Journal of Geophysical Research: Solid Earth最新文献

{"title":"On the Choice of Basis Functions for Modeling Earth's Elastic Deformation Due To Surface Loading","authors":"Fan Yang, Yingchun Shen, Weihang Zhang, Ehsan Forootan","doi":"10.1029/2025jb031662","DOIUrl":"https://doi.org/10.1029/2025jb031662","url":null,"abstract":"Accurately modeling Earth's elastic deformation due to surface loads is essential for geodetic and geophysical studies, including investigations of climate change, hydrology, and tectonics. Various basis functions, such as spherical harmonics, Green's functions, disk functions, and Slepian functions, are commonly used to describe the relationship between surface loads and deformation. However, the strengths and limitations of these basis functions have not been systematically compared, leading to potential uncertainties in the modeling results. This study evaluates six basis functions, including the above four and two newly developed approaches of infinite Green's functions and clustered disk-load Green's functions. We analyze their performance in forward modeling of Earth's vertical displacement and assess two primary sources of uncertainty: (a) native errors inherent to each basis function and (b) artificial errors introduced by improper configuration, for example, over-smoothing and aliasing. Our results demonstrate that these errors can be as significant as the uncertainties associated with Earth structure assumptions. Furthermore, we emphasize the importance of how surface load data is treated, whether as discrete point values, as uniform block values, or as block mean values, and how this choice impacts the selection of the basis function and the accuracy of the model. Based on our findings, we provide practical recommendations for selecting the most suitable basis function for different applications. Although our study focuses on vertical displacement, the insights gained are also relevant to modeling geoid changes, gravity variations, and strain fields. These findings contribute to improving the reliability of geodetic methods for studying Earth's dynamic processes.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"30 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145236027","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":"Mechanisms of Mass Transfer in Sediment-Rich Mélanges in Modern Subduction Zones","authors":"Anna M. Rebaza,&nbsp;Bridgett I. Holman,&nbsp;Ananya Mallik,&nbsp;Emily H. G. Cooperdock","doi":"10.1029/2024JB030991","DOIUrl":"10.1029/2024JB030991","url":null,"abstract":"<p>Sediment-rich mélange diapirs have been suggested to transport key chemical slab signatures and volatiles to arc magma sources. Here, we assess the phase equilibria, buoyancy and implications for chemical geodynamics of a previously unexplored hydrous shaly-rich mélange (5–10 wt.% H₂O) with minor ultramafic component, from deep forearc to subarc depths (2–3 GPa and 700–1,150°C). The solidus lies between &lt;645°C and 700°C and upon partial melting, produce dacitic to rhyolitic melts coexisting with a low-density pyroxenite enriched in mica, amphibole, quartz, garnet and accessory minerals. Our analysis shows that instabilities are likely in warm, slow-subducting and thinner channels with low viscosities compared to cold and fast subducting slabs where diapirism is likely limited, as they require extremely large channel thicknesses. Diapirism can occur in tectonic slabs with heat sources, such as nearby slab tears or plumes. However, those mélanges lose buoyancy upon thermal equilibration at temperatures above 850°C. While smaller diapirs may densify and stagnate near the channel, larger diapirs may maintain buoyancy, allowing them to remelt beneath the overriding lithosphere. Aqueous fluids and low-degree melts prevail near the channel, transferring high Large Ion Lithophile Element (LILE)/High-Field Strength Element (HFSE) ratios to arc magma sources, which resemble those found in arc lavas. High degree melting of mantle-wedge diapirs may explain arc lava diversity but not their ubiquitous high LILE/HFSE signatures. Overall, diapirism is highly conditional and likely originate in hot slabs. Thus, aqueous fluids and partial melts are the dominant mass-transfer agents of slab signatures to arc magma sources.