scholarly journals A non-uniform dip slip formula to calculate the coseismic deformation: Case study of Tohoku Mw9.0 Earthquake

2019 ◽  
Vol 11 (1) ◽  
pp. 1014-1024
Author(s):  
Yongzhi Zhang ◽  
Yipeng Wang ◽  
Hurong Duan ◽  
Yang Gao ◽  
Jiashuang Jiao
Keyword(s):  
Near Field ◽  
Analytical Formula ◽  
Tohoku Earthquake ◽  
Coseismic Deformation ◽  
Tectonic Deformation ◽  
Dislocation Model ◽  
Special Role ◽  
Vertical Displacements ◽  
Analytical Formulas ◽  
Kinetic Pattern

Abstract The distribution of slip faults along the fault plane plays a special role in the kinetic pattern of tectonic deformation. To better understand the coseismic deformation and geodynamics of the earthquake, this paper applied the pile-up theory and derived an analytical formula to describe the non-uniform slip distribution along the fault width. To validate the new formula, it was tested with the coseismic displacements at the global positioning system (GPS) stations for the Tohoku earthquake in 11 March, 2011. Then, the computed horizontal and vertical displacements calculated using NDSM were compared to back-slip model (BSM) using GPS data obtained from the Jet Propulsion Laboratory (JPL). Finally, the theoretical analysis revealed that the analytical formulas derived here can be perceived as the expansion and perfection of the uniform dislocation model. Meanwhile, our results showed that the characteristics of the spatial distribution deformation from NDSM are similar to those derived by GPS measurements. Furthermore, the near-field RMS errors indicated that the horizontal displacements estimated using NDSM is 27.5%, and 35.6% for the vertical components. Our new formulas and findings could assist better portray the crustal deformation in some region and geodynamics in specific earthquake.

scholarly journals Estimation of Far-field Coseismic Deformation Caused by the Recent Giant Earthquakes

2017 ◽  
Vol 33 (2) ◽  
Author(s):  
Nguyen Anh Duong ◽  
Vu Minh Tuan ◽  
Bui Van Duan
Keyword(s):  
Tohoku Earthquake ◽  
2011 Tohoku Earthquake ◽  
Coseismic Deformation ◽  
Tectonic Deformation ◽  
Earth Model ◽  
The 2011 Tohoku Earthquake ◽  
The North ◽  
2004 Sumatra Earthquake ◽  
Slip Region ◽  
The Difference

Abstract: In this paper, we estimate coseismic displacements in Vietnam caused by the 2004 Sumatra and the 2011 Tohoku earthquakes using static fault models in a layered spherical earth model. We find that the 2004 Sumatra earthquake caused southwestward movement of about 56 mm in Southern Vietnam and gradually decreasing to the north. While the 2011 Tohoku earthquake moved the area in the opposite direction, by about 0.9 mm to the east and about 0.4 mm to the north. The difference in amplitude of coseismic displacements is due to the distance from each source fault to the study area and the compact slip region of the 2011 Tohoku earthquake affected to the size of coseismic deformation area. Our results indicate that it is necessary to take into consideration of the coseismic deformation induced by the giant earthquakes on discussion of tectonic deformation in Vietnam.

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

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.

scholarly journals A new asymptotic method for the modeling of near-field accelerograms

1984 ◽  
Vol 74 (2) ◽  
pp. 539-557
Author(s):  
P. Bernard ◽  
R. Madariaga
Keyword(s):  
High Frequency ◽  
Near Field ◽  
Dislocation Model ◽  
Rupture Propagation ◽  
Time Step ◽  
Change Of Variables ◽  
High Frequency Waves ◽  
Stopping Phases ◽  
Simple Integration ◽  
Frequency Radiation

Abstract We study high-frequency radiation from a dislocation model of rupture propagation at the earthquake source. We demonstrate that in this case all the radiation emanates from the rupture front and, by a change of variables, that at any instant of time the high-frequency waves reaching an observer come from a line on the fault plane that we call isochrone. An asymptotic approximation to near-source velocity and acceleration is obtained that involves a simple integration along the isochrones for every time step. It is shown that wave front discontinuities (critical or stopping phases) are radiated every time an isochrone becomes tangent to a barrier. This leads to what we call the critical ray approximation which is given in a closed form. The previous results are compared with discrete wavenumber synthetics obtained by Bouchon (1982) for the Gilroy 6 recording of the Coyote Lake earthquake of 1980. The fit between the asymptotic and full numerical method is extremely good. The critical ray approximation permits the identification of different phases in Bouchon's synthetics and the prediction of the behavior of the signal in the vicinity of their arrival time.

