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

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

Scattering and absorption imaging of a highly fractured fluid-filled seismogenetic volume in a region of slow deformation

Regions of slow strain often produce swarm-like sequences, characterized by the lack of a clear mainshock-aftershock pattern. The comprehension of their underlying physical mechanisms is challenging and still debated. We used seismic recordings from the last Pollino swarm (2010–2014) and nearby to separate and map seismic scattering (from P peak-delays) and absorption (from late-time coda-wave attenuation) at different frequencies in the Pollino range and surroundings. High-scattering and high-absorption anomalies are markers of a fluid-filled fracture volume extending from SE to NW (1.5–6 Hz) across the range. With increasing frequency, these anomalies approximately cover the area where the strongest earthquakes occurred from the sixteenth century until 1998. In our interpretation, the NW fracture propagation ends where carbonates of the Lucanian Apennines begin, as marked by a high-scattering and low-absorption area. At the highest frequency (12 Hz) the anomalies widen southward in the middle of the range, consistently marking the faults active during the recent Pollino swarm. Our results suggest that fracture healing has closed small-scale fractures across the SE faults that were active in the past centuries, and that the propagation of fluids may have played a crucial role in triggering the 2010–2014 Pollino swarm. Assuming that the fluid propagation ended at the carbonates barrier in the NW direction, fractures opened new paths to the South, favoring the nucleation of the last Pollino swarm. Indeed, the recently active faults in the middle of the seismogenic volume are marked by a high-scattering and high-absorption footprints. Our work provides evidence that attenuation parameters may track shape and dynamics of fluid-filled fracture networks in fault areas. Keywords: Pollino, Seismic attenuation, Scattering, Fluids, Fractures, Healin

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 3D Attenuation Structure of Deception Island (Antarctica)

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Source and dynamics of a volcanic caldera unrest : Campi Flegrei, 1983–84

Acknowledgements We thank Tiziana Vanorio, Antonella Amoruso, Luca Crescentini, Nicholas Rawlinson, Yasuko Takei, and David Cornwell for the valuable suggestions regarding the methodology and interpretation. Reviews from Tim Greenfield and two anonymous reviewers helped improving both clarity of the manuscript and interpretation. The Royal Society of Edinburgh - Accademia dei Lincei Bilateral Agreement, the Santander Mobility Award of the College of Physical Sciences, University of Aberdeen, and the TIDES EU COST action granted L.D.S. travel grants for the realisation of this study. E.D.P. has been supported by the EPHESTO and KNOWAVES projects, funded by the Spanish Ministry of Education and Science.Peer reviewedPublisher PD

Thermo-Hydro-Mechanical Model and Caprock Deformation Explain the Onset of an On-going Seismo-volcanic Unrest

Acknowledgments The authors are grateful to the Editor, Prof. Ben‐Zion Yehuda, and the reviewers: Prof. Micol Todesco and an anonymous reviewer, whose comments and recommendations have significantly improved the quality of this work. The authors acknowledge the financial support of the Petroleum Technology Development Fund (PTDF) Nigeria for this research. The comparison of our models with monitoring data was made possible by the outstanding efforts of the staff at the INGV‐Osservatorio Vesuviano, who provide weekly information about geophysical parameters at the Campanian volcanoes (http://www.ov.ingv.it/ov/en/bollettini/272-campi-flegrei-bollettini-settimanali.html). The authors are particularly grateful to them for providing the accurate magnitude and hypocentral parameters used to create the earthquake magnitude–depth plot in this study. The authors also extend our appreciation to Prof. Derek Elsworth for his generous support in the FLAC3D software license usage.Peer reviewedPublisher PD

Pore Space Topology Controls Ultrasonic Waveforms in Dry Volcanic Rocks

Pore space controls the mechanical and transport properties of rocks. At the laboratory scale, seismic modeling is usually performed in relatively homogeneous settings, and the influence of the pore space on the recorded wavefields is determined by rock-fluid interactions. Understanding this influence in dry rocks is instrumental for assessing the impact of pore topology on waves propagating in heterogeneous environments, such as volcanoes. Here, we simulated the propagation of shear waves as a function of pore space parameters in computational models built as proxies for volcanic rocks. The spectral-element simulations provide results comparable with ultrasonic experiments, and the outcome shows that the size, shape, volume, and location of pores impact amplitudes and phases. These variations intensify in waveform coda after multiple scattering. Our results confirm that pore topology is one of the primary regulators of the propagation of elastic waves in dry rocks regardless of porosity