Management and FAIR sharing of DAS seismological data and metadata through Epos-France Seismological Data Center.

Since October 2023, the ABYSS ERC project has been continuously recording Distributed Acoustic Sensing (DAS) data using  instruments interrogating three underwater optical fibres spanning  450 km of the Chilean coast. This large-scale project addresses the classic challenges associated with the use of DAS in seismology, particularly in terms of efficient data processing, management and sharing. It is now well-established that DAS technology generates massive volumes that require new formats for data, and metadata that are different from those used in conventional seismology.

We developed an efficient management of data and metadata, that allow us to easily, create a visualization of the updated seismicity catalog every day and the sharing of events in QuakeML format via a web interface (https://pisco.unice.fr/#/), hosted and maintained at Geoazur.

To deal with a production rate of 660 GB per day and 30,000 virtual sensors, FAIR real-time data sharing of the entire dataset through the Seismological Data Center is not yet feasible. To ensure DAS data accessibility and FAIR data sharing, we distribute specific products, such as continuous time series with reduced spatial resolution compared to the complete DAS dataset, tailored for seismological monitoring. 

We have implemented data and metadata management that complies as closely as possible with current FDSN standards. Ground motion velocity data, sampled every 5 kilometers, are computed directly from DAS data directly on the instrument and transmitted in real time via a SeedLink protocol in miniSEED format. For data processing, and data transmission, we rely on an intuitive and versatile python tool called Xdas, which is now used by many collaborators in Europe. 

The metadata complies with the FDSN miniSEED 2.6 norm, enabling users to download the data via the dedicated web services. Data and metadata of the ABYSS project are shared within the Epos-France Seismological Data Centre (Epos-France SDC), the French representative in the management structures of the European Integrated Data Archive (EIDA).