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 10","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145216222","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":"Modeling Overpressure Development and the Mechanical Behavior of Sediments in a Complex, Tectonically Active Setting: East Coast Basin, New Zealand","authors":"E. E. Calderon Medina,&nbsp;J. Obradors-Prats,&nbsp;A. C. Aplin,&nbsp;S. J. Jones,&nbsp;M. Rouainia,&nbsp;A. J. L. Crook","doi":"10.1029/2024JB030585","DOIUrl":"10.1029/2024JB030585","url":null,"abstract":"<p>The East Coast Basin (ECB) is a complex, active convergent margin located on the North Island of New Zealand, where variable but commonly very high overpressures occur in Cretaceous to Pleistocene stratigraphy. Using a consistent set of sediment physical properties and a single value for tectonic compression, a multi-1D hydro-mechanical modeling approach was employed to evaluate the primary controls on overpressure and porosity across a 40 km section of the ECB. The 1D hydro-mechanical models simulated the geological histories of five key wells across the ECB and investigated overpressure generated by burial disequilibrium compaction and tectonic compression. Present-day overpressure is associated with tectonic compression within the last 3 million years due to the subduction of the Pacific Plate beneath the Australian Plate; this has generated up to 18 MPa of overpressure at a depth of 2,000 m. Burial disequilibrium compaction contributed up to 4 MPa at the same depth. Whilst erosive events can lead to the dissipation of overpressure, the effects of all but the most recent erosive event are masked and overprinted by subsequent sedimentation. In some areas and in specific parts of the stratigraphy, overpressure appears to dissipate through lateral fluid flow. Throughout a complex geological history including several episodes of burial, tectonic compression and erosion, critical state soil mechanics models suggest that mechanical changes in mudstones and fine-grained carbonates occur almost entirely through compaction rather than dilation (shear).</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 10","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030585","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145215774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sensitivity of Gravity Anomalies to Mantle Thermal Models at Mid-Ocean Ridges","authors":"Caicai Zha,&nbsp;Jian Lin,&nbsp;Tingting Zheng,&nbsp;Min Xu,&nbsp;Huizhe Di,&nbsp;Fan Zhang","doi":"10.1029/2025JB031863","DOIUrl":"10.1029/2025JB031863","url":null,"abstract":"<p>At mid-ocean ridges (MORs), accounting for plate cooling-related long-wavelength gravity anomalies is crucial for accurately estimating variations in crustal thickness and distributions of density anomalies within crust and mantle. Either the classic 1-D plate cooling model (PCM) or numerical models incorporating complex heat advection-conduction and melting processes are commonly employed for this purpose. However, the differences in gravity anomalies predicted by these thermal models have rarely been investigated. In this study, we quantitatively assess the sensitivity of gravity anomalies to various mantle thermal models, considering the influence of mantle rheology-related heat advection and latent heat of melting (LHM). Our results indicate that the PCM systematically overestimates the mantle temperature, predicting more pronounced negative gravity anomalies near the ridge axis compared to numerical models, with peak deviations exceeding 10 mGal and increasing as spreading rates decrease. The comparatively more positive gravity anomalies in numerical models are attributed to efficiency of rheology-related heat advection and LHM. Heat advection generally decreases as spreading rates decrease, resulting in more positive gravity anomalies which modulated by mantle rheologies. In contrast, LHM contributes to less positive gravity anomalies at slower spreading rates due to lower degrees of melting. Specifically, effect of LHM that commonly ignored in gravity modeling plays a more significant role than rheology-related heat advection in influencing axial gravity anomalies at intermediate- to fast-spreading rates. Our systematic work distinguishes the differences in gravity anomalies predicted by various mantle thermal models, providing insights for interpretation of local gravity anomalies at global MORs.