Fault Rupture Process Research Articles

Fluid-driven fault nucleation, rupture processes, and permeability evolution in oshima granite — Preliminary results and acoustic emission datasets

This study investigated the fault nucleation and rupture processes driven by stress and fluid pressure in fine-grained granite by monitoring acoustic emissions (AEs). Through detailed analysis of the spatiotemporal distribution of the AE hypocenter, P-wave velocity, stress-strain, and other experimental observation data under different confining pressures for stress-driven fractures and under different water injection conditions for fluid-driven fractures, it was found that fluid has the following effects: 1) complicating the fault nucleation process, 2) exhibiting episodic AE activity corresponding to fault branching and the formation of multiple faults, 3) extending the spatiotemporal scale of nucleation processes and pre-slip, and 4) reducing the dynamic rupture velocity and stress drop. The experiments also show that 1) during the fault nucleation process, the b-value for AEs changes from 1 to 1.3 to 0.5 before dynamic rupture, and then rapidly recovers to around 1–1.2 during aftershock activity and 2) the hydraulic diffusivity gradually increases from an initial pre-rupture order of 0.1 ​m2/s to 10–100 ​m2/s after dynamic rupture. These results provide a reasonable fault pre-slip model, indicating that hydraulic fracturing promotes shear slip before dynamic rupture, as well as laboratory-scale insights into ensuring the safety and effectiveness of hydraulic fracturing operations related to activities such as geothermal development, evaluating the seismic risk induced by water injection, and further researching the precursory preparation process for deep fluid-driven or fluid-involved natural earthquakes. The publicly available dataset is expected to be used for various purposes, including 1) as training data for artificial intelligence related to microseismic data processing and analysis, 2) predicting the remaining time before rock fractures, and 3) establishing models and assessment methods for the relationship between microseismic characteristics and rock hydraulic properties, which will deepen our understanding of the interaction mechanisms between fluid migration and rock deformation and fracture.

Crustal heterogeneity effects on coseismic deformation: numerical simulation of the 2008 MW 7.9 Wenchuan earthquake

Coseismic deformation of large earthquakes causes significant property damages and fatalities, which requires quantitative research of multiple disciplines such as geodesy, geological investigation, seismic tomography, and seismic dislocation theory. The finite element method accounts for material heterogeneity and geometric complexity, making it suitable for studying the coseismic deformation of large earthquakes. This paper develops a parallel elastic finite element program that utilizes split nodes and high-performance parallel computing technology on the FELAC software platform to study the coseismic deformation of large earthquakes. We verify the accuracy of the parallel elastic finite element program by comparing its results with the analytical solutions from seismic dislocation theory for four ideal earthquake cases. Finally, we established parallel elastic finite element models to study the coseismic deformation of the 2008 Wenchuan earthquake. The simulation results are consistent with the GPS and InSAR data. Coseismic surface deformation results are significantly influenced by medium regional heterogeneity with different layered structures besides the Longmenshan fault. The finite element program lay the foundation for the inversion of the coseismic fault rupture process based on the heterogeneous medium model and complex geometric model.

Nucleation Mechanism and Rupture Dynamics of Laboratory Earthquakes at Different Loading Rates

The loading rate of tectonic stress is not constant during long-term geotectonic activity and significantly affects the earthquake nucleation and fault rupture process. However, the mechanism underlying the loading rate effect is still unclear. In this study, we conducted a series of experiments to explore the effect of the loading rate on earthquake nucleation and stick–slip characteristics. Through lab experiments, faults were biaxially loaded at varying rates to produce a series of earthquakes (stick–slip events). Both shear strain and fault displacement were monitored during these events. The findings indicate a substantial effect of the loading rate on the recurrence interval and the shear stress drop of these stick–slip events, with the recurrence interval inversely proportional to the loading rate. The peak friction of the fault also decreases with the increasing loading rate. Notably, prior to the dynamic rupture of earthquakes, there exists a stable nucleation phase where slip occurs in a quasi-static manner. The critical nucleation length, or the distance required before the dynamic rupture, diminishes with both the loading rate and normal stress. A theoretical model is introduced to rationalize these observations. However, the rupture velocity of these lab-simulated earthquakes showed no significant correlation with the loading rate. Overall, this study enhanced our comprehension of earthquake nucleation and rupture dynamics in diverse tectonic settings.

