Heterogeneous Slip Research Articles

Heterogeneity of direct aftershock productivity of the main shock rupture

AbstractThe epidemic type aftershock sequence (ETAS) model is widely used to describe and analyze the clustering behavior of seismicity. Instead of regarding large earthquakes as point sources, the finite‐source ETAS model treats them as ruptures that extend in space. Each earthquake rupture consists of many patches, and each patch triggers its own aftershocks isotropically. We design an iterative algorithm to invert the unobserved fault geometry based on the stochastic reconstruction method. This model is applied to analyze the Japan Meteorological Agency (JMA) catalog during 1964–2014. We take six great earthquakes with magnitudes >7.5 after 1980 as finite sources and reconstruct the aftershock productivity patterns on each rupture surface. Comparing results from the point‐source ETAS model, we find the following: (1) the finite‐source model improves the data fitting; (2) direct aftershock productivity is heterogeneous on the rupture plane; (3) the triggering abilities of M5.4+ events are enhanced; (4) the background rate is higher in the off‐fault region and lower in the on‐fault region for the Tohoku earthquake, while high probabilities of direct aftershocks distribute all over the source region in the modified model; (5) the triggering abilities of five main shocks become 2–6 times higher after taking the rupture geometries into consideration; and (6) the trends of the cumulative background rate are similar in both models, indicating the same levels of detection ability for seismicity anomalies. Moreover, correlations between aftershock productivity and slip distributions imply that aftershocks within rupture faults are adjustments to coseismic stress changes due to slip heterogeneity.

Tsunami inundation variability from stochastic rupture scenarios: Application to multiple inversions of the 2011 Tohoku, Japan earthquake

We develop a framework for assessing the sensitivity and variability of tsunami inundation characteristics for stochastic physics-based scenarios of mega-thrust subduction earthquakes. The method is applied to the 2011 Tohoku, Japan earthquake, and tested against observed inundation maps at several locations along the Tohoku coast, using 11 different, previously published, rupture models for this devastating tsunamgenic earthquake. The earthquake rupture models differ in fault dimension (length and width), geometry (dip, strike and top-edge depth), as well as asperity characteristics (slip heterogeneity on the fault plane). The resulting source variability allows exploring a wide range of tsunami scenarios for an Mw9 mega-thrust subduction earthquake in the Tohoku region to conduct thorough sensitivity analyses and to quantify the inundation variability. The numerical results indicate a strong influence of the reference source models on inundation variability, and demonstrate significant sensitivity of inundation to the details of the rupture realization. Therefore, relying on a single particular earthquake rupture model as a representative case when varying earthquake source characteristics may lead to under-representation of the variability of potential scenarios. Moreover, the proposed framework facilitates the rigorous development of critical scenarios for tsunami hazard and risk assessments, which are particularly useful for tsunami hazard mapping and disaster preparedness planning.

Probabilistic Tsunami Hazard Analysis of the Pacific Coast of Mexico: Case Study Based on the 1995 Colima Earthquake Tsunami

This study develops a novel computational framework to carry out probabilistic tsunami hazard assessment for the Pacific coast of Mexico. The new approach enables the consideration of stochastic tsunami source scenarios having variable fault geometry and heterogeneous slip that are constrained by an extensive database of rupture models for historical earthquakes around the world. The assessment focuses upon the 1995 Jalisco-Colima Earthquake Tsunami from a retrospective viewpoint. Numerous source scenarios of large subduction earthquakes are generated to assess the sensitivity and variability of tsunami inundation characteristics of the target region. Analyses of nine slip models along the Mexican Pacific coast are performed and statistical characteristics of slips (e.g. coherent structures of slip spectra) are estimated. The source variability allows exploring a wide range of tsunami scenarios for a moment magnitude (Mw) 8 subduction earthquake in the Mexican Pacific region to conduct thorough sensitivity analyses and to quantify the tsunami height variability. The numerical results indicate a strong sensitivity of maximum tsunami height to major slip locations in the source, and indicate major uncertainty at the first peak of tsunami waves.

