MedMax. Mediterranean future sea level Maximum.
Global sea-level rise is the result of an increase in the ocean volume, which evolves from changes in ocean mass due to melting of continental glaciers and ice sheets, and expansion of ocean water as it warms. The elevation of ocean surface relatively to the ocean floor is defined as a ’relative sea level’ (RSL), and any shift on height of either of these two surfaces produces a RSL change. RSL varies due to a variety of processes, acting at different time scales. In the long term these factors are eustatic, deformation of the solid earth and tectonic. Our understanding of current rates of sea-level rise from tide gauge and satellite data, and of the ongoing mass loss from the major ice sheets requires correction for glacial isostatic adjustment (GIA) effects that are both calibrated to, and independently tested by, observations of former sea levels.
This project aims to create a database of Holocene (last 10 ka) geological data across the Mediterranean basin. This represents a tool of fundamental importance for understanding and tuning GIA models and to assess sea level rise hazards, which are particularly magnified in low-lying or subsiding coastal areas. In the Mediterranean, different kinds of RSL markers have been used to reconstruct RSLs: biological, sedimentological, geomorphological and archaeological. The production of such great amount of literature, which is still rapidly growing in number, has led to the obvious consequence of fragmented information, only occasionally reviewed in some localities, but never collected into an organic database to be analysed at the scale of the Mediterranean basin.
All observational data discussed and corrected using the same method will be of beneficial impact in assessing the potential sea-level rise over the next century in Mediterranean sea and, especially, on the largest cities of its southern coast.
In the framework of the MedMax project, we completed the review of 909 radiocarbon dated Relative Sea-Level (RSL) data-points along the western Mediterranean coast. It resulted in the first quality-controlled database constraining the Holocene sea-level histories along the Spanish, French, Italian, Slovenian, Croatian, Maltese and Tunisian coasts. We reviewed and standardized the RSL data-points using a new multi-proxy methodology based on the modern taxa assemblages in Mediterranean lagoons and marshes, beachrock characteristics (cement fabric and chemistry, sedimentary structures) and the modern distribution of Mediterranean fixed biological indicators. These RSL data-points were coupled with the large amount of archeological RSL indicators available for the western Mediterranean. We assessed the spatial variability of RSL histories for 22 regions and we compared them with the ICE-5G VM5a isostatic model. All the data-points of the database are freely available at the following link:
User can access the RSL history of a single region by clicking on the orange square or explore the single RSL data-point by clicking of the red dots.
For any further information, please contact Matteo Vacchi :