2D resistivity model around the rupture area of the 2011 Tohoku-oki earthquake (Mw 9.0)

The 2011 Tohoku-oki earthquake (Mw 9.0) was characterized by a huge fault slip on the shallowest part of the plate interface, where fault behavior had been believed to be aseismic. In this study, we modeled the two-dimensional resistivity distribution across the slip area based on ocean-bottom electromagnetic measurements to understand the physical properties around the plate interface controlling fault rupture processes. The optimal 2D resistivity model showed a conductive area around the shallowest plate interface where the huge coseismic slip was observed, whereas the deeper plate interface where the fault rupture was nucleated was relatively more resistive. The shallowest plate interface was interpreted to have a high pore seawater fraction, whereas the deeper interface was interpreted as a dry area. These findings are consistent with the hypothesis that aseismic frictional conditions changed to conditions enhancing fault rupture when the rupture propagated to the wet, clay-rich shallowest plate area. The optimal resistivity model also revealed a conductive area under the outer-rise area of the Pacific Plate. This finding supports the existence of a hydrated oceanic crust that supplied aqueous water to the subduction zone, including to the huge fault slip area.Graphical

A regional scale coseismic landslide analysis framework: Integrating physics-based simulation with flexible sliding analysis

This paper describes a framework for regional scale coseismic landslide evaluation that combines physics-based wave propagation simulation at a regional scale, with flexible sliding analysis at a site scale. The physics-based simulation incorporates fault rupture process, complex topography and dynamic site response. The sliding displacements of flexible masses are calculated by integrating seismic parameter k obtained from the physics-based simulation over seismic resistance.The framework is applied to the case study of coseismic landslides during the 2016 Mw 7.0 Kumamoto earthquake in Japan, which has well documented fault mechanism, geologic information and landslide inventory. The performance of the model prediction is evaluated by receiver operating characteristic (ROC) analysis. This study highlights the near-fault effect and soil nonlinear effect on landslide distribution, and it is demonstrated that the landslide prediction can be notably improved with the consideration of topographic amplification of ground motions. Empirical correlations between topographic amplification of key intensity measures and parameterized topographic features are developed. Overall, the simulation captures 58% of observed landslides in the inventory (using a displacement threshold of 15 cm), showing the proposed framework is a promising tool for regional coseismic landslide analysis.

Fault strength and rupture process controlled by fault surface topography

Faults are rarely completely smooth, with topographic undulations coming from the distribution of asperities along the fault surface. Understanding the effects of fault surface topography on fault strength and earthquake source properties has been limited due to a lack of in situ observations in the field. Here we use simulated earthquake cycles on metre-scale laboratory faults to show the effects of the degree of fault topographic heterogeneity, especially on macroscopic peak strength represented by the shear force required to commence macroscopic failure. Our results demonstrate that the less heterogeneous fault is weaker, due to its lower macroscopic peak strength, and produces a larger stress drop on average than the more heterogeneous fault. Rupture along the less heterogeneous fault tends to propagate at subshear speed while the more heterogeneous fault accommodates a wider range of rupture speeds, including slow slip and supershear rupture. These results reveal how fault topographic heterogeneity affects macroscopic peak strength at rupture initiation and stress drop during rupture propagation, which has important implications for understanding natural faults and earthquakes. Simulated earthquakes on metre-scale laboratory faults reveal that fault surfaces with more heterogeneous topography are stronger, and rupture at a wider range of propagation speeds, than those that are less heterogeneous.

Effects of pulse-like ground motions and wavelet asymmetry on responses of cantilever retaining wall

Fault-rupture processes produce pulse-like ground motions in near-fault regions. These motions are characterized as large-amplitude long-period pulsing that can cause severe structural damage. This study investigates their effect on cantilever retaining wall responses through finite-difference-based numerical simulations. We collect a suite of large-amplitude ground motions which are classified into pulse-like, non-pulse-like, and ambiguous using a pulse indicator. It turns out that relative wall movements by pulse- and non-pulse-like motions are not particularly different. Instead, relative wall movement is highly affected by ground motion Arias intensity, regardless of motion type. Additional simulations using original and reversed ground motion assess the effect of wavelet asymmetry (the ratio of peak amplitudes or energy values in wavelet positive and negative directions) on the wall response. Ground motion asymmetric to the wall movement direction generates larger wall displacement than ground motion asymmetric opposite to the wall movement direction. Relative wall displacements differ by up to approximately 46% depending on the direction of ground motion against the wall movement.

