| Title: |
Extreme Mediterranean rainfall impact on sedimentary routing systems: what can we learn from Storm Alex using in situ detrital 10Be? |
| Authors: |
Mariotti, Apolline; Blard, Pierre-Henri; Charreau, Julien; Toucanne, Samuel; Jorry, Stephan; Joseph, Olivier; Aster, Team |
| Contributors: |
Centre de Recherches Pétrographiques et Géochimiques (CRPG); Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS); German Research Centre for Geosciences - Helmholtz-Centre Potsdam (GFZ); Université libre de Bruxelles = Free University of Brussels (ULB); Geo-Ocean (GEO-OCEAN); Université de Bretagne Sud (UBS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO EPE)-Centre National de la Recherche Scientifique (CNRS); MUSEES DE FRANCE; Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement (CEREGE); Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE); This work was supported by funding from OTELo (Université de Lorraine, CNRS), INSU and the BRGM. |
| Source: |
ISSN: 0169-555X ; Geomorphology ; https://hal.science/hal-05463310 ; Geomorphology, 2026, 492, pp.110061. ⟨10.1016/j.geomorph.2025.110061⟩. |
| Publisher Information: |
CCSD; Elsevier |
| Publication Year: |
2026 |
| Collection: |
Université de Lorraine: HAL |
| Subject Terms: |
Heavy precipitation events; Cosmogenic 10Be; Sediment transport; Storm Alex; [SDU]Sciences of the Universe [physics] |
| Description: |
International audience ; Understanding how extreme meteorological events influence sediment transport is critical for predicting landscape evolution under a changing climate. Detrital cosmogenic 10Be can provide insights into sediment dynamics following extreme rainfall, but high-resolution datasets tracking 10Be variations before and after a storm, alongside long-term records, remain rare.The Var catchment (French Southern Alps) presents a unique case study, as its 10Be signal was well-documented before the October 2020 Storm Alex (>500 mm of rainfall/24 h), which triggered flash floods, mobilized large sediment volumes, and formed a 10 km-long sediment plume in the Mediterranean Sea. We compare 10Be concentrations in river sediments collected pre-storm (2016–2018), and at +7 days, +21 days, +4 months, and +7 months post-storm. We also use a historical offshore sample and contextualize these results with a 75 ka-long 10Be record from deep-sea sediment cores.At the Var outlet, 10Be concentrations initially increased by ∼25 % at +7 and +21 days, attributed to the mobilization of 10Be-rich sediments from the upstream Var and Tinée sub-catchments. Concentrations returned to pre-storm levels within four months, primarily due to dilution with 10Be-poor sediments from the Vésubie sub-catchment fluvioglacial terraces. While short-term 10Be fluctuations at the Var outlet reflect complex sediment sourcing, our comparison with the 0–75 ka record confirms that major glaciation events and potential anthropic influences remain distinguishable, demonstrating that 10Be is a robust proxy of denudation changes, even when extreme events are involved. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| Relation: |
WOS: 001609124700001 |
| DOI: |
10.1016/j.geomorph.2025.110061 |
| Availability: |
https://hal.science/hal-05463310; https://hal.science/hal-05463310v1/document; https://hal.science/hal-05463310v1/file/1-s2.0-S0169555X25004714-main.pdf; https://doi.org/10.1016/j.geomorph.2025.110061 |
| Rights: |
https://creativecommons.org/licenses/by/4.0/ ; info:eu-repo/semantics/OpenAccess |
| Accession Number: |
edsbas.A71A9C53 |
| Database: |
BASE |