Séminaire ISTeP - Romain Rubi

(Université de Liège)

New insights into sedimentary processes and related morphologies in tidal straits: the case of the Rio-Antirio Sill (Greece)

Straits are crossed by marine currents that are amplified due to the water constriction. These nearshore high-velocity flows are problematic for offshore infrastructures and coastal dynamics but constitute an under-estimated carbon-free energy source. Most of the straits are dominated by tidal currents which flow axially to the seaway, with reversal directions and phase difference between the two interlinked basins. These tidal currents interplay with: (i) sediment sources that also includes in situ carbonate production and estuaries - deltas, (ii) tectonic activity, and (iii) inherited lowstand features, all shaping the sea floor into complex geomorphologies. Previous studies have highlighted a common tidal-strait depositional model with a strait-center zone in erosion and on each side a dune-bedded strait zone with 3D and 2D tidal dunes and tidal ripples. Here, we document a tidal-strait system, which is interacting with active tectonics, and internal-tides along its axis. In results, Rion strait displays complex bathymetric features without any 3D or 2D tidal dunes. Thus, it provides a new end member to the tidal-strait depositional model. This end member is characterized by a re-localization of the erosion, bypass and deposition. It illustrates the key role of internal tides for straits located at the boundary between a confined deep-basin and the open-sea.

vendredi 19 novembre à 12h30

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Sujet : Séminaire Romain Rubi
Heure : 19 nov. 2021 12:30 PM Paris
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https://us02web.zoom.us/j/84828352432?pwd=T0NtUTAwVGRrd29lWXpGWElOL2J6Zz09
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