The Relationship between InSAR Coseismic Deformation and Earthquake-Induced Landslides Associated with the 2017 Mw 3.9 Ischia (Italy) Earthquake

We investigated the contribution of earthquake-induced surface movements to the ground displacements detected through Interferometric Synthetic Aperture Radar (InSAR) data, after the Mw 3.9 Ischia earthquake on 21 August 2017. A permanent displacement approach, based on the limit equilibrium method, allowed estimation of the spatial extent of the earthquake-induced landslides and the associated probability of failure. The proposed procedure identified critical areas potentially affected by slope movements partially overlapping the coseismic ground displacement retrieved by InSAR data. Therefore, the observed ground displacement field is the combination of both fault slip and surficial sliding caused by the seismic shaking. These findings highlight the need to perform preliminary calculations to account for the non-tectonic contributions to ground displacements before any estimation of the earthquake source geometry and kinematics. Such information is fundamental to avoid both the incorrect definition of the source geometry and the possible overestimation of the coseismic slip over the causative fault. Moreover, knowledge of the areas potentially affected by slope movements could contribute to better management of a seismic emergency, especially in areas exposed to high seismic and hydrogeological risks.

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Multifault complex rupture and afterslip associated with the 2018 Mw 6.4 Hualien earthquake in northeastern Taiwan

Geophysical Journal International ◽

10.1093/gji/ggaa474 ◽

2020 ◽

Vol 224 (1) ◽

pp. 416-434

Author(s):

Dezheng Zhao ◽

Chunyan Qu ◽

Xinjian Shan ◽

Roland Bürgmann ◽

Wenyu Gong ◽

...

Keyword(s):

Main Shock ◽

Near Field ◽

Active Faults ◽

Fault Model ◽

Body Waves ◽

Coseismic Deformation ◽

Coseismic Slip ◽

Coulomb Stress Changes ◽

Seismic Displacement ◽

Stress Changes

SUMMARY We investigate the coseismic and post-seismic deformation due to the 6 February 2018 Mw 6.4 Hualien earthquake to gain improved insights into the fault geometries and complex regional tectonics in this structural transition zone. We generate coseismic deformation fields using ascending and descending Sentinel-1A/B InSAR data and GPS data. Analysis of the aftershocks and InSAR measurements reveal complex multifault rupture during this event. We compare two fault model joint inversions of SAR, GPS and teleseismic body waves data to illuminate the involved seismogenic faults, coseismic slip distributions and rupture processes. Our preferred fault model suggests that both well-known active faults, the dominantly left-lateral Milun and Lingding faults, and previously unrecognized oblique-reverse west-dipping and north-dipping detachment faults, ruptured during this event. The maximum slip of ∼1.6 m occurred on the Milun fault at a depth of ∼2–5 km. We compute post-seismic displacement time series using the persistent scatterer method. The post-seismic range-change fields reveal large surface displacements mainly in the near-field of the Milun fault. Kinematic inversions constrained by cumulative InSAR displacements along two tracks indicate that the afterslip occurred on the Milun and Lingding faults and the west-dipping fault just to the east. The maximum cumulative afterslip of 0.4–0.6 m occurred along the Milun fault within ∼7 months of the main shock. The main shock-induced static Coulomb stress changes may have played an important role in driving the afterslip adjacent to coseismic high-slip zones on the Milun, Lingding and west-dipping faults.

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Source Model of the 2014 Mw 6.9 Yutian Earthquake at the Southwestern End of the Altyn Tagh Fault in Tibet Estimated from Satellite Images

Seismological Research Letters ◽

10.1785/0220190361 ◽

2020 ◽

Vol 91 (6) ◽

pp. 3161-3170

Author(s):

Xing Li ◽

Wenbin Xu ◽

Sigurjón Jónsson ◽

Yann Klinger ◽

Guohong Zhang

Keyword(s):

