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The Geysers geothermal field located in California, USA, is the largest geothermal site in the world, operating since the 1960s. We here investigate and quantify the correlation between temporal seismicity evolution and variation of the injection data by examination of time-series through specified statistical tools (binomial test to investigate significant rate changes, cross correlation between seismic and injection data, b-value variation analysis). To do so, we utilize seismicity and operational data associated with two injection wells (Prati-9 and Prati-29) which cover a time period of approximately 7 yr (from November 2007 to August 2014). The seismicity is found to be significantly positively correlated with the injection rate. The maximum correlation occurs with a seismic response delay of ∼2 weeks, following injection operations. Those results are very stable even after considering hypocentral uncertainties, by applying a vertical shift of the events foci up to 300 m. Our analysis indicates also time variations of b-value, which exhibits significant positive correlation with injection rates.

Flank instability and lateral collapse are recurrent processes during the structural evolution of volcanic edifices, and they affect and are affected by magmatic activity. It is known that dyke intrusions have the potential to destabilise the flanks of a volcano, and that lateral collapses may change the style of volcanism and the arrangement of shallow dykes. However, the effect of a large lateral collapse on the location of a new eruptive centre remains unclear. Here, we use a numerical approach to simulate the pathways of magmatic intrusions underneath the volcanic edifice, after the stress redistribution resulting from a large lateral collapse. Our simulations are quantitatively validated against the observations at Fogo volcano, Cabo Verde. The results reveal that a lateral collapse can trigger a significant deflection of deep magma pathways in the crust, favouring the formation of a new eruptive centre within the collapse embayment. Our results have implications for the long-term evolution of intraplate volcanic ocean islands. Flank instability and lateral collapse are a potential hazard at volcanic edifices. Here, the authors use numerical simulations to show that at Fogo volcano, lateral collapse can trigger a significant deflection of magma pathways in the crust, demonstrating how volcanic edifices may evolve.

AbstractMining, water-reservoir impoundment, underground gas storage, geothermal energy exploitation and hydrocarbon extraction have the potential to cause rock deformation and earthquakes, which may be hazardous for people, infrastructure and the environment. Restricted access to data constitutes a barrier to assessing and mitigating the associated hazards. Thematic Core Service Anthropogenic Hazards (TCS AH) of the European Plate Observing System (EPOS) provides a novel e-research infrastructure. The core of this infrastructure, the IS-EPOS Platform (tcs.ah-epos.eu) connected to international data storage nodes offers open access to large grouped datasets (here termed episodes), comprising geoscientific and associated data from industrial activity along with a large set of embedded applications for their efficient data processing, analysis and visualization. The novel team-working features of the IS-EPOS Platform facilitate collaborative and interdisciplinary scientific research, public understanding of science, citizen science applications, knowledge dissemination, data-informed policy-making and the teaching of anthropogenic hazards related to georesource exploitation. TCS AH is one of 10 thematic core services forming EPOS, a solid earth science European Research Infrastructure Consortium (ERIC) (www.epos-ip.org).

We performed so-far-unprecedented deep wireline vertical seismic profiling at the Groß Schönebeck site with the novel method of distributed acoustic sensing (DAS) to gain more detailed information on the structural setting and geometry of the geothermal reservoir, which is comprised of volcanic rocks and sediments of Lower Permian age. During the survey of 4 d only, we acquired data for 61 source positions using hybrid wireline fiber-optic sensor cables deployed in two 4.3 km deep, already existing wells. While most of the recorded data have a very good signal-to-noise ratio, individual sections of the profiles are affected by characteristic coherent noise patterns. This ringing noise results from incomplete coupling of the sensor cable to the borehole wall, and it can be suppressed to a large extent using suitable filtering methods. After conversion to strain rate, the DAS data exhibit a high similarity to the vertical component data of a conventional borehole geophone. We derived accurate time–depth relationships, interval velocities, and corridor stacks from the recorded data. Based on integration with other well data and geological information, we show that the top of a porous and permeable sandstone interval of the geothermal reservoir can be identified by a positive reflection event. Overall, the sequence of reflection events shows a different character for both wells explained by lateral changes in lithology. The top of the volcanic rocks has a somewhat different seismic response in both wells, and no clear reflection event is obvious at the postulated base of the volcanic rocks, so that their thickness cannot be inferred from individual reflection events in the seismic data alone. The DAS method enabled measurements at elevated temperatures up to 150 ∘C over extended periods and led to significant time and cost savings compared to deployment of a conventional borehole geophone string. This wireline approach finally suggests significant implications for observation options in old wells for a variety of purposes.