Full Aftershock Sequence of the M w 6.9 2003 Boumerdes Earthquake, Algeria: Space–Time Distribution, Local Tomography and Seismotectonic Implications

We present a detailed analysis of the aftershocks of the May 21, 2003 Boumerdes earthquake (M w = 6.9) recorded by 35 seismological stations and 2 OBS deployed in the epicentral area. This network recorded the aftershock activity for about 1 year and resulted in locating about 2500 events. The five main aftershocks (4.7 <M <5.8) display thrust faulting consistent with the main shock, except for the second event (M5.8, 29/05/2003) which depicts a strike-slip focal solution at the western tip of the rupture zone. Most aftershocks are clustered near the main rupture plane, in the footwall or at the westernmost tip of the 2003 Boumerdes rupture area. Many aftershocks last over the whole seismic crisis ahead (north) of the main rupture zone, forming a diffuse, low-angle surface within the footwall where the coseismic static stress change is predicted to increase. At the SW tip of the rupture, short-lived clusters locate at intersections of faults near the contact between the inner (Kabylia) and outer (Tell) zones. The tomographic inversion depicts high-velocity P- and S-wave anomalies coinciding with Miocene magmatic intrusive bodies in the upper crust, partially hidden by surrounding basins. The area of the main shock is associated with a large low-velocity body subdivided into sub-domains, including Neogene basins on land and offshore. Our results support a rupture model strongly controlled by geological inhomogeneities and extending as ramp–flat–ramp systems upward, favoring heterogeneous slip and segmentation in the fault plane with strong afterslip toward the surface. The diffuse aftershock activity in the footwall evidences an inherited discontinuity at mid-crustal depth that we interpret as the contact of Kabylian and African (Tethyan) continental crusts that were stacked during the Upper Miocene collision.

Why do aftershocks occur? Relationship between mainshock rupture and aftershock sequence based on highly resolved hypocenter and focal mechanism distributions

In order to clarify the origin of aftershocks, we precisely analyze the hypocenters and focal mechanisms of the aftershocks following the 2000 Western Tottori Earthquake, which occurred in the western part of Japan, using data from dense seismic observations. We investigate whether aftershocks occur on the mainshock fault plane on which coseismic slip occurred or they represent the rupture of fractures surrounding the mainshock fault plane. Based on the hypocenter distribution of the aftershocks, the subsurface fault structure of the mainshock is estimated using principal component analysis. As a result, we can obtain the detail fault structure composed of 8 best-fit planes. We demonstrate that the aftershocks around the mainshock fault are distributed within zones of 1.0–1.5 km in thicknesses, and their focal mechanisms are significantly diverse. This result suggests that most of the aftershocks represent the rupture of fractures surrounding the mainshock fault rather than the rerupture of the mainshock fault. The aftershocks have a much wider zone compared with the exhumed fault zone in field observations, suggesting that many aftershocks occur outside the fault damage zone. We find that most aftershocks except in and around the large-slip region are well explained by coseismic stress changes. These results suggest that the thickness of the aftershock distribution may be controlled by the stress changes caused by the heterogeneous slip distribution during the mainshock. The aftershock is also distributed within a much wider zone than the hypocenter distribution observed in swarm activity in the geothermal region, which is thought to be caused by the migration of hydrothermal fluid. This result implies a difference in generation processes: Stress changes due to the mainshock contribute primarily to the occurrence of aftershocks, whereas earthquake swarms in the geothermal region are caused by fluid migration within the localized zone. Graphical abstract.

Processing and characterization of continuous-cast AlMgSc(Zr) sheets for improved strength

A processing route is devised to enhance the precipitate strengthening in a continuous-cast/cold-rolled Al-3Mg-0.36Sc-0.14Zr alloy. Retaining sufficient Sc in the solid solution due to a higher cooling rate in a belt-caster, the thin as-cast slab also exhibits a fine-grained, uniformly equiaxed grain structure throughout the thickness. In the absence of any homogenization/solutionising treatment, the cold-rolled sheets are heat treated to produce precipitation either during an intermediate or a final age-hardening treatment. It is shown that the Al3Sc precipitates are considerably more effective in strengthening if precipitation occurs between the cold-roll passes, i.e. through an intermediate anneal process, as opposed to an age-hardening treatment at the final gauge. The strengthening mechanism is suggested to be precipitate-induced work hardening through a hybrid shearable/non-shearable interaction between the coherent Al3Sc precipitates and the moving dislocations. Such interactive deformation conditions create a uniform precipitate/dislocation network across the microstructure, as opposed to a heterogeneous slip structure developed in the absence of precipitates. The processing concept developed here enables one to further maximize the strength for a given Sc content in the alloy, thus not only lowering the overall need for Sc but also enabling potential higher-strength applications.

