Scientists make ‘astonishing’ discovery while studying 7,000-year-old underwater city

A ‘beautifully preserved’ sunken landscape, complete with a network of rivers and estuaries, has been mapped in 3D surrounding a submerged 7,000-year-old city. 

The scanning effort follows last year’s discovery of a nearby Stone Age road 13-feet beneath the Adriatic Sea, which once connected this ancient city to the mainland.

The city, known as Soline, was built on an artificial landmass by the ancient Hvar culture — but began to slowly sink off the coast of what is now Croatia as sea levels rose with the melting glaciers of the last Ice Age, starting around 12,000 BC.

An international team of researchers now hope to use this ‘astonishing’ and uniquely undisturbed drowned geography to better assist them in strategizing their deeper hunt for more of the Hvar people’s ancient submerged sites and artifacts.

‘It’s a more diverse landscape and it’s better preserved than we expected,’ according to geo-archaeologist Dr Simon Fitch, the new project’s lead investigator. Above, a 3D map from Dr Fitch’s past project mapping the submerged landscape of Doggerland in the North Sea

‘It’s a more diverse landscape and it’s better preserved than we expected,’ according to geo-archaeologist Dr Simon Fitch, the new project’s lead investigator.

‘The results,’ he said, ‘provided way more detail than we were expecting.’

The undersea landscape once walked by the Hvar was found in the waters near Croatia’s second-largest Split, where Dr Fitch traveled in March 2023 to initiate this first-ever seafloor scanning using state-of-the-art underwater 3D seismic sensors.

‘There are beautifully preserved rivers and estuaries buried beneath what is now the seafloor,’ Dr Fitch explained.

‘The unique environment of the area around Split, which is quite sheltered, has preserved a lot of it,’ he said.

Split’s portside coast opens on a bay protected from the more unpredictable currents of the wider Adriatic Sea by the islands of Brač and Šolta along Croatia’s Dalmatian archipelago.

The Adriatic, which divides Croatia from Italy, was long an ancient trade route between people connected by it and the larger, neighboring Mediterranean Sea.

Past explorations of its waters have dredged up Roman artifacts, a 2,200-year-old shipwreck and another Hvar settlement in nearby Gradina Bay 15-ft below sea level and ‘almost identical to the Soline settlement,’ according to the University of Zadar.

The new project builds off of Dr Fitch’s recent initiatives using offshore petroleum mining data, created and donated by the firm Petroleum Geo-Services who collects 3D geological maps using seismic equipment similar top earthquake warning data.

Dr Fitch and his team used the company’s data to map an ancient lost island in the North Sea, Doggerland, that once sat between Great Britain and the Netherlands.

But the new Adriatic project is taking this kind of 3D seismic mapping equipment and applying it directly for geological archeology for reportedly the first time.

An international team has collaborated on the underwater archaeological excavations of this site off the coast of Split in Croatia. Above, the dive team last May, who uncovered the 7,000-year-old road to the sunken neolithic city of Soline amid this parallel 3D mapping project

The Stone Age road’s remains were uncovered under layer of what scientists called ‘sea slime’

Dr Fitch, who teaches at the University of Bradford, said his team plans to dispatch another team of divers down to inspect some of the sites revealed by the new 3D mapping later this year. Above, an example of the 3D mapping data produced by the new Adriatic project

‘When we went in with our high resolution sensors, we found more rivers, more water in the landscape and more environments,’ Dr Fitch said. 

‘That’s amazing, because it suggests it is more likely that people lived there.’

Understanding where rivers once were, the researcher noted, will help his team better choose which sites were likely to have been inhabited by people, including more prehistoric settlements of Hvaric culture, improving their underwater digs’ chances of success.

‘Our ultimate goal is to find human artifacts,’ Dr Fitch noted, ‘and having this new understanding of the landscape makes that more likely.’ 

‘Croatia is the gateway to Europe,’ he added, ‘so if you think about the advance of farming into Europe, it is and always has been a very important landscape.’ 

Korčula, part of the Adriatic archipelago, was originally joined to the mainland but when sea levels began to rise at the end of the last Ice Age in 12,000 BC, flooding more or less led to the current layout from about 8,000 years ago

The same research team also uncovered another underwater settlement on the opposite side of Korčula 

Better understanding the Hvaric people’s lives will help bridge a gap between prehistory and the more well-known and storied era of the ancient Greeks and Romans along these seas made famous during their era of antiquity.

It may also help scientists understand how a past human civilization coped with the rising sea levels of climate change. 

‘The speed at which that landscape was lost to the sea is also important,’ Dr Fitch said. ‘It affected people and culture.’ 

‘So by understanding the landscape, we can begin to understand the whole archaeological picture so much more clearly.’

Dr Fitch, who teaches at the University of Bradford, said his team plans to dispatch another team of divers down to inspect some of the sites revealed by the new 3D mapping later this year.

Archeologist and art historian Vedran Barbarić, an associate professor from the  University of Split, presented the new findings with Dr Fitch at a public lecture in Split on May 10, 2024 and covered by local media Dalmacija Danas.

Their future work over the next few years will map both the Adriatic and North Sea, as they were between 10,000 and 24,000 years ago, during the last Ice Age, when sea levels were around 300 feet lower than they are today.

Archaeologists began making their surprising finds in this part of the Adriatic after analyzing satellite images of the water around the submerged Soline site of Soline, which was discovered in 2021 off the coast of the Croatian island of Korčula.

Radiocarbon analysis of preserved wood has indicated that the Soline settlement dates back to approximately 4,900 BC.

Soline was spotted by archaeologist Mate Parica, of the University of Zadar, who along with colleagues went diving down to the area for a closer look.

Artifacts made during the Neolithic era of the Hvar people that have been found thus far include ‘cream’ blades, stone axes and ‘fragments of sacrifices’ according to the University of Zadar.