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 10","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145215771","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":"Electrical Conductivity of Hydrous SiO2: Implications for the Superionic State and High Conductivity Anomalies Beneath Subduction Zones","authors":"Mako Inada,&nbsp;Yoshiyuki Okuda,&nbsp;Kenta Oka,&nbsp;Hideharu Kuwahara,&nbsp;Steeve Gréaux,&nbsp;Kei Hirose","doi":"10.1029/2025JB032641","DOIUrl":"10.1029/2025JB032641","url":null,"abstract":"<p>Electrical conductivity (EC) is a key physical property of minerals and rocks that constrains the composition and structure of Earth's deep interior. Theoretical studies predict that the CaCl₂-type hydrous Al-bearing SiO₂ phase, present in subducted crustal materials, becomes superionic—where protons are no longer bonded to specific oxygen atoms but instead become mobile within the SiO₂ lattice—under high-pressure and high-temperature conditions of the lower mantle. The enhancement of the EC upon such superionic transition has not been experimentally verified yet. Here, we measured the EC of Al-bearing SiO₂ containing 1,750 ppm H₂O at pressures up to 82 GPa and temperatures up to 2610 K by employing a recently developed technique designed for measuring transparent materials. Results demonstrate a sudden increase in EC to approximately 10 S/m at temperatures of 1,100–2,200 K, depending on pressure. This is several to 10 times higher than the conductivity of the surrounding shallow to mid-lower mantle and is consistent with a transition to the superionic state. If hydrous SiO₂ is substantially weaker than other coexisting phases and thus forms an interconnected film in subducted mid-oceanic ridge basalt (MORB) crust, the EC of the bulk MORB materials is significantly enhanced by superionic SiO₂ to ∼1,800 km depth, which may explain the high EC anomalies observed at subduction zones underneath northeastern China. The observed EC anomalies can be matched by the EC of subducted MORB materials containing Al-bearing SiO₂ with a water content of approximately 0.2 wt%, providing insights into deep H₂O circulation and mantle distribution.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 10","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JB032641","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145209686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The First Three Months of Postseismic Deformation of the 29 July 2021 Mw 8.2 Chignik Earthquake Provides New Constraints on the Down-Dip Extent of Coseismic Slip","authors":"Z. Zhuo,&nbsp;J. T. Freymueller,&nbsp;Z. Xiao,&nbsp;J. Elliott,&nbsp;R. Grapenthin","doi":"10.1029/2024JB030401","DOIUrl":"10.1029/2024JB030401","url":null,"abstract":"<p>Stress-based postseismic deformation modeling including afterslip and viscoelastic relaxation usually assumes the coseismic slip distribution and the associated stress perturbation as known. However, that assumption biases the postseismic modeling results by the assumptions that underlie the coseismic models. Importantly, this misses an opportunity to iteratively constrain the coseismic slip model with postseismic observations. We used a broad set of seismic and geodetic data to create multiple coseismic slip models that only differ in the down-dip extent of the rupture plane and fit the coseismic observations for the July 29, Mw 8.2 Chignik earthquake equally well. We then evaluated the quality of those coseismic slip models based on how well each of them predicts postseismic GNSS displacements using a stress-driven afterslip model. We find that coseismic slip models that generate afterslip too far down-dip systematically fail to predict postseismic deformation. We find that the postseismic observations are best predicted by a narrower coseismic slip model that terminates abruptly at its deepest extent. The model predictions improve further if stress-driven afterslip is combined with a superimposed viscoelastic relaxation response of a 50 km thick elastic lithosphere for the overriding plate and an elastic cold nose to the mantle wedge.