Mysterious 'monument' found on bottom of Sea of Galilee, but what is it?
An underwater photo courtesy of the American Friends of Tel Aviv University, shows the structure is made of basalt boulders. (Photo: Shmulik Marco).
Published Tuesday, June 11, 2013 1:01PM EDT
Researchers have discovered a mysterious, man-made monument lying deep beneath the surface of the Sea of Galilee.
The team of researchers from Tel Aviv University found the cone-shaped structure while conducting a survey of the seabed in 2003.
Side scan sonar, which can create a three-dimensional model of the ocean floor, revealed the 13-metre-high, 70-metre-wide, cone-shaped monument.
It appears to have been built roughly 6,000 years ago.
"Close inspection by scuba diving revealed that the structure is made of basalt boulders up to one metre long with no apparent construction pattern. The boulders have natural faces with no signs of cutting or chiselling," says a report published this week in the International Journal of Nautical Archeology.
Those boulders would have been transported at least several hundred metres from the nearest basalt quarry, and perhaps from as far away as two kilometres, the report states.
Archeologists have discovered evidence that the area, located in the south-western part of the Sea of Galilee in northern Israel, hosted a flourishing fishing industry that continued regardless of fluctuations in water levels over the years. As a result, one hypothesis put forward by the researchers is that the stone pile was built as an artificial reef, or nursery for fish.
In fact, the structure still attracts fish which prefer it over the sandy, structureless sea bottom surrounding it, the study says.
"Stone-built installations that are thought to be ancient fish nurseries are well known in the Sea of Galilee. They are found near the shores at regular intervals," says the study, though it points out that those structures were typically made with much smaller basalt stones, just one-third the size of those used in the monument. And the structures themselves were typically much smaller, just 1.5 to 4 metres in diameter.
And then there's the problem of building such a structure underwater in ancient times.
More likely, the study suggests, it was built on shore for some other, unknown purpose, and was later submerged either by rising sea levels, or tectonic activity which is known to occur in the region.
The structure is estimated to weigh roughly 60,000 tons: "Thus, the effort invested in such an enterprise is indicative of a complex, well-organized society, with planning skills and economic ability."
The researchers estimated the age of the structure by measuring the sand that has accumulated around its bottom. The base is currently two- to five metres below the sea floor, which would likely take a minimum of several thousand years to accumulate.
The research team believes the site may be a product of the Early Bronze Age, the only period in the region when megalithic structures are believed to have been constructed.
Next, researchers hope to conduct extensive underwater research to explore the foundation of the structure, or the surface on which it was constructed, search for artifacts used in its construction and more definitively date its construction.