The Experts below are selected from a list of 51 Experts worldwide ranked by ideXlab platform
Vyacheslav M Zobin - One of the best experts on this subject based on the ideXlab platform.
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Chapter 3 – Fundamentals of Volcanic Seismology
Introduction to Volcanic Seismology, 2017Co-Authors: Vyacheslav M ZobinAbstract:This chapter presents the theoretical and experimental basis for Volcanic Seismology. The ascent of magma and its movement to the surface from the magma reservoir may be considered as steady or unsteady multiphase flow. Seismic signals may be generated at any point in this system, but the type of seismicity depends on the physical processes and the state of the magmatic fluids at the each stage of magma flow. The experimental studies of the brittle fracturing in flowing magma explain the nature of volcano-tectonic, hybrid, and long-period earthquakes. Modeling of ascending magma within Volcanic conduits explains the nature of Volcanic tremor and the variety of seismic signals associated with explosive eruptions. General description of the source of seismic signals at volcanoes is presented in the terms of the seismic moment tensor.
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chapter 3 fundamentals of Volcanic Seismology
Introduction to Volcanic Seismology (Third Edition), 2017Co-Authors: Vyacheslav M ZobinAbstract:This chapter presents the theoretical and experimental basis for Volcanic Seismology. The ascent of magma and its movement to the surface from the magma reservoir may be considered as steady or unsteady multiphase flow. Seismic signals may be generated at any point in this system, but the type of seismicity depends on the physical processes and the state of the magmatic fluids at the each stage of magma flow. The experimental studies of the brittle fracturing in flowing magma explain the nature of volcano-tectonic, hybrid, and long-period earthquakes. Modeling of ascending magma within Volcanic conduits explains the nature of Volcanic tremor and the variety of seismic signals associated with explosive eruptions. General description of the source of seismic signals at volcanoes is presented in the terms of the seismic moment tensor.
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Introduction to Volcanic Seismology Ed. 3
2016Co-Authors: Vyacheslav M ZobinAbstract:Introduction to Volcanic Seismology, Third Edition covers all aspects of volcano Seismology, specifically focusing on recent studies and developments. This new edition expands on the historical aspects, including updated information on how Volcanic Seismology was handled in the past (instrumentation, processing techniques, number of observatories worldwide) that is compared to present day tactics. Updated case studies can be found throughout the book, providing information from the most studied volcanoes in the world, including those in Iceland. Additional features include descriptions of analog experiments, seismic networks, both permanent and temporal, and the link between volcanoes, plate tectonics, and mantle plumes. Beginning with an introduction to the history of Volcanic Seismology, the book then discusses models developed for the study of the origin of Volcanic earthquakes of both a volcano-tectonic and eruption nature. In addition, the book covers a variety of topics from the different aspects of volcano-tectonic activity, the seismic events associated with the surface manifestations of Volcanic activity, descriptions of eruption earthquakes, Volcanic tremor, seismic noise of pyroclastic flows, explosion earthquakes, and the mitigation of Volcanic hazards.Presents updated global case studies to provide real-world applications, including studies from Iceland Delivers illustrations alongside detailed descriptions of Volcanic eruptions Includes essential information that students and practitioners need to understand the essential elements of Volcanic eruptionsUpdates include information on how Volcanic Seismology was handled in the past (instrumentation, processing techniques, number of observatories worldwide) that are compared to the tactics of today
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Fundamentals of Volcanic Seismology
Introduction to Volcanic Seismology, 2012Co-Authors: Vyacheslav M ZobinAbstract:This chapter presents the theoretical and experimental basis for Volcanic Seismology. The ascent of magma and its movement to the surface from the magma reservoir may be considered as steady or unsteady multi-phase flow. Seismic signals may be generated at any point in this system, but the type of seismicity depends on the physical processes and the state of the magmatic fluids at the each stage of magma flow. The experimental studies of the brittle fracturing in flowing magma explain the nature of volcano-tectonic, hybrid, and long-period earthquakes. Modeling of ascending magma within Volcanic conduits explains the nature of Volcanic tremor and the variety of seismic signals associated with explosive eruptions. A general description of the source of seismic signals at volcanoes is presented in the terms of the seismic moment tensor.
