Article
Geochemistry & Geophysics
M. Ersen Aksoy, Mustapha Meghraoui, Alina Polonia, M. Namik Cagatay, Asli Zeynep Yavuzoglu, Sebnem Onder, Umut B. Ulgen, Luca Gasperini
Summary: This study focused on the westernmost segment of the North Anatolian fault in NW Turkey and found that the western termination of the 1912 earthquakes' surface ruptures ends about 37 km offshore in the Gulf of Saros. The research suggests that the eastern extension of the 9 August earthquake reached the Central Marmara Basin, with implications for seismic hazard in the Marmara coastal area.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Tae-Kyung Hong, Junhyung Lee, Jeongin Lee, Seongjun Park, Byeongwoo Kim, Sungchan Choi
Summary: Earthquakes in the Korean Peninsula often occur in subsurface hidden faults that are difficult to identify before seismic activity. In this study, a midcrustal subsurface hidden fault in a seismically quiet region of the central Korean Peninsula was investigated, which caused the M-L 4.1 earthquake on October 28, 2022. Combined analysis of seismicity, geophysical properties, and geological features provided constraints on the geometry of this hidden fault. The fault extends to the surface where a lineament with low gravity anomalies is present.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geosciences, Multidisciplinary
L. Jiao, Y. Klinger, L. Scholtes
Summary: Through numerical modeling, this study demonstrates that during shearing of a layer of brittle material, oblique Riedel fractures nucleate with a regular spacing controlled by the layer's thickness, which then influences the spatial structuration of the entire fault system. An analysis of horizontal stress distribution reveals a threshold at a ratio of 1.5 between inter-Riedel distance and material thickness, beyond which new fractures nucleate due to a switch from compressional to tensional stress.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Tahir Serkan Irmak, Seda Yolsal-Cevikbilen, Tuna Eken, Bulent Dogan, Ceyhun Erman, Evrim Yavuz, Hakan Alcik, Peter Gaebler, Ali Pinar, Tuncay Taymaz
Summary: The study investigates the source properties, aftershock behavior, and coseismic deformation of the 2019 earthquake in the Central Marmara Sea region, indicating that secondary structures play a key role in the crustal kinematics of the area and are likely responsible for the main shock activity.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geosciences, Multidisciplinary
Yann Klinger
Summary: This study investigates the origin of unexpected high frequency emissions during earthquakes and finds that the most likely source is the interaction between nearby misaligned faults. This finding highlights the discrete nature of strike-slip fault segments at seismogenic crustal scale and adds new constraints to earthquake rupture scenarios.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
S. Rost, G. A. Houseman, A. W. Frederiksen, D. G. Cornwell, M. Kahraman, S. Altuncu Poyraz, U. M. Teoman, D. A. Thompson, N. Turkelli, L. Gulen, M. Utkucu, T. J. Wright
Summary: Research using dense seismic data reveals the subsurface structure of the North Anatolian Fault Zone, with findings showing lateral incoherence of crustal interfaces, contrasting crustal structures on either side of the fault zone, and strong variations in structure both north-south and east-west within the study region. The results suggest the presence of major shear zones throughout the crust and into the lithospheric mantle beneath the fault zone, indicating a strong coupling of strain at these depths.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Lucan Mameri, Andrea Tommasi, Javier Signorelli, Riad Hassani
Summary: This research suggests that spatial variations in viscous anisotropy in the mantle can affect strain distribution in the entire lithosphere, and the reactivation of fossil mantle shear zones and strain localization in the crust depend on the orientation and intensity of olivine CPO in the mantle.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Lejun Lu, Yu Zhou
Summary: This study presents new geodetic observations of the 1976 Chaldiran earthquake in eastern Turkey, using historical KH imagery and modern Pleiades stereo imagery. The analysis reveals that the coseismic slip at the Hidirmentes segment is around 4.0 m, larger than the surface displacement of 3 m. This suggests that the earthquake deformation is a combination of slip on the primary fault and off-fault deformation. The study also finds a constant ratio of horizontal to vertical offsets, indicating characteristic slip behavior of the Chaldiran fault in the late Quaternary.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
