Correction to: Earthquake energy dissipation in a fracture mechanics framework (Nature Communications, (2024), 15, 1, (4736), 10.1038/s41467-024-47970-6) David S. Kammer, Gregory C. McLaskey, Rachel E. Abercrombie, Jean-Paul Ampuero, Camilla Cattania, Massimo Cocco, Luca Dal Zilio, Georg Dresen, Alice-Agnes Gabriel, Chun-Yu Ke, Chris Marone, Paul Antony Selvadurai, Elisa Tinti Nature Communications, 2024 The original version of this Article contained an error in the Acknowledgement Section, which incorrectly omitted the following: ‘Massimo Cocco participated in this work as Principal Investigator of the European Research Council (ERC) project FEAR (grant agreement No 856559) under the European Community’s Horizon 2020 Framework Programme. Paul Selvadurai, Elisa Tinti and Luca Dal Zilio participated in this work in the framework of the European Research Council (ERC) project FEAR (grant agreement No 856559) under the European Community’s Horizon 2020 Framework Programme.’ This has been corrected in both the PDF and HTML versions of the Article.
Earthquake energy dissipation in a fracture mechanics framework David S. Kammer, Gregory C. McLaskey, Rachel E. Abercrombie, Jean-Paul Ampuero, Camilla Cattania, Massimo Cocco, Luca Dal Zilio, Georg Dresen, Alice-Agnes Gabriel, Chun-Yu Ke, Chris Marone, Paul Antony Selvadurai, Elisa Tinti Nature Communications, 2024 Earthquakes are rupture-like processes that propagate along tectonic faults and cause seismic waves. The propagation speed and final area of the rupture, which determine an earthquake’s potential impact, are directly related to the nature and quantity of the energy dissipation involved in the rupture process. Here, we present the challenges associated with defining and measuring the energy dissipation in laboratory and natural earthquakes across many scales. We discuss the importance and implications of distinguishing between energy dissipation that occurs close to and far behind the rupture tip, and we identify open scientific questions related to a consistent modeling framework for earthquake physics that extends beyond classical Linear Elastic Fracture Mechanics.
The influence of AGEs and enzymatic cross-links on the mechanical properties of collagen fibrils Julia Kamml, Chun-Yu Ke, Claire Acevedo, David S. Kammer Journal of the Mechanical Behavior of Biomedical Materials, 2023 Collagen, one of the main building blocks for various tissues, derives its mechanical properties directly from its structure of cross-linked tropocollagen molecules. The cross-links are considered to be a key component of collagen fibrils as they can change the fibrillar behavior in various ways. For instance, enzymatic cross-links (ECLs), one particular type of cross-links, are known for stabilizing the structure of the fibril and improving material properties, while cross-linking AGEs (Advanced-Glycation Endproducts) have been shown to accumulate and impair the mechanical properties of collageneous tissues. However, the reasons for whether and how a given type of cross-link improves or impairs the material properties remain unknown, and the exact relationship between the cross-link properties and density, and the fibrillar behavior is still not well understood. Here, we use coarse-grained steered molecular models to evaluate the effect of AGEs and ECLs cross-links content on the deformation and failure properties of collagen fibrils. Our simulations show that the collagen fibrils stiffen at high strain levels when the AGEs content exceeds a critical value. In addition, the strength of the fibril increases with AGEs accumulation. By analyzing the forces within the different types of cross-links (AGEs and ECLs) as well as their failure, we demonstrate that a change of deformation mechanism is at the origin of these observations. A high AGEs content reinforces force transfer through AGEs cross-links rather than through friction between sliding tropocollagen molecules, which leads to failure by breaking of bonds within the tropocollagen molecules. We show that this failure mechanism, which is associated with lower energy dissipation, results in more abrupt failure of the collagen fibril. Our results provide a direct and causal link between increased AGEs content, inhibited intra-fibrillar sliding, increased stiffness, and abrupt fibril fracture. Therefore, they explain the mechanical origin of bone brittleness as commonly observed in elderly and diabetic populations. Our findings contribute to a better understanding of the mechanisms underlying impaired tissue behavior due to elevated AGEs content and could enable targeted measures regarding the reduction of specific collagen cross-linking levels.