A phase‐field model for quasi‐dynamic nucleation, growth, and propagation of rate‐and‐state faults

AbstractDespite its critical role in the study of earthquake processes, numerical simulation of the entire stages of fault rupture remains a formidable task. The main challenges in simulating a fault rupture process include the complex evolution of fault geometry, frictional contact, and off‐fault damage over a wide range of spatial and temporal scales. Here, we develop a phase‐field model for quasi‐dynamic fault nucleation, growth, and propagation, which features two standout advantages: (i) it does not require any sophisticated algorithms to represent fault geometry and its evolution; and (ii) it allows for modeling fault nucleation, propagation, and off‐fault damage processes with a single formulation. Built on a recently developed phase‐field framework for shear fractures with frictional contact, the proposed formulation incorporates rate‐ and state‐dependent friction, radiation damping, and their impacts on fault mechanics and off‐fault damage. We show that the numerical results of the phase‐field model are consistent with those obtained from well‐verified approaches that model the fault as a surface of discontinuity, without suffering from the mesh convergence issue in the existing continuous approaches to fault rupture (e.g., the stress glut method). Further, through numerical examples of fault propagation in various settings, we demonstrate that the phase‐field approach may open new opportunities for investigating complex earthquake processes that have remained overly challenging for the existing numerical methods.

On various mechanisms of shear wave generation from underground chemical explosions in hard rocks

SUMMARY Significant shear waves observed during underground explosions can make them look similar to natural earthquakes. In the near field, they can be caused by the source geometry and emplacement conditions, heterogeneous and anisotropic properties of the rock mass, relaxation of a non-uniform in situ stress around the source after the departure of the shock wave as well as by activation of nearby faults. The stress relaxation mechanism is important at depth when the difference in main principal stresses becomes significant. Another mechanism of shear motion generation is due to explosive gas flow from the source cavity into the cracks initiated by the shock wave and joints connected to the cavity. Also, the shock wave from the explosion can cause weakening of the rock either due to permanent damage or shock-induced liquefaction at saturated joints. Numerical modelling of underground chemical explosions in hard rock at various confinement stresses has been conducted to compare various mechanisms of shear wave generation and their seismic characteristics with that of a simple fault rupture process observed during an earthquake.

High‐Resolution Fault‐Rupture Imaging by Combining a Backprojection Method With Binarized MUSIC Spectral Image Calculation

AbstractBackprojection (BP) methods are widely used for estimating the fault rupture processes; however, they are inherently susceptible to noise. Hence, noise suppression is an important research target. In this paper, we develop a fault rupture imaging method by combining beamforming‐based BP and MUltiple Signal Classification (MUSIC), which realizes artificial noise suppression at a high spatial resolution. The stations are grouped into arrays according to the SH wave radiation coefficients, and MUSIC analysis is performed on each array. The MUSIC spectral images of these arrays are binarized and then multiplied by the BP images. Spatial filtering is also applied to the images based on the possible range of the rupture velocity and rise time. When tested using synthetic test data, the proposed method worked as expected. We then applied this method to the 2016 Kumamoto earthquake by interpolating the travel times from the observed travel times of relocated hypocenters using a 3‐D velocity structure model. In the area of large slip and slip rate approximately 30–50 km from the hypocenter on the Futagawa fault, the spatiotemporal evolution of the fault ruptures and waveform inversion results were generally in harmony. The distributions of the low‐ and high‐frequency seismic radiations are complementary, as is understood in the context of fault rupture physics. This method can aid in understanding and modeling the details of seismic radiation sources, enabling the accurate prediction of strong ground motion even in near‐fault areas.

Back‐Projection Imaging of a Tsunami Excitation Area With Ocean‐Bottom Pressure Gauge Array Data

AbstractA back‐projection method has been applied to many earthquakes in seismology due to its simple and low computational cost, and it can estimate complex fault rupture processes without any specific a priori information. In this study, we applied the back‐projection method to the tsunami records observed using an ocean‐bottom pressure gauge array and demonstrated it to be a powerful new tool other than the familiar waveform inversion. The obtained back‐projection image was consistent with the initial tsunami height distributions estimated by previous waveform inversions, and its spatial resolution appeared to be even better. Our result suggests that the fault size of the 2016 Off‐Fukushima earthquake was about half, different from the scaling law of standard earthquakes. The present tsunami back‐projection analysis can also estimate the feature of early tsunami propagations. In addition, the estimated image seems to be reliable even 30 min after the origin time, so the back‐projection analysis will be useful in an early detection of the location and spatial extent of a tsunami source. In the present case, the number of available stations in the analysis was found to be affected by the diffraction of tsunami propagation caused by the refraction by a high velocity zone near the Japan Trench. In other words, the further the source is from the coast, the more stations to be analyzed are available. Since most tsunami‐generating earthquakes occur near the subduction axis or its outer‐rise region, the back‐projection analysis should be effective for source estimation of the majority of tsunami‐generating earthquakes.

