Researchers say the watery setting for Venice was not always a coastal marsh but developed as sea levels rose and drowned landscapes that had supported dryland habitats and human activity.
Using seismic surveys and sedimentary cores collected from coastal basins along the northern Adriatic coast of Italy, Slovenia and northern Croatia, a team led by Samuele Ongaro at the University of Southampton built models of how sea level changed in the region over the last 10,000 years. The combined subsurface imaging and core data allowed the group to map where former hills, valleys and swamps once stood and when they were inundated.
The reconstructions show that features now beneath shallow water were once part of an inland plain several miles from the ancient shoreline. As water levels rose over millennia, those landforms were progressively flooded and reworked, producing the lagoonal environments that later became the site of Venice and its surrounding waterways.
The study highlights the long-term, large-scale reshaping of the northern Adriatic coast by gradual sea-level rise. By identifying the timing and pattern of inundation, the findings provide new context for how coastal environments evolved in the post-glacial period and for interpreting archaeological and geological records of human settlement in the area.
Authors emphasise that the results come from combining geophysical and sedimentary evidence across national boundaries in the northern Adriatic, offering a continuous regional view rather than isolated local studies. That integrated approach, they argue, improves understanding of how shorelines migrate and how low-lying landscapes respond to sustained sea-level change.
While focused on past changes, the work underlines how dynamic coastal zones can be over millennial timescales, with implications for present-day efforts to manage and protect heritage, ecosystems and infrastructure in regions vulnerable to rising seas.