Earthquake breakdown energy scaling despite constant fracture energy Chun-Yu Ke, Gregory C. McLaskey, David S. Kammer Nature Communications, 2022 In the quest to determine fault weakening processes that govern earthquake mechanics, it is common to infer the earthquake breakdown energy from seismological measurements. Breakdown energy is observed to scale with slip, which is often attributed to enhanced fault weakening with continued slip or at high slip rates, possibly caused by flash heating and thermal pressurization. However, seismologically inferred breakdown energy varies by more than six orders of magnitude and is frequently found to be negative-valued. This casts doubts about the common interpretation that breakdown energy is a proxy for the fracture energy, a material property which must be positive-valued and is generally observed to be relatively scale independent. Here, we present a dynamic model that demonstrates that breakdown energy scaling can occur despite constant fracture energy and does not require thermal pressurization or other enhanced weakening. Instead, earthquake breakdown energy scaling occurs simply due to scale-invariant stress drop overshoot, which may be affected more directly by the overall rupture mode – crack-like or pulse-like – rather than from a specific slip-weakening relationship.
Creep fronts and complexity in laboratory earthquake sequences illuminate delayed earthquake triggering Sara Beth L. Cebry, Chun-Yu Ke, Srisharan Shreedharan, Chris Marone, David S. Kammer, Gregory C. McLaskey Nature Communications, 2022 Earthquakes occur in clusters or sequences that arise from complex triggering mechanisms, but direct measurement of the slow subsurface slip responsible for delayed triggering is rarely possible. We investigate the origins of complexity and its relationship to heterogeneity using an experimental fault with two dominant seismic asperities. The fault is composed of quartz powder, a material common to natural faults, sandwiched between 760 mm long polymer blocks that deform the way 10 meters of rock would behave. We observe periodic repeating earthquakes that transition into aperiodic and complex sequences of fast and slow events. Neighboring earthquakes communicate via migrating slow slip, which resembles creep fronts observed in numerical simulations and on tectonic faults. Utilizing both local stress measurements and numerical simulations, we observe that the speed and strength of creep fronts are highly sensitive to fault stress levels left behind by previous earthquakes, and may serve as on-fault stress meters.
The Role of Background Stress State in Fluid-Induced Aseismic Slip and Dynamic Rupture on a 3-m Laboratory Fault S. B. L. Cebry, C.‐Y. Ke, G. C. McLaskey Journal of Geophysical Research Solid Earth, 2022 Fluid injection stimulates seismicity far from active tectonic regions. However, the details of how fluids modify on‐fault stresses and initiate seismic events remain poorly understood. We conducted laboratory experiments using a biaxial loading apparatus with a 3 m saw‐cut granite fault and compared events induced at different levels of background shear stress. Water was injected at 10 mL/min and normal stress was constant at 4 MPa. In all experiments, aseismic slip initiated on the fault near the location of fluid injection and dynamic rupture eventually initiated from within the aseismic slipping patch. When the fault was near critically stressed, seismic slip initiated only seconds after MPa‐level injection pressures were reached and the dynamic rupture propagated beyond the fluid pressure perturbed region. At lower stress levels, dynamic rupture initiated hundreds of seconds later and was limited to regions where aseismic slip had significantly redistributed stress from within the pressurized region to neighboring locked patches. We found that the initiation of slow slip was broadly consistent with a Coulomb failure stress, but that initiation of dynamic rupture required additional criteria to be met. Even high background stress levels required aseismic slip to modify on‐fault stress to meet initiation criteria. We also observed slow slip events prior to dynamic rupture. Overall, our experiments suggest that initial fault stress, relative to fault strength, is a critical factor in determining whether a fluid‐induced rupture will “runaway” or whether a fluid‐induced rupture will remain localized to the fluid pressurized region.
