ALBERT

Description: The GEOFON program consists of a global seismic network, a seismological data center, and a global earthquake monitoring system. The seismic network has regional focus in Europe and North Africa as well as throughout the Indian Ocean, but it operates stations on all continents, including Greenland on the North American continental plate and Antarctica. The data center provides real‐time seismic data through the SeedLink protocol and historical data from its large archive that currently comprises 120 TB of temporary and permanent seismic network data from GeoForschungsZentrums and third‐party partners made available via standard services as part of the European Integrated Data Archive and within the International Federation of Digital Seismograph Networks. GEOFON also provides global and rapid earthquake information. The rapid earthquake information service prioritizes fast information dissemination globally after moderate and large earthquakes based on automatic processing. Most operations are carried out using the SeisComP system. GEOFON distributes findable, accessible, interoperable, reusable data, services, products, and software free of charge, and it is used worldwide by hundreds of users and other data centers.

Description: The GEOFON program consists of a global seismic network (GE Network), a seismological data centre (GEOFON DC) and a global earthquake monitoring system (GEOFON EQinfo). These three pillars are part of the MESI research infrastructure of the Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences aiming at facilitating scientific research. GEOFON provides realtime seismic data, access to its own and third party data from the archive facilities as well as global and rapid earthquake information. The GEOFON Seismological Software can be considered a fourth cross-cutting module of the GEOFON Program. Data, services, products and software openly distributed by GEOFON are used by hundreds of scientists and data centres worldwide. Its earthquake information service is accessed directly by tens of thousands of visitors. The SeisComP software package is the flagship software provided to the community, which is geared for seismic observatory and data centre needs and used extensively to support our internal operations. As all other MESI (Modular Earth Science Infrastructure) modules GEOFON has the majority of users outside the GFZ as well as an external advisory committee that provides advice to the GFZ Executive Board and to the GEOFON team. This report describes the main activities carried out within the three GEOFON pillars and the software development group.

Description: Inferring the network topology from the dynamics of interacting units constitutes a topical challenge that drives research on its theory and applications across physics, mathematics, biology, and engineering. Most current inference methods rely on time series data recorded from all dynamical variables in the system. In applications, often only some of these time series are accessible, while other units or variables of all units are hidden, i.e. inaccessible or unobserved. For instance, in AC power grids, frequency measurements often are easily available whereas determining the phase relations among the oscillatory units requires much more effort. Here, we propose a network inference method that allows to reconstruct the full network topology even if all units exhibit hidden variables. We illustrate the approach in terms of a basic AC power grid model with two variables per node, the local phase angle and the local instantaneous frequency. Based solely on frequency measurements, we infer the underlying network topology as well as the relative phases that are inaccessible to measurement. The presented method may be enhanced to include systems with more complex coupling functions and additional parameters such as losses in power grid models. These results may thus contribute towards developing and applying novel network inference approaches in engineering, biology and beyond.

Description: 2023 marks thirty years since the start of GEOFON operations with the first three stations in Papua New Guinea (Port Moresby, PMG), the Czech Republic (Moravsky Beroun, MORC), in Ireland (Dublin, DSB). The GEOFON program started shortly after creation of the GFZ German Research Centre for the Geosciences in 1992 with the aim to promote global seismic monitoring, standardisation and data exchange. The program has evolved over the three decades in synergy with the seismological community through three important milestones: since late 1990s the development and community adoption of the SeedLink protocol enabling global real-time data exchange; in early 2000s, development of the Arclink protocol as key development to interconnect the EIDA federated data archives, only recently superseded by the use of FDSN web services at global scale; 2008 as the first public release of SeisComP, one of the most widely used seismological packages in seismology, a development triggered after the 2004 Aceh-Andaman earthquake and tsunami within the GITEWS project (German Indian Ocean Tsunami Early Warning System). Although GEOFON‘s heritage goes back to the 1990s and further down to 1889 building on the initial findings from Ernst von Rebeur-Paschwitz, the program is capable of leveraging third party funded challenging projects to keep modernising with the community. In this presentation we outline the most important developments of GEOFON through a journey in time over three decades, building links between current activities and vision still influenced by the initial aims which have shaped the current GEOFON mission.

Description: Findability, Accessibility, Interoperability and Reusability have become important principles in the geoscience community as it makes standardisation and openness a priority, so that these keywords are nowadays in focus for any new project at institutional, national and international levels. In seismology and its community that uptake has been extremely rapid and the level of FAIRness reached can be considered well above average within geoscience. But what “well above average” means and how to quantitatively assess FAIRness within this domain and compare seamlessly to others remains challenging.Taking advantage of ongoing national and international projects, a group of data managers from the EPOS seismological community started a collaboration with the FAIR-IMPACT project and its F-UJI developers aiming at enhancing the FAIR assessment process for specific domains. The group went through a process of mutually increasing awareness and understanding of FAIR definitions and their interpretations, including machine readability. Outcomes included F-UJI developers becoming more aware of the overall granularity and conception of research datasets including standard data and metadata formats used in seismology; revisions to landing pages; and updating guidelines to harmonise DataCite metadata for datasets within the domain. In this presentation we outline the liaison process established by the seismological data managers with F-UJI and introduce the first outcomes. We present the initial guidelines developed, a summary of selected FAIR assessments and finally we propose to further discuss FAIR assessment within the seismological formal governance body, namely the International Federation of Digital Seismograph Networks (FDSN) as a commission of IASPEI.

Description: Superficial geological layers can strongly modify the surface ground motion induced by an earthquake. These so‐called site effects are highly variable from one site to another and still difficult to quantify for complex geological configurations. That is why site‐specific studies can greatly contribute to improve the hazard prediction at a specific site. However, site‐specific studies have historically been considered difficult to carry out in low‐to‐moderate seismicity regions. We present here seismological datasets acquired in the framework of the French–German dense array for seismic site effect estimation project in the heavily industrialized area surrounding the French Tricastin Nuclear Site (TNS). TNS is located above an ancient canyon dug by the Rhône River during the Messinian period. The strong lithological contrast between the sedimentary fill of the canyon and the substratum, as well as its expected confined geometry make this canyon a good candidate for generating site effects that are variable on short spatial scales. To investigate the impact of this geological structure on the seismic motion, we conducted complementary seismic campaigns in the area. The first main campaign consisted of deploying 400 nodes over a 10 × 10 km area for one month and aimed at recording the seismic ambient noise. A second seismic campaign involved the deployment of 49 broadband stations over the same area for more than eight months. This complementary campaign aimed at recording the seismicity (including local, regional, and teleseismic events). These different designs allowed us to target a variety of seismic data at different spatial and temporal scales. Beyond the interest for local operational seismic hazard applications, these datasets may be valuable for studying seismic wave propagation within complex kilometer‐scale sedimentary structures. In this article, we present the deployment designs as well as initial analyses to provide information on the characteristics and the overall quality of the data acquired to future users.