Fault dip angle determination with the ℛ criterion and coulomb stress changes associated with the 2015 M 7.9 Gorkha Nepal earthquake revealed by InSAR and GPS data

In April 2015, a M7.8 earthquake occurred less than one month before a M7.3 earthquake near Kodari, Nepal. The Nepal earthquake sequences also include four larger (M > 6) aftershocks. To reveal the interrelation between the main shock and the aftershocks, we check the role of coseismic coulomb stress triggering on aftershocks that follow the M7.8 main shock. Based on the focal mechanisms of the aftershocks and source models of the main shock, the coulomb failure stress changes on both of the focal mechanism nodal planes are calculated. In addition, the coulomb stress changes on the focal sources of each aftershock are also calculated. A large proportion of the M > 6 aftershocks occurred in positive coulomb stress areas triggered by the M7.8 main shock. The secondary triggering effect of the M7.3 aftershock is also found in this paper. More specifically, the M7.3 aftershock promoted failure on the rupture plane of the M6.3 aftershock. Therefore, we may conclude that the majority of larger aftershocks, which accumulated positive coulomb stress changes during the sequence, were promoted or triggered by the main shock failure. It suggests that coulomb stress triggering contributed to the evolution of the Nepal M7.8 earthquake sequence.

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Investigation of Coulomb stress changes in south Tibet (central Himalayas) due to the 25th April 2015 M W 7.8 Nepal earthquake using a Coulomb stress transfer model

Earthquake Science ◽

10.1007/s11589-016-0163-2 ◽

2016 ◽

Vol 29 (5) ◽

pp. 271-279

Author(s):

Xu Cheng ◽

Guojie Meng

Keyword(s):

Stress Transfer ◽

Coulomb Stress ◽

Transfer Model ◽

Central Himalayas ◽

Coulomb Stress Changes ◽

Nepal Earthquake ◽

Stress Changes ◽

South Tibet

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ANALYSING POST-SEISMIC DEFORMATION OF IZMIT EARTHQUAKE WITH INSAR, GNSS AND COULOMB STRESS MODELLING

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsarchives-xli-b1-417-2016 ◽

2016 ◽

Vol XLI-B1 ◽

pp. 417-421 ◽

Cited By ~ 1

Author(s):

R. Alac Barut ◽

J. Trinder ◽

C. Rizos

Keyword(s):

Measurement Techniques ◽

Satellite System ◽

Northern Region ◽

Strike Slip ◽

Coulomb Stress ◽

North West ◽

Coulomb Stress Changes ◽

Izmit Earthquake ◽

The North ◽

Stress Changes

On August 17<sup>th</sup> 1999, a M<sub>w</sub> 7.4 earthquake struck the city of Izmit in the north-west of Turkey. This event was one of the most devastating earthquakes of the twentieth century. The epicentre of the Izmit earthquake was on the North Anatolian Fault (NAF) which is one of the most active right-lateral strike-slip faults on earth. However, this earthquake offers an opportunity to study how strain is accommodated in an inter-segment region of a large strike slip fault. In order to determine the Izmit earthquake post-seismic effects, the authors modelled Coulomb stress changes of the aftershocks, as well as using the deformation measurement techniques of Interferometric Synthetic Aperture Radar (InSAR) and Global Navigation Satellite System (GNSS). The authors have shown that InSAR and GNSS observations over a time period of three months after the earthquake combined with Coulomb Stress Change Modelling can explain the fault zone expansion, as well as the deformation of the northern region of the NAF. It was also found that there is a strong agreement between the InSAR and GNSS results for the post-seismic phases of investigation, with differences less than 2mm, and the standard deviation of the differences is less than 1mm.

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Multi-Segment Rupture Model of the 2016 Kumamoto Earthquake Revealed by InSAR and GPS Data

Remote Sensing ◽

10.3390/rs12223721 ◽

2020 ◽

Vol 12 (22) ◽

pp. 3721

Author(s):

Zhongqiu He ◽

Ting Chen ◽

Mingce Wang ◽

Yanchong Li

Keyword(s):

Field Investigation ◽

Slip Distribution ◽

Distribution Model ◽

Coseismic Deformation ◽

Gps Data ◽

Coulomb Stress ◽

2016 Kumamoto Earthquake ◽

Kumamoto Earthquake ◽

The 2016 Kumamoto Earthquake ◽

Stress Changes

The 2016 Kumamoto earthquake, including two large (Mw ≥ 6.0) foreshocks and an Mw 7.0 mainshock, occurred in the Hinagu and Futagawa fault zones in the middle of Kyushu island, Japan. Here, we obtain the complex coseismic deformation field associated with this earthquake from Advanced Land Observation Satellite-2 (ALOS-2) and Sentinel-1A Interferometric Synthetic Aperture Radar (InSAR) data. These InSAR data, in combination with available Global Positioning System (GPS) data, are then used to determine an optimal four-segment fault geometry with the jRi method, which considers both data misfit and the perturbation error from data noise. Our preferred slip distribution model indicates that the rupture is dominated by right-lateral strike-slip, with a significant normal slip component. The largest asperity is located on the northern segment of the Futagawa fault, with a maximum slip of 5.6 m at a 5–6 km depth. The estimated shallow slips along the Futagawa fault and northern Hinagu fault are consistent with the displacements of surface ruptures from the field investigation, suggesting a shallow slip deficit. The total geodetic moment release is estimated to be 4.89 × 1019 Nm (Mw 7.09), which is slightly larger than seismological estimates. The calculated static Coulomb stress changes induced by the preferred slip distribution model cannot completely explain the spatial distribution of aftershocks. Sensitivity analysis of Coulomb stress change implies that aftershocks in the stress shadow area may be driven by aseismic creep or triggered by dynamic stress transfer, requiring further investigation.

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The Stress Triggering of Aftershocks by Badong M5.1 Mainshock from Coulomb Stress Changes

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.971-973.2172 ◽

2014 ◽

Vol 971-973 ◽

pp. 2172-2175

Author(s):

Dong Ning Lei ◽

Jian Chao Wu ◽

Yong Jian Cai

Keyword(s):

Stress Change ◽

Coulomb Stress ◽

Coulomb Stress Change ◽

Coulomb Stress Changes ◽

Stress Changes ◽

Stress Triggering

TheCoulomb stress changes are usually adopted to make analysis on faultinteractions and stress triggering. This paper mainly deals with Coulomb stresschange of mainshock and affect on aftershocks. We preliminarily conclude thatthe mainshock produce Coulomb stress change on aftershocks most behavingpositive and triggered them. By calculating it is obvious that more aftershocksfell into stress increasing area and triggering percentage is up to ninety ofmaximum and seventy-one of minimum.

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