Geyser Velikan (Giant) is located on the left bank of the Geysernaya River. Before 2014, the area around was covered with geyserite deposits and colonies of thermophilic algae. T.I. Ustinova gave the geyser this name and described its eruptions in June 1941 when she observed only 2 eruptions (it erupted once every 3 hours). During a short (1–2 min) and powerful fountaining, the geyser ejected 20 cub.m of water to a height of 30–40 m: “The action of this geyser amazes with its grandeur and the abundance of violently erupting water. The geyser roars deafeningly” (Ustinova, 1955).
The Velikan Geyser was the largest, regularly active (period 3-12 hours) and most studied geyser in the Valley. Its regime was initially studied using visual observations (Ustinova, 1955; Raik, 1963; Sugrobova, 1982). In the 1980s and 1990s, there was introduced automatic systems, based on measuring the water level in the geyser channel: Valdai level gauges (Sugrobova, 1982), and later a system based on closing electrical contacts during water eruptions (Droznin, 1998). Automatic recording of the geyser periodicity was carried out continuously for several months each year, and numerous measurements of several hundred successive eruptions were obtained. Velikan has a big channel: 3 x 1.5 m on the surface, 0.8 sq. m at a depth and 10 m deep. Various experiments were conducted in its channel, including hydroprobing (Droznin et al., 1999) and video filming (Belousov et al., 2013). Since the beginning of the 21st century, the regime of the Valley's geysers, including the Velikan, has been studied using time-lapse cameras and temperature loggers (Kiryukhin et al., 2021; Belousov, Belousova, 2017, 2020). During Cyclone Elsa (October 4–6, 1981), when the wind speed reached 40 m/sec and the amount of precipitation exceeded 90 mm, Velikan did not erupt, and in the first days after the cyclone, its period was 3.5–4.5 hours (Sugrobova, 1985). In 2007, Velikan was not damaged by the landslide. In 2014, the wide channel of the Velikan geyser was almost completely clogged with boulder-gravel mudflow material. Video filming inside the channel (Belousov, 2014) showed that the boulder-gravel plug began in the channel at a depth of 2.5 m. This radically changed the geyser's regime, but did not stop its activity. The geyser's operating mode in 2014-2015 was very irregular, spasmodic, with a steam-water outbursts up to 2 m. Pulsating emissions slowly cleared the geyser channel. By 2016, the thickness of the plug and the amount of gravel fraction in the channel had noticeably decreased. In 2015-2023. the period was 50-80 min, fountaining 10-40 min, fountaining height reached 2-3 m. In 2024, the water depth in the channel increased up to 5 m, the geyser activity became more regular: the period became 40-50 min, and fountaining duration 10-15 min.
References
Belousov A., Belousova M., Nechayev A. Video observations inside conduits of erupting geysers in Kamchatka, Russia, and their geological framework: Implications for the geyser mechanism // Geology. 2013. Vol. 41. № 4. P. 387-390.  Kiryukhin A.V., Polyakov A.Y., Zhuravlev N.B., Tsuchiya N., Rychkova T.V., Usacheva O.O., Dubrovskaya I.K. Dynamics of natural discharge of the hydrothermal system and geyser eruption regime in the Valley of Geysers, Kamchatka // Applied Geochemistry. 2021. Vol. 136. № 105166. 1 p. Белоусов А.Б., Белоусова М.Г. Гейзеры – геотермальные источники, по которым можно сверять часы // Природа. 2024. № 9. С. 3-15. Белоусов А.Б., Белоусова М.Г. Образование гейзеров после обвала 2014 г. в Долине Гейзеров // Вулканизм и связанные с ним процессы. Материалы XXII Всероссийской научной конференции, посвящённой Дню вулканолога, 28-29 марта 2019 г. 2020. С. 47-50. Белоусов А.Б., Белоусова М.Г. Роль оползней в формировании гейзеров Долины Гейзеров, Камчатка // Вулканизм и связанные с ним процессы. Материалы XX ежегодной региональной научной конференции, посвящённой Дню вулканолога, 30-31 марта 2017 г. 2017. С. 155-157. Дрознин В.А., Бахтияров В.Ф., Левин В.Е. Измерения температуры в ванне гейзера Великан (Долина Гейзеров, Камчатка) // Вулканология и сейсмология. 1999. № 1. С. 46-53. Райк А.А. О режиме гейзеров Камчатки / Исследование природы Дальнего Востока. Таллин: Академия наук Эстонской ССР. 1963. С. 39-90. Сугробова Н.Г. Режим гейзера Великан // Вопросы географии Камчатки. 1982. Вып. 8. С. 66-68. Сугробова Н.Г., Сугробов В.М. Изменение режима термопроявлений Долины гейзеров под влиянием циклона "Эльза" // Вопросы географии Камчатки. 1985. № 9. С. 88-94. Устинова Т.И. Камчатские гейзеры / Отв. ред. Рихтер Г.Д., Никольская В.В. М.: Географгиз. 1955. 119 с.  |
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