M. Rodriguez, D. Sakellariou, C. Gorini, A. Janin, E. D'Acremont, L. Le Pourhiet, N. Chamot-Rooke, K. Tsampouraki-Kraounaki, I Morfis, G. Rousakis, P. Henry, A. Lurin, M. Delescluse, P. Briole, A. Rigo, S. Arsenikos, C. Bulois, D. Fernandez-Blanco, A. Beniest, C. Grall, F. Chanier, F. Caroir, J-X Dessa, D. Oregioni, A. Nercessian
Summary: This study uses seismic reflection lines to reveal the subsurface structure and sedimentary record in the North Aegean region, and finds that the two main branches of the North Anatolian Fault were formed 1.3-2 million years ago, and since the Early Pleistocene, the North Aegean Troughs have been propagating westwards to form horsetail basins.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
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
Yifan Yin, Percy Galvez, Elias Rafn Heimisson, Stefan Wiemer
Summary: A physics-based earthquake simulator can reproduce the empirical power-law behaviors of magnitudes and clustering. This can be achieved in 3-D continuum simulations with fault interactions and rate-and-state friction. The simulations show earthquake sequences with characteristic scaling and inter-event time distribution, indicating practical potential for hazard assessment and forecasting.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Qing Bian, Shang Deng, Huixi Lin, Jun Han
Summary: The connection between source rock and reservoir separated by salt strata is a global problem. This paper focuses on the No. 5 strike-slip fault passing through salt layers in the Tarim Basin. The seismic data reveals different structural styles in the salt layer, including transpression, transtension, and pure strikeslip. The impact of deep strike-slip salt tectonics on petroleum exploration is discussed using data from seven wells, showing that thicker salt layers result in poorer production.
MARINE AND PETROLEUM GEOLOGY
(2022)
Article
Geology
Ehsan Kosari, Matthias Rosenau, Sabrina Metzger, Onno Oncken
Summary: Understanding the seismogenic behavior of megathrusts is crucial for predicting seismic hazards in subduction zones. However, the relationship between frictional heterogeneity at depth and upper-plate deformation is not fully understood. Using a seismotectonic model, we found that the frictional locking heterogeneity generates segmented along-strike strain patterns in the short term but less pronounced permanent strain patterns in the long term. Our results suggest that along-strike upper-plate strain patterns can help interpret lateral variations in seismogenic behavior.
Article
Geochemistry & Geophysics
Yanchuan Li, Jean-Mathieu Nocquet, Xinjian Shan
Summary: This study combines GPS velocity field with InSAR results to investigate the interseismic deformation of the western Altyn Tagh fault (ATF) at longitude 86 degrees E. The findings show the presence of sinistral shear and NS shortening near the Manyi fault system, while the slip rate and locking depth across the ATF are relatively lower. Additionally, no significant offset between the surface fault trace and the fault at depth is observed, suggesting no lateral variations of the elastic strength across the ATF.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Yanchuan Li, Jean-Mathieu Nocquet, Xinjian Shan
Summary: By combining GPS velocity field with InSAR results, this study investigates interseismic deformation across the western Altyn Tagh fault (ATF) and identifies a sinistral shear and NS shortening area near the Manyi fault system. The research highlights how different data sets, data selection, and model assumptions can impact results on ATF slip rate, locking depth, and rheological contrast across the fault.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Lei Qin, Pieter-Ewald Share, Hongrui Qiu, Amir A. Allam, Frank L. Vernon, Yehuda Ben-Zion
Summary: Using seismic data, we imaged the internal structure of the San Jacinto fault zone near Anza, California, revealing three near-parallel surface traces that have experienced several Mw > 6 earthquakes. Analysis suggests the presence of a core damage zone in the fault zone, causing waveform changes and delays, as well as generating different types of fault zone trapped waves. The multiscale structural components observed relate to the geological and earthquake rupture history at the site, providing insights into the preferred northwest propagation of earthquake ruptures on the San Jacinto fault.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Multidisciplinary Sciences
