ALBERT

Description: The spectral element method, which provides an accurate solution of the elastodynamic problem in heterogeneous media, is implemented in a code, called RegSEM, to compute seismic wave propagation at the regional scale. By regional scale we here mean distances ranging from about 1 km (local scale) to 90° (continental scale). The advantage of RegSEM resides in its ability to accurately take into account 3-D discontinuities such as the sediment-rock interface and the Moho. For this purpose, one version of the code handles local unstructured meshes and another version manages continental structured meshes. The wave equation can be solved in any velocity model, including anisotropy and intrinsic attenuation in the continental version. To validate the code, results from RegSEM are compared to analytical and semi-analytical solutions available in simple cases (e.g. explosion in PREM, plane wave in a hemispherical basin). In addition, realistic simulations of an earthquake in different tomographic models of Europe are performed. All these simulations show the great flexibility of the code and point out the large influence of the shallow layers on the propagation of seismic waves at the regional scale. RegSEM is written in Fortran 90 but it also contains a couple of C routines. It is an open-source software which runs on distributed memory architectures. It can give rise to interesting applications, such as testing regional tomographic models, developing tomography using either passive (i.e. noise correlations) or active (i.e. earthquakes) data, or improving our knowledge on effects linked with sedimentary basins.

Description: 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 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.

Description: This data set contains continuous recordings of seismic noise, which have been made on the surface of a shallow volcanic crater in the Phlegrean Fields volcanic complex near Naples, Italy, where a significant level of volcanic-hydrothermal activity is presently concentrated (MED-SUV = Mediterranean Supersite Volcanoes). As part of the Phlegrean Fields, the Solfatara crater is a 0.4 × 0.5 km sub-rectangular structure whose geometry is mainly due to the control exerted by N40–50W and N50E trending normal fault systems, along which geothermal fluids can ascend. These systems crosscut the study area and have been active several times in the past.

Description: We investigate the effect of extended faulting processes and heterogeneous wave propagation on the early warning system capability to predict the peak ground velocity (PGV) from moderate to large earthquakes occurring in the southern Apennines (Italy). Simulated time histories at the early warning network have been used to retrieve early estimates of source parameters and to predict the PGV, following an evolutionary, probabilistic approach. The system performance is measured through the Effective Lead-Time (ELT), i.e., the time interval between the arrival of the first S-wave and the time at which the probability to observe the true PGV value within one standard deviation becomes stationary, and the Probability of Prediction Error (PPE), which provides a measure of PGV prediction error. The regional maps of ELT and PPE show a significant variability around the fault up to large distances, thus indicating that the system's capability to accurately predict the observed peak ground motion strongly depends on distance and azimuth from the fault.

Description: Nowadays, Tsunami Early Warning Systems (TEWS) issue the first alert between three and five minutes after the occurrence of a potentially tsunamigenic earthquake. For offshore earthquakes, for which a significant network azimuthal gap limits the accuracy of standard techniques for source location, this time is spent to obtain stable estimations of the event magnitude and depth. This large warning time affects the efficiency of TEWS for near-coastal large earthquakes. Recent developments in Earthquake Early Warning Systems (EEWS) mitigates this issue. Here, we consider a P-wave, shaking-forecast based EEW method (Zollo et al., 2023) to provide fast and accurate estimations of event location and magnitude along with the Potential Damage Zone (PDZ). As a first test of a combined E- and T- EWS, we applied the method by playing-back the simulated records of two events of Mw 6 and 7 in the Messina strait, with source characteristics that mimic the 1908 Messina earthquake. The events are simulated at the INGV and RAN seismic stations along the Sicily and Calabria coasts. We estimated stable and accurate hypocenter locations and magnitude determinations in 20-25 seconds for both events. The shape of the PDZ obtained after 30 s from the earthquake origin well reproduces the geometry of the rupture surface. These first results show that combining EEWS and TEWS can speed up the tsunami forecasting, thus increasing the lead-time available for actions to protect the exposed population.