Decades of photogrammetric records at Bezymianny, one of the most active volcanoes on Earth, allow unveiling morphological changes, eruption and intrusion dynamics, erosion, lava and tephra deposition processes. This data publication releases an almost 7-decade long record, retrieved from airborne, satellite, and UAV platforms. The Kamchatkan Institute of Volcanology and Seismology released archives of high-resolution aerial images acquired in 1967-2013. We complemented the aerial datasets with 2017 Pleiades tri-stereo satellite and UAV images. The images were processed using Erdas Imagine and Photomod software. Here we publish nine quality-controlled point clouds in LAS format referenced to the WGS84 (UTM zone 57N). By comparing the point clouds we were able to describe topographic changes and calculate volumetric differences, details of which were further analyzed in Shevchenko et al. (2020, https://doi.org/...). The ~5-decade-long photogrammetric record was achieved by 8 aerial and 1 satellite-UAV datasets. The 8 sets of near nadir aerial photographs acquired in 1967, 1968, 1976, 1977, 1982, 1994, 2006, and 2013 were taken with various photogrammetry cameras dedicated for topographic analysis, specifically the AFA 41-10 camera (1967, 1968, 1976, and 1977; focal length = 99.086 mm), the TAFA 10 camera (1982 and 1994; focal length = 99.120 mm), and the AFA TE-140 camera (2006 and 2013; focal length = 139.536 mm). These analog cameras have all an 18×18 cm frame size. The acquisition flight altitude above the mean surface of Bezymianny varied from 1,500-2,500 m above mean surface elevation, translating up to >5,000 m above sea level. For photogrammetric processing, we used 3-4 consecutive shots that provided a 60-70% forward overlap. The analog photo negatives were digitized by scanning with Epson Perfection V750 Pro scanner in a resolution of 2,400 pixels/inch (approx. pixel (px) size = 0.01 mm). The mean scale within a single photograph depends on the distance to the surface and corresponds on average to 1:10,000-1:20,000. Thus, each px in the scanned image represents about 10-20 cm resolution on the ground. The coordinates of 12 ground control points were derived from a Theo 010B theodolite dataset collected at geodetic benchmarks during a 1977 fieldwork. These benchmarks were established on the slopes of Bezymianny before the 1977 aerial survey and then captured with the AFA 41-10 aerial camera. The most recent was a satellite dataset acquired on 2017-09-09 by the PHR 1B sensor aboard the Pleiades satellite (AIRBUS Defence & Space) operated by the French space agency (CNES). The forward, nadir and backward camera configuration allows revisiting any point on earth and was tasked for the acquisition of Bezymianny to provide a 0.5 m resolution panchromatic imagery dataset. In order to improve the Pleiades data, we complemented them with UAV data collected on 2017-07-29 with DJI Mavic Pro during fieldwork at Bezymianny. This data publication includes a description of the data (in pdf format) and the nine processed and controlled three-dimensional point clouds (in LAS format). The point clouds can be easily interpolated and imported into most open and commercially available geographic information system (GIS) software. Further details on data and data handling are provided in Shevchenko et al. (2020).

EPOS is a Research Infrastructure plan that is undertaking the challenge of integrating data from different solid Earth disciplines and of providing a common knowledge-base for the Solid-Earth community in Europe, by implementing and managing a logically centralised catalog based on the CERIF model. The EPOS catalogue will contain the information about all the participating actors, such as Research Infrastructures, Organisations and their assets, in relationship with the people, their roles and their affilitation within the specific scientific domain. The catalogue will guarantee the discoverability of domain specific data, data products, software and services (DDSS) and enable the EPOS Integrated Core Services system to perform - on behalf of a end user – advanced operations on data as for instance processing and visualization. It will also foster the homogenisation of vocabularies, as well as supporting heterogeneous metadata. Clearly, the effort of accomodating the diversities across all the players needs to take into account of existing initiatives concerning metadata standards and institutional recommendations, trying to satisfy the EPOS requirements by incorporating and profiling more generic concepts and semantics. The paper describes the approach of the EPOS metadata working group, providing the rationale behind the integration, extension and mapping strategy to converge the EPOS metadata baseline model towards the CERIF entities, relationships and vocabularies. Special attention will be given to the outcomes of the mapping process between two elements of the EPOS baseline - Research Infrastructure and Equipment - and CERIF, by providing detailed insights and description of the two data models, of encountered issues and of proposed solutions.

Strong ground motion records and free open access to strong‐motion data repositories are fundamental inputs to seismology, engineering seismology, soil dynamics, and earthquake engineering science and practice. This article presents the current status and outlook of the Observatories and Research Facilities for European Seismology (ORFEUS) coordinated strong‐motion seismology services, namely the rapid raw strong‐motion (RRSM) and the engineering strong‐motion (ESM) databases and associated web interfaces and webservices. We compare and discuss the role and use of these two systems using the Mw 6.5 Norcia (Central Italy) earthquake that occurred on 30 October 2016 as an example of a well‐recorded earthquake that triggered major interest in the seismological and earthquake engineering communities. The RRSM is a fully automated system for rapid dissemination of earthquake shaking information, whereas the ESM provides quality‐checked, manually processed waveforms and reviewed earthquake information. The RRSM uses only data from the European Integrated Waveform Data Archive, whereas the ESM also includes offline data from other sources, such as the ITalian ACcelerometric Archive (ITACA). Advanced software tools are also included in the ESM to allow users to process strong‐motion data and to select ground‐motion waveform sets for seismic structural analyses. The RRSM and ESM are complementary services designed for a variety of possible stakeholders, ranging from scientists to the educated general public. The RRSM and ESM are developed, organized, and reviewed by selected members of the seismological community in Europe, including strong‐motion data providers and expert users. Global access and usage of the data is encouraged. The ESM is presently the reference database for harmonized seismic hazard and risk studies in Europe. ORFEUS strong‐motion data are open, “Findable, Accessible, Interoperable, and Reusable,” and accompanied by licensing information. The users are encouraged to properly cite the data providers, using the digital object identifiers of the seismic networks. © 2021 Seismological Society of America ISSN:0895-0695 ISSN:1938-2057

This article describes the Engineering Strong‐Motion Database (ESM), developed in the framework of the European project Network of European Research Infrastructures for Earthquake Risk Assessment and Mitigation (NERA, see [Data and Resources][1]). ESM is specifically designed to provide end users only with quality‐checked, uniformly processed strong‐motion data and relevant parameters and has done so since 1969 in the Euro‐Mediterranean region. The database was designed for a large variety of stakeholders (expert seismologists, earthquake engineers, students, and professionals) with a user‐friendly and straightforward web interface. Users can access earthquake and station information and download waveforms of events with magnitude≥4.0 (unprocessed and processed acceleration, velocity, and displacement, and acceleration and displacement response spectra at 5% damping). Specific tools are also available to users to process strong‐motion data and select ground‐motion suites for code‐based seismic structural analyses. [1]: #sec-13