Suchergebnisse

This paper reports on the expedition to the Cumbre Vieja volcano (Canary Islands, Spain) in November 2021 to assess stand-off laser-induced breakdown spectroscopy for real-time measurements of the lava streams from a safe point. The paper provides insight on the analytical approach to the problem, the rationale of the instrument design and construction carried out in three weeks, the experience with the new-born instrument at the volcano and the preliminary results. Despite the subtle spectral differences among the samples and the signal variability induced by the strong wind gusts at site, a statistical approach to data processing such as PCA, made possible to extract sufficient information and provide a robust classification tool. ; We express our sincere gratitude to the Spanish Unidad Militar de Emergencias (UME) for providing essential support, security, and expertise at the field. We would like to thank Carlos Malag ́on (Astro- shop, M ́alaga, Spain) for donating the telescope used in the stand-off LIBS instrument, to the personnel of the Chemical Analysis Area and the Machine Shop of the Central Facility for Research Support (SCAI-UMA) and to Profs. E.R. Losilla and A. Cabeza (Dept. Química Inorgánica, Cristalografía y Mineralogía, UMA) and D. Marrero (Dept. Física Aplicada I, UMA) for their valuable comments and advice with the surrogate samples. This work has been partially supported by the I Plan Propio de Investigaci ́on de la Universidad de M ́alaga, the Extraordinary Funding (RD 1078/2021, 7th December, Núm. 293 Sec. I. P ́ag. 150,995) and PID2020-113407RB-I00 granted by the Spanish Ministry of Science and Innovation (MICINN). Funding for open access charge: Universidad de Málaga / CBUA

20 p. - Supplementary material related to this article can be found, in the online version, at doi: https://doi.org/10.1016/j.ejrh.2021.100781. ; [EN] Study region Old Las Salinas spring in Medina del Campo, Duero river basin, central Spain. Study focus Medina del Campo groundwater body (MCGWB) is a multilayer semiconfined aquifer subject to intensive pumping since the 1970's, where the current existence of spas where there used to be traditional baths could confirm the existence of deep groundwater flow paths. The old spring of Las Salinas (OSLS) is a saline anomaly in an aquifer with predominance of CaCO3H waters whose occurrence has not yet been formally explained. Long-term geological, geophysical, hydrogeological and hydrochemical records were integrated and complemented with field work to clarify its existence. New hydrological insights for the region Outcomes led to the conclusion that the hydrochemistry of the Olmedo and Palacio de las Salinas salt baths is associated with the existence of a major threshold in the impervious basement of the aquifer, which intercepted deep regional groundwater flow and caused upwelling to the surface under unperturbed conditions. These results allow for the development of a conceptual flow model at the regional scale that explains the changes in natural water chemistry that have been identified in recent decades. ; This research has received funding from the European Union H2020 Programme under Grant Agreement No. 730497 for the research project NAIAD-NAture Insurance value: Assessment and Demonstration. ; Peer reviewed