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Location map of seismic stations and active volcanoes: 1-non-volcanic station, 2-volcanic station, 3-active volcano near which a seismic station is located, 4-active volcano at rest or near which there is no seismic station, 2011-2021.
Source publication
A study of spatiotemporal variability and synchronization effects in continuous seismic records (seismic noise) on a network of 21 broadband seismic stations on the Kamchatka Peninsula was carried out in connection with the occurrence of strong earthquakes, М = 7.2-8.3. Data of 1-min registrations of the vertical movements velocity Earth's surface...
Contexts in source publication
Context 1
... the eastern part of the Kamchatka Peninsula there is an area of modern volcanism including active volcanoes. Broadband seismic stations are located in the vicinity of some volcanoes ( Figure 2). During volcanic eruptions, volcanic and seismic signals can be recorded in seismic records at distances up to a few tens of kilometers from the centers of eruption [30,31]. ...
Context 2
... 2011-2021 the Sheveluch, Klyuchevskoy, Bezymyanny, Plosky Tolbachik, Kizimen, Avachinsky, and Ebeko volcanoes were in the stages of eruptions and increased fumarole and seismic activity (Figure 2). The high activity of northern volcanoes Sheveluch, Klyuchevskoy, Bezymyanny, Plosky, and Tolbachik was manifested in the records at seismic stations KIR, KLY, KOZ, and at TUMD station during the Kizimen volcano activation in [2011][2012][2013]. ...
Citations
... The second group includes articles confirming one or another model of seismicity behaviour in anticipation of a strong earthquake [3][4][5]. Finally, the third and most numerous group of articles consists of those analysing the results of long-term observations of the behaviour of various geophysical fields (seismic noise [6], seismicity [7][8][9], magnetotelluric field [10,11], deformation field [12], infrared radiation [13], vertical electric field in the atmosphere [14]) before strong earthquakes. We are confident that each of these articles will find an interested reader, and the whole collection will deserve the attention of representatives of the scientific community dealing with the problem of earthquake forecasting and the search for their precursors. ...
Dear Colleagues, Despite some success, the issue of earthquake forecasting has yet to be resolved. There are occasional discussions within the scientific community about the principal feasibility of earthquake forecasting, particularly in the short-term aspect. However, the bulk of these discussions were set in the Resolution of the General Assembly of the International Association of Seismology and Physics of the Earth's Interior (IASPEI) in 2009 in Cape Town: "Resolution 4: Earthquake Forecasting and Predictability Studies-IASPEI RECOGNIZING the opportunities provided by recent developments in earthquake science and technology RECOMMENDS that research on forecasting and predictability of earthquakes, and the validation and comparative testing of prediction methods be supported". However, it is not sufficient to precisely predict a future strong earthquake. It is necessary to make a correct, scientifically based assessment of the level of seismic hazard and the intensity of seismic shocks to be expected in a particular region, city and settlement. What should the administration of a megapolis do when it receives information about the likelihood of a strong earthquake? The problems of earthquake forecasting and seismic hazard assessment are, therefore, closely related to the problems of high-quality anti-seismic constructions. More than 13 years have passed since the adoption of the IASPEI Resolution. New earthquakes have occurred. Their study increased our knowledge regarding the physics of the seismic process, the physics of earthquake preparation processes and the search for earthquake precursors. The new data obtained became the basis for the development of new models of the behaviour of the ground under the influence of seismic waves and provided initial information for the development and parameterization of earthquake occurrence zone models and ground motion prediction equations. More than one and a half years have passed since the announcement of the Special Issue "Comprehensive Research in Earthquake Forecasting and Seismic Hazard Assessment" in the MDPI Journal of Applied Sciences. We invited representatives of the seismological community to present their results on these topics, to show the current view of the state of the problem, what has been achieved in the field of earthquake forecasting and seismic hazard assessment, what needs to be done next and in which direction to move forward. We expected to discuss the results and directions of further research on the physics of the seismic process-from experiments under laboratory conditions to rock bursts in mines and earthquakes in seismically active regions at the stage of preparation for strong earthquakes. As a result, 14 articles were published in the Special Issue, with authors representing different thematic areas and working in different institutions and organisations in Russia,
... They cause increased stresses, leading to deformations of the Earth's crust around an earthquake source. These changes in the stress-strain state of rocks lead to the anomaly occurrences, classified as earthquake precursors, in various geophysical fields [4][5][6][7][8][9]. ...