Ground Deformation ◽

Source Parameters ◽

Source Model ◽

Coseismic Slip ◽

Remote Sensing Technology ◽

Sensing Technology ◽

Altyn Tagh ◽

Coulomb Failure Stress Change ◽

Coulomb Failure ◽

Source Geometry

Abstract Multiple fault segments ruptured during the 2014 Yutian earthquake, but the detailed source parameters and the mechanism of rupture complexity remain poorly understood. Here, we use high-resolution TanDEM-X satellite data and Satellite Pour l’Observation de la Terre-6/7 images to map the coseismic ground deformation field of the event. We find that the majority of coseismic slip occurred in the upper 10 km with the maximum left-lateral fault slip of ∼2.5 m at ∼6 km depth. The fault ruptured across a large 4.5 km extensional stepover from one left-lateral fault segment to another, with some right-lateral relay faulting in between. We find that the earthquake was followed by shallow afterslip concentrating at the southwestern end of coseismic rupture, in an area of many aftershocks and positive Coulomb failure stress change. Our findings demonstrate the power of satellite remote sensing technology in constraining source geometry and slip model of complex earthquakes when ground measurements are limited.

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Triple junction kinematics accounts for the 2016 Mw7.8 Kaikoura earthquake rupture complexity

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1916770116 ◽

2019 ◽

Vol 116 (52) ◽

pp. 26367-26375 ◽

Cited By ~ 3

Author(s):

Xuhua Shi ◽

Paul Tapponnier ◽

Teng Wang ◽

Shengji Wei ◽

Yu Wang ◽

...

Keyword(s):

New Zealand ◽

Triple Junction ◽

Large Scale ◽

Strike Slip ◽

Plate Motion ◽

Fault System ◽

Coseismic Deformation ◽

Coseismic Slip ◽

Slab Geometry ◽

Kaikoura Earthquake

The 2016, moment magnitude (Mw) 7.8, Kaikoura earthquake generated the most complex surface ruptures ever observed. Although likely linked with kinematic changes in central New Zealand, the driving mechanisms of such complexity remain unclear. Here, we propose an interpretation accounting for the most puzzling aspects of the 2016 rupture. We examine the partitioning of plate motion and coseismic slip during the 2016 event in and around Kaikoura and the large-scale fault kinematics, volcanism, seismicity, and slab geometry in the broader Tonga–Kermadec region. We find that the plate motion partitioning near Kaikoura is comparable to the coseismic partitioning between strike-slip motion on the Kekerengu fault and subperpendicular thrusting along the offshore West–Hikurangi megathrust. Together with measured slip rates and paleoseismological results along the Hope, Kekerengu, and Wairarapa faults, this observation suggests that the West–Hikurangi thrust and Kekerengu faults bound the southernmost tip of the Tonga–Kermadec sliver plate. The narrow region, around Kaikoura, where the 3 fastest-slipping faults of New Zealand meet, thus hosts a fault–fault–trench (FFT) triple junction, which accounts for the particularly convoluted 2016 coseismic deformation. That triple junction appears to have migrated southward since the birth of the sliver plate (around 5 to 7 million years ago). This likely drove southward stepping of strike-slip shear within the Marlborough fault system and propagation of volcanism in the North Island. Hence, on a multimillennial time scale, the apparently distributed faulting across southern New Zealand may reflect classic plate-tectonic triple-junction migration rather than diffuse deformation of the continental lithosphere.

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Fling-step recovering from near-source waveforms and ground displacement attenuation models

10.5194/egusphere-egu2020-22285 ◽

2020 ◽

Author(s):

Maria D'Amico ◽

Erika Schiappapietra ◽

Giovanni Lanzano ◽

Sara Sgobba ◽

Francesca Pacor

Keyword(s):

