The number of explosive eruptions at Shiveluch Volcano has significantly increased over the past years, which requires close volcanic monitoring using all available techniques. In order to implement a new monitoring technique into integrated methods of volcano monitoring, the authors analyze response to the intensity of the vertical component in the atmospheric electrical field (EZ AEF) during the movement of ash clouds. Two eruptions of different intensity that occurred December 16, 2016 and June 14, 2017 at Shiveluch were selected for study. We used a combination of satellite, seismic, and infrasound data to select signals in the EZ AEF field. Signals with negative polarity that accompanied ashfalls in the EZ AEF dynamics were registered for both eruptions within the closest area (< 50 km). In the former case, the ash cloud was “dry” and thus it caused aerial-electrical structure of the negatively charged cloud. In the latter case, a strong explosion sent into the atmosphere the large volume of ash and volcanic gases (98% in form of vapour) that resulted in the formation of a dipolar aerial-electrical structure caused by eolian differentiation within the closest area. At the distance of more than 100 km we registered a positivegoing signal that is attributive to the aerial-electrical structure of the positively charged type of the cloud.

The paper presents the results of integrated geophysical observations of the Ebeko Volcano’s activity in late 2018 and early 2019. The instrument complex for observation was located at the Severo-Kurilsk seismic station at a distance of 7.2 km far from the volcanic crater. Three types of response in the vertical component of the electric field of the atmosphere have been distinguished during the drift of eruptive clouds from the Ebeko Volcano’s explosions, which gives evidence for various mechanisms of their occurrence. The registration of infrasonic acoustic signals in the near zone made it possible to estimate the trinitrotoluene equivalent for the strongest explosions, which was calculated to be about 100 kg of trinitrotoluene. The authors have revealed certain regularities in the dynamics of the volumetric activity of radon, associated with variations in meteorological values and hydrological features of the registration point. A long period of its activity and the proximity of the observation point to the crater give reason to suggest Ebeko Volcano to be a natural laboratory for studying the mechanisms of eruptions.

Growth of explosive activity of Ebeko volcano in April–June 2020

On March 24, 2017 Kambalniy Volcano started to erupt after a 500-year-long period of rest. The eruption continued till April 10, 2017. The paper provides the analysis of atmospheric wave disturbances as wavetrains of quasi-sinusoidal oscillations with a frequency of 8 Hz ("acoustic tremor" or AT), which occurred at certain moments during the eruption. Besides, the paper describes 3 strongest seismic signals registered at the initial stages of the eruptions simultaneously with AT, which was registered using an infrasound station IS44 installed 208 km NW far from the volcano. The nearest "Pauzhetka" seismic station installed 19 far from the volcano allowed monitoring the seismic build-up, which was short (2 days) and weak (Кmax = 8.6). Lack of definite discrete infrasound signals, which are usually caused by non-stationary process during explosive eruptions, gives evidence for peculiar pattern of formation and effusion of ash-and-gas emissions. Such uncommon acoustic radiations and seismic build-up prove the presumption that this eruption should be classified as a hydrothermal event.

Приводятся сведения об особенностях поведения временного ряда объемной активности радона за период 2000–2015 гг. в зоне влагонасыщения в районе Паратунского геотермального месторождения и временного ряда объемной доли молекулярного водорода газа теплоносителя скв. 016 Мутновского месторождения и их связи с сейсмичностью северо-западного обрамления Тихого океана. Сделан вывод, что длительные тренды в динамике объемной активности радона и высокая объемная доля молекулярного водорода в 2014 г. обусловлены изменением поля напряжений в зоне субдукции северо-западного фланга Тихого океана. Сделано предположение о возможности землетрясения с М > 7.5 в ближайшее 1.5 года. По данным академика С.А. Федотова, наиболее вероятный район этого события – от полуострова Шипунский до острова Шиашкотан (Средние Курилы)

Рассмотрена динамика газового состава теплоносителя Мутновской Геотермальной электростанции за период июнь - декабрь 2004 г. Выявлена тенденция снижения доли газа и понижения в нем отношения CO2/H2S.

В течение 1997-1999 гг. вблизи вулкана Карымский (∆ = 1.5 км) в рамках Российско-Американской экспедиции (начальник экспедиции с Российской стороны А.Ю. Озеров, научный руководитель Е.И. Гордеев) проводились комплексные наблюдения за сейсмическими и инфразвуковыми волнами, сопровождавшими эксплозивную активность вулкана. Регистрация сигналов осуществлялась цифровой аппаратурой с частотой дискретизации сигнала 125 Гц, амплитудно-частотные характеристики аппаратуры и ее калибровка приведены в работе [13]. В данной статье сделан предварительный анализ особенностей генерации акустических сигналов (АС) в атмосфере, сопровождавших эксплозивную деятельность вулкана.

The article presents new data from field observations at Karymskiy in August 2012, which were carried out by a complex of equipment allowing recording infrasonic fluctuations, aerodynamic noise and intensity of the atmospheric electric field and volumetric activity of underground radon. It is shown that integrated geophysical observations are quite informative to monitor explosive volcanic activity. The analysis of wave disturbances in the atmosphere (the aerodynamic noise, air shock waves) and seismic events accompanying the fragmentation of magma allow us to get an insight about the physics of the explosive process. The dynamics of volumetric activity of radon near to Karymskiy is correlated to the activity of the volcano, which indicates the perspective of such observations.