Using the results of instrumental observations, acoustic, electrical and magnetic effects caused by the explosive destruction of a bolide on 10/16/2023 near Tomsk were established. It is shown that the effects have a non-local character and are recorded at a significant epicentral distance from the point of explosion of the bolide both during the event itself and during the arrival of the infrasound signal at the point of instrumental observations. Using an approach based on the properties of the infrasound signal not to change the characteristic frequency with distance, the energy of the source was estimated to be 3.7.1013 J.
The geophysical effects of a fire in Moscow on December 09, 2022, which, along with open combustion, was accompanied by an explosion of containers with combustible materials, are analyzed. The results of instrumental observations have shown that during the maximum combustion period, not only acoustic signals, but also variations in the electric field intensity are clearly recorded at a distance of ~ 25 km. At the same distances, the fire caused changes in the wind rose. During the maximum development of the fire, geomagnetic disturbances were recorded at a distance of ~ 90 km from the fire source, which is explained by the effect of internal gravitational waves on the ionosphere, resulting from the formation of a powerful vertical flow of heated material.
Instrumental observations of variations of geophysical fields during mass explosions at Lebedinsky and Stoilensky quarries. Complex instrumental measurements of variations of microparticles in the atmosphere, the level of infrasound and the intensity of the electric field were carried out. Measurements were carried out in two stationary points. The observations made it possible to obtain adequate estimates of both the values of the concentration of solid particles in the air during mass explosions, and variations in the level of infrasound and electric field strength in settlements located in the immediate vicinity of quarries.
Instrumental observations of the dust and gas clouds development and microparticles emissions into the atmosphere were carried out during mass explosions at the Lebedinsky quarry. In the process of observations, a stationary observation point and a number of mobile points were organized. The results of observations made it possible to obtain estimates of both the maximum values of the solid particles concentrations and their average daily values in the settlements located in the immediate vicinity of the quarry. Sources of particulate matter emissions not related to technological operations at the quarry were also identified.
Using the results of instrumental observations, the acoustic, electrical and magnetic effects of the explosive destruction of the bolide on November 17, 2021 in the region of Izhevsk was established. It was found that the effects are non-local in nature and were registered at a significant epicentral distances from the explosion. It is noted that variations in the magnetic field were observed both during the fall of the bolide and during the arrival of the atmospheric signal at the registration point. Based on the characteristic frequency of the atmospheric signal, the bolide explosion energy was estimated, which was 9.4•1010 J.
Based on the analysis of the results of instrumental observations, it is shown that the explosion of the volcano caused a series of wave disturbances in the atmosphere, as well as variations in the electric and magnetic fields of the Earth at significant epicentral distances. Atmospheric disturbances were recorded in the form of Lamb waves with a source at the epicenter of the explosion, as well as a virtual source located at the antipode, and the formation of which is associated with the convergence and summation of signals propagating along the Earth's sphere. In addition to the primary waves, secondary and tertiary waves were registered, which were formed as a result of the repeated passage of the signal caused by the explosion around the Earth's sphere. The source energy has been estimated.
Based on the results of the analysis of coordinate data obtained as a result of constant registration at the Mikhnevo Geophysical Observatory of IDG RAS using a stationary GPS receiver, it is shown that during periods of strong geomagnetic disturbances, the positioning error increases significantly. It is shown that the variations of the positioning error in magnetic storms are characterized by a well-defined periodicity with a period of about 3 minutes. In this case, the maximum error is contained in the range of 4 ‒ 26 m and practically does not depend on the amplitude of the geomagnetic variation. The data obtained in this research allow us to consider the variations of the positioning error as an indicator of the disturbed state of the ionosphere and atmosphere during magnetic storms, as well as as a parameter that characterizes the degree of disturbance of the environment and the conditions for the propagation of a high-frequency electro-magnetic GPS signal in it.
The analysis of the results of instrumental observations of variations in geophysical fields during hurricanes in Moscow, recorded for the period 2009 ‒ 2017, is presented. The digital series of the vertical component of the electric field strength, micropulsations of atmospheric pressure and the amplitude of seismic noise were analyzed.
The paper presents the field observation data on variations in the pressure and electric field intensity in the near-surface atmospheric layer during the passage of the morning solar terminator in several regions of the Russian Federation. The results of experiments on the "SURA" heating stand designed for registering acoustic and electric fields are provided. Analysis of the data obtained shows that synchronous variations in pressure and electric field intensity occurring at operation of the heating stand are similar to those observed during the passage of the solar terminator.
