deep-Seated Gravitational Slope Deformation (DSGSD) along the southern and western slope of Monte Vettore.
Analysis of the 2016 Amatrice earthquake macroseismic data
Authors: Lorenzo Hofer  , Mariano Angelo Zanini  , Flora Faleschini
Published: June 2021

On August 24, 2016, a sudden MW 6.0 seismic event hit Central Italy, causing 298 victims and significant damage to residential buildings and cultural heritage. In the days following the mainshock, a macroseismic survey was conducted by teams of the University of Padova, according to the European Macroseismic Scale (EMS98). In this contribution, a critical analysis of the collected macroseismic data is presented and some comparisons were performed with the recent 2012 Emilia sequence.
Soil gas geochemical behaviour across buried and exposed faults during the 24 august 2016 central Italy earthquake
Authors: Giancarlo Ciotoli  , Alessandra Sciarra  , Livio Ruggiero  , Aldo Annunziatellis  , Sabina Bigi
Published: June 2021

Following the earthquake (ML=6.0) of 24 August 2016 that affected large part of the central Apennine between the municipalities of Norcia (PG) and Amatrice (RI) (central Italy), two soil gas profiles (i.e., 222Rn, 220Rn, CO2 and CO2 flux) were carried out across buried and exposed coseismic fault rupture of the Mt. Vettore fault during the seismic sequence. The objective of the survey was to explore the mechanisms of migration and the spatial behaviour of different gas species near still-degassing active fault. Results provide higher gas and CO2 flux values (about twice for 222Rn and CO2 flux) in correspondence of the buried sector of the fault than those measured across the exposed coseismic rupture. Anomalous peaks due to advective migration are clearly visible on both side of the buried fault (profile 1), whereas the lower soil gas concentrations measured across the exposed coseimic rupture (profile 2) are mainly caused by shallow and still acting diffusive degassing associated to faulting during the seismic sequence. These results confirm the usefulness of the soil gas survey to spatially recognise the shallow geometry of hidden faults, and to discriminate the geochemical migration mechanisms occurring at buried and exposed faults related to seismic activity.
The first month of the 2016 central Italy seismic sequence: fast determination of time domain moment tensors and finite fault model analysis of the ML 5.4 aftershock
Authors: Laura Scognamiglio  , Elisa Tinti  , Matteo Quintiliani
Published: June 2021

We present the revised Time Domain Moment Tensor (TDMT) catalogue for earthquakes with M_L larger than 3.6 of the first month of the ongoing Amatrice seismic sequence (August 24th - September 25th). Most of the retrieved focal mechanisms show NNW–SSE striking normal faults in agreement with the main NE-SW extensional deformation of Central Apennines. We also report a preliminary finite fault model analysis performed on the larger aftershock of this period of the sequence (M_w 5.4) and discuss the obtained results in the framework of aftershocks distribution.
The 2016 Amatrice seismic sequence in the Media
Authors: Gemma Musacchio  , Giovanna Piangiamaore
Published: June 2021

Media's power in setting the public’s agenda for discussion can affect perception and debate upon disasters.

In the frame of a dialogical approach to science communication, we challenge here the paradigm for which issues that experts considered valuable are not in the Media's agenda. We studied the way Media addressed the Amatrice 2016 sequence and discuss story-telling. Specific indicators were analyzed to assess to what extent the scientific coverage, risk reduction and damage issues are covered.

First results show that Media do think valuable to provide public with an in-depth scientific coverage and refers to authoritative sources. As time goes by and aftershocks Magnitude decreases a more reflexive thinking is triggered; news stories include more risk reduction indicators than damage. Although memory of past earthquakes is always part of the story one month after the main shock risk reduction disappear from the media agenda.

We also explored the level of public engagement in risk reduction and found out that Media still seem not believe that citizens should be active part of the debate upon their own safety.
Perceived Destination Image and Post-Visit Behaviour: An International MICE Visitors’ Perspective
Authors: Weru Joshua Ngacha
Published: June 2021

Africa including Kenya has continued to suffer negative images due to stereotypes, prejudice, and negative reporting by international media. This has continued to negatively affect the continents' share of the global leisure tourism market despite the rich and unique natural touristic resources. The continents’ MICE tourism, however, has been on the growth path before COVID 19 pandemic. This study, therefore, investigated the influence of perceived destination image by international MICE visitors on their post-visit behaviour. The study was carried out in the Kenyan capital city, Nairobi. The study followed a convenience sampling method with a total sample of 335 respondents. A model on destination image and post-visit behaviour was developed and tested. A blindfolding procedure in PLS showed the model had predictive relevance. Findings indicated that the cognitive image dimension had a positive and significant influence on affective image, overall image, and post-visit behaviour. Affective image positively influences overall image but not post-visit behaviour. Overall destination image had the greatest effect on post-visit behaviour. Destination Marketers in Kenya should pay particular attention to the destination’s cognitive image. The study provides valuable information for policymakers and destination marketers in developing actionable positioning strategies to enhance the destination’s image and competitiveness.