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Transnational access (TNA) allows cross-border, short-term and frequently free-of-charge access to world-class research facilities, to foster collaborations and exchanges of experience. Specifically, TNA aims to encourage open science and innovation and to increase the efficient and effective use of scientific infrastructure. Within EPOS, the European Plate Observing System, the Volcano Observatories and Multi-scale Laboratories communities have offered TNA to their high-quality research facilities through national and European funding. This experience has allowed the definition, design, and testing of procedures and activities needed to provide transnational access inn the EPOS context. In this paper, the EPOS community describes the main objectives for the provision of transnational access in the EPOS framework, based on previous experiences. It includes practical procedures for managing transnational access from a legal, governance, and financial perspective, and proposes logistical and technical solutions to effectively execute transnational access activities. In addition, it provides an outlook on the inclusion of new thematic communities within the TNA framework, and addresses the challenges of providing market-driven access to industry.

Understanding earth materials is critical to foster technological and environmental development, as well as to advance in Earth-science disciplines, like mineral- and rock-physics, as well as material-oriented (bio)geochemistry. EXCITE, a large-scale infrastructure project supported by the European Union’s Horizon-2020 program comprising 15 European institutions for electron and X-ray microscopy, enables free-of-charge Trans-National Access (TNA) to high-end microscopy and microanalysis facilities to develop community-driven technological advancements on Earth materials.The WP5 of EXCITE aims to facilitate mechanisms and procedures to provide TNA to world-class facilities, specifically addressing new, non-expert or early career users worldwide. By definition, TNA involves a researcher conducting science at a research facility located in a country different from the one in which they are working. The EXCITE TNA programme provides access to 24 imaging facilities in 9 countries. Access is provided on a per-call basis, and is granted following a proposal review process. During the first two TNA calls, almost 150 scientific projects have been supported. Two more calls from both academia and industry users will allow access to facilities until April 2024. Analytical techniques and scientific expertise offered include X-ray micro- to nano-tomography, EPMA, FIB-SEM, TEM, as well as SEM-based imaging, element mapping, EBSD, cathodoluminescence and other specialized imaging tools. Our contribution will present the architecture of the EXCITE-TNA programme and outcomes of the user evaluations, which clearly demonstrate the success of Excellence-driven TNA programmes as a strategic asset of the European research scenario, allowing networking and collaboration and favoring education & outreach in geosciences., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Transnational access (TNA) allows cross-border, short-term and frequently free-of-charge access to world-class research facilities, to foster collaborations and exchanges of experience. Specifical-ly, TNA aims to encourage open science and innovation and to increase the efficient and effective use of scientific infrastructure. Within EPOS, the European Plate Observing System, the Volcano Observatories and Multi-scale Laboratories communities have offered TNA to their high-quality research facilities through national and European funding. This experience has allowed the defi-nition, design, and testing of procedures and activities needed to provide transnational access in the EPOS context. In this paper, the EPOS community describes the main objectives for the provision of transnational access in the EPOS framework, based on previous experiences. It includes practical procedures for managing transnational access from a legal, governance, and financial perspective, and proposes logistical and technical solutions to effectively execute transnational access activities. In addition, it provides an outlook on the inclusion of new thematic communities within the TNA framework, and addresses the challenges of providing market-driven access to industry. © 2022, Editrice Compositori s.r.l.. All rights reserved.