Gen K. Li, Woodward W. Fischer, Michael P. Lamb, A. Joshua West, Ting Zhang, Valier Galy, Xingchen Tony Wang, Shilei Li, Hongrui Qiu, Gaojun Li, Liang Zhao, Jun Chen, Junfeng Ji
Summary: The research found that the fossilized particulate organic carbon (FOCash) in fly ash, a byproduct of coal burning, has a significant flux in rivers like the Chang Jiang in China. This highly recalcitrant FOCash is difficult to oxidize, unlike the more labile FOCrock derived from shale. The high FOCash flux in the Chang Jiang was attributed to increased coal combustion and construction of dams, leading to a substantial impact of anthropogenic activities on the global riverine FOC flux to the oceans.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Geosciences, Multidisciplinary
Elizabeth M. Berg, Fan-Chi Lin, Vera Schulte-Pelkum, Amir Allam, Hongrui Qiu, Konstantinos Gkogkas
Summary: The near-surface seismic velocity structure and Vp/Vs ratio have significant impacts on ground motion amplification during large earthquakes. By combining three datasets and using Bayesian joint inversion, this study investigates shallow crustal shear velocity and near-surface Vp/Vs ratio in Southern California. The results indicate a correlation between receiver functions and short-period Rayleigh wave ellipticity measurements, requiring the inclusion of a Vp/Vs parameter. The updated model suggests widespread shallow fracturing and/or groundwater undersaturation, with lower than expected Vp/Vs ratios outside sedimentary basins.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Ao Cai, Hongrui Qiu, Fenglin Niu
Summary: This study presents an improved semi-supervised algorithm-based network, called Wasserstein Cycle-GAN, for shear wave velocity inversion in surface wave tomography. It incorporates both model-generated and observed dispersion data, enhancing the training stability and accuracy. Benchmark tests conducted in Southern California show that the resulting Vs model exhibits large-scale geological features and provides clearer images of structures near faults compared to conventional machine learning methods.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Xian Zheng, Cuiping Zhao, Hongrui Qiu, Fenglin Niu, Ce Zhao
Summary: We image the Zhaotong-Ludian fault (ZLF) in the southeastern margin of the Tibetan plateau (SE Tibetan plateau) using waveforms from local and teleseismic earthquakes recorded by 14 seismic stations. We identify two types of fault zone head wave (FZHW) and find significant velocity contrast differences between the northeast and southwest segments of the fault.
SEISMOLOGICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Pieter-Ewald Share, Jared R. Peacock, Steven Constable, Frank L. Vernon, Shunguo Wang
Summary: The Southern San Andreas fault (SSAF) is a major seismic risk in California. This study uses magnetotelluric (MT) soundings to image a multistranded section of the SSAF and provide insights about its deeper structural properties. The results show a conductive column in the SSAF zone, with a vertical to steeply northeast dipping conductor at depths of 2-4 km and another prominent conductor in the ductile crust at 12 km depth. The interpretation suggests that the SSAF zone is mostly impermeable for northeast fluid migration but may have a secondary deep ductile crustal conductor.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geosciences, Multidisciplinary
Y. Sheng, A. Mordret, K. Sager, F. Brenguier, P. Boue, B. Rousset, F. Vernon, Q. Higueret, Y. Ben-Zion
Summary: By utilizing seismic tremors generated by freight trains, we are able to extract stable, high-frequency body waves, allowing us to observe small velocity perturbations in the crust with high spatial resolution. We have observed and mapped a two-month-long episode of velocity changes at the San Jacinto Fault, interpreting it as a previously undocumented slow-slip event. Such slow-slip events can stress their surroundings and potentially trigger a major earthquake on a fault section approaching failure.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Zhou Zhang, Yangfan Deng, Hongrui Qiu, Zhigang Peng, Jing LiuaZeng
