Slope Processes Hazards in Geothermal Areas: a Case Study of the Geysers Valley, Kamchatka

Abstract

The Geysers Valley (valley of the Geysernaya River) is located on the territory of Kronotskiy State Natural Biosphere Reserve (Kamchatka peninsula) being one of the most unique nature objects in Russia. The valley is known by numerous geysers and other hydrothermal manifestations and is a tourist attraction. It is included in UNESCO World Natural Heritage Complex Object “Volcanoes of Kamchatka”. The Geysernaya River cuts massif composed by lacustrine-volcanic hydrothermally altered deposits. These rocks contain a large number of zeolites and clay minerals, are broken by tectonic and sedimentary fractures, and unstable to humidifying. These and other geological and geomorphological factors such as high seismicity, contrast relief, steep slopes, rainfalls, intense snowmelt and inflow of thermal water control formation of different slope processes such as landslides, rockfalls, taluses, debris flows, mudflows etc. Interpretation of remote sensing data in combination with field work has shown that landslides in the studied area are developed widely. Based on implemented studies several maps were made including map of landslide types and map of landslide hazard assessment. Last catastrophic landslide with estimated volume of 16.3 million cubic meters was happened on June, 2007; it changed regime or totally destroyed some geysers and effected strongly on landscape in lower part of the Geysernaya River valley. Recently two debris flows took place in upper part of the valley. Slope displacement in the region is very intense that can be dangerous for tourists and also causes damage to geysers and hot springs regime.