scholarly journals Modeling long-term volcanic deformation at Kusatsu-Shirane and Asama volcanoes, Japan, using the GNSS coordinate time series

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Hiroshi Munekane
Keyword(s):  
Source Parameters ◽  
Tohoku Earthquake ◽  
Oblate Spheroid ◽  
Satellite System ◽  
Deformation Source ◽  
Postseismic Deformation ◽  
Tectonic Deformation ◽  
Linear Inversion ◽  
The 2011 Tohoku Earthquake

AbstractLong-term deformation of Kusatsu-Shirane and Asama volcanoes in central Japan were investigated using Global Navigation Satellite System (GNSS) measurements. Large postseismic deformation caused by the 2011 Tohoku earthquake—which obscures the long-term volcanic deformation—was effectively removed by approximating the postseismic and other recent tectonic deformation in terms of quadrature of the geographical eastings/northings. Subsequently, deformation source parameters were estimated by the Markov Chain Monte Carlo (MCMC) method and linear inversion, employing an analytical model that calculates the deformation from an arbitrary oriented prolate/oblate spheroid. The deformation source of Kusatsu-Shirane volcano was found to be a sill-like oblate spheroid located a few kilometers northwest of the Yugama crater at a depth of approximately 4 $$\text {km}$$ km , while that of Asama was also estimated to be a sill-like oblate spheroid beneath the western flank of the edifice at a depth of approximately 12 $$\text {km}$$ km , along with the previously reported shallow east–west striking dike at a depth of approximately 1 $$\text {km}$$ km . It was revealed that (1) volume changes of the Kusatsu-Shirane deformation source and the shallow deformation source of Asama were correlated with the volcanic activities of the corresponding volcanoes, and (2) the Asama deep source has been steadily losing volume, which may indicate that the volcano will experience fewer eruptions in the near future.

Analytical and 3D Finite Element Study of the Deflection of an Elastic Cantilever Bilayer Plate

2010 ◽  
Vol 78 (1) ◽  
Author(s):  
M. Chekchaki ◽  
V. Lazarus ◽  
J. Frelat
Keyword(s):  
Thin Films ◽  
Finite Element ◽  
Three Dimensional ◽  
Analytical Formula ◽  
Mechanical Stresses ◽  
Linear Elastic ◽  
Wide Range ◽  
Finite Element Calculations ◽  
Analytical Formulas ◽  
Three Dimensional Elasticity

The mechanical system considered is a bilayer cantilever plate. The substrate and the film are linear elastic. The film is subjected to isotropic uniform prestresses due for instance to volume variation associated with cooling, heating, or drying. This loading yields deflection of the plate. We recall Stoney’s analytical formula linking the total mechanical stresses to this deflection. We also derive a relationship between the prestresses and the deflection. We relax Stoney’s assumption of very thin films. The analytical formulas are derived by assuming that the stress and curvature states are uniform and biaxial. To quantify the validity of these assumptions, finite element calculations of the three-dimensional elasticity problem are performed for a wide range of plate geometries, Young’s and Poisson’s moduli. One purpose is to help any user of the formulas to estimate their accuracy. In particular, we show that for very thin films, both formulas written either on the total mechanical stresses or on the prestresses, are equivalent and accurate. The error associated with the misfit between our theorical study and numerical results are also presented. For thicker films, the observed deflection is satisfactorily reproduced by the expression involving the prestresses and not the total mechanical stresses.

On the Importance of the Tax System in Marginal Cost of Funds Calculations

2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Mickael Beaud
Keyword(s):  
General Equilibrium ◽  
Marginal Cost ◽  
Analytical Formula ◽  
Value Added ◽  
Tax Revenue ◽  
Empirical Estimates ◽  
Analytical Formulas ◽  
The Impact ◽  
Labor Income Taxation ◽  
Marginal Cost Of Funds

Abstract Several papers have attempted to derive computable analytical formulas for the Marginal Cost of Funds (MCF). However, this literature is often cast in the pure labor supply general equilibrium model, which is not completely consistent with real tax systems where Labor Income Taxation (LIT) is not the only instrument used by governments. Hence, we explicitly introduce Value-Added Taxation (VAT) on consumption goods in the conventional model, and we derive an analytical formula for the MCF which does incorporate general equilibrium interactions between the different tax bases. Then, we illustrate how much this matter for empirical estimates of MCF using French data. Our numerical example suggests that, when computing MCF for a LIT reform, taking account of the impact of LIT reform on tax revenue from VAT can make a great deal of difference, typically increasing MCF and accounting for around 0.2 to 0.8 of estimates. In addition, MCF is then really less likely to be less than one than in the conventional framework.

