geosciences Review Seismic Reflection Methods in Offshore Groundwater Research Claudia Bertoni 1,*, Johanna Lofi 2, Aaron Micallef 3,4 and Henning Moe 5 1 Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK 2 Université de Montpellier, CNRS, Université des Antilles, Place E. Bataillon, 34095 Montpellier, France; johanna.lofi@gm.univ-montp2.fr 3 Helmholtz Centre for Ocean Research, GEOMAR, 24148 Kiel, Germany;
[email protected] 4 Marine Geology & Seafloor Surveying, Department of Geosciences, University of Malta, MSD 2080 Msida, Malta 5 CDM Smith Ireland Ltd., D02 WK10 Dublin, Ireland;
[email protected] * Correspondence:
[email protected] Received: 8 April 2020; Accepted: 26 July 2020; Published: 5 August 2020 Abstract: There is growing evidence that passive margin sediments in offshore settings host large volumes of fresh and brackish water of meteoric origin in submarine sub-surface reservoirs. Marine geophysical methods, in particular seismic reflection data, can help characterize offshore hydrogeological systems and yet the existing global database of industrial basin wide surveys remains untapped in this context. In this paper we highlight the importance of these data in groundwater exploration, by reviewing existing studies that apply physical stratigraphy and morpho-structural interpretation techniques to provide important information on—reservoir (aquifer) properties and architecture, permeability barriers, paleo-continental environments, sea-level changes and shift of coastal facies through time and conduits for water flow. We then evaluate the scientific and applied relevance of such methodology within a holistic workflow for offshore groundwater research. Keywords: submarine groundwater; continental margins; offshore water resources; seismic reflection 1.