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 10","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030401","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145209687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A 43,000-Year-Long Paleoseismic Record Along the Southern Section of the Lijiang-Xiaojinhe Fault, Southeastern Tibetan Plateau, China","authors":"Z. Yuan,&nbsp;J. Huang,&nbsp;W. Xiao,&nbsp;P. Su,&nbsp;J. Gan,&nbsp;Z. Li,&nbsp;G. Liu,&nbsp;H. Liu,&nbsp;F. Yin,&nbsp;C. Wang","doi":"10.1029/2025JB031457","DOIUrl":"10.1029/2025JB031457","url":null,"abstract":"<p>Paleoseismic data on the timing of ground-rupturing earthquakes can help identify the sources of historical earthquakes and define the extent of seismic rupture gaps. The Lijiang-Xiaojinhe fault (LXF) is a left-lateral strike-slip fault that stretches 380 km along the southeastern margin of the Tibet Plateau, passing through the densely populated urban area of Lijiang City. In this study, we excavated four paleoseismic trenches at the Shuijing and Haitang sites along the southwestern section of the LXF and identified eight earthquakes over the past 43 Kyr through detailed trench logging and radiocarbon dating. The average recurrence interval (RI) for these eight events is 6.0 ± 4.8 Kyr, with a coefficient of variation (COV) of 0.80, indicating that earthquake recurrence is weakly periodic. In contrast, the average RI for the last five events is 3.1 ± 2.3 Kyr, with a COV of 0.72, indicating a stronger periodic behavior. Analyzing historical earthquake documents revealed that the most recent event corresponds to the M 6.8 Jianchuan earthquake in 1751 and may have involved a joint rupture along the LXF and the Zhongdian-Longpan-Qiaohou fault. Comparison with other sites along the LXF limits the extent of a seismic rupture gap to ∼70 km long between Lijiang and Ninglang. This gap has not experienced earthquakes for ∼2,000 years and accumulated a coseismic slip of ∼4.3 m, impending a large earthquake of Mw 7.2–7.6. Consequently, Lijiang City is currently at high risk of a large earthquake.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 10","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JB031457","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145209692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Learning From Finland: Variability of Subglacial Heat Flow in Greenland Explored From Geological Units and Radiogenic Heat Production","authors":"Judith Freienstein,&nbsp;Wolfgang Szwillus,&nbsp;Maja Zimmer,&nbsp;Jörg Ebbing","doi":"10.1029/2025JB031545","DOIUrl":"10.1029/2025JB031545","url":null,"abstract":"<p>It is well known that geothermal heat flow influences the dynamics of ice sheets. Especially small-scale variations may lead to strong effects, but are not resolvable in most available models. Here, we establish a relationship between large-scale radiogenic heat production (RHP) and geological units for Greenland to assess the local variability of geothermal heat flow (GHF). Our approach combines information on the variability of RHP from samples at coastal regions with geological maps to simulate small-scale variations of RHP under the ice and consequently GHF. We first test our approach for Finland where a unique RHP database is available before applying it to Greenland. RHP is simulated based on two different available geological maps for Greenland leading to different RHP variability. The different geological units with their unique RHP variability have a strong influence on the GHF, leading to significantly different results. For example, in central Greenland, the estimated GHF of the different maps has a difference of more than 20 mW/m². This demonstrates the importance of reliable knowledge of subglacial geology and thermal parameters in order to provide reasonable estimates of the basal conditions of the ice-sheet.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 10","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JB031545","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145209693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Consistency Between the Slip History Implied by in Situ 36Cl Exposure Dating on an Active Normal Fault and the Timing of Holocene Coastal Notch Formation, Central Greece","authors":"Jenni Robertson,&nbsp;Claudia Sgambato,&nbsp;Gerald Roberts,&nbsp;Zoe Mildon,&nbsp;Joanna Faure Walker,&nbsp;Francesco Iezzi,&nbsp;Sam Mitchell,&nbsp;Athanassios Ganas,&nbsp;Ioannis Papanikolaou,&nbsp;Elias Rugen,&nbsp;Varvara Tsironi,&nbsp;Joakim Beck,&nbsp;Silke Mechernich,&nbsp;Georgios Deligiannakis,&nbsp;Steve Binnie,&nbsp;Tibor Dunai,&nbsp;Klaus Reicherter","doi":"10.1029/2024JB030293","DOIUrl":"10.1029/2024JB030293","url":null,"abstract":"<p>We report agreement between the timing of slip on an active normal fault recovered from in situ ³⁶Cl cosmogenic fault scarp dating with independently ¹⁴C dated Holocene coastal notches deformed along the strike of the fault, reinforcing the validity of slip-rate timing and magnitude fluctuations implied by ³⁶Cl fault scarp