Earthquake energy dissipation in a fracture mechanics framework David S. Kammer, Gregory C. McLaskey, Rachel E. Abercrombie, Jean-Paul Ampuero, Camilla Cattania, et al. 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.
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, et al. 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.
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
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
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