EGU2020: Sharing Geoscience Online, 4-8 May, 2020, EPOS (European Plate Observing System) is an ESFRI Landmark and European Research Infrastructure Consortium (ERIC). The EPOS Thematic Core Service Multi-scale laboratories (TCS MSL) represents a community of European solid Earth sciences laboratories including high temperature and pressure experimental facilities, electron microscopy, micro-beam analysis, analogue tectonic and geodynamic modelling, paleomagnetism, and analytical laboratories. Participants and collaborating laboratories from Belgium, Bulgaria, France, Germany, Italy, Norway, Portugal, Spain, Switzerland, The Netherlands, and the UK are already organized in the TCS MSL. Unaffiliated European solid Earth sciences laboratories are welcome and encouraged to join the growing TCS MSL community. Members of the TCS MSL are also represented in the EPOS Sustainability Phase (SP). Laboratory facilities are an integral part of Earth science research. The diversity of methods employed in such infrastructures reflects the multi-scale nature of the Earth system and is essential for the understanding of its evolution, for the assessment of geo-hazards, and for the sustainable exploitation of geo-resources. Although experimental data from these laboratories often provide the backbone for scientific publications, they are often only available as supplementary information to research articles. As a result, much of the collected data remains unpublished, inaccessible, and often not preserved for the long term. The TCS MSL is committed to make Earth science laboratory data Findable, Accessible, Interoperable, and Reusable (FAIR). For this purpose the TCS MSL has developed an online portal that brings together DOI-referenced data publications from research data repositories related to the TCS MSL context (https://epos-msl.uu.nl/). In addition, the TCS MSL has developed a Trans-national access (TNA) program that allows researchers and research teams to apply for physical or remote access to the participating EPOS MSL laboratories. Three pilot calls were launched in 2017, 2018, and 2019, with a fourth call scheduled for 2020. The pilot calls were used to develop and refine the EPOS wide TNA principles and to initialize an EPOS brokering service, where information on each facility offering access will be available for the user and where calls for proposals are advertised. Access to the participating laboratories is currently supported by national funding or in-kind contribution. Based on the EPOS Data policy & TNA General Principles, access to the laboratories is regulated by common rules and a transparent policy, including procedures and mechanisms for application, negotiation, proposal evaluation, user feedback, use of laboratory facilities and data curation. Access to EPOS Multi-scale laboratories is a unique opportunity to create new synergy, collaboration and innovation, in a framework of trans-national access rules.

It is widely accepted that, for the correct interpretation of bulk rock compositions, degassing process controlling both loss of magmatic volatiles and significant changes in the contents of volatile chemical species must be considered. The continuous degassing experiments presented in this study attempt to determine the absolute and relative change in abundances of volatile components in the melt at shallow levels, simulating what might occur during slow and fast ascent of magma from depth without crystallization. We performed disequilibrium decompression experiments using as starting melt a bubblefree but volatile-bearing trachybasalt. The charges were isothermally decompressed at 1,150 °C from 400 MPa down to 50 MPa at rates of 0.01 MPa/s and 1 MPa/s. Results demonstrate that degassing of 1 wt% H2O of initial volatile content in the melt is not enough to induce melt compositional changes as well as H2O supersaturation in the trachybasaltic melt. In contrast, the minimum H2O threshold to observe Cl, B, and Li devolatilization corresponds to 3 wt% H2O and volatile supersaturation is attained at the fast decompression rate of 1 MPa/s. An increase of CO2 up to 0.3 wt% do not change the partitioning behaviour of these chemical species between vapor and trachybasaltic melt. Moreover, CO2 degassing is less efficient with respect to H2O transfer from the melt into the vapor phase. As a consequence, the trachybasaltic melt is preferentially supersaturated in CO2 with decreasing pressure. Disequilibrium degassing does not change the bulk oxidation state of the melt.

Pressurized gas drives explosive volcanic eruptions. Existing models can predict the amount and pressure of gas in erupting magma, but application and testing of such models is currently limited by the accuracy of input parameters from natural systems. Here, we present a new methodology, based on a novel integration of 1) high-speed imaging and 2) shock-tube modeling of volcanic activity in order to derive estimates of sub-second variations in the pressure, mass, and volume of gas that drive the dynamics of unsteady eruptions. First, we validate the method against laboratoryscale shock-tube experiments. Having validated the method we then apply it to observations of eruptions at Stromboli volcano (Italy). Finally, we use those results for a parametric study of the weight of input parameters on final outputs. We conclude that Strombolian explosions, with durations of seconds, result from discrete releases of gas with mass and pressure in the 4–714 kg and 0.10–0.56 MPa range, respectively, and which occupy the volcano conduit to a depth of 4–190 m. These variations are present both among and within individual explosions. Citation: Taddeucci, J., M. A. Alatorre- Ibargüengoitia, M. Moroni, L. Tornetta, A. Capponi, P. Scarlato, D. B. Dingwell, and D. De Rita (2012), Physical parameterization of Strombolian eruptions via experimentally-validated modeling of high-speed observations, Geophys. Res. Lett., 39, L16306, doi:10.1029/2012GL052772.

