Investigating the Apparent Seismic Diffusivity of Near-Receiver Geology at Mount St. Helens Volcano, USA

Acknowledgments: The SAGES VALIDATE forum provided travel money for the discussion of the methodology within De Siena and Benson.Peer reviewedPublisher PD

“I want to shake your hand before …”: The role of clients, knowledge exchange and market dynamics in southern Italian software firms

This study aims to assess the importance of clients in multi-scalar networks leading to learning competence and knowledge exchange. Furthermore, the difficulties encountered by firms located in a peripheral and marginally innovative area in signing commercial agreements with partners located in distant regions are tackled. Our findings, based on qualitative interviews, reveal that clients are considered to be the most important partners by the founders, owners and professionals of software firms located in the marginally innovative province of Lecce (southeastern Italy). Furthermore, being located in a peripheral area is not seen as a limitation from the technical–infrastructural viewpoint thanks to the opportunity offered by new technologies (e.g. the Internet) and computer-mediated communications. Conversely, the contracting of business agreements with partners located in distant markets is negatively influenced by the geographical distance from potential clients due to the need for previous acquaintance or face-to-face contact engendering trust.publishedVersio

Fluid migrations and volcanic earthquakes from depolarized ambient noise

Ambient noise polarizes inside fault zones, yet the spatial and temporal resolution of polarized noise on gas-bearing fluids migrating through stressed volcanic systems is unknown. Here we show that high polarization marks a transfer structure connecting the deforming centre of the caldera to open hydrothermal vents and extensional caldera-bounding faults during periods of low seismic release at Campi Flegrei caldera (Southern Italy). Fluids pressurize the Campi Flegrei hydrothermal system, migrate, and increase stress before earthquakes. The loss of polarization (depolarization) of the transfer and extensional structures maps pressurized fluids, detecting fluid migrations after seismic sequences. After recent intense seismicity (December 2019-April 2020), the transfer structure appears sealed while fluids stored in the east caldera have moved further east. Our findings show that depolarized noise has the potential to monitor fluid migrations and earthquakes at stressed volcanoes quasi-instantaneously and with minimum processing

Integrating ambient noise with GIS for a new perspective on volcano imaging and monitoring : The case study of Mt. Etna

We are very grateful to Professor G. Patane for the inspiration and financial support; S. La Delfa for assistance during the analysis. We also thank the Parco dell’Etna Staff who ensure the permission and regular support above the volcano. We would like to thank G. Vaccino and F. Zuccarello for the support during the field trip. Two anonymous reviewers provided comments that improved both the interpretation of the results and the clarity of the analyses. Finally, we are grateful to S. Castellaro, M. Neri, and G. Di Grazia for providing important methodological explanations, the DEM, and data of volcanic tremor during the period.Peer reviewedPostprin

Absorption and Scattering 2D Volcano Images from Numerically Calculated Space-weighting functions

Acknowledgments Yosuke Aoki and an anonymous reviewer greatly improved the quality of the paper. All calculations were made with Mathematica-10TM. Discussions with Marie Calvet, Danilo Galluzzo, Mario La Rocca, Salvatore De Lorenzo, Jessie Mayor and Ludovic Margerin are gratefully acknowledged. The authors are supported by MEDSUV European project and by Spanish Project Ephestos, CGL2011-29499-C02-01 and NOWAVES, TEC2015-68752. The TIDES EU travel Cost action provided travel money to support cooperation between Luca De Siena and the other authors.Peer reviewedPostprin

Mt. Etna feeding system and sliding flank : a new 3D image from earthquakes distribution in a customisable GIS

High-resolution seismic imaging enables the reconstruction of ascending paths of magma and fluids, shallow molten accumulation and flank collapse areas, all crucial information for developing an efficient eruption forecasting strategy. Here, the Marching Cubes algorithm (MC - generally applied to medical visualization and three-dimensional (3D) modeling) is applied to 16 years of earthquake location data at Mt. Etna (Italy). The algorithm defines three-dimensional seismic clusters that take into account seismic location uncertainties and are embedded in a novel volcano-oriented Geographyc Information Systems (VolGIS) offering an interpretational environment comprising tomographic images and alternative geophysical models. The results show that a volume of very-low-seismicity is embedded in a high-velocity body, and acts as a zone of transition between transient magmatic events (west) and eastern deep seismicity related to the sliding eastern flank. The eastern cluster represents the 3D seismic signature of a deep (2–8 km below sea level) instability, affecting the portion of the eastern flank nearest to the feeding systems. This instability is likely caused by a combination of gravitational spreading and magmatic intrusions

Mt. Etna Feeding System and Sliding Flank: A New 3D Image From Earthquakes Distribution in a Customisable GIS