The Doppler effect induced by earthquakes: A case study of the Wenchuan MS8.0 earthquake

Seismologists have found that the first arrival frequencies of P waves at different seismic stations have different widths, that is, different periods or frequencies, and they think that this phenomenon can be used to identify whether a Doppler effect is induced by earthquakes. However, the fault rupture process of a real earthquake is so complex that it is difficult to identify a frequency shift similar to the Doppler effect. A method to identify whether a Doppler effect is induced by an earthquake is proposed here. If a seismic station is in the direction of fault rupture propagation, this station could observe a Doppler effect induced by the earthquake. The Doppler effect causes the frequency of the seismic wave to shift from low frequency to high frequency, and the high frequency amplitudes become mutually superimposed. Under the combined influences of the absorption effect, geometric spreading effect and Doppler effect, the high frequency amplitude of the seismic wave will gradually become higher than the low frequency amplitude with increasing epicentral distance. If we find that the high frequency amplitude is higher than the low frequency amplitude with increasing epicentral distance in the direction of fault rupture propagation, then there is a Doppler effect. The fault that generated the Wenchuan earthquake is a reverse fault, and its horizontal rupture propagation velocity was low. To link fault rupture propagation velocity with the Doppler effect and identify the Doppler effect more easily, we decompose three-component records into two directions: the direction of fault rupture propagation and the direction perpendicular to the fault rupture propagation along the fault plane. The initial components of the two directions are processed by wavelet transform. Several seismic stations in the direction of fault rupture propagation of the Wenchuan earthquake were selected, and it was found that with increasing epicentral distance, the high frequency amplitudes of the wavelet spectra become obviously higher than the low frequency amplitudes. It can be concluded that due to the existence of the Doppler effect, high frequency amplitudes can overcome the influences of the absorption and geometric spreading effects on seismic waves in the fault rupture propagation process.

The 2017 Kos sequence: Aftershocks relocation and coseismic rupture process constrained from joint inversion of seismological and geodetic observations

On 20 July 2017 (22:31:10 UTC), an Mw6.6 earthquake took place offshore Kos Island, in the southeastern (SE) Aegean Sea, producing severe damage and loss of life in the city of Kos and several smaller cities and villages both in Kos Island (Greece) and in the Bodrum peninsula (Turkey). All available seismological data until the end of October 2017 were gathered from seismological stations located in Greece and Turkey for the relocation process. The relocated aftershocks are clustered at least in three distinctive patches, creating a zone reaching a total length of about 40 km, elongated in a nearly east-west direction, and are mainly concentrated at depths 8–15 km, with the main shock hypocenter placed at ~13 km, implying a seismogenic layer of 7 km thickness, indicative for normal faulting earthquakes with Mmax ~ 6.5. The aftershock fault plane solutions are predominantly normal faulting in response to the north–south extension of the back arc Aegean area and consistent with the broader regional stress field. We also applied the satellite radar interferometry (InSAR) technique to define the coseismic surface displacements, revealing the range of deformation on the Island and the surrounding mainland. We combined this deformation field along with the available vectors of displacement measured by the Global Navigation Satellite System (GNSS) technique with the seismological data to determine the fault geometry and rupture process. The resulted variable slip model indicates a rather elliptical rupture area of 306 km2, with the coseismic slip ranging between 0.5 and 2.3 m. The peak moment release occurred in the depth interval of 9–11 km, consistent with the depth distribution of seismicity in the study area. We used the variable slip model to calculate Coulomb stress changes and investigate possible triggering due to stress transfer to the nearby fault segments.

Rock dynamic fracture of a novel semi-circular-disk specimen

The relationship between velocity, acceleration, and dynamic fracture toughness during rapid crack propagation is difficult to effectively capture. In this study, a novel semi-circular holed disc bend is proposed to achieve a long fracture path. Hopkinson pressure rods with crack growth and strain gauges are used to impact the semi-circular holed disc bend specimens and to monitor the cracking process of a mode-I fracture. The experiments show that the crack growth speed increases to a critical value after crack initiation and then oscillates as a result of the reflected stress wave. The dynamic propagation fracture toughness ( K IC d ) increases with increasing crack velocity for steady crack propagation; however, this does not apply for unsteady propagation. An experimental–numerical–analytical method is developed to determine the dynamic stress intensity factor , which initially increases with time, then decreases, and ultimately increases again. The acceleration ( v ˙ ) can be used to investigate the unsteady crack propagation process. K IC d values for v ˙ < 0 are greater than those for v ˙ > 0. An energy release rate formula related to v ˙ and the crack propagation velocity ( v ) is proposed and verified by the experiments. A thorough understanding of v , v ˙ , and K IC d is important to analyze high-speed fault rupture processes.

