Article
Geochemistry & Geophysics
Jessica McBeck, Karen Mair, Francois Renard
Summary: Two key parameters, the strength and roughness of pre-existing fault surfaces, control the localization of deformation and seismicity along and surrounding crustal faults. Various models have been studied to investigate the mechanical behavior of healed faults in granite blocks during quasi-static triaxial compression. The anisotropy and amplitude of fault roughness are found to influence fracture network localization, fault slip, and stress concentrations along healed faults. Contrary to expectations, the compressive strengths of models with faults of varying roughness do not show significant variations, and fault roughness does not evolve similarly with slip. Smoother faults remain smoother throughout the simulation, but rougher faults produce more gouge, lubricating the fault and reducing the influence of roughness on compressive strength. Asperities on fault surfaces control slip by hindering fault-plane parallel slip and promoting fault-plane normal opening during fault movement.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
So Ozawa, Ryosuke Ando
Summary: The study suggests that aftershocks are likely to occur along the trace of the mainshock fault, but their exact location is uncertain due to positioning errors. It is hypothesized that most aftershocks actually occur on small subsidiary faults triggered by local stress increases resulting from the rough geometry of the mainshock fault. Numerical simulations show that the roughness of the main fault decreases the concentration of aftershocks around the tip of the mainshock fault.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Sam Wimpenny, Natalie Forrest, Alex Copley
Summary: Two almost identical M5.8 earthquakes occurred in the Mochiyama Fault in the Ibaraki-Fukushima region of Japan in 2011 and 2016. The short repeat time between the two earthquakes provides a rare opportunity to estimate the evolution of stress on the fault. Using observations of crustal deformation and numerical models, it was found that the rupture area on the Mochiyama Fault was reloaded by up to 50-80% of the stress drop from the 2011 earthquake. The weakening of the fault in the intervening 6 years suggests temporal changes in fault strength may modulate the timing of moderate-magnitude earthquakes.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Ryo Mizushima, Takahiro Hatano
Summary: This study investigates the dynamics of sliding friction, focusing on the state variable and slip velocity of the sliding interface. It reveals the challenge of reproducing stable periodic motion without radiation damping, and proposes two new evolution equations as potential solutions. These equations are examined in terms of experimental validity and relevance to slow earthquakes.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
N. M. Beeler
Summary: This article investigates the occurrence mechanism of low-frequency earthquakes on the San Andreas fault. The study finds that the dependence of brittle fault strength is significant for the occurrence of earthquakes. Additionally, the research reveals that pore pressure also plays a role in earthquake occurrence.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Editorial Material
Geochemistry & Geophysics
Ze'ev Reches, Jay Fineberg
Summary: Earthquakes are caused by dynamic fractures due to overstresses, not governed by the frictional properties of faults. Frictional interfaces can sustain a wide range of stresses before sliding, generating stress-fields and rupture dynamics. The values of stresses and energy dissipation are determined by fault frictional properties.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Naoyuki Kato
Summary: The numerical simulation studied earthquake cycles at a subduction zone using a specific friction law, finding that stable sliding occurs in deeper regions with velocity-strengthening friction while simulated earthquakes occur repeatedly in shallower regions. The detachment of plates due to shear stress concentration during interseismic periods leads to aseismic sliding events with lower velocities.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
A. Taboada, M. Renouf
Summary: We studied the formation and growth of a dry granular shear zone under seismic shearing and flash heating using a discrete element method. Our findings revealed that the shear zone undergoes three distinct phases: rupture initiation, shear-zone growth, and shear weakening. This research is important for understanding the behavior and mechanisms of rock shear zones.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Michel Bouchon, Hayrullah Karabulut, Mustafa Aktar, Serdar Ozalaybey, Jean Schmittbuhl, Marie-Paule Bouin, David Marsan
