Speaker
Description
Ignacio Lázaro Roche¹, Gergely Surányi²
¹ Low Background Noise Underground Research Laboratory (LSBB) CNRS/AU UAR3538 Rustrel, France
² HUN-REN Wigner Research Centre for Physics, Budapest, Hungary
Paleolithic decorated caves constitute an irreplaceable cultural heritage whose preservation critically depends on internal hydroclimatic stability. In coastal environments, sea-level rise and marine forcing introduce additional threats. The Cosquer Cave [1], a semi-submerged Upper Paleolithic site embedded in a low-permeability limestone massif in southeastern France and listed as a UNESCO World Heritage site, represents a unique case in which the sea plays a dual role: both a destructive agent and a temporary preservative mechanism.
Seasonal marine-induced pressurization of the submerged karst network generates air overpressure within the cave, temporarily lowering the internal water level and exposing the lowest decorated panels for several weeks. However, the mechanisms governing these pressurization events—including potential variations in permeability driven by groundwater dynamics—remain insufficiently understood [2].
We propose muography as a non-invasive, high-resolution imaging technique to investigate the internal structure of the cave and its surrounding karst system. By coupling muographic density imaging with continuous in-situ hydroclimatic monitoring, we aim to (i) characterize structural pathways controlling air inflow and outflow, and (ii) detect hidden conduits and secondary galleries through density contrasts.
High-resolution laser scanning of the cave [3] and its surface environment enables optimization of detector positioning and will be incorporated into the density inversion framework. The detector must operate passively and autonomously during a one-month campaign and will be deployed through a narrow 137 m-long access tunnel, including a 40 m submerged section, under strict heritage preservation constraints. These constraints impose strong requirements on robustness, compactness, and transportability.
This pioneering approach will support the exploration of previously uncharted galleries and refine the conceptual model of the Cosquer Cave hydrosystem, providing a basis for predictive simulations under future sea-level rise scenarios. More broadly, this study highlights the potential of next-generation portable muography systems for safeguarding vulnerable coastal karst heritage by integrating geophysical imaging with cultural conservation strategies.
Keywords: Soil permeability; Muography; coastal karst; Paleolithic heritage; sea-level rise.
[1] J. Collina-Girard. Prehistory and coastal karst area: Cosquer Cave and the “Calanques” of Marseille. Speleogenesis Journal : Speleogenesis and Evolution of Karst Aquifers, 2004, t. 2, 2.
[2] Hugo Pellet, Pierre Henry, Stéphanie Touron, Bruno Arfib, Cyril Montoya, et al.. Oceanographic and hydroclimatic data explain depressed water level in the coastal karst hosting the decorated Paleolithic Cosquer cave (France). Science of the Total Environment, 2026, 1012, pp.181149.
[3] Loic Jeanson, Caroline Font, Priscilia Barbuti, Valentin Grimaud, Stéphane Renault, et al.. La grotte Cosquer à Marseille : outils et méthodes numériques pour un objet d’étude complexe et difficilement accessible. JC3DSHS 2023 - Les Journées du Consortium 3D SHS, Nov 2023, Lyon, France. pp.29-39.