Based on the results of instrumental observations, it is shown that magnetic storms cause microbaric variations in atmospheric pressure with an amplitude of 2 to 20 Pa in the range of periods of 20 ‒ 80 min, as well as with frequencies close to the Brent-Väisälä frequency. The spectrum of microbaric variations during magnetic storms contains several quasiharmonic components.
The results of instrumental observations of strong earthquakes local seismoacoustic effects are presented. The observations were made at the Institute of Geosphere Dynamics Geophysical Observatory "Mikhnevo". We have selected more 22 events with a magnitude greater than 6.0 recorded by small aperture seismic array central broad band station. It is shown that earthquakes located at distances from ~ 1900 km to ~ 3200 km from the registration point cause atmospheric disturbances in the form of acoustic vibrations initiated by seismic waves.
Infrasound waves generated by auroras are usually recorded at high latitudes during periods of high geomagnetic activity. These waves are often characterized by high apparent velocities (usually from 400 to 1000 m/s), which means that their source locates at a high altitude. Currently, the relation between the atmosphere electric-field variations and infrasound in the near-surface atmospheric layer during magnetospheric substorms is determined. However, for the full-scale analysis of the said interaction, we must have a predictive picture of the infrasonic atmospheric response, which raises the need for its modeling.
Based on the analysis of instrumental observational data, it was shown that large fires manifest themselves in local variations of the electric field and the amplitude of acoustic vibrations. Above the fire area, the formation of the zone with altered thermodynamic characteristics causes the formation of acoustic-gravitational waves with a Brent-Väisälä frequency during the most intense burning. The examples of the strong fires in Moscow are considered.
We consider the disturbances of the magnetic field, electrical characteristics, and microbaric variations in the surface atmosphere caused by a strong earthquake that occurred in Turkey on January 24, 2020. The effects were recorded at the Mikhnevo observatory of Sadovsky Institute of Geosphere Dynamics of Russian Academy of Sciences which is located at distance of ~ 1900 km from the earthquake focus. It is shown that the acoustic effects accompanying the earthquake are caused by two sources: acoustic signal produced by arrival of seismic waves and acoustic signal propagating in the stratospheric waveguide. Using the data of the Mikhnevo observatory, we present the amplitudes of the induced variations in the electric field and atmospheric current. Also geomagnetic variations at different distances from the earthquake focus are presented.
Acoustic effects associated with volcanic eruptions are considered. The phenomenological classification of wave disturbances caused by volcanoes in the atmosphere is given. Wave disturbances classes that are characteristic of different types of volcanic activity are discussed. The basic mechanisms for generating low-frequency infrasound waves during large explosive eruptions of explosive type are described. As an example, acoustic effects caused by the eruption of the Stromboli volcano in July ‒ August 2019 are presented and discussed.
The study is devoted to the study of atmospheric, electromagnetic and ionospheric effects registered at a distance of about 2000 km from the earthquakes in Greece on May 24, 2014 and November 17, 2015 by the hardware complex of the geophysical observatory "Mikhnevo". One of the mechanisms that provide perturbations of geophysical fields at significant distances from the source is associated with the generation of acoustic waves caused by a surface seismic wave. When acoustic oscillations propagate to the atmosphere and ionosphere, they cause variations in the density of the neutral gas and the electron concentration in the ionosphere. In the D region, this leads to changes in the conductivity and modulation of horizontal ionospheric currents registered on the Earth's surface as variations of the geomagnetic field. The results obtained confirm the possibility of recording acoustic and electromagnetic effects at significant distances from the earthquake center.
A new approach to the prevention of atmospheric hazard in the form of hurricanes, squalls and heavy thunderstorms has been proposed. Anomalous variations of electric and magnetic fields, atmospheric current, as well as increased amplitudes of seismic vibrations and micropulsations of atmospheric pressure, recorded 1–8 hours before the arrival and the onset of the most intense manifestations of these phenomena, are considered as a complex prognostic sign. The obtained data can contribute to improving the reliability of the short-term forecast, as well as being of interest for the development of measures to prevent the negative and catastrophic consequences of strong atmospheric disturbances.
