Modeling of source parameters and moment tensors of local earthquakes occurring in the eastern Indian shield

2017 ◽  
Vol 89 (6) ◽  
pp. 619-630 ◽  
Author(s):  
Koushik Biswas ◽  
Prantik Mandal
Keyword(s):  
Source Parameters ◽  
Indian Shield ◽  
Moment Tensors ◽  
Local Earthquakes

Source parameters and focal mechanisms of local earthquakes: Single broadband observatory at ISM Dhanbad

2009 ◽  
Vol 74 (3) ◽  
pp. 413-419 ◽  
Author(s):  
J. R. Kayal ◽  
V. K. Srivastava ◽  
S. N. Bhattacharya ◽  
P. K. Khan ◽  
Rima Chatterjee
Keyword(s):  
Source Parameters ◽  
Focal Mechanisms ◽  
Local Earthquakes

scholarly journals SOURCE PARAMETERS of STRONG EARTHQUAKES OCCURRED in the BAIKAL REGION and TRANSBAIKALIA in 2015

2021 ◽  
pp. 217-225
Author(s):  
A. Filippova ◽  
N. Gileva
Keyword(s):  
Baikal Region ◽  
Source Parameters ◽  
Seismic Hazard Assessment ◽  
Normal Fault ◽  
Baikal Rift Zone ◽  
Body Waves ◽  
Small Scale ◽  
Seismic Events ◽  
Study Region ◽  
Moment Tensors

We calculated seismic moment tensors in a double-couple approximation (focal mechanisms, scalar seismic moments, and moment magnitudes) and hypocentral depths for twenty earthquakes with Mw≥4.2 that occurred in the Baikal region and Transbaikalia in 2015. The initial data were amplitude spectra of Rayleigh and Love waves obtained from their records at the broadband seismic stations of the IRIS and the DK networks and first-motion polarities of body waves recorded at regional distances. A combination of the normal fault and strike-slip movements dominate in the sources of the major part of the study earthquakes. For the strongest of the considered seismic events (Mw≥4.6), the subvertical compression and subhorizontal tension in the SE-NW direction prevail, i.e. the tension is perpendicular to the main structures of the Baikal rift zone. The seismic events with Mw<4.6 are characterized by a more scattered orientation of compression and tension axis that could be caused, for instance, by stress redistribution in small-scale crustal blocks after stronger earthquakes. The obtained results are of great value for issues concerned with seismic hazard assessment and the development of geodynamical models of the lithosphere evolution of the study region.

Seismic Source Processes of 25 Earthquakes (Mw>5) in the Gulf of California

2022 ◽  
Author(s):  
Eduardo Huesca-Pérez ◽  
Edahí Gutierrez-Reyes ◽  
Luis Quintanar
Keyword(s):  
Gulf Of California ◽  
Moment Tensor ◽  
Source Parameters ◽  
Seismic Source ◽  
Focal Mechanisms ◽  
Process Models ◽  
Moment Tensors ◽  
Time Space ◽  
Double Couple ◽  
Broadband Seismograms

ABSTRACT The Gulf of California (GoC) is a complex tectonic boundary that has been instrumented in the past several decades to record broadband seismograms. This volume of data has allowed us to study several source parameters systematically. Before, only a few source parameters of earthquakes greater than magnitude five had been studied in the GoC area. We re-examined the focal mechanisms of several earthquakes in the southern GoC that occurred over the last 20 yr using local–regional distance broadband seismograms. These focal mechanisms were then used as input data to retrieve the time–space history of the rupture for each earthquake. This work contributes to the study of 25 rupture-process models computed with the method proposed by Yagi et al. (1999). To investigate more about the nature of the seismicity in the GoC, we also calculated the non-double-couple component of moment tensors for 45 earthquakes. Previous studies (e.g., Ortega et al., 2013, 2016) have shown that non-double-couple components from moment tensors in this region are associated with complex faulting, suggesting that oblique faults or several parallel faults are interacting simultaneously. Our results show that, at least for moderate earthquakes (5 &lt; M &lt; 6), rupture processes in the GoC show a complex interaction between fault systems. It is revealed on the important contribution of non-double-couple component obtained in the full moment tensor analysis.

