scholarly journals Fault Slip Model of the 2018 Mw 6.6 Hokkaido Eastern Iburi, Japan, Earthquake Estimated from Satellite Radar and GPS Measurements

2019 ◽  
Vol 11 (14) ◽  
pp. 1667 ◽  
Author(s):  
Zelong Guo ◽  
Yangmao Wen ◽  
Guangyu Xu ◽  
Shuai Wang ◽  
Xiaohang Wang ◽  
...  
Keyword(s):  
Source Parameters ◽  
Fault Slip ◽  
Slip Distribution ◽  
Coseismic Deformation ◽  
Gps Data ◽  
Nonlinear Inversion ◽  
Slip Model ◽  
Seismogenic Fault ◽  
Geometry Model ◽  
Fault Slip Distribution

In this study, Sentinel-1 and Advanced Land Observation Satellite-2 (ALOS-2) interferometric synthetic aperture radar (InSAR) and global positioning system (GPS) data were used to jointly determine the source parameters and fault slip distribution of the Mw 6.6 Hokkaido eastern Iburi, Japan, earthquake that occurred on 5 September 2018. The coseismic deformation map obtained from the ascending and descending Sentinel-1 and ALOS-2 InSAR data and GPS data is consistent with a thrust faulting event. A comparison between the InSAR-observed and GPS-projected line-of-sight (LOS) deformation suggests that descending Sentinel-1 track T046D, descending ALOS-2 track P018D, and ascending ALOS-2 track P112A and GPS data can be used to invert for the source parameters. The results of a nonlinear inversion show that the seismogenic fault is a blind NNW-trending (strike angle ~347.2°), east-dipping (dip angle ~79.6°) thrust fault. On the basis of the optimal fault geometry model, the fault slip distribution jointly inverted from the three datasets reveals that a significant slip area extends 30 km along the strike and 25 km in the downdip direction, and the peak slip magnitude can approach 0.53 m at a depth of 15.5 km. The estimated geodetic moment magnitude released by the distributed slip model is 6.16   × 10 18   N · m , equivalent to an event magnitude of Mw 6.50, which is slightly smaller than the estimates of focal mechanism solutions. According to the Coulomb stress change at the surrounding faults, more attention should be paid to potential earthquake disasters in this region in the near future. In consideration of the possibility of multi-fault rupture and complexity of regional geologic framework, the refined distributed slip and seismogenic mechanism of this deep reverse faulting should be investigated with multi-disciplinary (e.g., geodetic, seismic, and geological) data in further studies.

scholarly journals Fault slip distribution of the 2014 Iquique, Chile, earthquake estimated from ocean-wide tsunami waveforms and GPS data

2015 ◽  
Vol 42 (4) ◽  
pp. 1053-1060 ◽  
Author(s):  
Aditya Riadi Gusman ◽  
Satoko Murotani ◽  
Kenji Satake ◽  
Mohammad Heidarzadeh ◽  
Endra Gunawan ◽  
...  
Keyword(s):  
Fault Slip ◽  
Slip Distribution ◽  
Gps Data ◽  
Chile Earthquake ◽  
Tsunami Waveforms ◽  
Fault Slip Distribution

scholarly journals Source Model and Stress Disturbance of the 2017 Jiuzhaigou Mw 6.5 Earthquake Constrained by InSAR and GPS Measurements

2018 ◽  
Vol 10 (9) ◽  
pp. 1400 ◽  
Author(s):  
Shunying Hong ◽  
Xin Zhou ◽  
Kui Zhang ◽  
Guojie Meng ◽  
Yanfang Dong ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Source Model ◽  
Descent Method ◽  
Slip Distribution ◽  
Steepest Descent Method ◽  
Nonlinear Inversion ◽  
Fault Geometry ◽  
Seismogenic Fault ◽  
Jiuzhaigou Earthquake ◽  
Geometry Model

Seismogenic fault geometry, especially for a blind fault, is usually difficult to derive, based only on the distribution of aftershocks and interference fringes of Interferometric Synthetic Aperture Radar (InSAR). To better constrain the fault geometry of the 2017 Jiuzhaigou Mw 6.5 earthquake, we first carried out a nonlinear inversion for a single fault source using multi-peak particle swarm optimization (MPSO), Monte Carlo (MC), and Markov Chain Monte Carlo (MCMC) algorithms, respectively, with constraints of InSAR data in multiple SAR viewing geometries. The fault geometry models retrieved with different methods were highly consistent and mutually verifiable, showing that a blind faulting with a strike of ~154° and a dip angle of ~77° was responsible for the Jiuzhaigou earthquake. Based on the optimal fault geometry model, the fault slip distribution jointly inverted from the InSAR and Global Positioning System (GPS) data by the steepest descent method (SDM) and the MC method showed that the slip was mainly concentrated at the depth of 1–15 km, and only one slip center appeared at the depth of 5–9 km with a maximum slip of about 1.06 m, some different from previous studies. Taking the shear modulus of μ = 32 GPa, the seismic moment derived from the distributed slip model was about 7.85 × 1018 Nm, equivalent to Mw 6.54, which was slightly larger than that from the focal mechanism solutions. The fault spatial geometry and slip distribution could be further validated with the spatial patterns of the immediate aftershocks. Most of the off-fault aftershocks with the magnitude > M2 within one year after the mainshock occurred in the stress positive stress change area, which coincided with the stress triggering theory. The static Coulomb stress, triggered by the mainshock, significantly increased at the Tazang fault (northwest to the epicenter), and at the hidden North Huya fault, and partial segments of the Minjiang fault (west of the epicenter).