Simplified Analytical Calculation and Modification of the Crushing Forces of Intersection Units in Vessel-Bridge Collisions

2020 ◽  
Author(s):  
Yin Faqiang ◽  
Pan Jin ◽  
Huang Shiwen ◽  
Xu Mingcai
Keyword(s):  
Small Angle ◽  
Large Angle ◽  
Analytical Formula ◽  
Analytical Calculation ◽  
Typical Structure ◽  
Analytical Formulas ◽  
Ship Collision ◽  
Collision Force ◽  
Inclined Angle ◽  
The Impact

Abstract Because of the increasingly busy maritime trade, the number of bridges damaged by ship-bridge collision also increases. In order to reduce the serious losses caused by ship-bridge collision incidents, it is necessary to make a rapid estimation of ship collision forces. The simplified analytical formulas can be used to rapidly evaluate the collision force in ship collision accidents, but it is found that the existing simplified formulas are only applicable to bulb structures including small-angle inclined elements and not suitable for large-angle inclined elements which exist in ship-bridge collision. In this paper, the quasi-static crushing simulation of the bulbous structure with small-angle inclined angle elements is carried out, and the applicability of the simplified analytical formula of the intersection unit to the typical structure is verified. By comparing the simplified analytical results of the bow with the quasi-static simulation results and the ratio of the strength reduction factor to the effective crushing distance, it is found that the inclined angle of the inclined element will affect the impact force of the simplified analytical calculation. Then, finite element analysis of the truncated-type intersection structure with different element inclination angles are carried out, and the results show that the existing simplified analytical formula is no longer suitable for the calculation of collision force when the inclined angle is greater than 40°. For this reason, the existing simplified analytical formulas are modified for the large-angle inclined elements, and it can provide a certain reference calculation value for the collision force of vessel-bridge collision which includes large-angle inclined elements.

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 Four-sphere head model for EEG signals revisited

2017 ◽  
Author(s):  
Solveig Næss ◽  
Chaitanya Chintaluri ◽  
Torbjørn V. Ness ◽  
Anders M. Dale ◽  
Gaute T. Einevoll ◽  
...  
Keyword(s):  
Analytical Formula ◽  
Mathematical Expression ◽  
Head Model ◽  
The Finite Element Method ◽  
Sphere Model ◽  
Eeg Signals ◽  
Scalp Eeg ◽  
Spherical Head ◽  
Analytical Formulas ◽  
Eeg Recordings

AbstractElectric potential recorded at the scalp (EEG) is dominated by contributions from current dipoles set by active neurons in the cortex. Estimation of these currents, called ’inverse modeling’, requires a ’forward’ model, which gives the potential when the positions, sizes, and directions of the current dipoles are known. Different models of varying complexity and realism are used in the field. An important analytical example is the four-sphere model which assumes a four-layered spherical head where the layers represent brain tissue, cerebrospinal fluid (CSF), skull, and scalp, respectively. This model has been used extensively in the analysis of EEG recordings. Since it is analytical, it can also serve as a benchmark against which numerical schemes, such as the Finite Element Method (FEM), can be tested. While conceptually clear, the mathematical expression for the scalp potentials in the four-sphere model is quite cumbersome, and we observed the formulas presented in the literature to contain errors. We here derive and present the correct analytical formulas for future reference. They are compared with the results of FEM simulations of four-sphere model. We also provide scripts for computing EEG potentials in this model with the correct analytical formula and using FEM.

Source properties of a Blue MT. Lake earthquake

1976 ◽  
Vol 66 (3) ◽  
pp. 677-683
Author(s):  
John G. Anderson ◽  
Jon B. Fletcher
Keyword(s):  
New York ◽  
Spectral Analysis ◽  
Field Component ◽  
Near Field ◽  
Earthquake Source ◽  
Dislocation Model ◽  
S Wave ◽  
Wave Pulse ◽  
Hypocentral Distance ◽  
Source Radius

abstract An accelerogram obtained at Blue Mt. Lake, New York is remarkable for the simplicity of its S-wave pulse. This results from (1) a nearly complete absence of scattering and reflections as second arrivals on the accelerogram, and (2) a very elementary earthquake source. The earthquake identified with this accelerogram had a magnitude mb = 2.2 and a hypocentral distance of about 1 km from the accelerometer. Spectral analysis of the S wave indicates the earthquake had a moment of 8 × 1018 dyne-cm, and a source radius of 20 to 40 m. When the accelerogram is integrated to obtain displacement, there is a step offset of about 5μ associated with a near-field component of the S-wave pulse. The S-wave, including the step offset, can be matched in remarkable detail by a dislocation model with a moment of 8.4 × 1018 dyne-cm.

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