Summary: The text discusses the uncertainty around the seismic activity preceding earthquakes, questioning whether it is random or indicates an impending rupture. By studying the nucleation of the Izmit and Duzce earthquakes, it is found that slow aseismic slip plays a key role in their nucleation process.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Colin N. Pennington, Qimin Wu, Xiaowei Chen, Rachel E. Abercrombie
Summary: It is important to study the rupture complexity of small earthquakes to understand their possible causes and effects. In the Parkfield, California area, we analyzed microearthquakes recorded by a high-resolution borehole network to quantify earthquake complexity. We found that complexity can be detected in earthquakes larger than magnitude 2, with the best resolution above M2.5. Ignoring the complexity of these small events can introduce errors or uncertainties in stress drop measurements, while focusing only on simple events could lead to bias and a lack of measurements in structurally complex regions.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Yoshihisa Iio, Satoshi Matsumoto, Yusuke Yamashita, Shin'ichi Sakai, Kazuhide Tomisaka, Masayo Sawada, Takashi Iidaka, Takaya Iwasaki, Megumi Kamizono, Hiroshi Katao, Aitaro Kato, Eiji Kurashimo, Yoshiko Teguri, Hiroo Tsuda, Takashi Ueno
Summary: To determine the sizes of earthquakes, we analyzed data from a temporary seismic observation network in the aftershock area of the 2016 Mw 6.2 Central Tottori earthquake in Japan. We compared the stress field estimated from focal mechanisms of aftershocks with the post-earthquake stress field and found that the differential stress before the earthquake was small near the horizontal edges. Similar results were obtained for the 2000 Mw 6.7 Western Tottori earthquake. This suggests that the fault size of large intraplate earthquakes can be determined by the region of small differential stress surrounding future earthquake faults.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
G. Pozzi, C. Collettini, M. M. Scuderi, T. Tesei, C. Marone, A. Amodio, M. Cocco
Summary: Magnetite-rich serpentinites, found in low-strain domains of shear zones, have the potential to nucleate unstable slip and induce earthquakes, especially at low slip velocities. Through laboratory experiments, we demonstrate that these rocks display strong sensitivity to loading rate and undergo two deformation mechanisms depending on mineralogical composition and structure, leading to stable and unstable slip.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Multidisciplinary Sciences
J. Biemiller, A. -A. Gabriel, T. Ulrich
Summary: Despite a lack of modern large earthquakes on shallowly dipping normal faults, evidence of Holocene M-w > 7 low-angle normal fault (LANF; dip<30 degrees) ruptures is found from paleoseismic and historical earthquake and tsunami accounts. However, the effects of non-linear off-fault plasticity and dynamically reactivated splay faults on shallow deformation and surface displacements in megathrust earthquakes are still not well-understood. In this study, the authors develop data-constrained 3D dynamic rupture models to investigate the competing mechanisms of shallow deformation during large LANF earthquakes, highlighting the role of synthetic splays and inelastic hanging-wall yielding in limiting shallow LANF rupture.
NATURE COMMUNICATIONS
(2023)
Article
Geochemistry & Geophysics
Francesco Lazari, Angela Castagna, Stefan Nielsen, Ashley Griffith, Giorgio Pennacchioni, Rodrigo Gomila, Phil Resor, Chiara Cornelio, Giulio Di Toro
Summary: The frictional power per unit area Q played a crucial role in controlling earthquake rupture nucleation, propagation, and arrest. However, determining Q using geophysical methods is challenging. In this study, we estimated Q dissipated on a fault patch exhumed from 7-9 km depth by combining theoretical models, experimental data, and geological constraints. Our findings suggest that the grain-scale roughness of the boundary between frictional melt and host rock decreases with increasing Q. The estimated Q values range from 4-60 MW m-2, which are at the lower end of previous estimates.(c) 2023 Elsevier B.V. All rights reserved.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Chemistry, Physical
Saviz Mowlavi, Ken Kamrin
Summary: The study investigates how hysteresis and nonlocality in granular materials interact with each other, incorporating the non-monotonicity of the flow rule into the nonlocal granular fluidity (NGF) model. By artificially tuning the strength of nonlocal diffusion, it is demonstrated that both ingredients are key to explaining certain features of the hysteretic transition between flow and arrest. The ability of the NGF model to quantitatively predict material behavior around the transition and in the flowing regime is assessed through stress-driven discrete element method (DEM) simulations.