FAULT SLIP DISTRIBUTION ALONG THE SOUTHERN 15 KM OF THE M7.1 RIDGECREST EARTHQUAKE SURFACE RUPTURE

2020 ◽  
Author(s):  
Sinan O. Akciz ◽  
◽  
Salena Padilla ◽  
James F. Dolan ◽  
Alex E. Hatem
Keyword(s):  
Fault Slip ◽  
Slip Distribution ◽  
Surface Rupture ◽  
Fault Slip Distribution

scholarly journals Coseismic fault-slip distribution of the 2019 Ridgecrest Mw6.4 and Mw7.1 earthquakes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yang Gao ◽  
HuRong Duan ◽  
YongZhi Zhang ◽  
JiaYing Chen ◽  
HeTing Jian ◽  
...  
Keyword(s):  
Strike Slip ◽  
Fault Slip ◽  
Slip Distribution ◽  
Synthetic Aperture ◽  
Seismic Events ◽  
Interferometric Synthetic Aperture Radar ◽  
The Past ◽  
Dextral Strike Slip Fault ◽  
Fault Slip Distribution ◽  
Dextral Strike Slip

AbstractThe 2019 Ridgecrest, California seismic sequence, including an Mw6.4 foreshock and Mw7.1 mainshock, represent the largest regional seismic events within the past 20 years. To obtain accurate coseismic fault-slip distribution, we used precise positioning data of small earthquakes from January 2019 to October 2020 to determine the dip parameters of the eight fault geometry, and used the Interferometric Synthetic Aperture Radar (InSAR) data processed by Xu et al. (Seismol Res Lett 91(4):1979–1985, 2020) at UCSD to constrain inversion of the fault-slip distribution of both earthquakes. The results showed that all faults were sinistral strike-slips with minor dip-slip components, exception for dextral strike-slip fault F2. Fault-slip mainly occurred at depths of 0–12 km, with a maximum slip of 3.0 m. The F1 fault contained two slip peaks located at 2 km of fault S4 and 6 km of fault S5 depth, the latter being located directly above the Mw7.1hypocenter. Two slip peaks with maximum slip of 1.5 m located 8 and 20 km from the SW endpoint of the F2 fault were also identified, and the latter corresponds to the Mw6.4 earthquake. We also analyzed the influence of different inversion parameters on the fault slip distribution, and found that the slip momentum smoothing condition was more suitable for the inversion of the earthquakes slip distribution than the stress-drop smoothing condition.

Slip Distribution of the 2020 Mw6.9 Samos Earthquake Using a Bayesian Approach

2021 ◽  
Author(s):  
Figen Eskikoy ◽  
Semih Ergintav ◽  
Uğur Dogan ◽  
Seda Özarpacı ◽  
Alpay Özdemir ◽  
...  
Keyword(s):  
Surface Deformation ◽  
Fault Plane ◽  
Source Parameters ◽  
Geodetic Data ◽  
Slip Distribution ◽  
Double Difference ◽  
Gps Data ◽  
Analysis Tool ◽  
Finite Fault ◽  
Continuous Gps

