The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
Bruce R. Julian - One of the best experts on this subject based on the ideXlab platform.
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Period doubling and other nonlinear Phenomena in volcanic earthquakes and tremor
Journal of Volcanology and Geothermal Research, 2000Co-Authors: Bruce R. JulianAbstract:Abstract Evidence of subharmonic period-doubling cascades has recently been recognized in seismograms of volcanic tremor from several volcanoes. This phenomenon occurs only in nonlinear systems, and is the commonest route by which such systems change from periodic to chaotic behavior. It is predicted to occur in a model of volcanic tremor excitation by flow-induced vibration, and it might well also occur in other volcano-Seismic source process. If the possibility of period doubling is not taken into account in interpreting spectra of tremor and long-period earthquakes, then low-frequency “sub-harmonic” oscillations may be mis-identified as normal modes of a linear acoustic resonator, leading to errors of an order of magnitude or more in inferred magma-body dimensions. This example illustrates the importance of nonlinear Phenomena in attempts to understand volcano-Seismic Phenomena physically. Linear systems are fundamentally incapable of causing earthquakes or exciting tremor, so nonlinearity is essential to any theory of volcano-Seismic Phenomena. Nonlinear processes are in many respects qualitatively different from linear ones. A few of their characteristics that might be relevant in volcanoes include the possibility: (1) that damping might increase, rather than decrease, oscillation frequencies; and (2) that these frequencies might be functions of the amplitude of oscillation, so that temporal variations in spectral peak frequencies might not be manifestations of changes of conditions within the magmatic system.
E. A. Jagla - One of the best experts on this subject based on the ideXlab platform.
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Viscoelastic effects in avalanche dynamics: a key to earthquake statistics.
Physical review letters, 2014Co-Authors: E. A. Jagla, François P. Landes, Alberto RossoAbstract:In many complex systems a continuous input of energy over time can be suddenly relaxed in the form of avalanches. Conventional avalanche models disregard the possibility of internal dynamical effects in the interavalanche periods, and thus miss basic features observed in some real systems. We address this issue by studying a model with viscoelastic relaxation, showing how coherent oscillations of the stress field can emerge spontaneously. Remarkably, these oscillations generate avalanche patterns that are similar to those observed in Seismic Phenomena. Language: en
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Velocity weakening and possibility of aftershocks in nanoscale friction experiments
Physical Review B, 2012Co-Authors: E. A. JaglaAbstract:We study the frictional behavior of small contacts as those realized in the atomic force microscope and other experimental setups, in the framework of generalized Prandtl-Tomlinson models. Particular attention is paid to mechanisms that generate velocity weakening, namely a decreasing average friction force with the relative sliding velocity.The mechanisms studied model the possibility of viscous relaxation, or aging effects in the contact. It is found that, in addition to producing velocity weakening, these mechanisms can also produce aftershocks at sufficiently low sliding velocities. This provides a remarkable analogy at the microscale, of friction properties at the macroscale, where aftershocks and velocity weakening are two fundamental features of Seismic Phenomena.
Dawid Mrocheń - One of the best experts on this subject based on the ideXlab platform.
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Land Surface Subsidence Due to Mining-Induced Tremors in the Upper Silesian Coal Basin (Poland)—Case Study
Remote Sensing, 2020Co-Authors: P. Sopata, T. Stoch, Artur Wójcik, Dawid MrocheńAbstract:Seismic Phenomena threaten land-based buildings, structures, and infrastructure and can transform land topography. There are two basic types of Seismic Phenomena, namely, tectonic and anthropogenic, which differ mainly in epicenter depth, surface impact range, and magnitude (energy). This article shows how a land surface was changed by a series of seven rock mass tremors of magnitude ML = 2.3–2.6 in March–May 2017. Their immediate cause was the “momentary” acceleration of void clamping, which was activated by local and short-term Seismic Phenomena caused by human activity. The induced Seismic events resulted from the geological structure of the rock mass, which in the specific region of examination was classified as being highly prone to mining tremors. The authors focused on describing vertical surface displacements in the Upper Silesian Coal Basin in the south of Poland. The surface deformations were identified using DInSAR technology, which allows quasi-continuous monitoring of large areas of land surface. The present research used freely available data from the Copernicus Program and Seismic data from the European Plate Observing System.
Alberto Rosso - One of the best experts on this subject based on the ideXlab platform.
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Viscoelastic effects in avalanche dynamics: a key to earthquake statistics.
Physical review letters, 2014Co-Authors: E. A. Jagla, François P. Landes, Alberto RossoAbstract:In many complex systems a continuous input of energy over time can be suddenly relaxed in the form of avalanches. Conventional avalanche models disregard the possibility of internal dynamical effects in the interavalanche periods, and thus miss basic features observed in some real systems. We address this issue by studying a model with viscoelastic relaxation, showing how coherent oscillations of the stress field can emerge spontaneously. Remarkably, these oscillations generate avalanche patterns that are similar to those observed in Seismic Phenomena. Language: en
P. Sopata - One of the best experts on this subject based on the ideXlab platform.
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Land Surface Subsidence Due to Mining-Induced Tremors in the Upper Silesian Coal Basin (Poland)—Case Study
Remote Sensing, 2020Co-Authors: P. Sopata, T. Stoch, Artur Wójcik, Dawid MrocheńAbstract:Seismic Phenomena threaten land-based buildings, structures, and infrastructure and can transform land topography. There are two basic types of Seismic Phenomena, namely, tectonic and anthropogenic, which differ mainly in epicenter depth, surface impact range, and magnitude (energy). This article shows how a land surface was changed by a series of seven rock mass tremors of magnitude ML = 2.3–2.6 in March–May 2017. Their immediate cause was the “momentary” acceleration of void clamping, which was activated by local and short-term Seismic Phenomena caused by human activity. The induced Seismic events resulted from the geological structure of the rock mass, which in the specific region of examination was classified as being highly prone to mining tremors. The authors focused on describing vertical surface displacements in the Upper Silesian Coal Basin in the south of Poland. The surface deformations were identified using DInSAR technology, which allows quasi-continuous monitoring of large areas of land surface. The present research used freely available data from the Copernicus Program and Seismic data from the European Plate Observing System.