Purdue team setting up the drone at Dana Island

Classics Professor & Archaeologist Nicholas Rauh & CLA Rosetta Team Uses Advanced Drone to Map Long Lost Mediterranean Outpost of Roman & Byzantine Empires

Featured Research News ROSETTA

At the end of July 2019, six Purdue researchers collaborated with a Turkish archaeological survey team to use LIDAR technology and other research tools to investigate an ancient harbor settlement on Dana Island along the southern coast of Turkey. Professor Nicholas Rauh, a Roman archaeologist inf the School of Languages and Cultures, together with his field school students, Kenneth Klimeck and Zoey Osterloh, assisted the research efforts of Civil Engineering Professor Ayman Habib, drone pilot Evan Flatt, and geologist Angus Moore from Purdue’s Department of Earth, Atmospheric, and Planetary Sciences. These Purdue researchers employed cutting-edge technology provided by the newly launched ROSETTA initiative supported by the College of Liberal Arts Office of Research led by Professor Sorin Adam Matei and by the Purdue Core Laboratory Grant Program.

Purdue team setting up the drone at Dana Island
Purdue team setting up the drone at Dana Island

The research team aimed to unlock the secrets of this once-thriving harbor. Archaeological remains extend for nearly 2 km. Along the sheltered western shore of this island. A long mountainous spine rises along the middle of the island and attains an altitude of 300 m. at its southern crest. There, the ridge harbors two round Iron Age fortresses (ca. 500 BC) that may have played a role in a naval battle recorded between a local Cilician king (Appuashu of Pirindu) and the Neo-Babylonian Emperor Neriglissar (557 BC). Although the island was clearly occupied in the Iron Age (it was known in antiquity as Pityoussa), its predominant era of settlement and development dates to the Late Roman or Early Christian era (250-800 AD). Some five Christian churches, a possible martyrium, several built terraces of houses, and hundreds of fragments of pottery, glass, and metal all demonstrate that the harbor was important to Late Roman coastal trade, particularly during the reign of the Byzantine Emperor Justinian the Great (527-565 AD).

The most notable features on the island are the dozens of large road-like quarry cuts that scar the landscape, more than 200 directly along the shore, and many others that extend for more than 100 meters toward the base of the mountain that looms over the settlement. During the Christian era, the island community appears to have serviced the construction needs of neighboring settlements in the region by excavating and transporting building stone for house construction. However, the sheltered western shore of the island, which slopes to sea level, also appears to have serviced the flow of cargo vessels along this coast. A line of large cisterns near the shore possibly furnished potable water to passing shippers, and other rectangular cuttings along the shore appear to have housed small sheds where products like garum (a form of fish sauce) were produced. A Late Roman bath complex and what appears to be an amphora kiln are also visible directly on the shore.

The ruins of Dana Island
The ruins of Dana Island

Since 2011, Professor Gunder Varinlioglu of Mimar Sinan University in Istanbul Turkey has been directing an archaeological survey, the Bogsak Maritime Archaeological Survey Project, intended to map the remains of this region. Her survey zone lies within the Silifke District of the Mersin Province of modern-day Turkey. In antiquity this mountainous region was known as Rough Cilicia, a barren rugged stretch of coast that was important for its high altitude timbering resources (such as cedar) for ship-building purposes, as well as for metals, textiles, woolen goods, wine, and olive-oil production. With Rauh’s help Varinlioglu began mapping Dana Island in 2016 and and 2017. The progress of their research efforts was immediately challenged by the dense scrub brush of this uninhabited off-shore island. The nearly impenetrable garrigue forest obscures the extant remains not only to standard means of on-site mapping (featuring drafted plans generated by hand-mapping, GPS-based total stations, and photogrammetry) but also through detection by aerial or satellite imagery. This made mapping of the archaeological remains very slow-going. In addition, considerable debate has arisen among Turkish archaeologists regarding the function of the hundreds of cuttings along the western shore of the island. One school of thought holds that the cuttings reflect the use of the island as a large naval base complete with dozens of ramp-like structures along the shore known as ship sheds. These structures are necessary to shelter ancient wooden war galleys during inclement weather and to allow for their maintenance like modern dry docks. The proposed date of the naval yard, Bronze Age (ca. 1200 BC) or Early Iron age (ca. 600 BC), contrasts significantly with the results of Rauh’s pedestrian survey of the island, where the bulk of the processed ceramic remains (68%) clearly date to the Late Roman era. No Bronze Age pottery was recorded during the 2017-2017 seasons of the survey and the only Iron Age pottery was found in the walls of the fortresses at the top of the mountain, where the ceramic fragments were used as aggregate for the construction of the fortification walls.

To resolve these questions, Professor Ayman Habib and Evan Flatt spent four days mapping the settled areas of Dana Island using drones equipped with high resolution camera and LIDAR drones. LIDAR technology enables the camera to penetrate the dense vegetation to reveal patterns of stone surfaces on the island, such as wall remains. The LIDAR generates clouds of points that will be refined at Purdue and interpreted to reveal the remains of structures otherwise invisible to other means of overhead photography. EAPS PhD student, Angus Moore, meanwhile, obtained samples from the corners of some 11 quarry cuts that he will submit to Cosmogenic Nuclide analysis. Once quarried limestone more than a meter below the surface gets exposed to cosmic rays through quarrying, it undergoes chemical transformations with a measurable half-life. Angus Moore will process these samples to see if he can confirm a date, +/_ 200 years, for the quarrying activity on the island, particularly for the cuttings along the shore. In this manner, Purdue researchers have brought to bear on an important archaeological project, new cutting edge technologies that will deliver results in ways previously unachievable through standard research methodologies. The two new research components, LIDAR mapping, and Cosmogenic nuclide analysis, are the first of their kind ever to have been employed in Turkey and will likely be incorporated by other projects on-going in this archaeologically rich country.

Dana Island Roman/Byzantine stone buildings
Dana Island Roman/Byzantine stone buildings

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