John N. Hooker, Hannah Riegel, Francesco Mirabella, Gabriele Casale
{"title":"How Fluid Pressures and Viscous Rheologies Affect Slip Patterns on Low‐Angle Normal Faults: The Example of the Altotiberina Fault, Northern Apennines, Italy","authors":"John N. Hooker, Hannah Riegel, Francesco Mirabella, Gabriele Casale","doi":"10.1029/2025jb031302","DOIUrl":"https://doi.org/10.1029/2025jb031302","url":null,"abstract":"Low‐angle normal faults are a mechanical anomaly, hosting normal‐sense slip despite having a dip shallower than 30°, in contravention of Andersonian prediction. Slip on such faults has been attributed to overpressurized fluids or low‐friction minerals. An example of such a fault is the Altotiberina Fault (ATF) in central Italy. The ATF hanging wall is cut by numerous seismically active, high‐angle normal faults called epidetachments. Active slip along the ATF manifests in myriad small (<jats:italic>M</jats:italic><jats:sub><jats:italic>L</jats:italic></jats:sub> < 2) earthquakes concentrated at depths >5 km, as well as infrequent, damaging earthquakes that may be shallower. In the area have been documented overpressurized, deeply sourced CO<jats:sub>2</jats:sub> and a complex mechanical stratigraphy with viscous lithologies. To better understand the relationship between fluid pressure, rheology, and earthquake patterns, we integrate these processes using the Mineralization, Earthquake, and Fluid‐flow Integrated SimulaTOr (MEFISTO). This numerical model simulates earthquakes with simultaneous changes in fluid pressure, porosity, permeability, and fault strength. We investigated the combined effects of epidetachments, which can serve as either pressure‐limiting hydraulic valves or fluid‐flow barriers, and pressure‐solution creep along the ATF fault‐zone. Model results reproduce salient features of the observed seismicity pattern. Upward‐propagating fluid‐pressure waves generate transient clusters of seismic activity. However, large, shallow–and therefore potentially damaging–earthquakes occur that are often not directly triggered by fluid‐pressure waves, limiting the waves' utility as hazard predictors.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"96 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145283415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhen Zhang, Fabian Walter, Brian W. McArdell, Tjalling de Haas, Christoph Wetter
{"title":"Seismic Signals Monitor Debris‐Flow Erosion and Channel Elevation","authors":"Zhen Zhang, Fabian Walter, Brian W. McArdell, Tjalling de Haas, Christoph Wetter","doi":"10.1029/2025gl118801","DOIUrl":"https://doi.org/10.1029/2025gl118801","url":null,"abstract":"Channel erosion not only amplifies debris‐flow magnitude and impact but also reshapes local geomorphology. However, the destructive and infrequent nature of debris flows makes in situ monitoring of channel‐bed erosion processes and flow characteristics challenging. Here, we investigate seismic signals for monitoring erosion‐driven geomorphic changes, using data from 18 well‐documented debris flows at Illgraben, Switzerland, between 2019 and 2023. We find that integrated seismically derived impact forces over each event correlate with channel‐bed elevation changes, revealing erosion thresholds. Seismic peak frequencies correlate with absolute channel‐bed elevations at seismic source regions, reflecting changes in wave propagation paths due to erosion. The correlation is evident, with peak frequency shifts exceeding 15 Hz while channel‐bed elevation changes were under 4 m during the 5‐year period. These findings demonstrate the capacity of seismic signals to characterize debris‐flow erosion and track absolute channel‐bed elevations, offering new insights into geomorphic processes.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"19 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145283420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Contrasting Crustal Signatures Across the 2021 MS6.0 Luxian (China) Induced Earthquake Revealed by Dense Seismic and Magnetotelluric Data","authors":"Tianyang Li, Chenguang Wang, Nian Yu, Rongzhi Lin, Yu Jeffrey Gu, Tao Yu, Sheng Zhang","doi":"10.1029/2024jb031083","DOIUrl":"https://doi.org/10.1029/2024jb031083","url":null,"abstract":"The 2021 Luxian earthquake has raised concerns about the seismic potential in the southern Sichuan Basin and highlighted the need to gain a further understanding of the area's seismic risks. To elucidate the underlying mechanisms driving the largest recorded hydraulic fracturing‐induced earthquake in China, this study investigates the local seismogenic environment of this notable event through an integrated seismic and magnetotelluric (MT) approach. Utilizing a linear Radon transform‐based mode‐separation method, we derived a 3‐D fine‐resolution velocity structure from dense seismic data. Corroborated by resistivity measurements using a co‐located MT array, our integrated data set provides compelling evidence for a complex upper‐crustal geological structure across the Huayingshan fault (HYS‐F). Apart from the low velocity and resistivity zones at 3–4 km depth within the HYS‐F, consistent with the location of fluid injection sites, we newly discovered a large‐scale low‐resistivity anomaly beneath the mainshock at depths exceeding 15 km. A comparable structural pattern emerges in the southeast of the HYS‐F, where the distribution and focal mechanisms of recently detected earthquakes, including and earthquakes, highlight the combined influence of shallow fluid injection and the ascent of deep metamorphic saline fluids in creating a breeding condition for seismicity. A prominent high‐velocity and high‐resistivity anomaly in the northwest, extending from the surface to depths exceeding 20 km, is potentially linked to intruded ancient materials originating from the lower crust. Our findings reveal that complex geological structures and dynamic processes strongly impact the occurrence and distribution of earthquakes in the Luxian earthquake region.