Significant variations in temperature, water chemistry and volume of the lake in the crater of Maly Semyachik volcano, Kamchatka, in 1965–2020 can be divided in three main stages. The first stage, until about the mid-1980s, was characterized by intense volcanic-hydrothermal activity, high (above 40 °C) temperature, high salinity (up to 40 g/l) and an increase in the level (and volume) of the lake. During the second stage, which lasted 25–30 years, since the mid-1980s until the mid-2000s, the lake cooled down, until freezing in winter, the mineralization decreased (up to 1.6 g/l), and the volume of the lake remained almost constant. After the mid-2000s until present, there is a period of activation of the Maly Semyachik volcano, which is expressed in an increase in temperature, mineralization and a sharp increase in the volume of the crater lake. The water balance of the lake and the input and composition of the thermal acid chloride solution are estimated based on the analysis of changes in chemical and physical parameters over time, using a box model.

1965 年至 2020 年堪察加半岛 Maly Semyachik 火山火山口的温度、水化学和湖泊体积的显着变化可分为三个主要阶段。第一阶段，直到 1980 年代中期，其特点是火山热液活动强烈、温度高（40 °C 以上）、盐度高（高达 40 g/l）以及那个湖。第二阶段持续 25-30 年，从 1980 年代中期到 2000 年代中期，湖水降温，直至冬季结冰，矿化减少（高达 1.6 g/l），湖几乎保持不变。从 2000 年代中期至今，Maly Semyachik 火山有一段活化期，表现为温度升高、矿化和火山口湖体积急剧增加。