Radon gas is the subject of a great deal of research because its concentration builds up into indoor air and the long-term radon exposure is considered the second cause of lung cancer, after smoking. In addition to that, the release of radon from soil is under investigation in active volcanic and seismic areas because radon anomalies are believed to occur before earthquakes and volcanic eruptions. Several papers report results of laboratory experiments on the effects of activity concentration of 222Rn and 220Rn precursors, humidity content and grain size of geological materials over the radon emission. However no correspondent studies have targeted the effect of the temperature on radon release. The present contribution focuses on the influence of temperature, varying from 20° to 60° C, on 222Rn and 220Rn emission from two volcanic rocks, a tuff and a lava flow. The experimental apparatus consists of a small accumulation chamber coupled to solid-state alpha spectroscopy; it also allows to select and keep constant the experimental temperatures applied to the rock sample. The effect of ambient temperature on detection efficiency is also investigated. Results show a significant enhancement of radon emissions from rocks with increasing temperature. The results of these experiments suggest that thermal enhancement of radon emission can be used to investigate more precisely the correlation between physical mechanisms determining damage in stressed rocks and radon release, taking advantage of the improved radon emission. Experimental test with a better resolution are the key to interpret radon anomalies preceding earthquakes or volcanic eruption.

""Positive radon anomalies are commonly used as a tool to predict dynamic failure in the crust, as stated by the widely-used dilatancy model for earthquake prediction. The model foresees that the formation and propagation of cracks prior to rupture will serve to create new surface area and hence increase radon emanation. However, this simplified picture is not only occasionally contradicted by negative radon anomalies, but sometimes negative anomalies are measured at the seismic source, whilst contemporaneous positive anomalies are recorded at monitoring stations located hundreds of kilometres away. Mysteriously, alternating increases and decreases or no significant variations have also been recorded. Hence, despite early promise, radon emanation does not appear to be a very compelling warning signal and many questions remain unresolved. Although numerous studies have investigated field radon emanation from rocks under natural stress conditions, only few have attempted to experimentally relate rock deformation with radon change. . Here we present, for the first time to our knowledge, an original experimental set-up consisting of a new accumulation chamber made of a drypack material, a polyester-aluminum-polyethylene bag, containing the rock specimen and connected in a closed-loop configuration to the RAD 7. The drypack-chamber is loaded under a uniaxial press, without being damaged during rock deformation. Radon gas concentration emitted from the samples is simultaneously and continuously monitored by the system; therefore, the originality of the experiments consists in a real time monitoring of radon emission changes during the whole process of rock deformation. Additionally, the drypack-chamber is surrounded by a heating belt that allows us to investigate the effect of high temperature conditions (up to 90 °C) on radon emission. It needs to be stressed that the radonometer is alpha-spectrometry based and is able to measure simultaneously 222Rn (radon) and 220Rn (thoron) activity concentrations. The great advantage of determining thoron is the possibility of recording any activity change in the closed system within the length of a single run cycle (30 minutes), due to the short half-life of 220Rn (55.6 seconds) that reaches any new equilibrium conditions in about 5 minutes.. Results demonstrate that radon exhalation from the rock specimen drastically increases with increasing the experimental temperature. This finding allows us to discriminate low variations in radon emissions when rock samples are uniaxially loaded under the press. Uniaxial compressive tests performed on highly porous (47 %) volcanic tuff from Vico Volcanic District (central Italy) shows that the radon emission decreases with increasing load. Such a variation is proportional to a reduction of porosity associated with the compaction of the tuff sample. When the specimen fails, a drastic increase of emission is verified.. Moreover, long-term experiments (in the order of weeks) performed by maintaining a constant load on the tuff specimen show that the deformation increases with time. The radon signal coherently continues to decrease up to the complete closure of pores. At that point, a further increase of load does not induce any additional compaction and any radon emission change, with a constant exhalation up to the failure. This has strong implications in the field of radon anomalies prior to earthquakes, showing that the seismic event can be preceded by no significant radon anomalies, as already documented in literature. . Our experimental investigation sheds light on several apparently contradictory signals recorded by radon monitoring stations near active faults and volcanoes. Results demonstrate that emanation rate is governed by the prevalent deformation mechanism. In terms of seismic and volcanic hazard, the deformation mechanism of rocks under stresses should be carefully considered to properly interpret data from geochemical field monitoring. . . ""

