Assessment of the impact of anthropogenic activities on the marine environment and biodiversity - Focus on the disposal of unexploded historical ordnance

Résumé :

Anthropogenic activities, like offshore construction and underwater explosions, can adversely affect marine environment and biodiversity, with the potential to generate seismic events and noise pollution, and thus to cause impact on coastal buildings and marine species. This presentation focuses more particularly on the disposal of unexploded historical ordnance (UXO) that must be destroyed quickly after discovery to ensure the safety of divers and ships.

This disposal, operated by the French Navy Mine Warfare Office, relies on higher-order detonation. However, the possible consequences of UXO disposal on the marine environment and coastal buildings are difficult to assess upstream the underwater explosions. Indeed, as it was shown by field experiments, seismo-acoustic wave propagation in shallow water environments with spatially-variable properties is very complex. Therefore, this propagation may not be properly modeled if approximate methods and/or simplification of the marine environment are considered. Using HPC 3D full-wave modeling may then be one solution, but such a modeling induces significant challenges in terms of meshing and computational resources. The presentation discusses these challenges for the case of wave simulation in the Bay of Hyères (Mediterranean Sea, France) conducted using a 3D spectral-element method. The simulations were performed up to 30 Hz on a GPU supercomputer. This work is a first step towards our objective to simulate seismo-acoustic wave propagation beyond 100 Hz using exascale supercomputers. The results can be valuable to gain insights on how HPC can be used to achieve more precise and efficient results in assessing seismic risks and underwater noise pollution induced by anthropogenic activities.

...

This work was part of the POSA project (grant ANR-15-ASTR-0001 POSA) and the ChEESE project funded by the EU’s Horizon 2020 research and innovation program under the Grant Agreement 823844. It is also part of the ChEESE-2P project funded by EuroHPC (GA 101093038) and PEPR NumPex, and the SEASOUNDS project funded by the European Union under the Marie Sklodowska-Curie GA 101119769.

...

Le mardi 13 mai 2025 à 11h00 / Amphithéâtre François Canac, LMA

Voir en ligne : plus d’informations concernant l’orateur