Confined viscoplastic flows with heterogeneous wall slip

The steady, pressure-driven flow of a Herschel-Bulkley fluid in a microchannel is considered, assuming that different power-law slip equations apply at the two walls due to slip heterogeneities, allowing the velocity profile to be asymmetric. Three different flow regimes are observed as the pressure gradient is increased. Below a first critical pressure gradient G 1, the fluid moves unyielded with a uniform velocity, and thus, the two slip velocities are equal. In an intermediate regime between G 1 and a second critical pressure gradient G 2, the fluid yields in a zone near the weak-slip wall and flows with uniform velocity near the stronger-slip wall. Beyond this regime, the fluid yields near both walls and the velocity are uniform only in the central unyielded core. It is demonstrated that the central unyielded region tends towards the midplane only if the power-law exponent is less than unity; otherwise, this region rends towards the weak-slip wall and asymmetry is enhanced. The extension of the different flow regimes depends on the channel gap; in particular, the intermediate asymmetric flow regime dominates when the gap becomes smaller than a characteristic length which incorporates the wall slip coefficients and the fluid properties. The theoretical results compare well with available experimental data on soft glassy suspensions. These results open new routes in manipulating the flow of viscoplastic materials in applications where the flow behavior depends not only on the bulk rheology of the material but also on the wall properties.

Fatigue strain mapping via digital image correlation for Ni-based superalloys: The role of thermal activation on cube slip

A deformation mechanism map for a Ni-based superalloy is presented during cyclic loading at low (300°C), intermediate (550°C), and high (700°C) temperatures for low (0.7%) and high (1.0%) applied strain amplitudes. Strain mapping is performed via digital image correlation (DIC) during interrupted fatigue experiments at elevated temperatures at 1, 10, 100 and 1000 cycles, for each specified loading and temperature condition. The DIC measurements are performed in a scanning electron microscope, which allows high-resolution measurements of heterogeneous slip events and a vacuum environment to ensure stability of the speckle pattern for DIC at high temperatures. The cumulative fatigue experiments show that the slip bands are present in the first cycle and intensify with number of cycles; resulting in highly localized strain accumulation. The strain mapping results are combined with microstructure characterization via electron backscatter diffraction. The combination of crystal orientations and high-resolution strain measurements was used to determine the active slip planes. At low temperatures, slip bands follow the {111} octahedral planes. However, as temperature increases, both the {111} octahedral and {100} cubic slip planes accommodate strain. The activation of cubic slip via cross-slip within the ordered intermetallic γ’ phase has been well documented in Ni-based superalloys and is generally accepted as the mechanism responsible for the anomalous yield phenomenon. The results in this paper represent an important quantifiable study of cubic slip system activity at the mesoscale in polycrystalline γ-γ’ Ni-based superalloys, which is a key advancement to calibrate the thermal activation components of polycrystalline deformation models.

Factors controlling high-frequency radiation from extended ruptures

Small-scale slip heterogeneity or variations in rupture velocity on the fault plane are often invoked to explain the high-frequency radiation from earthquakes. This view has no theoretical basis, which follows, for example, from the representation integral of elasticity, an exact solution for the radiated wave field. The Fourier transform, applied to the integral, shows that the seismic spectrum is fully controlled by that of the source time function, while the distribution of final slip and rupture acceleration/deceleration only contribute to directivity. This inference is corroborated by the precise numerical computation of the full radiated field from the representation integral. We compare calculated radiation from four finite-fault models: (1) uniform slip function with low slip velocity, (2) slip function spatially modulated by a sinusoidal function, (3) slip function spatially modulated by a sinusoidal function with random roughness added, and (4) uniform slip function with high slip velocity. The addition of “asperities,” both regular and irregular, does not cause any systematic increase in the spectral level of high-frequency radiation, except for the creation of maxima due to constructive interference. On the other hand, an increase in the maximum rate of slip on the fault leads to highly amplified high frequencies, in accordance with the prediction on the basis of a simple point-source treatment of the fault. Hence, computations show that the temporal rate of slip, not the spatial heterogeneity on faults, is the predominant factor forming the high-frequency radiation and thus controlling the velocity and acceleration of the resulting ground motions.