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"135 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145283409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Magnetofossil Contribution to Sedimentary Magnetic Records and Sediment Provenance Reconstruction: A Case From the Bengal Fan","authors":"Rong Huang, Liao Chang, Pengfei Xue, Mingming Li, Shengfa Liu, Xuefa Shi, Somkiat Khokiattiwong, Narumol Kornkanitnan","doi":"10.1029/2025jb031531","DOIUrl":"https://doi.org/10.1029/2025jb031531","url":null,"abstract":"Environmental magnetism is widely employed for sediment provenance study, particularly in detrital‐dominated marine and lake systems. However, magnetofossils can complicate magnetic signals for accurate reconstructions of source‐to‐sink processes, yet their impact remains underexplored. The Bengal Fan, the largest submarine fan in the world, provides an ideal setting for studying sediment transport for its diverse sediment sources and transport pathways. Here, we combine magnetic and electron microscope analyses on a large set of surface sediments from the central and lower Bengal Fan to characterize magnetofossil contributions to magnetic properties. Results demonstrate widespread magnetofossil occurrence. Quantitative unmixing of isothermal remanent acquisition curves and first‐order reversal curve‐principal component analysis, assisted with direct transmission electron microscopic imaging of magnetofossils reveal that the southernmost region contains the highest magnetofossil contribution. Total organic carbon influences the magnetofossil abundance, while the magnetofossil morphology compositions are likely modulated by redox conditions impacting the diversity of magnetotactic bacteria species. Fuzzy <jats:italic>c</jats:italic>‐means clustering analysis identifies four sediment clusters. Cluster 1 derives from Indian Peninsula. Cluster 2 represents Himalayan–Burma–Indian mixtures, transported by the active channel with fining downstream. Cluster 4 and the southern part of cluster 3 show anomalous magnetic grain size trends linked to high magnetofossil contributions. The magnetofossil presence alters detrital magnetic records, showing high correlation between magnetofossil magnetization and bulk magnetic grain size parameter, thus complicates provenance interpretations. We demonstrate the combined use of rock magnetism and electron microscopy to quantify magnetofossil contributions for robust magnetic interpretation, especially in high detrital input regions where magnetofossils are often overlooked.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"119 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145283419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jingxu Wang, Haoyu Zhang, Shijie Feng, Zhongyi Li, Zhengzhong Liu
{"title":"Undue Blames on the Air Pollution Leakage From Affluent Provinces in China","authors":"Jingxu Wang, Haoyu Zhang, Shijie Feng, Zhongyi Li, Zhengzhong Liu","doi":"10.1029/2025gl117242","DOIUrl":"https://doi.org/10.1029/2025gl117242","url":null,"abstract":"Interregional trade significantly drives PM<jats:sub>2.5</jats:sub> pollution in regions exceeding China's air quality standards. While production‐based accounting ignores pollution transfers embodied in trade, conventional consumption‐based accounting (CBA) overlooks regional disparities in emission control. Using a Multi‐Regional Input‐Output model, this study applies a technology‐adjusted CBA (TCBA) to reassess China's air pollutant footprint and environmental‐economic inequality. Under TCBA, most of the affluent eastern provinces show notable footprint reductions, shifting from net emission importers to exporters due to their efforts on emission control. Conversely, less‐developed regions with lax controls show increased footprints. Regional inequality weakens under TCBA, with trade pairs showing absolute inequality dropping from 37% to 28%. Our study emphasizes the importance of acknowledging regional efforts on green production in future environment and climate governance.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"24 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145283410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tracking Hurricane‐Induced Water Storage Changes Using GRACE and GRACE‐FO Measurements","authors":"Hao‐si Li, Shuang Yi, He Tang","doi":"10.1029/2025gl116973","DOIUrl":"https://doi.org/10.1029/2025gl116973","url":null,"abstract":"Landfalling hurricanes pose significant hydrological risks, yet monitoring their terrestrial water storage (TWS) dynamics remains challenging. Here we employed a new technique that estimates daily regional gravity changes from orbital perturbation measurements of the Gravity Recovery and Climate Experiment and its follow‐on mission to characterize TWS variations during Hurricanes Katrina (2005) and Laura (2020). Our spatiotemporal water storage maps reveal ∼40 Gt of accumulation by Katrina and a coastally localized ∼15 Gt by Laura, with coastal regions retaining up to 80% of precipitation but draining several days faster than inland areas. Despite differing magnitudes, both storms exhibited similar precipitation‐to‐TWS conversion patterns, implying consistent scaling of hydrological responses across intensities. Our observations also indicate that current land surface models, lacking surface inundation modeling, result in underestimations of flood recession rates. This work highlights satellite gravimetry's potential for continuous hurricane‐induced flood monitoring, offering a new tool to alleviate current observational difficulties.