Monitoring volcanic and geothermal areas by full seismic moment tensor inversion: are non-double-couple components always artefacts of modelling?

Panza, G. F.; Saraò, Angela

doi:10.1046/j.1365-246x.2000.01250.x

Cited by 66 publications

(50 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Mislocation of the hypocentre and the use of an inadequate model of the medium may enlarge the error bars of the source time function by about 20%. Nevertheless, when introducing the variance due to the noise present in the data and to the modelling of the Green's functions, the error analysis SILENY, 1998) indicates the level of reliability of the solutions (PANZA and SARAO`, 2000). On the other hand if the percentage of non-double-couple components can be affected by systematic errors due to poor structural modeling, when looking at data sharing similar paths in the same area, their variation and the observed trend are free from such a shortcoming (SARAO`et al, 2001).…”

Section: Earthquake Source Processesmentioning

confidence: 99%

“…The solutions are stable even when few stations are used (SILENY et al, 1992). Indeed for the determination of the six independent components of the moment tensor in time domain, the six independent data are obtained from P, SV and SH arrivals at two stations (e.g., STUMP and JOHNSON, 1977;PANZA and SARAO`, 2000) and two three-component stations or three vertical component stations, are mathematically sufficient, to solve the moment tensor components.…”

Section: Earthquake Source Processesmentioning

confidence: 99%

See 1 more Smart Citation

Three Decades of Seismic Activity at Mt. Vesuvius: 1972?2000

Natale

Kuznetzov

Kronrod

et al. 2004

Pure and Applied Geophysics

View full text Add to dashboard Cite

We analyse the seismic catalogue of the local earthquakes which occurred at SommaVesuvius volcano in the past three decades . The seismicity in this period can be described as composed of a background level, characterised by a low and rather uniform rate of energy release and by sporadic periods of increased seismic activity. Such relatively intense seismicity periods are characterised by energy rates and magnitudes progressively increasing in the critical periods. The analysis of the b value in the whole period evidences a well-defined pattern, with values of b progressively decreasing, from about 1.8 at the beginning of the considered period, to about 1.0 at present. This steady variation indicates an increasing dynamics in the volcanic system. Within this general trend it is possible to identify a substructure in the time sequence of the seismic events, formed by the alternating episodes of quiescence and activity. The analysis of the source moment tensor of the largest earthquakes shows that the processes at the seismic source are generally not consistent with simple double-couples, but that they are compatible with isotropic components, mostly indicating volumetric expansion. These components are shown to be statistically significant for most of the analysed events. Such focal mechanisms can be interpreted as the effect of explosion phenomena, possibly related to volatile exsolution from the crystallising magma.The availability of a reduced amount of high quality data necessary for the inversion of the source moment tensor, the still limited period of systematic observation of Vesuvius micro-earthquakes and, above all, the absence of eruptive events during such interval of time, cannot obviously permit the outlining of any formal premonitory signal. Nevertheless, the analysis reported in this paper indicates a progressively evolving dynamics, characterised by a generally increasing trend in the seismic activity in the volcanic system and by a significant volumetric component of recent major events, thus posing serious concern for a future evolution towards eruptive activity.

show abstract

Section: Earthquake Source Processesmentioning

confidence: 99%

Section: Earthquake Source Processesmentioning

confidence: 99%

Three Decades of Seismic Activity at Mt. Vesuvius: 1972?2000

Natale

Kuznetzov

Kronrod

et al. 2004

Pure and Applied Geophysics

View full text Add to dashboard Cite

show abstract

“…The resolved MTs are typically decomposed into volumetric and deviatoric components, using various decomposition schemes allowing for an understanding of the detailed physical kinematic source processes, regardless of the type of seismicity and event magnitude. The MT inversion has been applied to resolve the displacements in the source for large and small natural earthquakes (Vavryčuk et al, 2008;Scognamiglio et al, 2010;, induced microseismicity (Ross et al, 1996;Panza and Saraò, 2000;Šílený and Milev, 2006;Cesca et al, 2013;Guilhem et al, 2014;Johnson, 2014a,b), as well as for acoustic emission activity measured in situ (Manthei et al, 2001;Collins et al, 2002) or in laboratory experiments on rocks samples (Sellers et al, 2003;Thompson et al, 2009;Graham et al, 2010;Charalampidou et al, 2011;Kwiatek, Goebel, and Dresen, 2014). The analysis of seismic MTs sheds light on numerous issues of earthquake physics, such as rupture dynamics (McGarr and Fletcher, 2003;McGarr et al, 2010), fault complexity (McLaskey and Glaser, 2011;McGarr, 2012), the role of pore pressure in seismogenic processes (Fischer and Guest, 2011), and damage-related radiation of seismic energy (Ben-Zion and Ampuero, 2009;Castro and Ben-Zion, 2013, among others).…”