Article
Materials Science, Multidisciplinary
Michael Mello, Harsha S. Bhat, Ares J. Rosakis
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2016)
Article
Multidisciplinary Sciences
Vahe Gabuchian, Ares J. Rosakis, Harsha S. Bhat, Raul Madariaga, Hiroo Kanamori
Article
Multidisciplinary Sciences
V. Rubino, A. J. Rosakis, N. Lapusta
NATURE COMMUNICATIONS
(2017)
Article
Materials Science, Multidisciplinary
V. Rubino, N. Lapusta, A. J. Rosakis, S. Leprince, J. P. Avouac
EXPERIMENTAL MECHANICS
(2015)
Article
Mechanics
Jonathan M. Mihaly, Jonathan D. Tandy, A. J. Rosakis, M. A. Adams, D. Pullin
JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME
(2015)
Article
Physics, Applied
J. D. Tandy, J. M. Mihaly, M. A. Adams, A. J. Rosakis
JOURNAL OF APPLIED PHYSICS
(2014)
Editorial Material
Mechanics
Ares J. Rosakis
JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME
(2019)
Article
Multidisciplinary Sciences
M. Gori, V Rubino, A. J. Rosakis, N. Lapusta
NATURE COMMUNICATIONS
(2018)
Article
Geochemistry & Geophysics
V Rubino, A. J. Rosakis, N. Lapusta
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2020)
Article
Multidisciplinary Sciences
Yuval Tal, Vito Rubino, Ares J. Rosakis, Nadia Lapusta
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2020)
Article
Multidisciplinary Sciences
Ahmed Elbanna, Mohamed Abdelmeguid, Xiao Ma, Faisal Amlani, Harsha S. Bhat, Costas Synolakis, Ares J. Rosakis
Summary: Research has shown that ground motions due to strike-slip earthquakes can contribute to the generation of large tsunamis under certain conditions. Supershear ruptures propagating along strike-slip faults, traversing narrow and shallow bays, are prime candidates for tsunami generation. The characteristic dynamic focusing and large horizontal displacements of strike-slip earthquakes are critical drivers for tsunami hazard.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Engineering, Mechanical
Kaiwen Xia, J. Ares Rosakis
Summary: The study investigates the effect of Low Velocity Zone (LVZ) on faulting using a laboratory fault model. Results show that the thickness of LVZ and the load level can affect the rupture speed and mode of the fault.
EXTREME MECHANICS LETTERS
(2021)
Article
Geochemistry & Geophysics
Yuval Tal, Vito Rubino, Ares J. Rosakis, Nadia Lapusta
Summary: This study investigates how the asymmetric geometry of thrust faults affects earthquake dynamics, with experimental results showing asymmetries in motion velocities between the hanging and footwalls. Surface velocity attenuation is found to be larger at the hanging wall, with experimental measurements consistent with numerical simulations and field observations. The findings suggest that the interaction of ruptures with the free surface leads to reduced normal stress near the surface in thrust earthquakes.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Hongyu Zeng, Shengji Wei, Ares Rosakis
Summary: This study investigates the impact of source-side 3D velocity structure on teleseismic travel-time in back projection analysis of large earthquakes. Travel-time data recorded by the Hi-Net array is used to reveal how travel-time errors vary with source location. The study proposes a new interpolation scheme to calibrate the travel-time error by using earthquakes located around the mainshock rupture, and validates it through relocating inland M > 5.0 earthquakes in central Japan. The calibrated back projection result is then applied to image the rupture of the 2002 Denali earthquake, revealing useful information about the rupture process.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Multidisciplinary Sciences
Marcello Gori, Vito Rubino, Ares J. Rosakis, Nadia Lapusta
Summary: This study reveals that fast fluid injection rates lead to dynamic ruptures at lower pressure levels and smaller spatial scales, while slow injection rates result in gradual nucleation processes consistent with accelerating slow slip behaviors. The presence of fluids influences friction properties and pore-pressure increase rate needs to be considered in nucleation processes.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)