scholarly journals Grid-Based Moment Tensor Inversion Technique by Using 3-D Green’s Functions Database: A Demonstration of the 23 October 2004 Taipei Earthquake

2010 ◽  
Vol 21 (3) ◽  
pp. 503 ◽  
Author(s):  
Shiann-Jong Lee ◽  
Bor-Shouh Huang ◽  
Wen-Tzong Liang ◽  
Kou-Cheng Chen
2021 ◽  
Vol 9 ◽  
Author(s):  
Yuanhang Huo ◽  
Wei Zhang ◽  
Jie Zhang

The MW 5.7 Changning earthquake occurred in southern Sichuan basin on 17 June 2019 and was the largest event ever recorded in this region. There are still some arguments existing about the causes of the earthquake and its possible links with water injections. Many studies on this earthquake have been performed, but the event depths obtained among them are significantly different and the source mechanisms also exhibit variations. In this study, we design an inversion scheme and use 3D Green’s functions considering the rugged topography of this region to determine the event location and moment tensor of the Changning earthquake based on waveform fittings. The 3D model can reduce the uncertainty due to the approximation of 1D model and better constrain the solutions. The latitude and the longitude of event location are 28.34°N and 104.82°E respectively and the depth is 3.14 km. The nodal plane solutions are strike 295°/dip 88°/rake 14° and strike 204°/dip 76°/rake 178°. The percentages of DC, CLVD and ISO components are 10, −83, and −7%, respectively. The good waveform fittings at 17 broadband stations indicate the reliability of the source mechanism in this study.


2020 ◽  
pp. 1691-1704
Author(s):  
Hasanain Jasim Mohammed ◽  
Ali M. Al-Rahim

     The study area is encompassed by the 33.59-34.93°N latitudes and 45.44-46.39°E longitudes and divided into four groups with respect to earthquake event locations. We determined fault plane solutions, moment magnitudes, focal depths, and trend of slip with the direction of the moment stress axes (P, N, and T) for 102 earthquakes. These earthquakes had a local magnitude in the range between 4.0 and 6.4 for the time period from January 2018 to the end of August 2019, with focal depths ranged between 6 and 17 km. Waveform moment tensor inversion technique was used to analyze the database constructed from seismic stations on local and neighboring country networks (Iraq, Iran, and Turkey). We separated the studied events into four regional subsets (circles). The types of the obtained fault plane solutions are predominantly thrust fault and strike-slip, with the focal depths ranging from 8 to 21 km.      A new scaling relation between local magnitude (Ml) and the estimated moment magnitude (Mw) has been developed utilizing a linear regression. Good match results obtained in the present research good match with both seismic trends concluded from earthquake locations and mapped faults. Generally, direction shows NW–SE striking focal planes corresponding with the tectonic framework of the Arabian–Eurasian continental collision zone. The anticlockwise rotation of the Arabian plate that appears accountable for strike-slip displacements on fault surfaces.


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