EPOS Architecture
The EPOS architecture is based on four main elements, which compose its legal, financial and operational backbone (Fig. 1). At the bottom of the chain the National Research Infrastructures (NRI) provide data through their respective Thematic Core Service (TCS), i.e. a thematic community that develops data and services that are specific for a subdiscipline of solid Earth science. The TCSs act as a middle layer before the data and services are eventually integrated by the Integrated Core Services (ICS) into a single, multidisciplinary data portal accessible for all users. The TCS-ICS federated system is the skeleton of the 'EPOS Delivery Framework' and represents the solution for integrating distributed infrastructures via shared standards for data and metadata (Fig. 1). The EPOS ERIC governs and oversees this entire process.
Fig. 1. The EPOS Architecture and its 4 components: the National Research Infrastructures (NRI), the Thematic (TCS) and Integrated (ICS) Core Services, of which the latter two compose the EPOS Delivery Framework. The ICS and the Executive Coordination Office (ECO) fall under the EPOS ERIC legal subject. This figure was provided by EPOS ERIC.
National Research Infrastructures (NRI)
The NRIs represent the foundations of the EPOS architecture. They are existing and operational organizations, which provide high-quality earth science data and services at a national level for the different geoscience communities. NRIs contributing to EPOS are owned and managed at a national level.
Thematic Core Services (TCS)
TCS Cocco et al
Fig. 2. The 10 Thematic Core Services currently integrated into EPOS. Figure taken from Cocco et al. (2022).
The TCSs represent the transnational governance level of the different thematic communities contributing to EPOS. They ensure the management, standardization, and quality control of the data and metadata produced by the NRIs to ensure integrated access through the ICS. Each TCS coordinates a number of service providers, i.e. organizations that are responsible for the key TCS services. These services primarily consist of providing harmonized access to the data through standardized web APIs available from TCS community portals and data nodes. The TCS are governed by consortia that are linked to the EPOS ERIC via legal collaboration agreements.
Currently, the following thematic communities exist (Fig. 2):
  1. Seismology
  2. Near-Fault Observatories
  3. GNSS Data and Products
  4. Volcano Observations
  5. Satellite Data
  6. Geomagnetic Observations
  7. Anthropogenic Hazards
  8. Geological Information and Modeling
  9. Multi-Scale Laboratories
  10. Tsunami (Candidate TCS)
More detailed information on the scientific expertise, data and services provided by these thematic communities can be found by clicking the corresponding hyperlinks.
Integrated Core Services (ICS)
The ICS, which stands at the core of the EPOS e-infrastructure, is the platform where all heterogeneous data and services are integrated, ensuring interoperability with the data and services provided by the TCSs. The ICS system architecture has been designed to provide the tools to facilitate the discovery of Data, Data products, Software and Services (DDSS) and the integration of these resources to fulfil users requests across the EPOS community. The ICS consists of a Central (ICS-C) and Distributed (ICS-D) hub. The former provides the user access to all multidisciplinary data and products made available by the TCSs through the newly launched EPOS Data Portal, while the latter aims to be a virtual research environment that will give access to external tools for services as computation, visualization and modelling. ICS-D pilot implementations are currently in progress. More information on the architecture of the Integrated Core Services can be found here.
The following videos give a tutorial on how to access and use the EPOS Data Portal:

The following training session goes into more depth on how to apply the EPOS Data Portal in research/education:

EPOS ERIC (European Research Infrastructure Consortium)
To govern the integration of the above elements and to coordinate the long-term integration of research infrastructures for solid Earth science in Europe, EPOS was established as an ERIC in 2018. An ERIC is a legal entity that facilitates the development and operation of research infrastructures with a pan-European dimension. ERIC receives financial contributions from the above member countries to support its working. More information on the legal structure of EPOS ERIC and its members can be found here.