Estimation of source parameters of local earthquakes in the environs of Koldam site

2013 ◽  
Vol 8 (1) ◽  
pp. 227-238 ◽  
Author(s):  
Vinod Paidi ◽  
Ashwani Kumar ◽  
S. C. Gupta ◽  
Arjun Kumar
Keyword(s):  
Source Parameters ◽  
Local Earthquakes

Seismicity and source parameters of local earthquakes in Bilaspur region of Himachal Lesser Himalaya

2013 ◽  
Vol 7 (6) ◽  
pp. 2257-2267 ◽  
Author(s):  
Ashwani Kumar ◽  
Arjun Kumar ◽  
S. C. Gupta ◽  
A. K. Jindal ◽  
Vandana Ghangas
Keyword(s):  
Source Parameters ◽  
Lesser Himalaya ◽  
Local Earthquakes ◽  
Himachal Lesser Himalaya

Optimization of the fault plane and coseismic slip from tide-gauge data for the 2nd May 2020 Ierapetra, Crete, Earthquake (Mw 6.6) and the associated tsunami

2021 ◽  
Author(s):  
Enrico Baglione ◽  
Alessandro Amato ◽  
Beatriz Brizuela ◽  
Hafize Basak Bayraktar ◽  
Stefano Lorito ◽  
...  
Keyword(s):  
Tide Gauge ◽  
Moment Tensor ◽  
A Priori ◽  
Source Parameters ◽  
Early Warning Systems ◽  
Tsunami Source ◽  
Coseismic Slip ◽  
Moment Tensors ◽  
Tsunami Early Warning ◽  
Oblique Convergence

&lt;p&gt;We present a tsunami source solution for the 2nd May 2020, Mw 6.6 earthquake that occurred about 80 km offshore south of Crete on the shallow portion of the Hellenic Arc Subduction Zone (HASZ). This earthquake generated a small local tsunami recorded by the Ierapetra tide gauge on Crete island's southern coast. We used these single-marigram data to constrain the main features of the causative rupture. We modelled synthetic tsunami waveforms and measured their misfits with the observed data for each set of source parameters, scanned systematically around the values constrained by some of the available moment tensors.&lt;/p&gt;&lt;p&gt;In the attempts to discriminate between the two auxiliary fault planes of the moment tensor solutions, our results identify a shallow highly-dipping back-thrust fault as the source of this earthquake with the lower misfit. However, a rupture on a lower angle fault, possibly a splay fault of the subduction interface, with a sinistral component due to the oblique convergence on this segment of the HASZ, cannot be ruled out.&lt;/p&gt;&lt;p&gt;These results are relevant in the framework of the tsunami hazard assessments and Tsunami Early Warning Systems. In these frameworks, in addition to the subduction interface and possible ruptures on splay faults, other rupture types, such as those on secondary structures of the considered subduction system, cannot be excluded a priori. This circumstance bears important consequences because, as well as splay faulting, back thrust faulting might enhance the tsunamigenic potential where the subduction itself is less tsunamigenic due to the oblique convergence.&lt;/p&gt;

Spectral source parameters for weak local earthquakes in the Pannonian basin

2010 ◽  
Vol 2 (4) ◽  
Author(s):  
Bálint Süle
Keyword(s):  
Stress Drop ◽  
Seismic Moment ◽  
Pannonian Basin ◽  
Source Parameters ◽  
Active Regions ◽  
P Wave ◽  
Local Earthquakes ◽  
Scaling Relationship ◽  
Dynamic Source ◽  
Relationship Of

AbstractDynamic source parameters are estimated from P-wave displacement spectra for 18 local earthquakes (1.2 < ML < 3.7) that occurred in two seismically active regions of Hungary between 1995 and 2004. Although the geological setting of the two areas is quite different, their source parameters cannot be distinguished. The source dimensions range from 200 to 900 m, the seismic moment from 6.3x1011 to 3.48×1014 Nm, the stress drop from 0.13 to 6.86 bar, and the average displacement is less than 1 cm for all events. The scaling relationship between seismic moment and stress drop indicates a decrease in stress drop with decreasing seismic moment. A linear relationship of M w = 0.71 M L + 0.92 is obtained between local magnitude and moment magnitude.

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