UGUCA: A spectral-boundary-integral method for modeling fracture and friction David S. Kammer, Gabriele Albertini, Chun-Yu Ke Softwarex, 2021 Uguca is a C++ parallel implementation of the spectral-boundary-integral method to model the dynamic failure of interfaces between two elastic half-spaces. Due to its computational efficiency, uguca is suitable for fundamental research on dynamic fracture mechanics, decohesion of composite interfaces, and the onset of frictional sliding. Therefore, its potential applications range from engineering sciences to earthquake mechanics modeling. The code architecture of uguca enables straight-forward implementation of additional constitutive interface laws, which provides the user with the option of tailoring the interface mechanics to the physics of their interest.
The earthquake arrest zone Chun-Yu Ke, Gregory C McLaskey, David S Kammer Geophysical Journal International, 2021 SUMMARY Earthquake ruptures are generally considered to be cracks that propagate as fracture or frictional slip on pre-existing faults. Crack models have been used to describe the spatial distribution of fault offset and the associated static stress changes along a fault, and have implications for friction evolution and the underlying physics of rupture processes. However, field measurements that could help refine idealized crack models are rare. Here, we describe large-scale laboratory earthquake experiments, where all rupture processes were contained within a 3-m long saw-cut granite fault, and we propose an analytical crack model that fits our measurements. Similar to natural earthquakes, laboratory measurements show coseismic slip that gradually tapers near the rupture tips. Measured stress changes show roughly constant stress drop in the centre of the ruptured region, a maximum stress increase near the rupture tips and a smooth transition in between, in a region we describe as the earthquake arrest zone. The proposed model generalizes the widely used elliptical crack model by adding gradually tapered slip at the ends of the rupture. Different from the cohesive zone described by fracture mechanics, we propose that the transition in stress changes and the corresponding linear taper observed in the earthquake arrest zone are the result of rupture termination conditions primarily controlled by the initial stress distribution. It is the heterogeneous initial stress distribution that controls the arrest of laboratory earthquakes, and the features of static stress changes. We also performed dynamic rupture simulations that confirm how arrest conditions can affect slip taper and static stress changes. If applicable to larger natural earthquakes, this distinction between an earthquake arrest zone (that depends on stress conditions) and a cohesive zone (that depends primarily on strength evolution) has important implications for how seismic observations of earthquake fracture energy should be interpreted.
Rupture Termination in Laboratory-Generated Earthquakes Chun‐Yu Ke, Gregory C. McLaskey, David S. Kammer Geophysical Research Letters, 2018 Earthquakes are dynamic rupture events that initiate, propagate, and terminate on faults within the Earth's crust. Understanding rupture termination is essential for accurately estimating the maximum magnitude earthquake a region might experience. We study termination on sequences of M − 2.5 earthquakes that rupture a 3‐m granite laboratory sample. At this large scale, nucleation, propagation, and termination are either completely or partially confined within the sample–unique observations for experiments on rock. We compare measured termination locations to estimates from a fracture mechanics‐based model to quantify the fracture energy of the laboratory earthquakes, which compare well with estimates from small natural quakes. Our results provide a mathematical framework that links micrometer‐scale friction parameters to meter‐scale earthquake mechanics, shows that a 3‐m slab of granite can behave similar to a 200‐mm sheet of glassy polymer, and demonstrates how small events can prime a fault for larger, damaging ones.
