An Accidental Discovery
The Kamchatka Peninsula's Valley of Geysers, the second-largest concentration of geysers on Earth, remained unknown to science until April 1941. Geologist Tatyana Ustinova and her guide Anisifor Krupenin were surveying the Shumnaya River for the Kronotsky Nature Reserve when they discovered a tributary. While resting, they witnessed a powerful jet of hot water erupting from the opposite bank. Ustinova named the first geyser Pervenets, or "Firstborn," and the river Geysernaya. Further exploration was delayed by World War II, but the initial find revealed a six-kilometer-long canyon containing approximately ninety geysers and numerous hot springs.
The valley's hydrothermal activity is fueled by a magma chamber beneath the Uzon-Geyser caldera complex. Water from the Geysernaya River seeps deep into the ground, where it is heated to temperatures as high as 250°C. This superheated water then rises through a network of underground channels and fractures, emerging as the steam vents, mud pots, and erupting geysers in the valley. The largest geyser, Velikan ("Giant"), can shoot water up to 40 meters in the air.
A System Reset
On June 3, 2007, the valley's hydrothermal system was violently disrupted. A massive landslide sent an estimated 20 million cubic meters of mud, snow, and rock down the canyon at speeds of 35-40 km/h. The debris flow buried two-thirds of the valley, covering waterfalls, thermal pools, and several major geysers, including Pervenets. The slide formed a large dam on the Geysernaya River, creating a new thermal lake that submerged even more features.
The event was first considered an irreversible catastrophe. Seven large geysers were buried, and others were drowned by the rising lake. However, the valley's plumbing system began to adapt. The new dam altered the water table and pressure dynamics throughout the geyser field. Within days, some submerged geysers were observed erupting through the surface of the new lake. Velikan geyser, which was not buried, returned to a stable eruption cycle after a period of adjustment. By 2013, natural erosion had breached the dam, causing the lake level to drop and re-exposing some geysers that were presumed lost. The 2007 mudslide, while destructive, allowed scientists to see how a large-scale hydrothermal system responds to sudden and dramatic change.