Microstructural heterogeneity in rate-dependent plasticity of multiphase titanium alloys

Polycrystalline rate-dependent plasticity is found to originate from heterogeneous slip system/phase rate response. Micro-mechanism under low stress and low temperature (T< 0.3Tm) has been shown to be different from conventional rate sensitivity expectations. Hence the constitutive framework developed is dependent on the crystallographic orientation, properly capturing micro-scale anisotropic rate behaviour.The intrinsic rate anisotropy of the HCP α prism and basal and BCC β phase slip systems in Ti-6242, recently determined from micro-pillar and crystal plasticity modelling, have been utilised to investigate the structural strain rate sensitivities of colonies, polycrystals, bimodal and basket weave microstructures.The rate sensitivity of colony structures is dominated by the HCP α phase behaviour, at least for alloys containing up to ∼20% volume fraction β phase, and is largely independent of β-lath orientation. The apparent anisotropy of a1, a2 and a3 basal resolved shear stresses in Ti-6242 colonies is shown to originate from the local crystal stress states established as opposed to the α−β interfaces.Texture and α−β morphology are shown to affect rate dependence and to corroborate that the basal rate sensitivity is stronger than that for prism slip in Ti-6242. Morphological effects are shown to affect rate dependence but not strongly, but the number of HCP α phase variants in basketweave structures is found to have a significant effect with higher numbers of variants leading to lower strain rate sensitivities. This is potentially important in designing alloys to resist cold dwell fatigue.

Numerical Study of Magnetic Field on Rough Porous Narrow Journal Bearing with Heterogeneous Surface

This paper examines theoretical study of effect of magnetic field on infinitely short rough porous journal bearing with the heterogeneous slip/ no-slip surface. Using Christensen stochastic model, Reynolds equation for uni-directional longitudinal roughness pattern is derived. The expressions for pressure and load carrying capacity are obtained as a function of various parameters like Hartmann number, roughness parameter, slip parameter, permeability parameter. It is observed that inclusion of roughness effect and Hartmann number boosts the load carrying capacity.

Spatial Variability of the Directivity Pulse Periods Observed during an Earthquake

The ground velocity pulses generated by rupture directivity effects in the near‐fault region can cause a large amount of damage to structures. Proper estimation of the period of such velocity pulses is of particular importance in characterizing near‐fault seismic hazard and mitigating potential damage. We propose a simple equation to determine the pulse period as a function of the site location with respect to the fault rupture (defined by the hypocentral distance hypD , the closest distance to the rupture area clsD , and the length of the rupture area that breaks toward the site D ) and some basic rupture properties (average rupture speed and average rise time). Our equation is first validated from a dataset of synthetic velocity time histories, deploying simulations of various strike‐slip extended ruptures in a homogeneous medium. The analysis of the synthetic dataset confirms that the pulse period does not depend on the whole rupture area, but only on the parameter D . It also reveals that the pulse period is not sensitive to the level of slip heterogeneity on the fault plane. Our model is tested next on a real dataset build from the Next Generation Attenuation‐West2 Project database, compiling 110 observations of velocity pulse periods from 10 strike‐slip events and 6 non‐strike‐slip events. The standard deviation of the natural logarithm residuals between observations and predictions is ∼0.5. Furthermore, the correlation coefficient between observations and predictions equals ∼0.8, indicating that despite its simplicity, our model explains fairly well the spatial variability of the pulse periods.

Hybrid stochastic ground motion modeling of the Mw 7.8 Gorkha, Nepal earthquake of 2015 based on InSAR inversion

We derive the coseismic slip distribution on a fault for the 2015, Mw 7.8 Gorkha earthquake based on ALOS-2 wide scan data and the inversion code, SDM (Steepest Descend Method). The results show that the maximum slip is 4.7m, and the total released seismic moment is 6.02×1020Nm, equivalent to an earthquake of Mw ∼7.82. Static stress and slip heterogeneity analyses show that both the average stress drop and corner wavenumber are at a low level. Additionally, we model the observed impulsive behavior at the near-source KATNP station using a hybrid stochastic approach, which combines an analytical approach at low frequencies with a stochastic approach at high frequencies. The good agreement between the hybrid modeling and observed records reveals that the input parameters, such as stress drop or slip distribution, are suitable for the Gorkha earthquake. The success of the modeling indicates that, in addition to the smooth onset of STF (slip-rate time function), the low stress drop and low degree of slip heterogeneity are also responsible for the low level of high-frequency ground motion during the Gorkha earthquake.