Low Frequency ◽

Time History ◽

Strong Motion ◽

Response Spectra ◽

Ground Displacement ◽

Permanent Displacement ◽

Processing Scheme ◽

Long Period ◽

Fling Step ◽

Attenuation Models

We present a processing scheme (eBASCO, extended BASeline COrrection) to remove the baseline of strong-motion records by means of a piece-wise linear de-trending of the velocity time history. Differently from standard processing schemes, eBASCO does not apply any filtering to remove the low-frequency content of the signal. This approach preserves both the long-period near-source ground-motion, featured by one-side pulse in the velocity trace, and the offset at the end of the displacement trace (fling-step). Hence, the software is suitable for the identification of fling-containing strong-motion waveforms. Here, we apply eBASCO to reconstruct the ground displacement of more than 400 three-component near-source waveforms recorded worldwide (NESS1, http://ness.mi.ingv.it/; Pacor et al., 2019) with the aim of: 1) extensively testing the eBasco capability to capture the long-period content of near-source records; 2) calibrating attenuation models for peak ground displacement (PGD), 5% damped displacement response spectra (DS), permanent displacement amplitude (PD) and period (Tp). The results could provide a more accurate estimate of ground motions, to be adopted for different engineering purposes such as performance-based seismic design of structures.Pacor F., Felicetta C., Lanzano G., Sgobba S., Puglia R., D&#8217;Amico M., Russo E., Baltzopoulos G., Iervolino I. (2018). NESS v1.0: A worldwide collection of strong-motion data to investigate near source effects. Seismological Research Letters. https://doi.org/10.1785/0220180149

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COSEISMIC DEFORMATION FIELD AND FAULT SLIP DISTRIBUTION OF THE 2015 CHILE Mw8.3 EARTHQUAKE

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

10.5194/isprsarchives-xli-b7-827-2016 ◽

2016 ◽

Vol XLI-B7 ◽

pp. 827-834

Author(s):

Chunyan Qu ◽

Ronghu Zuo ◽

Xin Jian Shan ◽

Guohong Zhang ◽

Yingfeng Zhang ◽

...

Keyword(s):

Elastic Half Space ◽

Fault Slip ◽

Deformation Field ◽

Coseismic Deformation ◽

Postseismic Deformation ◽

Coseismic Slip ◽

Single Plane ◽

Rupture Length ◽

Continental Plate ◽

Before And After

On September 16, 2015, a magnitude 8.3 earthquake struck west of Illapel, Chile. We analyzed Sentinel-1A/IW InSAR data on the descending track acquired before and after the Chile Mw8.3 earthquake of 16 September 2015. We found that the coseismic deformation field of this event consists of many semi circular fringes protruding to east in an approximately 300km long and 190km wide region. The maximum coseismic displacement is about 1.33m in LOS direction corresponding to subsidence or westward shift of the ground. We inverted the coseismic fault slip based on a small-dip single plane fault model in a homogeneous elastic half space. The inverted coseismic slip mainly concentrates at shallow depth above the hypocenter with a symmetry shape. The rupture length along strike is about 340 km with maximum slip of about 8.16m near the trench. The estimated moment is 3.126×1021 N.m (Mw8.27)，the maximum depth of coseismic slip near zero appears to 50km. We also analyzed the postseismic deformation fields using four interferograms with different time intervals. The results show that postseismic deformation occurred in a narrow area of approximately 65km wide with maximum slip 11cm, and its predominant motion changes from uplift to subsidence with time. that is to say, at first, the postseismic deformation direction is opposite to that of coseismic deformation, then it tends to be consistent with coseismic deformation.It maybe indicates the differences and changes in the velocity between the Nazca oceanic plate and the South American continental plate.

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GPS observations of coseismic deformation following the 2016, August 24, Mw 6 Amatrice earthquake (central Italy): data, analysis and preliminary fault model

Annals of Geophysics ◽

10.4401/ag-7269 ◽

2016 ◽

Vol 59 ◽

Author(s):

Daniele Cheloni ◽

Enrico Serpelloni ◽

Roberto Devoti ◽

Nicola D'Agostino ◽

Grazia Pietrantonio ◽

...

Keyword(s):

Central Italy ◽

Three Dimensional ◽

Coseismic Deformation ◽

Coseismic Slip ◽

Global Positioning ◽

Systematic Biases ◽

The Individual ◽

Good Agreement ◽

Gps Observations ◽

Geometry And Kinematics

We used continuous Global Positioning System (GPS) measurements to infer the fault geometry and the amount of coseismic slip associated to the August 24, 2016 Mw 6 Amatrice earthquake. We realized a three dimensional coseismic displacement field by combining different geodetic solutions generated by three independent analyses of the raw GPS observations. The coseismic deformation field described in this work aims at representing a consensus solution that minimizes the systematic biases potentially present in the individual geodetic solutions. Because of the limited number of stations available we modeled the measured coseismic displacements using a uniform slip model, deriving the geometry and kinematics of the causative fault, finding good agreement between our geodetically derived fault plane and other seismological and geological observations.