Fil: Guardo, Roberto. Universidad Nacional de Río Negro. Instituto de Investigación en Paleobiología y Geología. Río Negro, ArgentinaFil: De Siena, Luca. Johannes Gutenberg University. Institute of Geosciences. Mainz, AlemaniaFil: Dreidemie, Carola. Universidad Nacional de Río Negro. LVCC Laboratorio de Investigación y Desarrollo en Tecnologías de Visualización, Computación Gráfica y Código Creativo. Río Negro, ArgentinaEl artículo incluye un anexo de 8 páginas.High-resolution seismic imaging enables the reconstruction of ascending paths of magma and fluids, shallow molten accumulation and flank collapse areas, all crucial information for developing an efficient eruption forecasting strategy. Here, the Marching Cubes algorithm (MC - generally applied to medical visualization and three-dimensional (3D) modeling) is applied to 16 years of earthquake location data at Mt. Etna (Italy). The algorithm defines three-dimensional seismic clusters that take into account seismic location uncertainties and are embedded in a novel volcanooriented Geographyc Information Systems (VolGIS) offering an interpretational environment comprising tomographic images and alternative geophysical models. The results show that a volume of very-low-seismicity is embedded in a high-velocity body, and acts as a zone of transition between transient magmatic events (west) and eastern deep seismicity related to the sliding eastern flank. The eastern cluster represents the 3D seismic signature of a deep (2–8 km below sea level) instability, affecting the portion of the eastern flank nearest to the feeding systems. This instability is likely caused by a combination of gravitational spreading and magmatic intrusions.Las imágenes sísmicas de alta resolución permiten la reconstrucción de trayectorias ascendentes de magma y fluidos, áreas de acumulación de líquido fundido poco profundo y áreas de colapso de flancos, toda información crucial para desarrollar una estrategia eficiente de pronóstico de erupciones. Aquí, el algoritmo Marching Cubes (MC - generalmente aplicado a visualización médica y modelado tridimensional (3D)) se aplica sobre 16 años de datos de ubicación de terremotos en Mt. Etna (Italia). El algoritmo define conglomerados sísmicos tridimensionales que tienen en cuenta las incertidumbres de ubicación sísmica y están integrados en un novedoso Sistema de Información Geografía (VolGIS) orientado a los volcanes que ofrece un entorno interpretativo que comprende imágenes tomográficas y modelos geofísicos alternativos. Los resultados muestran que un volumen de muy baja sismicidad está incrustado en un cuerpo de alta velocidad y actúa como una zona de transición entre eventos magmáticos transitorios (oeste) y sismicidad profunda oriental relacionada con el flanco este deslizante. El cúmulo oriental representa la firma sísmica 3D de una inestabilidad profunda (2 a 8 km por debajo del nivel del mar), que afecta la parte del flanco oriental más cercana a los sistemas de alimentación. Esta inestabilidad probablemente sea causada por una combinación de dispersión gravitacional e intrusiones magmáticas

The evolutionary dynamic of the main urban Labour Market Areas

If the Labour Markets Areas consist of «territorial units identified by a set of adjacent municipalities approximated with travel-to-work daily commuting flows», the change in the number of municipalities that make them, can be considered as an indicator of the changes in the levels of socio-economic interaction within the LMAs. In particular, in the hierarchical-functional LMAs, where the daily commute for work move from the periphery of the system toward its center, the variation in the number of municipalities that are part of it can be interpreted as the result of a change in the attractiveness of the economic and employment level of the center on its immediate geographical surroundings. Following any changes in the spatial configuration of the 21 local labor systems of the major Italian urban areas and crossing data with that relating to demographic and economic level, you can build an interpretive framework of the evolutionary dynamics of these metropolitan areas and the role that they occupy within the national urban system

The attenuation and scattering signature of fluid reservoirs and tectonic interactions in the Central-Southern Apennines (Italy)

Despite the high detection level of the Italian seismic network and the risk associated with its fault networks, Central-Southern Italy has no unique geophysical model of the crust able to illuminate its complex tectonics. Here, we obtain seismic attenuation and scattering tomography models of this area; both reveal high attenuation and scattering anomalies characterizing the entire Apenninic Chain and related to its East- and West-dipping extensional Quaternary tectonic alignments. Fault-associated fractured zones become preferential ways for circulating and degassing high-attenuation CO2-bearing fluids. A previously undetected fluid source area is a high-attenuation volume below the Matese complex, while a similar smaller anomaly supports a fluid source near L'Aquila. The most prominent low attenuation and scattering volumes reveal a locked aseismic zone corresponding to the Fucino-Morrone-Porrara fault systems, representing a zone of significant seismic hazard