The paper presents the results of experimental studies of the influence of the level of tonal acoustic noise on the times of simple human reactions, such as a simple auditory-motor reaction, a simple visual-motor reaction, a simple tactile-motor reaction, as well as a detection reaction. Experimental studies have shown that during the action of tonal acoustic noise with a frequency of 100 Hz, the subjects experienced an increase in the times of all the simple reactions being analyzed. The effect of tonal noise with a frequency of 100 Hz on the detection response is less pronounced.
The effect of infrasonic pulsed radiation from the Chelyabinsk bolide on the perturbations of the electron concentration in the D region of the Earth's ionosphere is considered. According to the electromagnetic measurements in the geophysical observatory Mikhnevo of the Institute of Geospheres Dynamics of Russian Academy of Science (IDG RAS), an estimate of the displacement of the reflection point of the SDV signals is obtained. Influence of infrasound radiation on the propagation of VLF signals on the Novosibirsk-Mikhnevo path is considered. The amplitude of the displacement of particles of the environment from infrasonic radiation is estimated. There is a good agreement between theoretical and experimental estimates.
The paper presents the results of experimental studies of the effect of acoustic noise of the sound and infrasonic frequency bands on the auditory, visual, motor, tactile responses of a person, as well as on the time of making decisions. A method for estimating the time of human reactions was proposed, which was implemented by the authors as a software application for mobile devices. The obtained results unequivocally show an increase in the reaction time of all types under the influence of sound and infrasound noise even of a small level.
The paper deals with the assessment of the Chelyabinsk meteoroid energy based on long-period infrasonic waves in the atmosphere. A new technique is proposed, which utilizes the integral energy distribution in the power spectrum. The obtained results are in satisfactory agreement with the independent energy estimates.
We present experimental results of the study of acoustic gravity waves and electric field generation during auroras. Vertical component of electric field in the atmosphere surface layer and atmosphere pressure were recorded during the field study. Analysis of the obtained data shows that synchronous variations of the pressure and electric field strength appear with the development of auroras. It is seen that the amplitude of electric field perturbations is approximately proportional to the amplitude of variation in the pressure.
Given are results of analysis of data obtained by instrumental observations of infrasound vibrations performed in the area of Leninsky Avenue, Moscow. It was found that most intensive sources of infrasound are traffic lights and crossroads. Article illustrates difference in amplitude and spectral characteristics of infrasound depending on traffic flow regime. It contains date evidencing relation of infrasound noise with avenue load.
It describes new approach to assessment of energy sources of infrasound perturbations by spectrum of fluctuations in atmospheric pressure given stratigraphy of the atmosphere. It offers phenomenological model of spread of infrasound in standard atmosphere based on data of instrumental observations made during studying infrasound signals from powerful explosive atmospheric sources. There has been developed technique for assessment of energy which uses integral dependence of energy on power spectrum. Obtained results are consistent with known researches data.
Analysis of microbaric variations and variations of the electric field during atmosphere strong disturbances were carried out on the base of the data of instrumental registrations obtained in the geophysical observatory "Mikhnevo" of the Institute of Geospheres Dynamics of the Russian Academy of Sciences (IGD RAS). It is shown the hurricanes and storms are accompanied by high-amplitude variations of acoustic and electrical fields. Amplitudes of variations of these fields increase in a several hours before front arrival. This fact in the aggregate with meteorological parameters could be considered as a predicted indication of approaching hurricane or storms. It is determined that thundery front arrival is forestalled by long period electric field variations, internal gravity waves and increased acoustic impedance. Regularities, which were determined resulting from investigations, could be raise of forecast reliability and efficiency.
This paper describes the results of experimental study influences of urban planning and green spaces on the acoustic transport noises. The contribution of green spaces to the acoustic noise attenuation is shown.
KEYWORDS: Signal analyzers, Wavelets, Wavelet transforms, Signal detection, Acoustics, Signal generators, Protactinium, Atmospheric physics, Chemical analysis, Physics
The paper presents the results of the wavelet analysis of infrasound signals from ground-based low-power explosions. It was found that in most cases, the spectral structure of the infrasound signal has the character of a monotonic decrease of the oscillation period. For these types of signals from the explosion with the power tab order of 0.01 × 10-3 kT at a distance of up to 300 km infrasound signal spectral structure has the character of a linear decrease of the period of pressure fluctuations from time to time according to the law T = Т0 - B × t, where the most probable values of the initial period Т0 take values from 0.97 and index decreasing in the period - 0.25.
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