In the upper reaches of the Geyser River at the foot of the Kikhpinych Volcano, there is a small valley measuring two kilometers by 100–500 meters where animals regularly perish.
Special investigations have shown that the death of animals and birds is due to the high concentration of poisonous gases, mainly hydrogen sulfide, carbon dioxide, carbon disulphide, and others.
Death Valley was discovered in late July 1975 by volcanologist V.L. Leonov and independently by reserve ranger V.S. Kalyayev. The remarkable thing is that the area near Death Valley had been previously well studied by geologists. Moreover, only 300 meters from the main part of Death Valley, there was a rest stop for tourists hiking between Uzon Caldera and the Valley of the Geysers. This was probably the most significant discovery in the reserve since the finding of three hot springs in the canyon of the Stary (Old) Semyachik River by V.N. Ryzhkin, A.N. Kiselyov, and V.S. Kalyayev in 1972.
From 1975 to 1983, the reserve carried out regular observations of the valley, and volcanologists analyzed its gas contents. In this time period, over 200 carcasses of animals and birds were collected, including 12 species of small mammals, 15 species of birds, and numerous insects. Most of the animals that perished were small rodents, passerines, however, specimens also included bears, foxes, wolverines, and — among birds — ravens and Steller’s sea eagles. Since then, golden eagles and lynx have been added to this list. One dog belonging to a reserve ranger also died here.
The process is like an ecological domino effect: the first victims are small birds, attracted to thawed patches of snow in the spring; then the foxes come to eat the birds; and after that wolverines and bears, as well as ravens and golden eagles, arrive. When the carcasses are removed, the chain is broken, and the number of victims decreases.
Death Valley is situated upwind of deep gas jets. It is no accident that there are sulfur deposits on the sides and bottom of the river. Large concentrations of gases accumulate in low areas, snow gullies and alcoves, especially when the sky is overcast and the weather is calm. In open and windswept areas, the concentration of gases is not dangerous.
The times when animals tend to perish coincides with periods when the valley is snow-free (May — October).
Herbivores (e.g., ground squirrels, hares, pikas, ptarmigans) die less often, and for understandable reasons — the slopes and river bottom, which are bare of vegetation, hold no attraction for them.
It is phenomenal that the carcasses are preserved for so long without decaying. This is because the poisonous atmosphere of the valley suppresses oxidizing activity of bacteria.
Scientists working in Death Valley have experienced headaches, heat in their temples, dizziness, and overall weakness. But if they leave the danger zone in time, climbing to windy uplands, they recover rather quickly.
Natural phenomena like Death Valley are known on other parts of the planet where volcanic activity is found: Yellowstone Natural Park in the USA (Death Canyon), and on the island of Java in Indonesia, where there are several “death valleys.” There is another dangerous place in a limestone mine close to Naples in Italy (Grotta del Cane). Everywhere the reason for tragedy is carbon dioxide accumulating in low-lying air layers. Elsewhere in Russia, periodic wildlife deaths (primarily auks) are known on Ushishir Island (in the Kuril Island chain) as a result of fumaroles. In Kronotsky Reserve, there are also powerful upwellings of hydrogen sulfide near the summit of Kizimen and Komarov volcanoes. But these areas are virtually void of life and so there is a low probability of animal deaths.
The Uzon Caldera can be a rather dangerous place near Fumarole Lake where, in addition to hydrogen sulfide, areas with high-levels of mercury are found.
The contents of the poisonous cocktail in Kamchatka’s Death Valley, however, are much more complex, aggressive, and dangerous than those of other death valleys, and it is unlike any other in the world.