Chokrak Lake

Chokrak Lake, a complex that includes a resort, a mud lake, mineral springs, and in the future probably also a seacoast. In recent times only the lake has been used. Ch. o. is located 14 km to the southwest of the city of Kerch, belongs to the Kerch-Feodosia group of lakes of the Crimean Peninsula, and is separated from the Azov Sea lying to the north by a low spit up to 300 m wide. The shape of the lake is rarely-shaped, with the elongated end facing south. Area 750 hectares; circumference about 12.5 km. Ch. o., according to Mushketov, is a bay-like salt lake and owes its existence to the rise in the level of the Black Sea after the connection of the latter with the Mediterranean and the subsequent formation of the spit. The western and eastern shores of the lake are quite high, often steep; they are composed mainly of Tertiary limestone rocks. Therapeutic mud in the form of a black, soft, delicate, and perfectly homogeneous silt covers almost the entire bottom of the lake; it has a hydrogen sulfide odor, an alkaline reaction, and due to its high light absorption quickly heats up. Brine covers the bottom of the lake to a depth of no more than half a meter. Its concentration reaches a limit in the second half of the summer, and sometimes even in June, and then the "crystallization" of fairly pure salt begins, which has made it possible for salt production to develop since ancient times. Salt production invariably lowers the concentration of the brine. The replenishment of salts from the sea lags due to the absence of a sea channel in the spit, as is the case with Lake Sakskoye. The metamorphosis coefficient, i.e., the ratio ~⁸-yag-*== = 0.62; thus, in terms of sulfate ion content, the brine of Ch. o. is closer to Black Sea water than the brine of Lake Sakskoye, and belongs, according to Kurnakov's terminology, to Class I brines. From analyses of the brine, the most recent one (Nikolaev and Kosman, 1929) gives the following figures: Cl-15.63%; SO₄"-7.46%; Mg"-5.74%; K'-1.23%; Na-2.14%. In addition to the usual components, the brine contains 0.3% boric acid, and the same content is found in the mud. A detailed analysis of the mud (Kosman and Pastak, 1931) showed that the mud is of the same type as Sakskoye mud but is favorably distinguished by the absence of gypsum and a higher content of ferrous sulfide. The mineral springs of Ch. o. are located on the eastern shore. Most of them are hydrogen sulfide springs. At three—Upper Chokrak (No. 1), Lower Chokrak (No. 2), and Distant (No. 3)—there are analyses from 1929 and 1931; the latter belongs to the Crimean Scientific Research Institute (Table 1). The highest concentration is at Distant (No. 3), the hydrogen sulfide content there is greater than even at Matsesta (0.2218); even Lower Chokrak (No. 2) is twice richer in hydrogen sulfide than the Sergievsky springs. If only the 2nd and 3rd springs are used, up to 250 hydrogen sulfide baths can be obtained per day; with appropriate hydraulic engineering works, the flow rate can be increased. The capture of springs either does not exist or has fallen into disrepair, and the rooms for receiving sulfur baths have also been destroyed. Since there are no independent meteorological observations on Chokrak, one has to use those of the city of Kerch (Tables 2 and 3). Table 2. Meteorological factors VI VII VIII Average for the year Temperature Humidity Precipitation . . 0.5 87 24 0.3 85 20 3.4 82 23 9.6 78 27 15.9 20.9 24.0 23.4 17.8 12.7 6.1 83 30 2.1 87 28 11.3 78 375 Table 3. Meteorological factors Winter Spring Summer Autumn Winds..... Precipitation . . Temperature . . 9.1 2.1 22.1 12.2 24.0 23.4 17.8 12.7 6.1 83 30 2.1 87 28 11.3 78 375 The average wind speed is 4.6 m/s; in summer, northeasterly winds, which have a dry heatwave character, predominate; they dry out the soil and vegetation, but the resort, lying in a basin surrounded by highlands on all sides, is quite well protected from winds. Precipitation is of the continental type, with a maximum in June and July and partly in August. However, rains are rare in summer, but when they occur they are torrential. The warmest month is July, the coldest is January, although winter is not severe, while summer is quite hot. The frost-free period is 221 days. The duration of sunshine is 1,944 hours per year, 5.3 hours on average per day; the maximum of daily sunshine falls in August (10.9 hours). This circumstance allows the use in summer of natural heating in the open air for oval mud bath plates 7-10 cm thick, into which patients are wrapped. In cloudy weather, artificially heated diluted mud baths are used. Prolonged sunshine and relatively high temperature make summer residence at the resort quite burdensome, however the air at Ch. o. is excellent, unusually clean and saturated with salt. The surrounding landscape is predominantly wormwood steppe with patches of feather grass. Treatment is of a combined nature: it begins with brine baths, passes to mud baths, and ends again with brine baths, and previously also sulfur baths. With the reconstruction of the resort, sulfur baths will have independent significance. At present, the capacity is up to 150 people at a time and up to 400 people in the season. There is a mud clinic, a solarium, and a dining rotunda. Drinking water is from wells. Communication: to Kerch by rail; from Kerch on horses or bus 14 km. Season from May 1 to September 1. Indications: rheumatism, diseases of the peripheral nervous system (sciatica), scrofula, tuberculous lesions of joints and bones (especially in the initial stage), chronic skin diseases, chronic diseases of the female genital sphere, general obesity, old syphilis.