Limans

LIMANS (from the Greek limen—bay, harbor, later adopted by the Tatars and Turks), salt water bodies scattered along the sea coasts (in the USSR along the coasts of the Black, Azov, and Caspian Seas). They are marine formations of the dam type, representing for the most part narrow, elongated basins separated from the sea by a so-called "sandbar." Many of them have been salt-bearing since time immemorial and served as a rich source for salt extraction; some, however, have become health resorts. The entire Black Sea region is distinguished by a particular abundance of limans (closed and open). Limans are divided into 3 main groups: Bessarabian-Odessa, Tauric, and Kuban-Caucasian; of these, the most studied are the Odessa limans—Kuyalnik and Khadzhibey [see Vol. VII (pp. 801-802), map]. The water of these limans, despite its marine origin, differs from seawater not only in its significantly higher concentration but also in the different character of its salt mass. From the moment of complete separation from the sea, a liman begins to live its own special, peculiar life, submitting to the influence of a wide variety of new factors and undergoing further physical-topographical, chemical, and other transformations. The geological-chemical equilibrium established during the formation of mineral springs and wells is maintained with some constancy over the centuries; this law of the constancy of the composition of mineral springs and waters is equally applicable to salt water bodies. The water of different limans is distinguished by different quantitative content of salts in them (different concentration), measured by a Baumé hydrometer; it fluctuates for different limans from 0.5° to 26° Baumé (at 26° Baumé, self-precipitating salt falls out). To characterize limans, along with a description of their ionic and salt composition, the chlorine coefficient and water concentration are also used. The significance of limans is generally determined either by their therapeutic properties or by their salt-bearing capacity as sources for the extraction of NaCl. Of all the limans of the northern coast of the Black Sea, the above-mentioned Odessa limans, which are the most important and characteristic, have gained the greatest fame as health resorts. To the northeast of Odessa, two limans adjoin the Odessa Bay: Kuyalnik and Khadzhibey; both stretch in deep narrow ravines, the first for 30 km, the second for 33 km, with an average width of about 2 km. Both limans, like others, in times distant from us constituted bays that joined into one huge bay, at the remaining part of which Odessa now stands. On ancient maps of the Black Sea, this bay is called "Istrianon."

Leveling performed by the expedition of the Novorossiysk Society of Naturalists (1894) showed that the level of the Kuyalnik Liman on the morning of August 25, 1894, was 5.14 m below sea level, and the Khadzhibey Liman at the same moment was 1.78 m below. In terms of depth, the Odessa limans differ sharply from each other. Measurements taken in 1895 showed that the maximum depth of the Kuyalnik Liman reaches only 2.2 m. The bottom of the liman represents an almost flat surface. Due to the gentleness of the shores, the size of the area occupied by the liman water changes strongly with changes in its level, and the dimensions of evaporation from the surface of the lake, the concentration of brine (liman water), etc., are subject to the same fluctuations. Measurements of the Khadzhibey Liman, taken in 1896, showed that it is a water body with a fairly significant depth. Initially, counting from the "sandbar," the depth is insignificant, in places it reaches 5 m, but then it increases and reaches 13-14 m.

The area of the Kuyalnik Liman, delineated by the map contour, by June 1894 was about 6,142 hectares; the volume corresponding to it was equal to 98,055,000 m³. These numbers can change from year to year depending on the fluctuation of the level. The level of both limans and the density of their water mass are subject to periodic fluctuations depending on the amount of atmospheric precipitation, the speed of snow melting, the average summer temperature, and the force of evaporation from the surface of the lake, etc. These conditions can combine from year to year in the most diverse ways, acting either jointly in one direction or in opposite directions to each other. The result of such combinations is either a progressive fall in the water level in the liman and a gradual strengthening of the concentration of salts in it for several years in a row, or the opposite phenomenon—a sudden rise in the water horizon and a weakening of its density. All these conditions apparently develop differently for both limans, thereby causing significant differences in the limits of fluctuations in density and water horizon.

Measurements of the water density of the Kuyalnik Liman have been carried out since 1860 in the northeastern part of the liman by the "Salt Industry." Over a 60-year observation period, the density fluctuated within the range of 4.5° to 27° Baumé. The greatest thickening of the brine during the summer reaches 5° Baumé. Systematic observations of the water density of the Khadzhibey Liman showed that the extreme fluctuations in density over a 10-year observation period do not exceed 4° Baumé; seasonal fluctuations barely reach 2° Baumé; the minimum density is 3.5°, the maximum is 7.5° Baumé. Over a 10-year period of continuous observations, it turns out that the years of the highest and lowest brine density of both limans fully coincide, with the lower limits of the water density of both limans being quite close, whereas the higher limits differ significantly from each other.

The water temperature in the limans is characterized by great constancy and never gives such sudden and significant fluctuations as are observed in the coastal northern strip of the Black Sea. Temperatures: Extreme fluctuations in summer months: Kuyalnik Liman 19.25–33.75°, Khadzhibey Liman 12.5–31.25°. Average seasonal: Kuyalnik Liman 23.6°, Khadzhibey Liman 23.25°. Average monthly: in June: Kuyalnik Liman 22.75°, Khadzhibey Liman 23°; in August: Kuyalnik Liman 25.25°, Khadzhibey Liman 22.75°. Chemical composition of liman mud—see Mud. Wave action in the Kuyalnik Liman is small. The average wave height according to Kozlovsky's observations is 4.6 cm. The maximum wave height reached 25 cm. A mirror-like surface of the liman is noted in approximately 30% of all observations. Wave action on the Khadzhibey Liman is much more significant; the average wave height is 11.4 cm. The maximum wave height observed in the liman reached 76 cm. In the average conclusion by months: in June—12.5 cm, in July—12 cm, in August—10 cm; wave action is greater in the morning and afternoon and decreases towards evening. A mirror-like surface of the liman was noted 784 times during the entire observation period, and wave breaking—2389 times. Consequently, in 30% of all observations, there was no wave action. Summarizing briefly the features of the Odessa limans, we obtain the following characterization of each of them: The Kuyalnik Liman is distinguished, therefore, by a shallower depth, a much higher water density, a higher temperature, and weaker wave action; its level is below sea level and below the level of the Khadzhibey Liman. The distinctive features of the Khadzhibey Liman consist of its greater depth, significantly lower concentration of its brine, lower temperature, and stronger wave action.

The chemical composition of the water of both limans, according to the latest analyses by E. S. Burkser and N. B. Lapkina, is presented in the table (p. 118). The therapeutic agents of the limans are water or brine and sedimentary silt from the bottom of the liman—therapeutic mud (see Therapeutic Mud). Brine is used 1) in the form of warm treatment with heated brine, diluted, and carbonated baths of various temperatures and densities in the form of an independent method—brine therapy—and in combination with mud baths as an integral part of a mud therapy course (see), and 2) in the form of cold treatment. The probable salt composition includes sodium chloride, potassium, calcium, magnesium, and calcium sulfate.