Share this article with friends
by Vladimir KUZNETSOV, Dr. Sc. (Hist.), RAS Institute of Archeology; Vitaly LATARTSEV, General Director, PYOTR Center of Underwater Operations (Voronezh)
The World Ocean lives a life of its own-now stepping back and leaving behind years of dry land for the benefit of the people, and then advancing on the shore and engulfing whole cities with their surroundings. These fluctuations depend on a whole number of factors and a rise of 1 C in the mean annual temperature, for example, can push up the level of the World Ocean by about 2 meters. From the point of view of our science it is vitally important to try and determine the time-scale of what we call the processes of transgression and regression.
Located on what is now Russian territory today (mainly on the Taman Peninsula) are several ancient Greek cities which are flooded, fully or in part, by waters of the Black and the Azov seas. In most of these cases, unfortunately, nothing of these cities has been preserved under water. One rare exception is Phanagoria situated on the shore of the Tamansky Gulf.* Studies of the submerged part of this ancient center can help us determine the beginning of its flooding.
It was the British researcher N. Flemming who pioneered the dating of fluctuations of the level of the World Ocean in his studies of the Mediterranean coast. In this country the first serious studies in undersea archeology were launched in 1958 in the Tamansky Gulf. They were organized by the Institute of Archeology of the USSR Academy of Sciences and the project was headed by Prof. V. Blavatsky. The technical equipment and methods of his expedition were very simple: the scientists were using IPSA oxygen masks and some home-made diving gear (later replaced with commercial models).
This primitive technical base of the expedition put unfortunate limits on the results of their efforts because mere visual observations of the seabed, covered with algae, and the drilling of a tiny well (4x4 m) failed to provide an adequate picture of the flooded section of the ancient city. All of these things underlined the need of conducting underwater studies at the modern state of the art, so to speak. With this aim in view the RAS Institute of Archeology pooled its efforts and resources with the PYOTR Center for undersea operations (in Voronezh).
The objective of the first stage of the joint expedition consisted in investigating the seabed in the flooded section of Phanagoria. The studies were conducted with the help of the most up-to-date equipment, including a hydroacoustic station, a
* See: V. Kuznetsov, "Dead Town's History", Science in Russia, No. 3, 2000. -Ed.
satellite navigation plotter and a digital echo sounder with an independent power supply. The equipment was mounted on an inflatable boat with a payload of one ton. A portable computer was provided for recording of some of the most interesting sonograms (hydroacoustic images of the seabed).
Operating in the regime of lateral scanning provided an uninterrupted sonogram in two channels (on the left and right sides of the carrier). And the antenna, located 10- 12 meters above the bottom, was "drawing" the picture of a band up to 100 m wide. But since the flooded section of the ancient city lies at the depth of 1-5 m, the band width of observations did not exceed 30 m.
When the boat was moving parallel to the shore, the operator was
observing the seabed on the computer display and all of the data (including the geographical bearings of the boat and observation time) was recorded on magnetic tape for subsequent processing. The hydroacoustic station we used also made possible to operate in the modes of circular (at angles of up to 360 to the horizon) and conduct what we call sectoral observations (at angles of up to 180 on the azimuth orientation from 0 to 360). This, as different from lateral viewing, made it possible to study the bottom up to the mooring point of our boat. This mode of operation is used when we have to have an especially accurate "matching" of a discovered underwater object with the
geodesic base. And we can also use what we called an "electronic tape" right from the deck of our boat to measure distances to the submerged objects. Using two cursors, moved by the operator along the display, one can measure the linear dimensions of objects under investigation, its distance to the carrier or height parameters (accuracy of +- 10 cm).
Using the aforesaid gear we carried out a total hydroacoustic survey of the flooded section of the ancient city. The tacks* were drawn parallel to the base line located on shore with reference points placed at intervals of 50 m. The passage of each such point was fixed by the operator's commands from shore. A special line was introduced into the sonogram and thanks to that we were able to later combine the individual passages of our beat into a general picture. The width of the observation band was chosen at 30m and this ensured a good resolution with respect to the objects of observations, such as heaps of stones and separate slabs, etc. The width of the zone of our studies (from the shoreline) approached 270 m. An on-the-spot examination of the findings obtained and their subsequent processing in the lab revealed a number of interesting objects in various points of the surveyed area and helped us determine the border of the flooded section of the ancient city.
The main obstacle to locator identification of ancient objects in studies of this kind is a thick blanket of algae and sea-grass which distorts the results of any hydroacoustic measurements: the factor of ultrasound reflection from the natural background and the investigated objects is the same which obscures the sonogram image and makes it difficult to identify the "true" signal. Because of that the operator has problems in pinpointing an object which is almost fully buried in the ground and thus produces no clear ultrasonic "shadow" on the sonogram. This being so, one can get a most "objective" picture of the seabed in early spring, before the sea-weeds grow up. This is what we now have in mind for the future.
Using a metal test rod we were able to establish that under the algae layer of the flooded city there is a layer of soil washed up by the sea, with the thickness from 30 to 70 cm. The cultural layer formed before the flooding is located underneath. Preserved within it are many structures and architectural bits and pieces, ceramics and other ancient artifacts. Building blocks are mostly of a large size unlike those in the unflooded part of the city. This can be explained by the fact the cultural layer of the unflooded section was often plundered by some locals who were looking for building materials which are few and far between in this part of Taman.
As a result of our preliminary studies (near the center of the flooded city section) we discovered a large pile of building stones and slabs. We decided to clean it up from a thin layer of sand to get a better picture of what was there under. We built a divers' platform and mounted upon it a diesel pump, a hydroejector (water gun) and a lift for stone artifacts to be lifted from the bottom. The hydroejector was fitted out with a special mesh filter to protect it from being clogged by sand. To increase the visual contrast between the stone slabs and the bottom background we removed with the help of a dirt pump the top layer of silt, sand and algae to the depth of 20-25 cm on an area of 40x10 m in the central part of the city. During this stripping the flux of water carried into the filtering mesh some minor objects with the bigger ones being picked up by hand and brought up into the boat. What we saw as a result was that most of the inspected area was covered with cut building stones of different shapes and sizes, including many of a parallelepiped shape and a number of marble slabs. The latter fact makes it possible to assume that the site was occupied by some public building. Since marble had to be brought in (most likely from the Aegean coast), using it for building construction must have been very costly which attests to the importance of this or that structure. This assumption is born out by fragments of architectural decor and a huge plate, probably used as a stepstone, three drums of large columns (some 92 cm in diameter), pedestals of statues and a fragment of a female statue.
The aforesaid heap of building stones could be the remains of one of Phanagoria's main temples-a conjecture which calls for further investigations.
Summing it up, the first impressions of our finds are as follows: the cultural layer is washed out and mixed up to a large extent by sea-storms (due to a shallow depth of the Tamansky Gulf even minor hurricanes could have done that). And if this assumption is correct, the ancient artifacts of the seabed were all mixed up making their dating a really difficult job. But we do not give up hopes and shall try to establish the historical dates when Phanagoria "sunk" to the bottom of the Tamansky Gulf.
Permanent link to this publication:
LRussia LWorld Y G