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"12 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145283353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Nanoscale Plastic Wear of α‐Quartz Asperities During Shear Sliding: Insights From Molecular Dynamics Simulations","authors":"Sheng Li, Eiichi Fukuyama","doi":"10.1029/2025gl116288","DOIUrl":"https://doi.org/10.1029/2025gl116288","url":null,"abstract":"Fault slip inevitably causes the multiscale wear damage of asperities, ranging from nanometers to meters. However, the nanoscale asperity wear mechanism remains poorly understood. While plastic wear has been inferred as one of the dominant wear modes, the dynamic wear mechanism of plastic wear has not been thoroughly investigated. Here, we explicitly present a series of nanoscale 3‐D plastic wear processes of <jats:italic>α</jats:italic>‐quartz asperities by using molecular dynamics method, where asperity climbing mode dominates during the sliding. We identify a transition from atom‐by‐atom wear damage to layer removal of <jats:italic>α</jats:italic>‐quartz asperities with increasing normal forces. Moreover, nanoscale wear volume evolution depends on the normal force and loading velocity and shows sublinear increase with loading distance. We confirm that the tangential shear work can well predict the nanoscale plastic wear volume under various loading conditions due to the proportional relation.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"119 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145283408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Role of Accretionary Wedge in the Dynamic Rupture of Tsunami Earthquakes","authors":"Kenichi Tsuda, Bunichiro Shibazaki, Jean‐Paul Ampuero","doi":"10.1029/2025gl117571","DOIUrl":"https://doi.org/10.1029/2025gl117571","url":null,"abstract":"Tsunami earthquakes occur in the shallow parts of subduction megathrust interfaces, which are often in contact with the accretionary wedge. Here, by conducting dynamic rupture simulations, we investigate how an accretionary wedge affects the rupture process of tsunami earthquakes and the resulting ground motions. We constructed a dynamic source model of the 2010 Mentawai tsunami earthquake (M<jats:sub>w</jats:sub> 7.8), constrained by the slip distribution obtained by a source inversion analysis. The model reproduces the basic observed features of the event, including its recorded ground motions and its inferred slow rupture speed. The simulation results also show that seismic wave energy is efficiently trapped inside the accretionary wedge, which contributes to our understandings of the observation that tsunami earthquakes produce weaker ground motions than regular earthquakes of the same magnitude.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"20 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145283418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ji Zhang, Aitaro Kato, Wei Wang, Shigeki Nakagawa, Ahmet Anil Dindar
{"title":"Structure Heterogeneity Around the Western End of the 1999 Izmit Earthquake Rupture Revealed by Distributed Acoustic Sensing","authors":"Ji Zhang, Aitaro Kato, Wei Wang, Shigeki Nakagawa, Ahmet Anil Dindar","doi":"10.1029/2025gl116809","DOIUrl":"https://doi.org/10.1029/2025gl116809","url":null,"abstract":"We use distributed acoustic sensing along a submarine fiber‐optic cable to provide the first high‐resolution two‐dimensional shear‐wave velocity (Vs) model of the North Anatolian Fault (NAF) in the Marmara Sea. Using 7 days of ambient noise recordings, we extract Scholte wave dispersion curves via slant‐stacking and invert for the Vs structure, identifying a pronounced low‐velocity layer (∼0.6 km/s), indicative of unconsolidated sediments. Autocorrelation and natural migration profiles reveal a ∼3‐km‐wide fracture zone (WFZ), which we interpret as a legacy of long‐term slip on the NAF. The low Vs and structural complexity suggest the WFZ functions as a soft barrier. Hence, it could have contributed to arrest rupture propagation during the 1999 M7.6 Izmit earthquake, as well as partitioning stress between fault segments. We also resolve a flower‐like structure of faults. These results may demonstrate how fault zone heterogeneity controls rupture dynamics and stress accumulation, offering mechanistic insights into seismic segmentation.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"119 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145283411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nora Hirsch, Andrew M. Dolman, Thomas Münch, Thomas Laepple
{"title":"Greenland Ice Core Isotope Variability Strongly Influenced by Systematic Changes in Depositional Noise","authors":"Nora Hirsch, Andrew M. Dolman, Thomas Münch, Thomas Laepple","doi":"10.1029/2025gl116529","DOIUrl":"https://doi.org/10.1029/2025gl116529","url":null,"abstract":"Stable water isotopes from ice cores are a unique proxy for reconstructing polar climate variability. Their interpretation is, however, challenging due to the impact of depositional noise. Here, we analyze the centennial‐ to millennial‐scale isotope variability of the Greenland ice cores NGRIP, GRIP, and GISP2 to investigate how their coherent signal and local noise have evolved over the last 100,000 years. We show that the noise systematically depends on the climate state, with higher levels under colder temperatures and lower accumulation rates. Most of the noise originates from local stratigraphic disturbances, while additional noise variability only emerges in the Greenland stadials. The remaining climate signal variability is higher in the last glacial period compared to the Holocene, but does not systematically differ between stadials and interstadials. We show that, by considering systematic changes of noise, it is possible to achieve more accurate estimates of past climate variability.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"19 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145283412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}