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Introduction to Volcanic Seismology Ed. 2
2011Co-Authors: Vyacheslav M ZobinAbstract:Volcanic Seismology represents the main, and often the only, tool to forecast Volcanic eruptions and to monitor the eruption process. This book describes the main types of seismic signals at volcanoes, their nature and spatial and temporal distributions at different stages of eruptive activity. Following from the success of the first edition, published in 2003, the second edition consists of 19 chapters including significant revision and five new chapters. Organized into four sections, the book begins with an introduction to the history and topic of Volcanic Seismology, discussing the theoretical and experimental models that were developed for the study of the origin of Volcanic earthquakes. The second section is devoted to the study of volcano-tectonic earthquakes, giving the theoretical basis for their occurrence and swarms as well as case stories of volcano-tectonic activity associated with the eruptions at basaltic, andesitic, and dacitic volcanoes. There were 40 cases of Volcanic eruptions at 20 volcanoes that occurred all over the world from 1910 to 2005, which are discussed. General regularities of volcano-tectonic earthquake swarms, their participation in the eruptive process, their source properties, and the hazard of strong volcano-tectonic earthquakes are also described. The third section describes the theoretical basis for the occurrence of eruption earthquakes together with the description of Volcanic tremor, the seismic signals associated with pyroclastic flows, rockfalls and lahars, and Volcanic explosions, long-period and very-long-period seismic signals at volcanoes, micro-earthquake swarms, and acoustic events. The final section discuss the mitigation of Volcanic hazard and include the methodology of seismic monitoring of Volcanic activity, the examples of forecasting of Volcanic eruptions by seismic methods, and the description of seismic activity in the regions of dormant volcanoes. This book will be essential for students and practitioners of Volcanic Seismology to understand the essential elements of Volcanic eruptions. Provides a comprehensive overview of seismic signals at different stages of volcano eruption. Discusses dozens of case histories from around the world to provide real-world applications. Illustrations accompany detailed descriptions of volcano eruptions alongside the theories involved.
Liu Yinbin - One of the best experts on this subject based on the ideXlab platform.
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Low-Frequency Resonance in Strong Heterogeneity
2019Co-Authors: Liu YinbinAbstract:Multiple scattering of wave in strong heterogeneity can cause resonance-like wave anomaly where the signal exhibits low-frequency, high intensity, and slowly propagating wave packet velocity. For example, long period event in Volcanic Seismology and plasma oscillations in wave-particle interactions. Collective behaviour in a many-body system is thought to be the source for generating the anomaly, however the detailed mechanism is not fully understood. Here I show that the physical mechanism is associated with low-frequency resonance (LFR) in strong small-scale heterogeneity through seismic wave field modeling for bubble cloud heterogeneity and 1D heterogeneity. LFR is a kind of wave coherent scattering enhancement or emergence phenomenon that occurs in transient regime. Its resonance frequency decreases with increasing heterogeneous scale, impedance contrast, or random heterogeneous scale and velocity fluctuations; its intensity diminishes with decreasing impedance contrast or increasing random heterogeneous scale and velocity fluctuations. LRF exhibits the characteristics of localized wave in space and the shape of ocean wave in time and is a ubiquitous wave phenomenon in wave physics. The concept of LFR can open up new opportunities in many aspects of science and engineering.Comment: 16 pages, 7 figure
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Low-frequency resonance in strong heterogeneity
2017Co-Authors: Liu YinbinAbstract:Multiple scattering of wave in strong heterogeneity can cause resonance-like wave anomaly where the signal exhibits low-frequency, high intensity, and slowly propagating wave packet velocity. For example, long period event in Volcanic Seismology and plasma oscillations in wave-particle interactions. Collective behaviour in a many-body system is thought to be the source for generating the anomaly, however the detailed mechanism is not fully understood. Here I show that the physical mechanism is associated with low-frequency resonance (LFR) in strong small-scale heterogeneity through seismic wave field modeling for bubble cloud heterogeneity and 1D heterogeneity. LFR is a kind of wave coherent scattering enhancement or emergence phenomenon that occurs in transient regime. Its resonance frequency decreases with increasing heterogeneous scale, impedance contrast, or random heterogeneous scale and velocity fluctuations; its intensity diminishes with decreasing impedance contrast or increasing random heterogeneous scale and velocity fluctuations. LRF exhibits the characteristics of localized wave in space and the shape of ocean wave in time and is a ubiquitous wave phenomenon in wave physics. The concept of LFR can open up new opportunities in many aspects of science and engineering.Science, Faculty ofEarth, Ocean and Atmospheric Sciences, Department ofUnreviewedFacult
Yinbin Liu - One of the best experts on this subject based on the ideXlab platform.
