A river's glacial memory
The Charyn Canyon stretches over 154 kilometers, a massive gash in the semi-arid steppe east of Almaty. Its red sedimentary rock walls tower up to 300 meters high, sculpted by millions of years of erosion. But the most detailed story is not in the 12-million-year-old rocks themselves, but in the giant steps carved into their sides. These are ancient river terraces, the fossilized floodplains of the Charyn River.
There are six distinct terrace levels visible in the canyon. Each represents a complete cycle of glacial and interglacial climate. During warmer interglacial periods, the river flowed more placidly, depositing thick layers of sediment and creating a wide, flat floodplain. When the climate shifted toward an ice age, massive glaciers building up in the Tian Shan mountains locked away vast amounts of water. Then, during periods of intense melting, huge volumes of water and abrasive sediment surged down the river. This super-charged flow gave the river immense power to cut down into its own bed, a process called river incision. The old floodplain was left high and dry, becoming a terrace. This cycle repeated six times, with each new glacial pulse carving the canyon deeper and leaving a new step in the geological staircase.