dating. The ³⁶Cl-dated Pisia fault, central Greece, shows slip-rate fluctuations but the timing of slip derived from this cosmogenic isotope have not been confirmed with an independent dating approach. However, Holocene coastal notches dated with ¹⁴C on fossils occupying the notches exist around the Pisia fault, these can only form when the interplay between eustatic sea-level and tectonics result in stable relative sea-level. The ³⁶Cl site close to the center of the Pisia fault records ongoing slip from ∼9.6 to 5.2 (±0.5) ka and 2.0 ± 0.5 ka to the present day which was interrupted by a low slip-rate period. Holocene sea-level stabilized close to its current elevation after 7.0–6.5 ka, so the combination of low slip-rate and stable sea-level allowed notch formation. During this time, notches were uplifted by slip on the offshore Strava fault, indicated by elastic half-space modeling. Toward the center of the Pisia-Skinos fault, these notches were then submerged during the high slip period from 2.0 ± 0.5 ka. Our findings reveal that spatial patterns of deformed radiocarbon-dated Holocene notches agree with the timing of high slip earthquake clusters/quiescent anti-clusters from ³⁶Cl slip histories and support use of ³⁶Cl to investigate normal faults, crustal rheologies and seismic hazard.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 10","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030293","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Little Murray Ridge Subduction Controls the Segmentation of Megathrust and Co-Seismic Rupture Along the Eastern Makran Margin","authors":"Haobo Xu,&nbsp;Xiaodong Yang,&nbsp;Jonas B. Ruh,&nbsp;Jian Lin,&nbsp;Lijie Wang,&nbsp;Rebecca E. Bell,&nbsp;Christopher K. Morley,&nbsp;Yiduo Liu,&nbsp;Fan Zhang,&nbsp;Qiang Qiu,&nbsp;Jinchang Zhang","doi":"10.1029/2025JB031876","DOIUrl":"10.1029/2025JB031876","url":null,"abstract":"<p>Whether subducted seafloor topography can generate or inhibit large earthquakes is a long-standing debate, primarily due to the lack of three-dimensional constraints on megathrust morphology and frictional properties over large earthquake ruptures. The eastern Makran subduction zone is characterized by the subduction of the Little Murray Ridge and a strong segmentation in seismicity and large earthquake ruptures. By integrating 6,200 km of 2D seismic profiles and 50-m-resolution multibeam bathymetry with the critical wedge theory, we show that the ridge subduction has locally developed a rough plate interface, characterized by high apparent basal friction <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msubsup>\u0000 <mi>μ</mi>\u0000 <mi>b</mi>\u0000 <mo>′</mo>\u0000 </msubsup>\u0000 </mrow>\u0000 <annotation> ${mu }_{b}^{mathit{prime }}$</annotation>\u0000 </semantics></math> (0.09–0.14), and significant yield stress variations, while the non-ridge segment exhibits a smooth plate interface, low <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msubsup>\u0000 <mi>μ</mi>\u0000 <mi>b</mi>\u0000 <mo>′</mo>\u0000 </msubsup>\u0000 </mrow>\u0000 <annotation> ${mu }_{b}^{mathit{prime }}$</annotation>\u0000 </semantics></math> (0.06), and less yield stress variation. These distinct structural and mechanical properties effectively controlled the rupture behavior of the 1945 Mw 8.1 and 2017 Mw 6.3 earthquakes, which were both facilitated by the smooth plate interface, but halted upon encountering the rough segment. Moreover, the 1945 Mw 8.1 earthquake nucleated at a basement high front, where the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msubsup>\u0000 <mi>μ</mi>\u0000 <mi>b</mi>\u0000 <mo>′</mo>\u0000 </msubsup>\u0000 </mrow>\u0000 <annotation> ${mu }_{b}^{mathit{prime }}$</annotation>\u0000 </semantics></math> is elevated. This nucleation location, combined with the earthquakes rupture behavior, suggests that subducted topography can act as both an asperity and a barrier. To the best of our knowledge, the 1945 Mw 8.1 event is likely the largest instrumental event generated by a subducted topographic feature, contrasting with previously globally observed magnitude ∼7 events linked to rough asperities. Therefore, the earthquake potential associated with subducting topographic features has likely been underestimated in global active margins, and requires re-evaluation.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 10","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145195065","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}