Reprocessing 2-D airgun seismic reflection data SALTFLU (salt deformation and sub-salt fluid circulation in the Algero-Balearic abyssal plain) in the Balearic promontory and the Algerian basin

Abstract In an ever more challenging context for the acquisition of seismic data in Mediterranean Sea, reprocessing to improve quality legacy has become increasingly important. This work presents newly reprocessed, open access dataset SALTFLU acquired Algerian basin by National Institute Oceanography and Applied Geophysics (OGS) 2012. We apply a ‘broadband’ strategy adapted offset-limited (3 km streamer target 4 below sea level) airgun reflection deep water settings. then assess if reprocessed images provide new geological insights on sub-surface. The workflow relies integrated approach combining geophysics interpretation iteratively build velocity model. this way we aim tackle some challenges linked imaging complex structures containing high contrasts with 2-D, data. first broaden bandwidth through multi-domain de-noising, deghosting source designature using operator derived from seabed reflection. perform iterative migration analysis, pre-stack time multiple attenuation Radon domain obtain time-migrated images. initial model is resulting velocities, geologically driven updates are generated combination travel-time tomography, major salt horizons gradient flooding. flooding aims reproduce large scale first-order variations, while tomography resolve smaller second-order variations. results our knowledge under-explored down base pre-salt. Fluid indicators imaged within Plio-Quaternary basin, which interpret as thermogenic or biogenic gas sourced either Messinian Upper Unit pre-salt, migrating hydro-fractured salt. image lateral vertical facies variation units that could shed light tectono-stratigraphic processes acting during Salinity Crisis. It also reveals numerous previously unresolved volcanic Formentera basin.