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Finite Element Modelling of a Series of Ground Displacement Episodes and Stress Relief Procedures

ASME-ARPEL 2019 International Pipeline Geotechnical Conference ◽

10.1115/ipg2019-5339 ◽

2019 ◽

Author(s):

Hamid Karimian ◽

Pete Barlow ◽

Chris Blackwell ◽

Chris Campbell

Keyword(s):

Finite Element ◽

Stress Relief ◽

Ground Movement ◽

Ground Displacement ◽

Ground Movements ◽

Before And After ◽

Translational Slide ◽

Lower Slope ◽

Upper Slope ◽

Ground Displacements

Abstract The Wapiti River South Slope (the Slope) near Grand Prairie, Alberta, Canada, is 500 m long and consists of a steep lower slope and a shallower upper slope. Both the upper and the lower slopes are located within a landslide complex with ground movements of varying magnitudes and depths. The Alliance Pipeline (Alliance) NPS 42 Mainline (the pipeline) was installed in the winter of 2000 using conventional trenching techniques at an angle of approximately 8° to the slope fall line. Evidence of slope instability was observed in the slope since 2007. The surficial geology of the slope comprises a colluvium layer draped over bedrock formation in the lower slope, and glacial deposits in the upper slope. Available data indicated two different slide mechanisms. In the lower slope, there is a shallow translational slide within a colluvium layer, and in the upper slope there is a deep-seated translational slide within the glacial deposits. Both the upper and lower slope landslides have been confirmed to be active in the past decade. Gradual ground displacements in the order of several centimeters per year were observed in both the upper and lower slopes between 2007 and 2012. Large ground displacements in the order of several meters were observed between 2012 and 2014 in the lower slope that led to the first stress relief and subsequent slope mitigation measures in the spring and summer of 2014. Monitoring of the slope after mitigations indicated significant reduction in the rate of ground movement in the lower slope. Surveying of the pipeline before and after stress relief indicated an increase in lateral pipeline deformation in the direction of ground movement, following the stress relief. This observation raised questions regarding the effectiveness of partial stress relief to reduce stresses and strains associated with ground movements. Finite element analysis (FEA) was conducted in 2016 to aid in assessing the condition of the pipeline after being subject to ground displacements prior to 2014, stress relief in 2014, and subsequent ground displacement from July 2014 to December 2016. The results and findings of the FEA reasonably matched the observed pipeline behaviour before and after stress relief in the lower slope. The FEA results demonstrated that while the lateral displacement of the pipeline, originally caused by ground movement, increased following the removal of the soil loading during the stress relief, the maximum pipeline strain was reduced within the excavated portion. The FEA was also employed to assess the pipeline response to potential ground displacement scenarios following December 2016. For this assessment, three ground displacement scenarios that comprise different lengths of the pipeline were analyzed. An increased rate of ground displacement, with a pattern that matched one of the analyzed scenarios, was observed in the upper slope in the spring of 2017. The results of FEA were used to assess the pipeline response to the increased rate of displacement in the upper slope. Subsequently a decision was made to stress-relieve the pipeline. The second stress-relief was conducted in the summer of 2017. This stress relief was conducted locally at the toe and head of the active slide in the upper slope, where the FEA showed the greatest stress concentrations in the pipeline.

