TephAta – an online collection of tephra datafrom the Atacama Desert

Abstract

Tephrostratigraphy and tephrochronology are powerful tools using volcanic ash (tephra) layers for establishing stratigraphic correlations and/or to obtain chronological information for different kinds of sedimentary archives. To develop robust tephrostratigraphic frameworks it is essential to precisely characterize the physical, geochemical and chronological properties of tephra layers and their sampling sites. These frameworks allow newly discovered tephra layers to be correlated with established sequences, providing stratigraphic and chronological context and enhancing reconstructions of the spatial and temporal patterns of regional volcanic activity. Tephrostratigraphic frameworks have been developed or are currently emerging in many regions of the world. However, for some regions their potential remains underutilized. One such region is the Atacama Desert of northern Chile, despite its long history of frequent volcanism and associated tephra deposition. Within the framework of the Collaborative Research Centre “Earth – Evolution at the Dry Limit” (CRC1211), the glass phase geochemical compositions of Pleistocene tephra layers were recently systematically investigated to refine their stratigraphic and chronological placement. Alongside this effort, a dedicated tephra database, TephAta was created to provide a long-term repository for tephrochronological research in the Atacama Desert. TephAta enables the comprehensive digital documentation of diverse tephra-related datasets within a single platform and offers search functionalities that support and streamline ongoing expansion of the regional framework, following FAIR (findability, accessibility, interoperability, and reusability) data principles. A first data release contains 106 tephra samples from 91 deposits, with continued spatial and temporal growth planned. All data are accessible via the TephAta portal (https://www.crc1211db.uni-koeln.de/tephata, last access: 29 May 2026) and datasets described in this paper are available at https://doi.org/10.60520/IEDA/114209 (Leicher, 2026). Beyond serving as a stratigraphic and chronological tool for paleoenvironmental or mapping studies, TephAta also facilitates investigations into the regions explosive volcanic history and supports volcanic hazard and risk assessment.