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Low Frequency Scattering Resonance Wave in Strong Heterogeneity
arXiv: Classical Physics, 2015Co-Authors: Yinbin LiuAbstract:Multiple scattering of wave in strong heterogeneity can cause resonance-like wave phenomenon where signal exhibits low frequency, high intensity, and slowly propagating velocity. For example, long period event in Volcanic Seismology and surface plasmon wave and quantum Hall effect in wave-particle interactions. Collective behaviour in a many-body system is usually thought to be the source for generating the anomaly. However, the detail physical mechanism is not fully understood. Here I show by wave field modeling for microscopic bubble cloud model and 1D heterogeneity that the anomaly is related to low frequency scattering resonance happened in transient regime. This low frequency resonance is a kind of wave coherent scattering enhancement phenomenon in strongly-scattered small-scale heterogeneity. Its resonance frequency is inversely proportional to heterogeneous scale and contrast and will further shift toward lower frequency with random heterogeneous scale and velocity fluctuations. Low frequency scattering resonance exhibits the characteristics of localized wave in space and the shape of ocean wave in time and is a common wave phenomenon in wave physics that includes mechanical, electromagnetic, and matter waves.
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Low-Frequency Resonance in Strong Heterogeneity
arXiv: Classical Physics, 2015Co-Authors: Yinbin LiuAbstract:Multiple scattering of wave in strong heterogeneity can cause resonance-like wave anomaly where the signal exhibits low-frequency, high intensity, and slowly propagating wave packet velocity. For example, long period event in Volcanic Seismology and plasma oscillations in wave-particle interactions. Collective behaviour in a many-body system is thought to be the source for generating the anomaly, however the detailed mechanism is not fully understood. Here I show that the physical mechanism is associated with low-frequency resonance (LFR) in strong small-scale heterogeneity through seismic wave field modeling for bubble cloud heterogeneity and 1D heterogeneity. LFR is a kind of wave coherent scattering enhancement or emergence phenomenon that occurs in transient regime. Its resonance frequency decreases with increasing heterogeneous scale, impedance contrast, or random heterogeneous scale and velocity fluctuations; its intensity diminishes with decreasing impedance contrast or increasing random heterogeneous scale and velocity fluctuations. LRF exhibits the characteristics of localized wave in space and the shape of ocean wave in time and is a ubiquitous wave phenomenon in wave physics. The concept of LFR can open up new opportunities in many aspects of science and engineering.
Cadena Ibarra - One of the best experts on this subject based on the ideXlab platform.