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Safety of Nuclear Power Plants with Respect to the Fault Displacement Hazard

Applied Sciences ◽

10.3390/app10103624 ◽

2020 ◽

Vol 10 (10) ◽

pp. 3624

Author(s):

Tamás János Katona

Keyword(s):

Seismic Design ◽

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Ground Displacement ◽

Design Basis ◽

Hazard Level ◽

Definition Of ◽

Fault Displacement ◽

Probabilistic Criteria

The hazard of permanent ground displacements/deformations can challenge the safety of the nuclear power plants. Increasing knowledge of the hazard and development of methods for structure–fault–displacement interaction motivates the designing of nuclear power plants for permanent ground displacement instead of abandoning the sites that could be affected by this kind of hazard. For the design basis, permanent ground displacement should be defined at the hazard level that complies with the probabilistic criteria for accounting for the natural hazards in the design that also ensure compliance with probabilistic safety criteria. In this paper, a procedure is proposed for the definition of the design basis permanent ground displacement that is based on the deaggregation of seismic design basis hazard. The definition of the displacement for the margin evaluation is also proposed. The feasibility of safe design is also demonstrated for the proposed definition of design basis hazard via qualitative judgement on the sensitivity of the structures, systems and components ensuring the fundamental safety functions with respect to the permanent ground displacement that is supported by existing case studies.

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The 2018 Palu Tsunami: Coeval Landslide and Coseismic Sources

Seismological Research Letters ◽

10.1785/0220200009 ◽

2020 ◽

Vol 91 (6) ◽

pp. 3148-3160

Author(s):

Amy L. Williamson ◽

Diego Melgar ◽

Xiaohua Xu ◽

Christopher Milliner

Keyword(s):

Survey Data ◽

Field Survey ◽

Tide Gauge ◽

Hazard Analysis ◽

Strike Slip ◽

Coseismic Deformation ◽

Coseismic Slip ◽

Video Footage ◽

Run Up ◽

Tsunami Model

Abstract On 28 September 2018, Indonesia was struck by an MW 7.5 strike-slip earthquake. An unexpected tsunami followed, inundating nearby coastlines leading to extensive damage. Given the traditionally non-tsunamigenic mechanism, it is important to ascertain if the source of the tsunami is indeed from coseismic deformation, or something else, such as shaking induced landsliding. Here we determine the leading cause of the tsunami is a complex combination of both. We constrain the coseismic slip from the earthquake using static offsets from geodetic observations and validate the resultant “coseismic-only” tsunami to observations from tide gauge and survey data. This model alone, although fitting some localized run-up measurements, overall fails to reproduce both the timing and scale of the tsunami. We also model coastal collapses identified through rapidly acquired satellite imagery and video footage as well as explore the possibility of submarine landsliding using tsunami raytracing. The tsunami model results from the landslide sources, in conjunction with the coseismic-generated tsunami, show a greatly improved fit to both tide gauge and field survey data. Our results highlight a case of a damaging tsunami the source of which is a complex mix of coseismic deformation and landsliding. Tsunamis of this nature are difficult to provide warning for and are underrepresented in regional tsunami hazard analysis.

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Minor shallow gravitational component on the Mt. Vettore surface ruptures related to MW 6, 2016 Amatrice earthquake

Annals of Geophysics ◽

10.4401/ag-7299 ◽

2016 ◽

Vol 59 ◽

Author(s):

Matteo Albano ◽

Michele Saroli ◽

Marco Moro ◽

Emanuela Falcucci ◽

Stefano Gori ◽

...

Keyword(s):

Parametric Analysis ◽

Central Italy ◽

Normal Fault ◽

Field Observations ◽

Permanent Displacement ◽

The West ◽

Slope Deposits ◽

Surface Ruptures ◽

Displacement Approach ◽

2016 Amatrice Earthquake

On 24th August 2016 a ML 6.0 earthquake occurred near Amatrice (central Italy) causing nearly 300 fatalities. The mainshock ruptured a NNW-SSE striking, WSW dipping normal fault. The earthquake produced several coseismic effects at ground, including landslides and ground ruptures. In particular, ground surveys identified a 5.2 km long continuous fracture along the Mt. Vettore flank, both on rock and slope deposits, along one of the active normal fault segments bounding the relief to the west. In this work, we evaluated the contribution of seismically-induced surface instabilities to the observed ground fractures by means of a permanent-displacement approach. The results of a parametric analysis show that the computed seismically-induced gravitational displacements (about 2-10 cm) are not enough to explain field observations, testifying to a mean 20-25cm vertical offset. Thus, the observed ground fractures are the result of primary faulting related to tectonics, combined with gravitational phenomena.

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