Relationship Between Asperities and Velocity Pulse Generation Mechanism

Near-fault ground motion records often capture instances of pulse-like behavior, where a burst of energy is expressed as large wave amplitude that occur over short time. The pulse-like ground motion can cause serious damage to long-period structures. Using numerical simulations of near-fault ground motions, we analyze the mechanisms involved in the generation of velocity pulses in the 1994 Northridge Earthquake and the 1979 Imperial Valley Earthquake. The degree to which the asperities affect the pulse generation process is investigated by identifying individual velocity pulses from the superposition process of sub-fault ground motions. Pulse indicators Ep and PGVp represent pulse characteristics in the ground motions at the stations located near the epicenter (near-epicenter stations) and the stations located along the forward rupture propagation direction of the asperity (rupture-direction stations), respectively. To observe the effects of the asperities and the spatial relationship between the pulse-like ground motion stations and the asperities, we determine the contribution of the sub-fault motions to the pulse amplitude. Furthermore, we analyze the pulse indicators and the frequency components using simulated ground motions from two different slip distributions. The near-epicenter station ground motions, produced by homogeneous slip distribution, exhibit higher pulse amplitude and more concentrated low-frequency energy than those generated by the inhomogeneous slip distribution. The rupture-direction station ground motions, produced by inhomogeneous slip distribution, present higher pulse amplitude and more concentrated low-frequency energy than those generated by the homogeneous slip distribution. Our analysis reveals that during the fault rupture process, the pulse energy and the pulse amplitude are influenced by both the slip distribution on the fault plane and the spatial relationship between the seismic station and the asperity.

Geometry-dependent rupture process of the 2015 Gorkha, Nepal, earthquake determined using a dip-varying inversion approach with teleseismic, high-rate GPS, static GPS and InSAR data

SUMMARYFault geometry is widely recognized as one of the most important factors that affect the rupture process and damages of earthquakes. However, there have been few earthquake cases in which the close relation between the fault geometry and rupture process is resolved from inversions of seismic and geodetic observations. In this study, we develop an approach to simultaneously estimate the rupture process and dip-angle variation on the fault. The effectiveness of our new approach was validated through inverse numerical tests. We apply the new approach to the 2015 Mw7.8 Gorkha earthquake and obtain a dip-varying rupture model by jointly inverting the teleseismic, near-fault high-rate GPS, static co-seismic GPS and InSAR data. Our results show a ramp–flat décollement-ramp fault geometry of the earthquake. The shallow ramp may have prevented the rupture from breaking through to the surface. The variation of dip angle changing with depth leads to significantly different rupture velocities and rupture lengths at shallow and deep fault portions. Particularly, the northeastern downdip ramp behaves as a geometric barrier and rapidly slows down the rupture propagation in 35–45 s after the rupture initiation. In contrast, the rupture duration and fault length in the updip portion are relatively long since there is no significant lateral dip change. Furthermore, the approach can improve our understanding of the relationship between rupture behaviour and fault geometry for other thrust low-dip-angle (dip &amp;lt; 45°) earthquakes.

Rapid Earthquake Source Description Using Variometric-Derived GPS Displacements toward Application to the 2019 Mw 7.1 Ridgecrest Earthquake

AbstractUsing near-field high-rate Global Positioning System (GPS) displacements to invert for earthquake fault slips in real time has the potential to improve the accuracy of earthquake early warning or tsunami early warning. For such applications, real-time retrieval of high-accuracy GPS displacements is essential. Here, we report on rapid modeling of the 2019 Mw 7.1 Ridgecrest earthquake with real-time GPS displacements derived from a variometric approach with readily available broadcast ephemeris. This method calculates station variations in real time by differencing continuous phase observations and does not rely on precise orbit and clock information. The phase ambiguity is also removed, and thus the method does not suffer from a relatively long convergence time. To improve the accuracy of variometric displacements, we use a local spatial filter to decrease the influence of residual errors that cannot be removed completely by the time difference. We invert for the centroid moment tensor, static fault slips, and fault rupture process from the derived displacements. Our results show that all inverted models are available within about 65 s after the origin time of the earthquake and are comparable with models inverted by real-time precise point positioning displacements. This study highlights the great value of variometric displacements for the rapid earthquake source description with only broadcast ephemeris.