RECENT SCHOLAR PUBLICATIONS
Physical Controls on the Shape of Earthquake Source Time Functions CY Wang, CY Ke 2026
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Earthquake Populations from Stochastic Stress Fields GC McLaskey, D Kammer, CY Ke ESS Open Archive eprints 518, 92073 , 2025 2025
Earthquake Rupture Speed Dependence on Normal Stress in Laboratory Experiments CY Ke, G Chang, G McLaskey, C Marone EGU General Assembly Conference Abstracts, EGU25-8191 , 2025 2025
Scripts from: Nonlocal dissipation far from the rupture tip affects both rupture dynamics and arrest DJ Basu, CY Ke, DS Kammer, GC McLaskey 2025
Data for: Linear and nonlinear elastodynamic signatures of fractured rock in relation to fault characteristics inferred from in-situ synchrotron X-ray computed tomography E Bozek, P Borate, M Rivers, C Wood, C Ke, LSS Pillarisetti, C Williams, ... 2025
Author Correction: Earthquake energy dissipation in a fracture mechanics framework DS Kammer, GC McLaskey, RE Abercrombie, JP Ampuero, C Cattania, ... nature communications 15 (1), 5146 , 2024 2024
Earthquake energy dissipation in a fracture mechanics framework DS Kammer, GC McLaskey, RE Abercrombie, JP Ampuero, C Cattania, ... Nature communications 15 (1), 4736 , 2024 2024 Citations: 56
Earthquake energy dissipation in a fracture mechanics framework. Nat Commun 15: 4736 DS Kammer, GC McLaskey, RE Abercrombie, JP Ampuero, C Cattania, ... 2024 Citations: 5
Understanding elastic wave propagation across rough interfaces in stressed fractured rock through coupled in-situ synchrotron X-ray imaging and ultrasound E Bozek, P Borate, M Skiadopoulos, C Williams, CY Ke, C Wood, ... AGU Fall Meeting Abstracts 2023, MR12A-04 , 2023 2023
Complex laboratory earthquake sequences and direct observations of creep fronts illuminate the mechanics of delayed earthquake triggering SBL Cebry, CY Ke, S Shreedharan, C Marone, DS Kammer, ... AGU Fall Meeting Abstracts 2023, MR11A-02 , 2023 2023
The influence of AGEs and enzymatic cross-links on the mechanical properties of collagen fibrils J Kamml, CY Ke, C Acevedo, DS Kammer journal of the mechanical behavior of biomedical materials 143, 105870 , 2023 2023 Citations: 66
Complex laboratory earthquake sequences show asperity interactions through creep fronts and illuminate the mechanics of delayed earthquake triggering SB Cebry, CY Ke, S Shreedharan, C Marone, D Kammer, G McLaskey EGU General Assembly Conference Abstracts, EGU-10664 , 2023 2023
Understanding contact acoustic nonlinearity through coupled synchrotron x-ray imaging and dynamic acoustoelastic measurements under stress CY Ke, P Borate, C Wood, M Rivers, J Riviere, P Shokouhi The Journal of the Acoustical Society of America 153 (3_supplement), A202-A202 , 2023 2023
Illuminating Fundamental Processes Governing Evolution of Fault Zone Permeability and Elastodynamic Properties due to Dynamic Stressing using a Coupled X-Ray Imaging and Active … CY Ke, P Borate, C Marone, D Elsworth, J Riviere, P Shokouhi AGU Fall Meeting Abstracts 2022, H51F-02 , 2022 2022
An Integrated Experimental and Multi-Physics Numerical Study on the Interplay Between Hydraulic and Elastic Properties of Fractured Rock Interfaces Under Stress Perturbations CY Ke, C Wood, A Rathbun, C Marone, D Elsworth, J Riviere, P Shokouhi AGU Fall Meeting Abstracts 2022, MR55A-07 , 2022 2022
Decoupling the poromechanics of particle remobilization and interface stiffness of dynamically stressed tensile fractured rock C Wood, CY Ke, J Riviere, D Elsworth, C Marone, P Shokouhi AGU Fall Meeting Abstracts 2022, MR45B-0072 , 2022 2022
Creep fronts and complexity in laboratory earthquake sequences illuminate delayed earthquake triggering SBL Cebry, CY Ke, S Shreedharan, C Marone, DS Kammer, ... Nature Communications 13 (1), 6839 , 2022 2022 Citations: 45