Accuracy evaluation of both Wallace-Bott and BEM-based paleostress inversion methods

Four decades after their introduction, the validity of fault slip inversion methods based on Wallace (1951) and Bott (1959) hypothesis, which states that the slip on each fault surface has the same direction and sense as the maximum resolved shear stress, is still a subject of debate. According to some authors, this hypothesis is questionable since fault mechanical interactions induce slip reorientations as confirmed by geomechanical models. This leads us to ask as to what extent the Wallace-Bott simplifications are reliable as a basis hypothesis for stress inversion from fault slip data. In this paper, we compare two inversion methods; the first is based on the Wallace-Bott hypothesis, and the second relies on geomechanics and mechanical effects on fault heterogeneous slip distribution. In that context, a multi-parametric stress inversion study covering (i) the friction coefficients (μ), (ii) the full range of Andersonian state of stress and (iii) slip data sampling along the faults is performed. For each tested parameter, the results of the mechanical stress inversion and the Wallace-Bott (WB) based stress inversion for slip are compared in order to understand their respective effects. The predicted discrepancy between the solutions of both stress inversion methods (based on WB and mechanics) will then be used to explain the stress inversions results for the chimney Rock case study. It is shown that a high solution discrepancy is not always correlated with the misfit angle (ω) and can be found under specific configurations (R−, θ, μ, geometry) invalidating the WB solutions. We conclude that in most cases the mechanical stress inversion and the WB based stress inversion are both valid and complementary depending on the fault friction. Some exceptions (i.e. low fault friction, simple fault geometry and pure regimes) that may lead to wrong WB based stress inversion solutions are highlighted.

Slip heterogeneity and directivity of the ML 6.0, 2016, Amatrice earthquake estimated with rapid finite‐fault inversion

AbstractOn 24 August 2016 a magnitude ML 6.0 occurred in the Central Apennines (Italy) between Amatrice and Norcia causing nearly 300 fatalities. The main shock ruptured a NNW‐SSE striking, WSW dipping normal fault. We invert waveforms from 26 three‐component strong motion accelerometers, filtered between 0.02 and 0.5 Hz, within 45 km from the fault. The inferred slip distribution is heterogeneous and characterized by two shallow slip patches updip and NW from the hypocenter, respectively. The rupture history shows bilateral propagation and a relatively high rupture velocity (3.1 km/s). The imaged rupture history produced evident directivity effects both N‐NW and SE of the hypocenter, explaining near‐source peak ground motions. Fault dimensions and peak slip values are large for a moderate‐magnitude earthquake. The retrieved rupture model fits the recorded ground velocities up to 1 Hz, corroborating the effects of rupture directivity and slip heterogeneity on ground shaking and damage pattern.

Shallow slip amplification and enhanced tsunami hazard unravelled by dynamic simulations of mega-thrust earthquakes.

The 2011 Tohoku earthquake produced an unexpected large amount of shallow slip greatly contributing to the ensuing tsunami. How frequent are such events? How can they be efficiently modelled for tsunami hazard? Stochastic slip models, which can be computed rapidly, are used to explore the natural slip variability; however, they generally do not deal specifically with shallow slip features. We study the systematic depth-dependence of slip along a thrust fault with a number of 2D dynamic simulations using stochastic shear stress distributions and a geometry based on the cross section of the Tohoku fault. We obtain a probability density for the slip distribution, which varies both with depth, earthquake size and whether the rupture breaks the surface. We propose a method to modify stochastic slip distributions according to this dynamically-derived probability distribution. This method may be efficiently applied to produce large numbers of heterogeneous slip distributions for probabilistic tsunami hazard analysis. Using numerous M9 earthquake scenarios, we demonstrate that incorporating the dynamically-derived probability distribution does enhance the conditional probability of exceedance of maximum estimated tsunami wave heights along the Japanese coast. This technique for integrating dynamic features in stochastic models can be extended to any subduction zone and faulting style.