Selective clast survival in an experimentally-produced pseudotachylyte

On-fault processes during earthquakes contribute to seismic rupture propagation and slip. Here we investigate clast fragmentation in an experimental pseudotachylyte (solidified seismic melt) produced with a rotary shear machine. We slid for 0.44 m (corresponding to Mw ≥ 6 earthquakes), at slip rates > 1 m/s, pre-cut samples of quartz + phyllosilicates + plagioclase + sillimanite + garnet -bearing ultramylonite, that hosts pseudotachylytes in nature. The ultramylonite minerals extensively preserved as clasts in the experimental pseudotachylyte are quartz, plagioclase, and sillimanite. Garnet is scarcely preserved, despite having a melting temperature similar to plagioclase, probably due to having low thermal shock resistance. This selective clast survival is identical to the one found in the natural pseudotachylytes. Based on these experimental observations and assuming non-equilibrium melting, the preservation of a mineral, as a clast, in the melt appears to be controlled by its thermal shock properties as well as by its melting temperature. Since the mechanical effects of rupture propagation in these experiments were negligible, we conclude that, for Mw ≥ 6 earthquakes, (i) frictional slip and heating of the slipping zone plus (ii) thermomechanical properties of minerals, rather than fault rupture processes, control mineral comminution and clast survival in frictional melts.

Source Characteristics of the 2020 Mw 7.4 Oaxaca, Mexico, Earthquake Estimated from GPS, InSAR, and Teleseismic Waveforms

AbstractOn 23 June 2020, an Mw 7.4 earthquake struck offshore Oaxaca, Mexico, providing a unique opportunity to understand the seismogenic tectonics of the Mexican subduction zone. In this study, near-field coseismic deformation caused by the event was retrieved from Global Positioning System (GPS) observations and Interferometric Synthetic Aperture Radar (InSAR) measurements. Given static geodetic measurements, high-rate GPS waveforms, and teleseismic waveforms, the fault geometry and rupture process for the 2020 Oaxaca earthquake were robustly determined by nonlinear joint inversions. The main slip was located at a depth of 20–30 km with a peak slip of 3.4 m near the epicenter. The total released moment was 1.70×1020 N·m, corresponding to Mw 7.4. The whole rupture process lasted 14 s, with the dominant rupture slip occurring 5–8 s after initial rupture. The mainshock rupture mostly occurred along the fault strike, covering a size of ∼55 km(along strike)×∼35 km(along dip) and totally overlapping with the 1965 Mw 7.5 rupture zone. We speculate that this 2020 earthquake is a repeat event following that in 1965. Fluid percolation under the slab may be one of the key factors affecting the seismogenic depth in the Oaxaca region.

Effects of Barriers on Fault Rupture Process and Strong Ground Motion Based on Various Friction Laws

A barrier may induce a supershear rupture on a fault. This paper focuses on two questions: One is whether the existence of a barrier accelerates the propagation speed of a whole fault rupture, and the other is what are the effects of friction laws and strength of a barrier on the rupture propagation process. For these purposes, classical slip-weakening, rate-state, and modified slip-weakening friction laws are employed to simulate the effect of a barrier on the fault rupture process. The simulation results showed that the rupture speed of the fault obviously decreases when the rupture front propagates to the barriers, and the rupture speed obviously increases when the rupture front leaves barriers. It was also found that a barrier on a fault may induce a supershear rupture via the rate-state friction law. The simulation results also showed that with the increase of barrier strength, the rupture speed near barriers fluctuates more and more; when the barrier strength exceeds a certain level, a supershear rupture area appears on the fault; with the increase of barrier strength, the propagation distance of the rupture at supershear wave velocity correspondingly increases. In addition, with the increase of barrier strength, the overall rupture duration of the fault slightly increases. This indicates that a barrier cannot shorten the total duration of a fault rupture. Though a barrier will lead to a supershear rupture, it just regulates the distribution of the rupture speed on the fault surface. Moreover, with the increase of barrier strength, the peak ground acceleration caused by rupture through the barrier also increases, indicating that the existence of a barrier may lead to the intensification of seismic hazards.