Article
Geochemistry & Geophysics
Xuchao Chai, Pei Zhang, Chuang Wang, Qingliang Wang
Summary: Highly similar waveforms recorded from repeating earthquakes can be utilized to evaluate the data quality of seismic stations. We established a data quality detection model based on repeating earthquakes and verified its effectiveness by evaluating 842 permanent broadband stations in mainland China. Most of the stations function well, and utilizing repeating earthquakes to analyze waveform quality can reduce the need for extensive calculations and minimize the impact of uncertainties and structural complexity on the results.
SEISMOLOGICAL RESEARCH LETTERS
(2022)
Article
Geology
Alba M. Rodriguez Padilla, Michael E. Oskin, Thomas K. Rockwell, Irina Delusina, Drake M. Singleton
Summary: Large, multi-fault earthquakes increase the threat of strong ground shaking and reshape the probability of future events across a system of faults. A study in California revealed that the San Andreas and San Jacinto faults co-ruptured multiple times in the past through the Cajon Pass earthquake gate. These co-rupture events have significant implications for seismic activity in the region.
Article
Geochemistry & Geophysics
Dawei Gao, Honn Kao, Jianxin Liu
Summary: This study addresses the issue of identifying repeaters by deriving logical criteria based on theoretical calculations. The proposed approach is demonstrated to be superior in identifying repeating earthquakes in challenging cases in California, providing new insights into hierarchical fault structures. The findings are also applicable to repeating seismic events on other planetary bodies, potentially avoiding misinterpretations of physical processes in Earth and planetary interiors.
SEISMOLOGICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Randolph T. Williams, Christie D. Rowe, Kristina Okamoto, Heather M. Savage, Erin Eves
Summary: This study documents the mechanical and geochemical processes of fault rock development in the shallow San Andreas fault (Mojave segment), highlighting the diverse suite of fault rocks and significant changes in frictional strength caused by the interdependence of these processes. Spatial variations in fault-rock mineralogy and geochemistry indicate marked variations in their relative contribution to fault-rock evolution, suggesting a substantial departure from simple structures envisioned for near-surface seismogenic faults in numerical models is required.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geochemistry & Geophysics
Yixiao Sheng, William L. Ellsworth, Ariel Lellouch, Gregory C. Beroza
Summary: The seismic velocity reduction caused by the 2004 Parkfield earthquake is found to be strongly frequency dependent, with low-frequency components being more affected by the velocity alteration than high-frequency components. This suggests that the coseismic velocity reduction primarily occurs at a shallow depth and is expressed in low-frequency energy resulting from reverberations near the Earth's surface.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Multidisciplinary Sciences
Junle Jiang, Yehuda Bock, Emilie Klein
Summary: By investigating the geophysical observations of the 2004 Parkfield earthquake, researchers have revealed the rapid evolution of afterslip in the early post-rupture period, showing its control on aftershock behavior. This study highlights the important roles of aseismic source processes and structural factors in seismicity evolution, offering potential prospects for improving aftershock forecasts.
Article
Geology
Genevieve L. Coffey, Heather M. Savage, Pratigya J. Polissar, Stephen E. Cox, Sidney R. Hemming, Gisela Winckler, Kelly K. Bradbury
Summary: Assessing seismic hazard on creeping faults is challenging as they can participate in rupture without nucleating large earthquakes. By studying the San Andreas fault, it was found that the creeping section showed evidence of significant displacements during earthquakes. The measured ages provide a maximum constraint on earthquake age, with the youngest earthquakes occurring within the last 3 million years.
Article
Geochemistry & Geophysics
Dunyu Liu, Benchun Duan, Katherine Scharer, Doug Yule
Summary: Understanding the mechanical conditions that lead to complexity in earthquakes is crucial for seismic hazard analysis. This study uses physics-based dynamic models to simulate the effects of complex fault geometry and interseismic stress accumulation on earthquake recurrence. The findings show that these factors contribute to rupture segmentation and variability in earthquake recurrence. The study provides important insights for ground shaking assessment in the region.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Multidisciplinary Sciences
Kelian Dascher-Cousineau, Noah J. Finnegan, Emily E. Brodsky
Summary: Successive earthquakes drive landscape evolution, as shown in the Carrizo Plain, California. A model was developed and validated to quantify the competition between fault slip and aggradation, providing insights into the factors influencing drainage network reorganization.
Article
Geochemistry & Geophysics
Colton Lynner, Susan L. Beck
Summary: Monitoring seismic velocity variations surrounding active volcanoes provides insights into crustal deformation caused by eruptions and earthquakes. In this study, seismic noise-generated surface waves were used to characterize the upper crustal velocity variations following a seismic sequence at Turrialba volcano. The results show a rapid velocity drop immediately following the seismic event, indicating widespread damage and/or a readjustment of local stress.
BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA
(2023)
Article
Geosciences, Multidisciplinary
Paul Lundgren, Zhen Liu, S. Tabrez Ali
Summary: This study investigates the impact of changes in groundwater storage in California's Central Valley on crustal and fault stress. The results show that stress changes on the central San Andreas fault are correlated with shallow seismicity and low frequency earthquakes, providing important insights for understanding observed crustal uplift.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
David Blank, Julia Morgan
Summary: The study presents a binary classification model based on deep learning techniques to predict complete-interface rupture on a numerical megathrust fault. By comparing two neural networks trained on three types of data, it is demonstrated that the networks can differentiate imminent rupture precursors and provide relative size and time forecasts. The results confirm that precursory deformation scales with upcoming event size, and the proposed methods are adaptable for future use with 3D data.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Ellis J. Vavra, Hongrui Qiu, Benxin Chi, Pieter-Ewald Share, Amir Allam, Matthias Morzfeld, Frank Vernon, Yehuda Ben-Zion, Yuri Fialko
Summary: The configuration of the Southern San Andreas Fault at seismogenic depths in the Coachella Valley has been a mystery. By analyzing space geodetic and seismic observations, it has been revealed that the straight southernmost section of the fault is dipping to the northeast, connecting with clusters of seismic activity. This dipping fault geometry has significant implications for fault slip rate, ground shaking intensity, and fault strength.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geosciences, Multidisciplinary
Brenton Hirao, Heather Savage, Emily E. Brodsky
Summary: The study found shallow triggered creep events along the northern edge of the San Andreas Fault's central creeping section following the 2003 and 2004 earthquakes, with significant changes in creep rate between regional earthquakes. This suggests that triggering connects behavior in the northern San Andreas Fault to the southern section and other regional faults.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
P. -E. Share, F. L. Vernon, Y. Ben-Zion
Summary: Key factors controlling earthquake ruptures include fault geometry, continuity, and seismic velocity structure around the fault. A novel tool is presented to better inform these factors in the San Jacinto fault zone in southern California. The results reveal a continuous bimaterial interface and deep northeast dipping fault segments within the fault zone, with implications for earthquake rupture speed, mode, directivity, and frictional heating.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