Data from: Creep fronts and complexity in laboratory earthquake sequences illuminate delayed earthquake triggering SBL Cebry, CY Ke, S Shreedharan, C Marone, DS Kammer, ... 2022
Raw Simulation Data: Creep fronts and complexity in laboratory earthquake sequences illuminate delayed earthquake triggering CY Ke, GC McLaskey, DS Kammer ETH Zurich , 2022 2022
The influence of AGEs and enzymatic cross-links on the mechanical properties of collagen fibrils J Kamml, CY Ke, C Acevedo, DS Kammer journal of the mechanical behavior of biomedical materials 143, 105870 , 2023 2023 Citations: 66
Earthquake energy dissipation in a fracture mechanics framework DS Kammer, GC McLaskey, RE Abercrombie, JP Ampuero, C Cattania, ... Nature communications 15 (1), 4736 , 2024 2024 Citations: 56
Creep fronts and complexity in laboratory earthquake sequences illuminate delayed earthquake triggering SBL Cebry, CY Ke, S Shreedharan, C Marone, DS Kammer, ... Nature Communications 13 (1), 6839 , 2022 2022 Citations: 45
The role of background stress state in fluid‐induced aseismic slip and dynamic rupture on a 3‐m laboratory fault SBL Cebry, CY Ke, GC McLaskey Journal of Geophysical Research: Solid Earth 127 (8), e2022JB024371 , 2022 2022 Citations: 43
The Earthquake Arrest Zone CY Ke, GC McLaskey, DS Kammer Geophysical Journal International 224 (1), 581-589 , 2021 2021 Citations: 38
UGUCA: A spectral-boundary-integral method for modeling fracture and friction DS Kammer, G Albertini, CY Ke SoftwareX 15, 100785 , 2021 2021 Citations: 19
Groove generation and coalescence on a large‐scale laboratory fault EE Brodsky, GC McLaskey, CY Ke AGU Advances 1 (4), e2020AV000184 , 2020 2020 Citations: 12
Earthquake energy dissipation in a fracture mechanics framework. Nat Commun 15: 4736 DS Kammer, GC McLaskey, RE Abercrombie, JP Ampuero, C Cattania, ... 2024 Citations: 5
Physical Controls on the Shape of Earthquake Source Time Functions CY Wang, CY Ke 2026
Scripts from: Earthquake Populations from Stochastic Stress Fields GC Mclaskey, DS Kammer, CY Ke 2026
Earthquake Populations from Stochastic Stress Fields GC McLaskey, D Kammer, CY Ke ESS Open Archive eprints 518, 92073 , 2025 2025
Earthquake Rupture Speed Dependence on Normal Stress in Laboratory Experiments CY Ke, G Chang, G McLaskey, C Marone EGU General Assembly Conference Abstracts, EGU25-8191 , 2025 2025
Scripts from: Nonlocal dissipation far from the rupture tip affects both rupture dynamics and arrest DJ Basu, CY Ke, DS Kammer, GC McLaskey 2025
Data for: Linear and nonlinear elastodynamic signatures of fractured rock in relation to fault characteristics inferred from in-situ synchrotron X-ray computed tomography E Bozek, P Borate, M Rivers, C Wood, C Ke, LSS Pillarisetti, C Williams, ... 2025
Author Correction: Earthquake energy dissipation in a fracture mechanics framework DS Kammer, GC McLaskey, RE Abercrombie, JP Ampuero, C Cattania, ... nature communications 15 (1), 5146 , 2024 2024
Understanding elastic wave propagation across rough interfaces in stressed fractured rock through coupled in-situ synchrotron X-ray imaging and ultrasound E Bozek, P Borate, M Skiadopoulos, C Williams, CY Ke, C Wood, ... AGU Fall Meeting Abstracts 2023, MR12A-04 , 2023 2023
Complex laboratory earthquake sequences and direct observations of creep fronts illuminate the mechanics of delayed earthquake triggering SBL Cebry, CY Ke, S Shreedharan, C Marone, DS Kammer, ... AGU Fall Meeting Abstracts 2023, MR11A-02 , 2023 2023
Complex laboratory earthquake sequences show asperity interactions through creep fronts and illuminate the mechanics of delayed earthquake triggering SB Cebry, CY Ke, S Shreedharan, C Marone, D Kammer, G McLaskey EGU General Assembly Conference Abstracts, EGU-10664 , 2023 2023