""Radon anomalies are commonly observed prior to. dynamic failure in the crust and are interpreted as cracking. of the medium, thus attracting considerable attention in. understanding the precursory phenomena of earthquakes. and volcanic activity. In this study we have compared the. starting radon emissions from low porosity crystalline lava. (phonolite) samples with those from damaged and failed. samples. The damaged sample was loaded up to just beyond. the end of the linear elastic phase, as evidenced by the output. of AE energy, the increase in total porosity and a. decrease in P‐wave and S‐wave velocity relative to the. intact sample. Whereas, the failed sample showed deformation. behaviour characteristically brittle with increasing. values of AE output and porosity as the sample approached. macroscopic failure. Radon measurements have evidenced. that dilatational microcracking of deformed sample produced. no significant variation in radon emanation with. respect to the intact sample. In contrast, after macroscopic. failure, radon emanation drastically increased. Therefore,. major finding from this study is that, in the case of low. porosity and relatively high strength crystalline lavas, the. development of a macroscopic fracture provides new large. exhaling surface resulting in a substantial increase in radon. emission rate""

""Anomalous radon and thoron emissions are regarded as valuable precursors of earthquakes and volcanic eruptions and are related to increasing damage of the medium. However both positive and negative anomalies are observed in the field prior ruptures, thus indicating competing deformation mechanisms. Initial porosity (P) plays a key role for natural lithologies in controlling damage accumulation and strain localisation processes. Thus investigating how elastic properties of low to high porosity rocks are affected from increasing loading is required to quantitatively interpret the positive and negative anomalies observed. . Here we present an experimental dataset where measurements of radon (222Rn) and thoron (220Rn) emissions are carried out on low to high porosity lithologies incrementally loaded up to failure. The following samples are investigated: a high porosity lithophysae-rich tuff (P = 47.0 %) and a low porosity phonolitic lava flow (P = 3.6%). Cylindrical samples of 120 (length) x 60 (diameter) mm, have been uniaxially loaded at constant strain rate in servo-controlled uniaxial machines. Samples have been either 1) mechanically damaged to the end of the elastic phase, before the onset of dilatancy or 2) loaded up to the failure. Radon and thoron exhalation rates are carried out by using a solid-state alpha detector, connected to a small accumulation chamber kept at the constant temperature of 60°C. Measurements are performed on two samples at once to achieve stronger signals and repeated several times in order to verify their reproducibility.. Results show that a decrease of radon and thoron emissions are evidenced at the end of the ‘damage phase’ for the high porosity tuff, while a slight increase is observed for the low porosity lava flow. At the end of the elastic phase the tuff reduces its radon and thoron exhalation rates, because of pervasive pore collapse of the macropores, with a P reduction up to 40.1 %. In contrast, for the lava flows the loading slightly increases the crack damage and, consequently, P increases up to 5.1 %. This change does not significantly affect the radon exhalation. At the failure, new rupture surfaces are generated. The total exhaling surface of the samples increases and an increase of radon emission is observed for both lithologies. ""

