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Showing 1 to 16 of 16 for “"moment tensor"”.
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UNRAVELLING VOLCANIC TREMOR SOURCE AT MOUNT ETNA FROM QUANTITATIVE MULTIPARAMETRIC ANALYSIS AND MOMENT TENSOR INVERSION
… QUANTITATIVA MULTIPARAMETRICA ED INVERSIONE DEL TENSORE MOMENTO. Lo sviluppo di reti multiparametriche di monitoraggio, tecniche di analisi in tempo reale e l'acquisizione di dati ad alta risoluzione, hanno permesso di migliorare la conoscenza delle strutture e delle dinamiche che caratterizzano …
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Microseismic mapping and source characterization for hydrofracture monitoring : a full-waveform approach
… full-waveform approach is developed for complete moment tensor inversion. By using synthetic data, we show that, for events in the near-field of a single monitoring well, a stable, complete moment tensor can be retrieved by matching the waveforms without additional constraints. At far-field range, …
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Ground motions and source mechanisms of earthquakes in multiscales : microseismicity to macroseismicity
… their uncertainties, a waveform-based Bayesian moment tensor inversion approach was developed and validated by synthetic tests. The Bayesian approach estimates the source parameters and the uncertainties by generating a posterior probability density function of the source parameters. The effects …
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Inversion of seismic source parameters for weak mining-induced and natural earthquakes
… seismicity is generally investigated only by moment tensor inversion routines, with no attempt to resolve source duration or finite source parameters. In this work, automated multi-step inversion schemes are applied to both datasets with the aim of resolving point source parameters, both using …
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Determining the focal mechanisms of earthquakes by full waveform modeling
… with intervals of 1 km. Then, we calculate the moment tensor for 6840 different combinations of strikes, dips, and rakes for each of those depths. These are convolved with Green's function and with an assumed smooth ramp source time function to produce the different synthetic seismograms …
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A quasi-dynamic and self-consistent rupture model to simulate earthquake ruptures
… plane is defined by a previously performed moment tensor inversion. The simultanously inverted scalar seismic moment allows an estimation of the extension of the rupture. The modeled rupture plane is discretized by a set of rectangular boundary elements. For each boundary element an applied …
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Source Parameters and Tectonic Setting of the 2017 St. Elias Earthquake Sequence near the Southern Terminus of the Eastern Denali Fault, Northwestern Canada
… were followed by more than 2,700 aftershocks. Moment-tensor inversion of the mainshock signals shows that the initial event produced reverse slip on a steeply dipping fault with a NW-SE strike direction, while the second produced left-lateral strike-slip on a near-vertical fault with an E-W …
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Non-destructive evaluation of laboratory scale hydraulic fracturing using acoustic emission
… Individual microcrack analysis methods include moment tensor inversion techniques to elucidate the mode of failure, crack slip and crack normal direction vectors, and relative volumetric deformation of an individual microcrack. Differentiation between individual microcrack analysis and AE cloud …
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Investigations of Anomalous Earthquakes at Active Volcanoes
… Two seismicity catalogs from the Global Centroid Moment Tensor (CMT) Project are used to search for further examples of shallow earthquakes with robust vertical-CLVD focal mechanisms. CMT solutions for approximately 400 target earthquakes are calculated and 86 vertical-CLVD earthquakes are …
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Deep learning framework bridges lab and field scale microseismic focal mechanism
… diagnostic tool for these sites. Where possible, moment tensor inversion of microseismic source mechanisms is particularly useful as these tensors can highlight the kinematics and kinetics of subsurface deformation. However, these inversions can be difficult to constrain and automate in field …
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Robust Bayesian inference via optimal transport misfit measures: applications and algorithms
… biased and less dispersed. In particular, we use moment tensor inversion, a seismic inverse problem, as our primary motivating application and demonstrate improved inversion performance of the TL loss—by a variety of statistical and physical metrics—for a range of increasingly complex inversion …
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Real-time GNSS for fast seismic source inversion and tsunami early warning
… for tsunami early warning. To be exact, centroid moment tensor inversion, uniform slip inversion using a single Okada fault and distributed slip inversion in layered crust on a curved plane were conducted using co-seismic displacements recorded during 2014 Pisagua earthquake. While the inversion …
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Space-time rupture properties of large earthquakes
… of both an ordinary earthquake and a smooth moment-release transient of longer duration. Low-frequency normal-mode based studies which support the compound event hypothesis have suggested that low-frequency source-spectra of some slow earthquakes require that the slow-component initiated …
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Geophysical signatures of crack initiation and growth in rocks under uniaxial compression
… using various approaches based on the moment tensor decomposition components and the polarity of the AE signals. Tensile cracking was identified as the dominant mode of deformation during brittle creep experiments regardless of the applied stress. These observations are very useful to …
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Shallow and deep deformation in northern Apennines region using seismological data
… deformation has been studied using seismic moment tensors information. For our purpose we used the methods described in Arvidsson and Ekstrom (1998) that allowing the use in the inversion of surface waves [and not only of the body waves as the Centroid Moment Tensor (Dziewonski et al., 1981) …
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Retrieval of earthquake source parameters in inhomogeneous anisotropic mediawith application to swarm events in West Bohemia in 2000
… assume isotropic rock properties. By means of moment tensors, equivalent forces acting at the source are used to explain the radiated wavefield. Conversely, seismic anisotropy, i.e. directional dependence of elastic properties, has been observed in the earth's crust and mantle such as in West …