Estimation of Earthquake Source Parameters in the Kachchh Seismic Zone, Gujarat, India, from Strong-Motion Network Data Using a Generalized Inversion Technique

2011 ◽  
Vol 101 (4) ◽  
pp. 1719-1731 ◽  
Author(s):  
P. Mandal ◽  
U. Dutta
Keyword(s):  
Source Parameters ◽  
Strong Motion ◽  
Earthquake Source ◽  
Network Data ◽  
Seismic Zone ◽  
Inversion Technique ◽  
Generalized Inversion ◽  
Earthquake Source Parameters ◽  
Generalized Inversion Technique ◽  
Strong Motion Network

Non-parametric spectral modelling of source parameters, path attenuation and site effects from broad-band waveforms of the Alborz earthquakes (2005–2017)

2019 ◽  
Vol 219 (3) ◽  
pp. 1514-1531
Author(s):  
Somayeh Ahmadzadeh ◽  
G Javan Doloei ◽  
Stefano Parolai ◽  
Adrien Oth
Keyword(s):  
Source Parameters ◽  
Broad Band ◽  
Site Amplification ◽  
Earthquake Source ◽  
Frequency Range ◽  
S Wave ◽  
Magnitude Range ◽  
Earthquake Source Parameters ◽  
Generalized Inversion Technique ◽  
Non Parametric

SUMMARY S-wave spectral amplitudes from 312 crustal earthquakes recorded at the Iranian National Broadband Seismic Network in the Alborz region between 2005 and 2017 are analysed in order to evaluate earthquake source parameters, path attenuation and site amplification functions using the non-parametric generalized inversion technique (GIT). We exploit a total number of 1117 seismograms with ML 3–5.6 in the frequency range 0.3–20 Hz. The evaluated non-parametric attenuation functions decay uniformly with distance for the entire frequency range and the estimated S-wave quality factor shows low Q values with relatively strong frequency dependence. We assume the omega-square source model to retrieve earthquake source parameters from the inverted source spectra. The obtained stress drops range from 0.02 to 16 MPa with a mean value of 1.1 MPa. Stress drop and radiated energy show fairly self-similar scaling with seismic moment over the available magnitude range; however, the magnitude range of this study is too narrow to draw a definite conclusion on source scaling characteristics. The obtained moment magnitude Mw and the local magnitude ML are linearly correlated and approximately equivalent in the range of Mw 3–4. For larger events, Mw generally underestimates ML by about 0.1–0.5 magnitude units. The estimated site amplification functions for horizontal component (GIT H) are nearly flat with no obvious pre-dominant frequency peaks for most stations, as expected for the sites of permanent broad-band seismic stations located on rock, though a few stations show amplification peaks from 1 to 8 Hz, with a maximum amplification of about a factor of 7 with respect to the reference site. The evaluated site responses for the vertical components present remarkable amplification or deamplification, leading to differences of the H/V amplitude levels in comparison with the GIT H amplification curves. The results of this study provide a valuable basis for predicting appropriate ground motions in a context of seismic hazard assessment.

scholarly journals Teleseismic body wave inversion

2018 ◽  
Vol 40 (3) ◽  
pp. 1177
Author(s):  
A. Moshou ◽  
P. Papadimitriou ◽  
K. Makropoulos
Keyword(s):  
Body Wave ◽  
Moment Tensor ◽  
Source Parameters ◽  
Singular Value Decomposition Method ◽  
Wave Inversion ◽  
Generalized Inversion ◽  
Earthquake Source Parameters ◽  
Generalized Inversion Technique ◽  
Double Couple ◽  
Value Decomposition

Body wave inversion methodology is developed to determine the earthquake source parameters in teleseismic distances. The generalized inversion technique, based on the singular value decomposition method, is applied to determine the deviatone moment tensor which is decomposed in two parts. The first one is related to the pure Double Couple (DC) and the second one to the compensated linear vector dipoles (CLVD). The best solution of the overdetermined problem is obtained by minimizing the misfit between observed and synthetic seismograms. The proposed methodology is applied for the four strongest earthquakes that occurred recently in Greece (2001-2006)

scholarly journals Earthquake source parameters that display the first digit phenomenon

2015 ◽  
Vol 22 (5) ◽  
pp. 625-632
Author(s):  
P. A. Toledo ◽  
S. R. Riquelme ◽  
J. A. Campos
Keyword(s):  
Seismic Moment ◽  
Waiting Times ◽  
Source Parameters ◽  
Tohoku Earthquake ◽  
Earthquake Source ◽  
Coseismic Slip ◽  
Self Organized ◽  
Earthquake Source Parameters ◽  
Self Organized Criticality

Abstract. We study the main parameters of earthquakes from the perspective of the first digit phenomenon: the nonuniform probability of the lower first digit different from 0 compared to the higher ones. We found that source parameters like coseismic slip distributions at the fault and coseismic inland displacements show first digit anomaly. We also found the tsunami runups measured after the earthquake to display the phenomenon. Other parameters found to obey first digit anomaly are related to the aftershocks: we show that seismic moment liberation and seismic waiting times also display an anomaly. We explain this finding by invoking a self-organized criticality framework. We demonstrate that critically organized automata show the first digit signature and we interpret this as a possible explanation of the behavior of the studied parameters of the Tohoku earthquake.

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