In seismically active regions of the Earth, to which the Kamchatka peninsula refers, pre-seismic anomalies are recorded in different geophysical fields. One of such fields is the acoustic emission of rocks, the anomalies of which are recorded 1–3 days before earthquakes at the distance of the first hundreds of kilometers from their epicenters. Results of joint acoustic-deformation measurements showed that growth of geoacoustic radiation intensity occurs during the increase in the level of deformations in rock masses by more than one order compared to the background values. Simulation studies of the areas with increased deformation are realized to understand the causes of anomalous acoustic-deformation disturbance occurrences before strong earthquakes. The model is based on the assumption that the Earth’s crust in the first approximation can be considered as a homogeneous isotropic elastic half-space, and an earthquake source can be considered as a displacements along a rectangular fault plane. Based on these assumptions, deformation regions of Earth’s crust were modeled during the preparations of two earthquakes with local magnitudes ML≈5 occurred on the Kamchatka Peninsula in 2007 and 2009. The simulation results were compared for the first time with the data of a laser strainmeter-interferometer installed at the Karymshina observation site (52.83∘ N, 158.13∘ E). It was shown that, during the preparation of the both earthquakes, the Karymshina observation site was within the region of shear deformations ≈10−7, which exceeded the tidal ones by an order. On the whole, simulation results corresponded to the results of the natural observations. Construction of an adequate model for the generation of acoustic-deformation disturbances before strong earthquakes is topical for the development of an early notification system on the threat of catastrophic natural events.
... ISSN 2079-6641 акустической эмиссии [1], электромагнитном излучении [2], геомагнитном поле [3], ионосфере [4]. Такие аномалии классифицируются как предвестники землетрясений и наблюдаются во многих сейсмоактивных регионах планеты, в том числе и на Камчатке [5,6,7,8,9]. Исследованию процессов, протекающих в геосфере посвящен обширный перечень работ. ...
Статья посвящена математическому моделированию областей повышенных деформаций земной коры, возникающих при подготовке камчатских землетрясений. Для этого произведено обобщение классической модели косейсмических деформаций земной коры, которое заключалось во введении повышающих коэффициентов, зависящих от эффективности снятия энергии упругих деформаций. На основании разработанной модели произвдено моделирование полей деформации, возникающих при подготовке двух камчатских землетрясений. Показано, что области повышенных деформаций распространяются на сотни километров от очагов готовящихся землетрясений как на поверхности земной коры, так и в ее толще.
The article is devoted to mathematical modeling of increased deformations areas of the Earth’s crust that occur during the preparation of Kamchatka earthquakes. For this purpose, a generalization of the classical model of the Earth’s crust co-seismic deformations, proposed by Yu. Okada, was made. The generalization is consisted in the introduction of increasing coefficients depending on the seismic efficiency. Based on the developed model, the deformation fields, that occurred during the preparation of two Kamchatka earthquakes, were simulated. It is shown that the areas of increased deformations extend hundreds of kilometers from the sources of upcoming earthquakes both on the surface of the Earth’s crust and in its thickness.
В основу изучения свойств сейсмического шума на Камчатке положена идея, что шум является важным источником информации о процессах, предшествующих сильным землетрясениям. Рассматривается гипотеза, что увеличение сейсмической опасности сопровождается упрощением статистической структуры сейсмического шума и увеличением пространственных корреляций его свойств. В качестве статистик, характеризующих шум, использованы энтропия распределения квадратов вейвлет-коэффициентов, ширина носителя мультифрактального спектра сингулярности и индекс Донохо-Джонстона. Значения этих параметров отражают сложность: если случайный сигнал близок по своим свойствам к белому шуму, то энтропия максимальна, а остальные два параметра минимальны. Используемые статистики вычисляются для шести кластеров станций. Для каждого кластера станций вычисляются ежесуточные ме-дианы свойств шума в последовательных временных окнах длиной 1 сутки, в результате чего образуется 18-мерный (3 свойства и 6 кластеров станций) временной ряд свойств. Для выделения общих свойств изменения параметров шума используется метод главных компонент, который применяется для каждого кластера станций, в результате чего информация сжимается до 6-мерного ежесуточного временного ряда главных компонент. Пространственные когерентности шума оцениваются как совокупность максимальных попарных квадратичных спектров когерентности между главным компонентами кластеров станций в скользящем временном окне длиной 365 суток. С помощью вычисления гистограмм распределения номеров кластеров, в которых достигаются минимальные и максимальные значения стати-стик шума в скользящем временном окне длиной 365 суток, оценивалась миграция областей сейсмической опасности в сопоставлении с сильными землетрясениями с магнитудой не менее 7.