How heterogeneous coseismic slip affects regional probabilistic tsunami hazard assessment: A case study in the South China Sea

AbstractRupture complexity, typically in the form of heterogeneous slip distribution pattern, significantly affects the local tsunami wave field. However, the effect of rupture complexity is not commonly considered in any form of tsunami hazard assessment. Taking rupture complexity into account significantly increases the computational load, particularly in regional‐scaled probabilistic tsunami hazard assessments (PTHAs) that usually require a large number of simulations based on synthetic scenarios. In this study, we investigate how the heterogeneous slip distribution affects the regional‐scaled PTHA by taking the South China Sea (SCS) as an example. By doing this, we update PTHA for the SCS by incorporating the best available information of seismic tsunamigenic sources along the Manila megathrust. We integrate a stochastic source model into a Monte Carlo‐type simulation, in which a broad range of slip distribution patterns is generated for large numbers of synthetic earthquake events. Green's function technique is employed to efficiently calculate the nearshore tsunami wave amplitude along the SCS coastlines. Our result suggests that for a relatively small and confined region like the SCS, the commonly used approach based on the uniform slip model significantly underestimates tsunami hazard not only in the near‐source region like west Luzon, as expected, but also in the relative far field, such as south China and central Vietnam. Additionally, our sensitivity test of the patch size effects suggests that large patch size is unable to adequately resolve the details of heterogeneous seafloor deformation, and such approaches considerably underestimate the potential tsunami hazard for the SCS coasts.

Dislocations and deformation microstructure in a B2-ordered Al28Co20Cr11Fe15Ni26 high-entropy alloy.

High-entropy alloys are multicomponent metallic materials currently attracting high research interest. They display a unique combination of chemical disorder and crystalline long-range order, and due to their attractive properties are promising candidates for technological application. Many high-entropy alloys possess surprisingly high strength, occasionally in combination with high ductility and low density. The mechanisms effecting these attractive mechanical properties are not understood. This study addresses the deformation mechanism of a Al28Co20Cr11Fe15Ni26 high-entropy alloy, which is a two-phase material, consisting of a B2-ordered matrix and disordered body-centred inclusions. We quantitatively analyse the microstructure and dislocations in deformed samples by transmission-electron-microscopic methods including weak-beam imaging and convergent-beam electron diffraction. We find that the deformation process in the B2 phase is dominated by heterogeneous slip of screw dislocations gliding on planes. The dislocations are perfect superdislocations of the B2 lattice and show no dissociation. This indicates that the antiphase-boundary energy in the structure is very high, inhibiting spread of the dislocation core. Along with the observation of a widely extending strain field associated to the dislocations, our results provide a possible explanation for the high strength of this high-entropy alloy as a direct consequence of its dislocation structure.

Can slip heterogeneity be linked to earthquake recurrence?

AbstractThe rupture process of two M4 repeating earthquake sequences in eastern Taiwan with contrasting recurrence behavior is investigated to demonstrate a link between slip heterogeneity and earthquake recurrence. The M3.6–3.8 quasiperiodic repeating earthquakes characterized by 3 years recurrence interval reveal overlapped slip concentrations. Inferred slip distribution for each event illustrates two asperities with peak slip of 47.7 cm and peak stress drop of 151.1 MPa. Under the influence of nearby M6.9 event, the M4.3–4.8 repeating earthquakes separated only by 6–87 min, however, reveal an aperiodic manner. There is a distinct rupture characteristic without overlap in the slip areas, suggesting that shortening of the recurrence interval by the nearby large earthquake may change the slip heterogeneity in a repeatedly ruptured asperity. We conclude that the inherent heterogeneity of stress and strength could influence the distribution of coseismic slip, which is strongly tied to the recurrence behavior.

Evidence for Truncated Exponential Probability Distribution of Earthquake Slip

Earthquake ruptures comprise spatially varying slip on the fault surface, where slip represents the displacement discontinuity between the two sides of the rupture plane. In this study, we analyze the probability distribution of coseismic slip, which provides important information to better understand earthquake source physics. Although the probability distribution of slip is crucial for generating realistic rupture scenarios for simulation‐based seismic and tsunami‐hazard analysis, the statistical properties of earthquake slip have received limited attention so far. Here, we use the online database of earthquake source models (SRCMOD) to show that the probability distribution of slip follows the truncated exponential law. This law agrees with rupture‐specific physical constraints limiting the maximum possible slip on the fault, similar to physical constraints on maximum earthquake magnitudes. We show the parameters of the best‐fitting truncated exponential distribution scale with average coseismic slip. This scaling property reflects the control of the underlying stress distribution and fault strength on the rupture dimensions, which determines the average slip. Thus, the scale‐dependent behavior of slip heterogeneity is captured by the probability distribution of slip. We conclude that the truncated exponential law accurately quantifies coseismic slip distribution and therefore allows for more realistic modeling of rupture scenarios. Online Material: Figures showing scaling of slip area with seismic moment and Q – Q plots and tables listing earthquakes, rupture models, and fits of various distributions to the empirical probability distribution.