Issyk (river)
The Issyk (, "Esik") is a river in Kazakhstan that crosses the Issyk Lake (not to be confused with the much greater Issyk Kul Lake in Kyrgyzstan) and the town of Esik. It is a tributary of the river Ili. One of the largest rivers on the northern slope of the Trans-Ili Alatau, its headwaters come from 32 active glaciers that cover an area of . The largest glaciers are the Zharsai with an exposed length of and an area of , the Grigoriev with a length of and an area of , and the Pal'gov at long with a surface  of . They descend from the crest of the main divide, which has an average absolute height of more than . Within the mountains the river is long, the gradient of its longitudinal profile is per kilometer, and the basin area is . In its upper reaches the river flows down a very steep slope (10-15°) over the deposits of a moraine overgrown with some vegetation and forms a deep (as much as 70 m) canyon; then, in front of the terminal vegetation-free moraine of the Pal'gov glacier, its longitudinal profile flattens out abruptly_ Here the river forms numerous branches  over an outwash plain. Below Lake Akkul' (its absolute elevation is 3,140 m), the longitudinal profile undergoes another sharp drop because a large mountainous obstruction damming the lake and, perhaps, because of moraines buried under the obstruction. In 1963, the overspill of Issyk Lake caused a large flood.