We performed 31 friction experiments on glassy basalts (GB) and glass-free basalts (GFB) at slip rates up to 6.5 m s-1 and normal stress up to 40 MPa (seismic conditions). Frictional weakening was associated to bulk frictional melting and lubrication. The weakening distance (Dw) was about 3 times shorter in GB than in GFB, but the steady state friction was systematically higher in GB than in GFB. The shorter Dw in GB may be explained by the thermal softening occurring at the glass transition temperature (Tg ∼500°C), which is lower than the bulk melting temperature (Tm ∼1250°C) of GFB. Postexperiment microanalyses suggest that the larger crystal fraction measured in GB melts results in the higher steady state friction value compared to the GFB melts. The effect of interstitial glass is to facilitate frictional instability and rupture propagation in GB with respect to GFB. ©2014. American Geophysical Union. All Rights Reserved.

The Roman Comagmatic Province (RCP) developed along the NW-SE striking extensional Tyrrhenian margin of Italy since middle Pleistocene and includes ultrapotassic small eruptive centers and large volcanic districts. By means of a review and statistical analysis of a large data set of radiometric ages we demonstrate that in the RCP, major eruptive cycles occurred at different volcanic districts almost simultaneously and with an almost constant recurrence time. Our analysis started with the Alban Hills Volcanic District, where a detailed 40Ar/ 39Ar chronology of the eruptive cycles has been recently achieved, and then extended to include a database of 264 radiometric ages of the RCP volcanics published since 1980. Statistical treatment of the data set shows a marked non-Poissonian behavior of volcanic activity through the whole magmatic province, with climax of each major eruptive cycle occurring simultaneously at the different districts approximately every 48 kyr. The concomitant eruption of many volcanic districts spreading over a 250-km-long chain implies a control mechanism acting at a regional scale. After discussing the possible relationship between tectonics, sea level changes, and volcanic activity we hypothesize that constant rates of slab retreat during middle Pleistocene could have been a key factor controlling the rate of magma upwelling and the major cycles of recharge of the magma chambers. As a working hypothesis, we propose that the duration of the cycles may be related to (1) progressive weakening of the crust due to magma underplating or (2) cyclic injection of convective plumes into the mantle wedge. Copyright 2004 by the American Geophysical Union.

International audience; The inherent instability of volcanic edifices, and their resultant propensity for catastrophic collapse, is a constant source of volcanic risk. Structural instability of volcanic edifices may be amplified by the presence of carbonate rocks in the sub-volcanic strata, due to the debilitating response of carbonates to thermally-induced alteration. Nonetheless, decarbonation reactions (the primary weakening mechanism), may stall when the system becomes buffered by rising levels of a reaction product, carbon dioxide. Such thermodynamic stalling might be inferred to serve to circumvent the weakness of volcanic structures. However, the present study shows that, even when decarbonation is halted, rock physical properties continue to degrade due to thermal microcracking. Furthermore, as a result, the pathways for the escape of carbon dioxide are numerous within a volcanic edifice. Therefore, in the case of an edifice with a subvolcanic sedimentary basement, the generation of carbon dioxide via decarbonation is unlikely to hinder its impact on instability, and thus potentially devastating flank collapse

[1] Explosive volcanic eruptions are defined as the violent ejection of gas and hot fragments from a vent in the Earth's crust. Knowledge of ejection velocity is crucial for understanding and modeling relevant physical processes of an eruption, and yet direct measurements are still a difficult task with largely variable results. Here we apply pioneering high-speed imaging to measure the ejection velocity of pyroclasts from Strombolian explosive eruptions with an unparalleled temporal resolution. Measured supersonic velocities, up to 405 m/s, are twice higher than previously reported for such eruptions. Individual Strombolian explosions include multiple, sub-second-lasting ejection pulses characterized by an exponential decay of velocity. When fitted with an empirical model from shock-tube experiments literature, this decay allows constraining the length of the pressurized gas pockets responsible for the ejection pulses. These results directly impact eruption modeling and related hazard assessment, as well as the interpretation of geophysical signals from monitoring networks.