Decoding the Interplay Between Tidal Notch Geometry and Sea‐Level Variability During the Last Interglacial (Marine Isotope Stage 5e) High Stand

• Published in: Geophysical Research Letters
• Main Authors: Georgiou, N., Stocchi, P., Casella, E., Rovere, A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2024
• Subjects: Settore GEO/04 - Geografia Fisica e Geomorfologia; Antarctic; Greenland; Antarc*
• Online Access: https://hdl.handle.net/10278/5053201; https://doi.org/10.1029/2023gl106829

Relic coastal landforms (fossil corals, cemented intertidal deposits, or erosive features carved onto rock coasts) serve as sea-level index points (SLIPs), that are widely used to reconstruct past sea-level changes. Traditional SLIP-based sea-level reconstructions face challenges in capturing continuous sea-level variability and dating erosional SLIPs, such as tidal notches. Here, we propose a novel approach to such challenges. We use a numerical model of cliff erosion embedded within a Monte Carlo simulation to investigate the most likely sea-level scenarios responsible for shaping one of the best-preserved tidal notches of Last Interglacial age in Sardinia, Italy. Results align with Glacial Isostatic Adjustment model predictions, indicating that synchronized or out-of-sync ice-volume shifts in Antarctic and Greenland ice sheets can reproduce the notch morphology, with sea level confidently peaking at 6 m and only under a higher than present erosion regime. This new approach yields insight into sea-level trends during the Last Interglacial.