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CÁLCULO DE HIPOCENTROS PARA SISMOS VOLCÁNICOS ASOCIADOS A MOVIMIENTO DE FLUIDOS EN EL VOLCÁN GALERAS, COLOMBIA (Hypocenters calculation for Volcanic earthquakes associated with movement of fluid in the Galeras volcano, Colombia)
2009Co-Authors: Roberto Armando, Torres Corredor, Oscar Ernesto, Cadena IbarraAbstract:One of the most important tasks in the Volcanic Seismology is the location of the seismic sources. Given the difficulty of identification of the seismic phases and the measurement of its arrival times, an algorithm develops for the determination of the hypocenter of these earthquakes based on the attenuation of the extents of the waveforms and the application of Gauss-Newton's method. The basic principle is the calculation of the hypocentral parameters of the earthquake by means of the simultaneous minimization of the residual ones of the extents of the waveforms from several observations. The method uses an adjustment of square minimums developed in a series of Taylor in its first approximation. It is considered to be a variation of the hypocentral parameters of an initial supposed location (initial model) and those have to by means of an iterative procedure minimize simultaneously the residues of the calculated extents and the observed ones of the records in a network of seismic stations. The investment of the extents to estimate the location of the seismic source is supported in a physical model of attenuation that describes the relation between the amplitudes and parameters of the source, taking into account the geometric amplitude, anelastic absorption, orientation of the seismometer components, effects of free surface and topography. The convergence of the solution strongly depends on the proximity of the initial model suppositions with reality.
Bernard A. Chouet - One of the best experts on this subject based on the ideXlab platform.
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Trends in long-period seismicity related to magmatic fluid compositions
Journal of Volcanology and Geothermal Research, 2001Co-Authors: M.m Morrissey, Bernard A. ChouetAbstract:Abstract Sound speeds and densities are calculated for three different types of fluids: gas–gas mixture; ash–gas mixture; and bubbly liquid. These fluid properties are used to calculate the impedance contrast ( Z ) and crack stiffness ( C ) in the fluid-driven crack model (Chouet: J. Geophys. Res., 91 (1986) 13,967; 101 (1988) 4375; A seismic model for the source of long-period events and harmonic tremor. In: Gasparini, P., Scarpa, R., Aki, K. (Eds.), Volcanic Seismology, IAVCEI Proceedings in Volcanology, Springer, Berlin, 3133). The fluid-driven crack model describes the far-field spectra of long-period (LP) events as modes of resonance of the crack. Results from our calculations demonstrate that ash-laden gas mixtures have fluid to solid density ratios comparable to, and fluid to solid velocity ratios lower than bubbly liquids (gas-volume fractions Spectral characteristics are described in terms of the quality factor Q −1 . Q −1 is measured by the ratio of the frequency of the dominant spectral peak to the bandwidth of the peak measured at one half of its amplitude. This factor expresses the losses of energy due to elastic radiation Q r −1 and other dissipative mechanisms Q i −1 at the source, Q −1 = Q r −1 + Q i −1 . Spectra for LP events recorded at active volcanoes such as Galeras in Colombia and Kilauea in Hawaii, have Q −1 factors in the range of 0.1–0.002. The Q r −1 factors due to radiation loss calculated for a sphere filled with a H 2 O–CO 2 or H 2 O–SO 2 gas mixture, vary between 0.0015 and 0.0040 with a change in wt% H 2 O at 800–1600 K and 10–50 MPa. For gas-rich mixtures, Q r −1 has a strong dependence on resonator geometry (spherical versus rectangular). The spectra from a resonating sphere filled with gas-rich mixture yields values of Q r −1 an order of magnitude smaller than those from a rectangular crack. For a resonating crack filled with an ash–gas mixture (or pseudogas), Q r −1 varies parabolically from ∼0.006 for an ash-rich mixture, to 0.0015 or 0.0023 for a H 2 O-rich or CO 2 -rich mixture at 800 K and 25 MPa. For low ( Q r −1 are independent of crack geometry. Spectra associated with a foam (gas-volume fractions 10–90%) or bubbly basalt (gas-volume fractions Q r −1 on the order of 0.01 and 0.1, respectively. The spectra from a resonating sphere filled with a foam containing >20% gas-volume fraction yields values of Q r −1 similar to those for a rectangular crack. As with gas–gas and ash–gas mixtures, an increase in mass fraction narrows the bandwidth of the dominant mode and shifts the spectra to lower frequencies. Including energy losses due to dissipative processes in a bubbly liquid increases attenuation. Attenuation may also be higher in ash–gas mixtures and foams if the effects of momentum and mass transfer between the phases were considered in the calculations.