<p>On 2020 October 30, an M<sub>w</sub>6.9 earthquake struck offshore Samos Island. Severe structural damages were observed in Greek Islands and city of Izmir (Turkey). 114 people lost their lives and more than a thousand people were injured in Turkey. The earthquake triggered local tsunami. Significant seismic activity occurred in this region following the earthquake and ~1800 aftershocks (M>1) were recorded by KOERI within the first three days. In this study, we analyze the slip distribution and aftershocks of the 2020 earthquake.</p><p>For the aftershock relocations, the continuous waveforms were collected from NOA, Disaster and Emergency Management Authority of Turkey (AFAD) and KOERI networks. The database   was created based on merged catalogs from AFAD and KOERI. For estimating optimized aftershock location distribution, the P and S phases of the aftershocks are picked manually and relocated with double difference algorithm. In addition, source mechanisms of aftershocks M>4 are obtained from regional body and surface waveforms.</p><p>The surface deformation of the earthquake was obtained from both descending and ascending orbits of the Sentinel-1 A/B and ALOS2 satellites. Since the rupture zone is beneath the Gulf of Kusadası, earthquake related deformation in the interferograms can only be observed on the northern part of the Samos Island. We processed all possible pairs chose the image pairs with the lowest noise level.</p><p>In this study, we used 25 continuous GPS stations which are compiled from TUSAGA-Aktif in Turkey and NOANET in Greece. In addition to continuous GPS data, on 2020 November 1, GPS survey was initiated and the earthquake deformation was measured on 10 GNSS campaign sites (TUTGA), along onshore of Turkey.</p><p>The aim of this study is to estimate the spatial and temporal rupture evolution of the earthquake from geodetic data jointly with near field displacement waveforms. To do so, we use the Bayesian Earthquake Analysis Tool (BEAT).</p><p>As a first step of the study, rectangular source parameters were estimated by using GPS data. In order to estimate the slip distribution, we used both ascending and descending tracks of Sentinel-1 data, ALOS2 and GPS displacements. In our preliminary geodetic data based finite fault model, we used the results of focal mechanism and GPS data inversion solutions for the initial fault plane parameters. The slip distribution results indicate that earthquake rupture is ~35 km long and the maximum slip is ~2 m normal slip along a north dipping fault plane. This EW trending, ~45° north dipping normal faulting system consistent with this tectonic regime in the region. This seismically active area is part of a N-S extensional regime and controlled primarily by normal fault systems.</p><p><strong>Acknowledgements</strong></p><p>This work is supported by the Turkish Directorate of Strategy and Budget under the TAM Project number 2007K12-873.</p>

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

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.

scholarly journals Fault slip distribution and fault roughness

2011 ◽  
Vol 187 (2) ◽  
pp. 959-968 ◽  
Author(s):  
Thibault Candela ◽  
François Renard ◽  
Jean Schmittbuhl ◽  
Michel Bouchon ◽  
Emily E. Brodsky
Keyword(s):  
Fault Slip ◽  
Slip Distribution ◽  
Fault Roughness ◽  
Fault Slip Distribution

scholarly journals Coseismic Deformation and Speculative Seismogenic Fault of the 2017 MS 6.6 Jinghe Earthquake, China, Derived From Sentinel-1 Data

2021 ◽  
Vol 9 ◽  
Author(s):  
Wei Feng ◽  
Zechao Bai ◽  
Jinwei Ren ◽  
Shuaitang Huang ◽  
Lin Zhu
Keyword(s):  
European Space Agency ◽  
Image Data ◽  
Junggar Basin ◽  
Deformation Field ◽  
Slip Distribution ◽  
Coseismic Deformation ◽  
Dislocation Model ◽  
Seismogenic Fault ◽  
Geological Investigation ◽  
Maximum Deformation

A MS 6.6 earthquake struck Jinghe County in Bortala Mongol Autonomous Prefecture of Xinjiang Uygur Autonomous Region on August 9, 2017. The earthquake occurred near the eastern part of the Kusongmuxieke Piedmont Fault (KPF) in the southwest of Junggar Basin. Using two pairs of coseismic SAR image data from the ascending and descending tracks from Sentinel-1 (European Space Agency), we processed the interferograms to obtain the coseismic deformation field. We calculate the fault slip distribution of the earthquake based on the elastic half-space rectangular dislocation model with the available location, geometry from seismic data and the coseismic deformation data. The results show that the earthquake deformation field has the typical characteristics of thrust faulting. The uplift deformation field is about 28 km long and 20 km wide. The maximum displacements of InSAR line-of-sight to the ascending and descending tracks are 49 and 68 mm, respectively. The main slip is concentrated at the depth of 10–20 km. The inverted seismic moment is equivalent to a moment magnitude MW 6.3. This result is very similar to the slip distribution from the seismological inversion. The maximum deformation area and the distribution of aftershocks are both on the west side of the mainshock. They mutually confirm the characteristics of a unilateral rupture. According to stress triggering theory, the aftershocks within 1 month after the mainshock in the layer 10–14 km deep may have been triggered by the mainshock, and the transferred stress increases the seismic risk of the eastern section of the KPF fault. After more than 1 year, a MS 5.4 earthquake occurred to the southwest of the MS 6.6 Jinghe earthquake. Beacause the stress drop change (<0.01 MPa) is too small for the MS 5.4 earthquake to have been directly triggered. Based on the analysis of multisource data and the detailed geological investigation, the thrust Jinghenan fault which north of Kusongmuxieke Piedmont fault is inferred to be the seismogenic fault of the MS 6.6 Jinghe earthquake.

scholarly journals Author Correction: Coseismic fault-slip distribution of the 2019 Ridgecrest Mw6.4 and Mw7.1 earthquakes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yang Gao ◽  
HuRong Duan ◽  
YongZhi Zhang ◽  
JiaYing Chen ◽  
HeTing Jian ◽  
...  
Keyword(s):  
Fault Slip ◽  
Slip Distribution ◽  
Fault Slip Distribution
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