Section: Introductionmentioning

confidence: 99%

HybridMT: A MATLAB/Shell Environment Package for Seismic Moment Tensor Inversion and Refinement

Kwiatek

Martínez‐Garzón

Bohnhoff

2016

Seismological Research Letters

View full text Add to dashboard Cite

We present the software package hybridMT which allows performing seismic moment tensor inversion and refinement, optimized for earthquake data recorded by regional-to-local seismic networks as well as for acoustic emission activity. The provided software package is designed predominantly for use in MATLAB (see Data and Resources)/shell environments. The algorithm uses first P-wave amplitudes to invert for unconstrained full, deviatoric, and double-couple constrained moment tensors. Uncertainty assessment is performed by bootstrap resampling. The moment tensor inversion may be performed directly in the shell environment (by a dedicated command-line tool) or conveniently through the MATLAB interface (m-functions). In addition to moment tensor inversion, we also provide the MATLAB implementation of the hybrid moment tensor technique. This methodology increases the quality of calculated seismic moment tensors from events forming a spatial cluster by assessing and correcting for poorly known path and site effects. We tested hybridMT on synthetic datasets, acoustic emission data recorded during laboratory rock deformation experiments, and induced seismicity data from a geothermal reservoir. The package is supplemented with extensive documentation, tutorials, and a dedicated website. HybridMT is freely available and distributed under General Public License.

show abstract

“…Several procedures have been proposed to estimate the focal mechanism of low-magnitude earthquakes by using high-frequency seismograms recorded at local stations (e.g. Šílený et al 1992;Mao et al 1994;Panza & Sarao 2000;Sarao et al 2001;Vavryčuk & Kühn 2012).…”

mentioning

confidence: 99%

Probabilistic waveform inversion for 22 earthquake moment tensors in Hungary: new constraints on the tectonic stress pattern inside the Pannonian basin

Wéber¹

2015

Geophysical Journal International

View full text Add to dashboard Cite

S U M M A R YWe have successfully estimated the full moment tensors of 22 local earthquakes with local magnitude ranging from 1.2 to 4.8 that occurred in the Hungarian part of the Pannonian basin between 1995 and 2014. We used a probabilistic waveform inversion procedure that takes into account the effects of the random noise contained in the seismograms, the uncertainty of the hypocentre determined from arrival times and the inaccurate knowledge of the velocity structure, while estimating the error affecting the derived focal parameters. The applied probabilistic approach maps the posterior probability density functions (PPDFs) for both the hypocentral coordinates and the moment tensor components. The final estimates are given by the maximum likelihood points of the PPDFs, while solution uncertainties are presented by histogram plots. The estimated uncertainties in the moment tensor components are plotted on the focal sphere in such a way, that the significance of the double couple (DC), the compensated linear vector dipole (CLVD) and the isotropic (ISO) parts of the source can be assessed. We have shown that the applied waveform inversion method is equally suitable to recover the source mechanism for low-magnitude events using short-period local waveforms as well as for moderate-size earthquakes using long-period seismograms. The non-DC components of the retrieved focal mechanisms are statistically insignificant for all the analysed earthquakes. The negligible amount of the ISO component implies the tectonic nature of the investigated events. The moment tensor solutions reported by other agencies for five of the M L > 4 earthquakes studied in this paper are very similar to those calculated by the applied waveform inversion algorithm. We have found only strike-slip and thrust faulting events, giving further support to the hypothesis that the Pannonian basin is currently experiencing a compressional regime of deformation. The orientations of the obtained focal mechanisms are in good agreement with the main stress pattern published for the Pannonian region. The azimuth of the subhorizontal P principal axis varies from about NNE-SSW in SW Hungary through NE-SW well inside the basin to around E-W in the NE part of the country. Most of the analysed earthquakes occurred on faults or subfaults differently oriented than the main fault system.

show abstract

Monitoring volcanic and geothermal areas by full seismic moment tensor inversion: are non-double-couple components always artefacts of modelling?

Cited by 66 publications

References 23 publications

Three Decades of Seismic Activity at Mt. Vesuvius: 1972?2000

Three Decades of Seismic Activity at Mt. Vesuvius: 1972?2000

HybridMT: A MATLAB/Shell Environment Package for Seismic Moment Tensor Inversion and Refinement

Probabilistic waveform inversion for 22 earthquake moment tensors in Hungary: new constraints on the tectonic stress pattern inside the Pannonian basin

Contact Info

Product

Resources

About