Summary: This study investigates the fault zone structures and velocity reduction in the creeping section of the Haiyuan fault by deploying a dense temporary seismic network. The results reveal a narrow inner damage zone and a clear bi-material velocity contrast across the fault.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geosciences, Multidisciplinary
Hongrui Qiu, Benxin Chi, Yehuda Ben-Zion
Summary: We conducted high-resolution seismic imaging of the central Garlock fault using data from two dense seismic arrays. The results show that the Garlock fault is a sharp bimaterial interface, with P waves traveling approximately 5% faster in the northern crustal block. This velocity contrast agrees with regional tomography models and generates clear P-wave reflections in recorded waveforms. The findings provide important constraints for further earthquake studies, simulations of ruptures and ground motion, and future imaging research related to the Garlock fault.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Lei Qin, Jamison H. Steidl, Hongrui Qiu, Nori Nakata, Yehuda Ben-Zion
Summary: Subsurface structures play significant roles in seismic ground motion, crustal hydrology, and stability of the built environment. By constraining the temporal changes of subsurface shear wave velocity, valuable information can be provided for these topics and the field of hydrological monitoring using seismic velocity.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Malcolm C. A. White, Zhendong Zhang, Tong Bai, Hongrui Qiu, Hilary Chang, Nori Nakata
Summary: This article describes a new data schema called HDF5eis for handling big multidimensional time series data in high-performance computing applications. HDF5eis extends the popular Hierarchical Data Format 5 with additional conventions for fast and flexible data input and output. It supports storage of arbitrary ancillary data and enables simple and efficient access to big data sets distributed across multiple files.
Article
Geochemistry & Geophysics
Lei Qin, Hongrui Qiu, Nori Nakata, Sizhuang Deng, Alan Levander, Yehuda Ben-Zion
Summary: High-frequency seismic data on Mars are dominated by wind-generated lander vibrations, which are partially radiated to the subsurface. Autocorrelation functions (ACFs) of seismic data on Mars filtered between 1 and 5 Hz show clear phases at around 1.3, 2.6, and 3.9 seconds. Daily changes in arrival times correlate well with ground temperature changes, exhibiting a 5% daily variation and a 50-minute apparent phase delay. Two possible mechanisms are proposed to explain these observations: interference of two predominant spectral peaks at around 3.3 and 4.1 Hz, assumed to be lander resonance modes, and interference of lander vibration and its reflection from an interface approximately 200 meters below the lander. The driving mechanism behind the 50-minute delay is likely thermoelastic strain affecting the lander-ground coupling and subsurface structures. The presented methodology and results contribute to the analysis of ACFs with limited data and enhance our understanding of subsurface materials on Mars.
SEISMOLOGICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Y. Sheng, A. Mordret, F. Brenguier, P. Boue, F. Vernon, T. Takeda, Y. Aoki, T. Taira, Y. Ben-Zion
Summary: This study proposes a systematic workflow to seek powerful seismic sources for monitoring fault zones' seismic velocity changes. The algorithm is tested in California and Japan, and multiple sites close to fault zones show stable high-frequency correlation functions. These findings have great potential for fault zone monitoring.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
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)
Article
Geochemistry & Geophysics
Zhendong Zhang, Malcolm C. A. White, Tong Bai, Hongrui Qiu, Nori Nakata
Summary: This study analyzes the behavior of microseismicity induced by hydraulic fracturing in the Montney Formation and performs imaging using distributed acoustic sensing (DAS) data. The lack of 2D/3D variations in the fiber geometry increases the nonuniqueness of the image point location, but P-wave particle motions derived from three-component (3C) geophones data can effectively eliminate the location ambiguity. The updated spatiotemporal distribution of earthquake locations agrees with the fracking schedule, and the predicted travel times also match the observed waveforms.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2023)