CASPIAN SEA

Wairarapa Times-Age, 26 August 1942, Page 4

CASPIAN SEA

VAST LAND DEPRESSION PHYSICAL FEATURES. FLUCTUATIONS IN WATER LEVEL. The Caspian Sea. the west shore of which is included in the present German strategical objective, is slightly larger in area than the Baltic and in volume, because of its great depths, is greater than the North and Baltic Seas combined. It is about 800 miles long, with an average width of about 100 miles.

It fills the deepest part of the AraloCaspian depression. At the present time its surface is about 85 feet below the level of the ocean and 248 feet below that of the Aral Sea, with which it once was joined. The northern section of the Caspian is being gradually silted up by deposits brought down by the rivers Volga, Ural and Terek and the larger steamers have to lighten their loads 40 miles off the Volga delta shore. The Volga is constantly eroding its banks, especially during the spring floods, this occasionally making it necessary to move back towns and loading ports. The suspended matter silts the delta channels as well as the seabed and constant dredging is necessary to maintain at eight feet the channel 70 miles long, between Astrakhan and the coast, A PARALLEL BRANCH. The fact that the Volga has developed 200 mouths in its wide delta is not the only, arresting feature of- its lower reaches. A few miles north of Stalingrad the river sends off a branch, the Akhtuba, which runs parallel with it for 330 miles. Flood waters often cover the intervening land and form lakes 15 to 35 miles wide. The western shore of the Caspian from the Volga delta to the Kuma River is gashed by thousands of narrow channels or lagoons, termed limans, from 10 io 30 miles long, and separatd in some cases by chains of hillocks, in other by sand banks. The channels arc filled sometimes with sea water and sometimes with the overflow of the Volga and the Kuma. The sea water in this area is fairly low in salinity and is drinkable. In the middle section of the Caspian, starting at a line through Kuma, the west shore is higher and the depth, of the sea much, greater, reaching a maximum of 2500 feet. A feature of the west shore is a spur of the Caucasus which approaches very close to the water at Derbent. The flat narrow strip hero has been fortified for centuries, it being a vital point in the Europe-Asia land bridge. It is known to history as the Caspiae Pylae or the Albanae Portae. CONTROL BY EVAPORATION. The wide shallow Gulf of Karaboghaz, on the east shore of this section, is remarkable for the fact that although it has no outlet a constant current flows into it through the narrow entrance. Heavy evaporation accounts for the phenomenon and explains a salinity reaching 200 per cent in the gulf. Without general evaporation the sea would rise over three feet annually. Its level is subject to both periodic and seasonal fluctuations. It usually rises when the Volga, which provides twothirds of its inflow,_ pours in its flood waters. In dry periods the level may fall to a point where navigation in the shallow reaches is affected. The southern section starting on the Baku line, where a submarine ridge links the main range of the Caucasus and the Kopet-dagh in the Transcaucasian region, is the deepest, reaching over 3000 feet, but a more arresting thought to a military realist is that the south shore of this section is part of the northern frontier of Iran. The northern section of the Caspian and the lower reaches of the rivers running into it form a fishing ground of extraordinary richness, many millions of tons of fish being taken each year. Below the level of 1960 feet, however, there is no life owing to the absence of oxygen.