Asymmetrical pulses, the periodicity and synchronization of low frequency microseisms

Соболев, Г. А.; Lyubushin, A. A.; Zakrzhevskaya, N. A.

doi:10.1134/s074204630802005x

Cited by 16 publications

(2 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…То же относится и ко второму подходу, в котором используется вероятностная оценка сейсмической опасности на основе комплексного анализа коррелированности сейсмической активности, регулярности землетрясений, плотности событий в пространстве и во времени, а также ряда более сложных параметров [Sobolev, 2014;Lyubushin, 2014aLyubushin, , 2014bSobolev et al, 2008]. Уделяя относительно небольшое внимание физике процесса, сейсмологи, работающие в рамках этого направления, смогли достигнуть значительных успехов в определении статистических закономерностей сейсмичности, часто оказывающихся полезными для долгосрочного и среднесрочного прогноза.…”

Section: о локализации деформаций в очаге и подходах к прогнозу землеunclassified

Laboratory studies of slip along faults as a physical basis for a new approach to short-term earthquake prediction

Кочарян

Батухтин

2018

Geodin. tektonofiz.

View full text Add to dashboard Cite

The physical effects that may prove useful for developing a new approach to short-term earthquake prediction have been studied in laboratory conditions. In seismology and earthquake foci mechanics, one of the major challenges is searching for indicators of an upcoming seismic event and attempting to reliably record such indicators by available instruments. In this regard, the best result of the laboratory studies of dynamic slip along faults would be the identification of specific macroscopic parameters controlling the deformation process, which are measurable in field. Dynamic stiffness of a fault zone seems to be an appropriate parameter. The recent laboratory experiments have shown that the value of this parameter predetermines the slip mode along the fault (unstable slip, creep, tremor, etc.), and a radical decrease in shear stiffness takes place as the fault zone reaches the metastable state. The effect discovered in the laboratory conditions gives grounds to suggest that changes in the stress-strain state of the fault zone at the final stage of earthquake preparation are detectable from the parameters of microseismic noise in the low-frequency range. Apparently, the noise records during and after the arrival of surface waves from distant earthquakes can provide the best opportunity for determining the parameters characterizing the study area. The wave oscillations with a period of a few dozen seconds have significant amplitudes and duration, which contributes to the excitation of resonance oscillations of the blocks. There are problems requiring additional laboratory experiments: estimating the size of a fault, which predetermines regularities in decreasing of the own frequency of the block-fault system; determining the ratio of the mechanical parameters of the fault in the nucleation zone and on the periphery of the future rupture, etc. Having analyzed the results of experimental studies carried out by other researchers, we conclude that laboratory experiments under normal conditions and low pressures can successfully address a number of fundamental issues on the way to creating a new approach to short-term earthquake prediction. Increasing pressure and temperature to values characteristic of seismogenic depths does not lead to the occurrence of any fundamentally new features in the behavior of the block-fault system at the stage when dynamic slip is being prepared. During slip, friction reduces due to melting, physical and chemical transformations at the micro- and nanoscales and other processes on the slipping surface, but these effects play no role at the stage when dynamic rock failure and the onset of slip are being prepared.

show abstract

Section: о локализации деформаций в очаге и подходах к прогнозу землеunclassified

Laboratory studies of slip along faults as a physical basis for a new approach to short-term earthquake prediction

Кочарян

Батухтин

2018

Geodin. tektonofiz.

View full text Add to dashboard Cite

show abstract

“…Микросейсмические колебания природного происхождения несут в себе информацию обо всем многообразии деформационных процессов, происходящих в земной коре на различных энергетических уровнях,от перемещений тектонических плит и связанных с ними катастрофических землетрясений до лунно-солнечных приливных деформационных процессов и микроземлетрясений. В последние годы широко развиваются способы сейсмического мониторинга, основанного на выделении и анализе компонент волнового поля микросейсм, которые направлены на получение прогностических данных [Saltykov, 2017;Sobolev, 2004Sobolev, , 2011Sobolev, Ponomarev, 2003;Sobolev et al, 2008;Lyubushin, 2011]. Примером удачного прогноза сейсмического события по микросейсмам (с выделением долгосрочных предвестников) является прогноз катастрофического землетрясения Тохоку (Япония) 11 марта 2011 г. с магнитудой М=9 [Lyubushin, 2011;Sololev et al, 2008].…”

Section: Introductionunclassified

Ambient Seismic Noise Variations Before Earthquakes in the Baikal Rift System

Korol

Sankov

Добрынина

et al. 2022

Geodin. tektonofiz.

View full text Add to dashboard Cite

This paper proposes a method to observe the pre-earthquake features based on the variations in ambient noises using local moderate and strong seismic events as an example. Eight earthquakes in the Baikal rift system with energy classes K=10.1–15.9 were associated to a significant decrease in the level of ambient noises at epicentral distances from 3 to 81 km a few hours before the shock. The observed decrease in the ambient noise level can be classified as a short-term precursor of the medium consolidation 4–5 hours before the earthquake.

show abstract

Anomalous Seismic Noises from the December 9, 2020 MW = 5.6 KUDARA Earthquake in the Baikal Basin

et al. 2023

View full text Add to dashboard Cite

Studies have been conducted on the variations of microseismic noise recorded by broadband and short-period seismic stations in the area of South Baikal before and after the large December 9, 2020 Kudara earthquake with Mw = 5.6. Ten days before the earthquake, there was a gradual increase of oscillation amplitudes in the frequency range from 0.01 to 0.1 Hz, with an increasing background observed also during 4 days after the main shock (period from December 1, 2020 to January 12, 2021). The maximum amplitude increase is 19.5 against the background. During this time, there were recorded 48 aftershocks. The analysis of direction of particle motion in seismic waves over the reporting period showed an abrupt change in the orientation of oscillations, which is fully consistent with the azimuth for the main shock epicenter. The analysis of seismograms over the next period (from December 13) did not show similar effects in the microseismic noise field. Apparently, the microseismic noise field reflected the process of slow faulting before the earthquake and after the main shock with subsequent attenuation.

show abstract

Asymmetrical pulses, the periodicity and synchronization of low frequency microseisms

Cited by 16 publications

References 20 publications

Laboratory studies of slip along faults as a physical basis for a new approach to short-term earthquake prediction

Laboratory studies of slip along faults as a physical basis for a new approach to short-term earthquake prediction

Ambient Seismic Noise Variations Before Earthquakes in the Baikal Rift System

Anomalous Seismic Noises from the December 9, 2020 MW = 5.6 KUDARA Earthquake in the Baikal Basin

Contact Info

Product

Resources

About