what mountains run between the black sea and the caspian sea
The entire region is regularly subjected to strong earthquakes from this activity.  While the Greater Caucasus Mountains have a mainly folded sedimentary structure, the Lesser Caucasus Mountains are largely of volcanic origin. 
The northern slopes of the Greater Caucasus Mountains are covered by oak, hornbeam, maple, and ash forests at lower elevations while birch and pine forests take over at higher elevations. Some of the lowest areas of the region are covered by steppes and grasslands. The slopes of the Northwestern Greater Caucasus (Kabardino-Balkaria, Cherkessia, etc.) also contain spruce and fir forests. The alpine zone replaces the forest at around 2,000 metres (6,600 ft) above sea level. The permafrost/glacier line generally starts around 2,800–3,000 metres (9,200–9,800 ft). The southeastern slopes of the Greater Caucasus Mountains are covered by beech, oak, maple, hornbeam, and ash forests. Beech forests tend to dominate in higher locations. The southwestern slopes of the Greater Caucasus are covered by Colchian forests (oak, buxus, beech, chestnut, hornbeam, elm) at lower elevations with coniferous and mixed forests (spruce, fir and beech) taking over at higher elevations. The alpine zone on the southern slopes may extend up to 2,800 metres (9,200 ft) above sea level while the glacier/snow line starts at 3,000–3,500 metres (9,800–11,500 ft).
Caucasus, Russian Kavkaz, mountain system and region lying between the Black Sea (west) and the Caspian Sea (east) and occupied by Russia, Georgia, Azerbaijan, and Armenia.
The northern slopes of the Greater Caucasus are not as steep as the southern. The middle of the system is comparatively narrow, but its western and eastern ends have widths of 100 miles (160 km) or more. The main axis of the system contains, in addition to Mount Elbrus, Mount Dombay-Ulgen (Dombey-Yolgen; 13,274 feet [4,046 metres]), in the western sector; Mounts Shkhara, Dykhtau, and Kazbek, all over 16,000 feet (4,800 metres), in the central sector; and Mounts Tebulosmta and Bazardyuzyu, both over 14,600 feet (4,550 metres), in the east. Spurs tonguing north and south from the main axis occasionally reach elevations approaching 10,000 feet (3,000 metres).
On paper, such a region would appear to offer world-class adventure and exploration opportunities for the intrepid and responsible outdoor enthusiast. Despite this, the region remains relatively little-visited, and the benefits of responsible enjoyment of geography remain unrealised. Access to wilderness areas is difficult due to a lack of reliable, recent and detailed data. The best available topographic maps are Soviet-made military maps dating back to before the Cold War, unavailable to the public and decades out of date. Public domain aerial imagery is inconsistent and often at too low a resolution to be useful to the hiker. Open-source mapping varies enormously in accuracy and completeness, often having been created by untrained hobbyists from second-hand sources.
At first glance, however, most obvious to the adventurous traveller are the dramatic natural landscapes of the Greater and Lesser Caucasus Mountains, two of the most fierce and impenetrable ranges in the world, which form two distinct geological corridors. The richness of biodiversity within the folds of these mountains has resulted in the region becoming a ‘hotspot’ for conservationists, biologists, birdwatchers and botanists alike, ranging from high-altitude grasslands and permanently-snowcapped crags, to coniferous and deciduous forests on the mid-altitude slopes, to shrubby plateaus and swamp forests at lower elevations. Of the 6,500 plant species found in the Caucasus, approximately 25 percent exist nowhere else on earth. And there is a strikingly varied complement of fauna, including wolf, brown bear, Caucasian leopard, jackal, lynx, hyena, gazelle, and the iconic Bezoar goat.
Instrument: Terra — MODIS
Google Earth – November 9, 2008KML
There are two types of sea currents in the Black Sea: the surface currents, caused by the cyclonic pattern of the winds, and the double currents in the Bosporus Strait and Kerch Strait, caused by the exchange of waters with adjacent seas. The surface currents form two closed circles. The width of the western circle, opposite the Danube Delta, reaches 100 km and decreases towards the south. The velocity of the current is about 0.5 km per hour. The width of the eastern circle varies between 50 and 100 km, and the velocity is 1 km per hour.
In the 19th century the most important historical event in the Black Sea region was the Crimean War. In 1918 the new Ukrainian state included the Black Sea coast from the mouth of the Dnister to Mariupol on the Sea of Azov. The Army of the Ukrainian National Republic occupied the Crimea in April 1918 but abandoned it in response to German demand. This led to Ukraine’s loss of the Black Sea Fleet in Sevastopol, which had already raised the Ukrainian flag. During the existence of the Hetman state the Crimea recognized Ukrainian suzerainty, but further events made it impossible to put this suzerainty into effect.