Description: We estimate the source parameters of small-magnitude earthquakes that occurred during 2008–2020 in the Irpinia faults area (southern Italy). We apply a spectral decomposition approach to isolate the source contribution from propagation and site effects for ∼3000 earthquakes in the local magnitude range between ML 0 and 4.2. We develop our analyses in three steps. First, we fit the Brune (1970) model to the nonparametric source spectra to estimate corner frequency and seismic moment, and we map the spatial distribution of stress drop across the Irpinia area. We found stress drops in the range 0.4– 8.1 MPa, with earthquakes deeper than 7 km characterized by higher average stress drop (i.e., 3.2 MPa). Second, assuming a simple stress-release model (Kanamori and Heaton, 2000), we derive fracture energy and critical slip-weakening distance. The spatial variability of stress drop and fracture energy allows us to image the present stress conditions of fault segments activated during the 23 November 1980 Ms 6.9 earthquake. The variability of the source parameters shows clear patterns of the fault mechanical properties, suggesting that the Irpinia fault system can be divided into three main sectors, with the northern and southern ones showing different properties fromthe central one. Our results agree with previous studies indicating the presence of fluids with different composition in the different sectors of the Irpinia fault system. In the third step, we compare the time evolution of source parameters with a time series of geodetic displacement recorded near the fault system. Temporal trends in the correlation between geodetic displacement and different source parameters indicate that the poroelastic deformation perturbation generated by the karst aquifer recharge is modulating not only the occurrence rate of microseismicity (D’Agostino et al., 2018) but may lead to rupture asperities with different sizes and characteristics.

Description: The Geo-INQUIRE (Geosphere INfrastructure for QUestions into Integrated REsearch) project, supported by the Horizon Europe Programme, is aimed at enhancing services to allow data, products and software to be accessible to the Geoscience scientific community. In the framework of Geo-INQUIRE, Transnational Access (TA, both remote and physical) will be provided at six test beds across Europe:the BedrettoLab, Switzerland; the Ella-Link Geolab, Portugal; the Liguria-Nice-Monaco submarine infrastructure, Italy/France; the Irpinia Near-Fault Observatory, Italy; the Eastern Sicily facility, Italy; and the Corinth Rift Laboratory, Greece. These test beds are state-of-the-art research infrastructures, covering the Earth’s surface, subsurface, and marine environments over different spatial scales, from small-scale experiments in laboratories to kilometric submarine fibre cable. TA will be also offered for software and workflows belonging to the EPOS-ERIC and the ChEESE Centre of Excellence for Exascale in Solid Earth. TA are grounded on simulation of seismic waves, tsunamis and landslides. Geo-INQUIRE will grant TA to researchers to develop their own experiments with the aim of advancing scientific knowledge of Earth processes while fostering cross-disciplinary research across Europe. To be granted, researchers submit a proposal to the yearly TA calls that will be issued three times during the project life. Calls will be advertised at the Geo-INQUIRE web page https://www.geo-inquire.eu/ and through the existing community channels. The first call is expected to be issued in Fall 2023.The proposals, for both TA and training, will be evaluated by a panel that reviews the technical and scientific feasibility of the project.

Description: Modern scientific endeavours already have the capacity to call upon a vast variety of data, often in huge volumes. However, the challenge is not only how to make the most of such a resource, but also how to make it available to the wider scientific community. Fifty-one institutions from 13 countries are currently working together in the Geo-INQUIRE (Geosphere INfrastructure for QUestions into Integrated REsearch) project.The goal of this new project is to enhance, give access to, and make interoperable, key datasets of the Geoscience community. This will include "big" data streams and high-performance computing codes which are critical to studying the temporal variation of the solid Earth, forecasting multi-hazards, evaluating Georesources and the analysis of the interface between the solid Earth as well as oceans and atmosphere. About 150 access points – both on-site and virtually are involved. Several European Research Infrastructure Consortia take part, namely the European Plate Observing System (EPOS) for solid Earth and geodynamics observations, the European Multidisciplinary Seafloor and Water Column Observatory (EMSO) for deep-sea and coastal observations, and ECCSEL for CO2 capture, utilization, transport, and storage, and geoenergy. This 16 million Euro project started in October 2022, within the Horizon Europe Infrastructure program.The presentation will briefly describe the project and give examples of curiosity-driven research topics which will be made possible through such a multi-disciplinary project. We will finally present the challenges and efforts made to comply with FAIR principles and accompany the dissemination of the data with innovative and cross-disciplinary training activities.