Journal of Geophysical Research: Solid Earth最新文献

{"title":"Potential Ice Sheet Modulation of Volcanism in West Antarctica: Constraints on the Cadence and Magnitude of Melt Delivery Into the Crust","authors":"Sean Wanket, A. Mark Jellinek, Catherine L. Johnson","doi":"10.1029/2024JB029730","DOIUrl":"https://doi.org/10.1029/2024JB029730","url":null,"abstract":"<p>Variations in continental ice mass related to changes in Earth's obliquity can modulate volcanism. At Marie Byrd Land, increases in crustal temperature related to the transfer of magmas and to the insulating effects of the West Antarctic Ice Sheet will reduce the effective viscosity of wall rocks, causing the volcanic response to be reduced in magnitude and delayed by up to <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation> ${sim} $</annotation>\u0000 </semantics></math>10.25 kyr. For sufficiently high levels of crustal warming, magma storage is enhanced such that there is a negligible volcanic response. Tephra layers correlated to Mount Berlin volcanism signal increases in the frequency of silicic eruptions following maxima in the rate of deglaciation over 0–40 ka (interval 1) and possibly 100–135 ka (interval 2). During interval 1, an increase in eruption frequency at <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>≈</mo>\u0000 </mrow>\u0000 <annotation> ${approx} $</annotation>\u0000 </semantics></math>8 ka lags deglaciation by <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>≈</mo>\u0000 </mrow>\u0000 <annotation> ${approx} $</annotation>\u0000 </semantics></math>6.5–9 kyr. An increase in volcanism at 110 ka, by contrast, may lag deglaciation by <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>≥</mo>\u0000 </mrow>\u0000 <annotation> ${ge} $</annotation>\u0000 </semantics></math>10.25 kyr. We hypothesize that a decrease in lag time of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation> ${sim} $</annotation>\u0000 </semantics></math>10 ka reflects a period of reduced crustal warming related to a waning mantle melt supply. Using thermal models of the effects of ice sheet insulation and a time-dependent magma supply on the viscoelastic response of rocks hosting volcanically active magma reservoirs, we show that a periodic magma supply can drive oscillations between rheological regimes favoring eruption or storage. With additional constraints on the regional geothermal heat flux and eruption rate at Mount Berlin, an evolving response between 110 and 8 ka is consistent with magma injections with a period of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 <mn>1</mn>\u0000 <msup>\u0000 <mn>0</mn>\u0000 <mn>6</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> ${sim} 1{0}^{6}$</annotation>\u0000 </semant","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB029730","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281420","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":"New Pattern of Uplift-Depression of the Pre-Cambrian Basement in the Sichuan Basin: Constraints From Multi-Seismic Parameter Imaging","authors":"Zhi Wang,&nbsp;Qiuding Du,&nbsp;Jian Wang,&nbsp;Yinyu Wen,&nbsp;Gang Zhou,&nbsp;Yuan He,&nbsp;Xiugen Fu","doi":"10.1029/2024JB030152","DOIUrl":"https://doi.org/10.1029/2024JB030152","url":null,"abstract":"<p>The structural configuration of the pre-Cambrian basement in the Sichuan Basin, a highly promising region for hydrocarbon exploration, has been a subject of long-standing debate. Here, we determined the fine-scale three-dimensional seismic models of the Sichuan Basin using 187,356 high-quality P- and S-wave travel time pairs recorded by 627 recently installed seismic stations. Meanwhile, 595 petroleum wells were collected to investigate their spatial distribution associated with the basement structures. Our findings reveal two depression belts, one extending through the western regions of Chengdu, Mianyang, and Wanyuan, and another in the eastern regions of Wanzhou, Fuling, and Chishui, forming a distinctive horseshoe-shaped depression structure. Concurrently, the central and southwest regions exhibit two uplift zones, constituting an L-shaped uplift structure. Approximately 76% of the petroleum wells are situated within the L-shaped uplift structure and its slope, while around 21% of the gas wells are located in the transitional zones between the depression structures or along their edges. The development of the depression structure is attributed primarily to the complex triple collision system involving the Qinghai-Tibet block in the west, the Cathsysia block in the southeast, and the North China block in the north. Conversely, the uplift structure is mainly caused by the southeastward movement of the Songpan-Ganze block and the northwestward movement of the Cathsysia block. These new findings reveal a significant correlation between the paleo-uplift structures, the distribution of hydrocarbon resources, and the geological conditions conducive to petroleum reservoirs in the Sichuan Basin, providing valuable insights for predicting potential petroleum reservoirs.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030152","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281421","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":"Timescales of Surface Faulting Preservation in Low-Strain Intraplate Regions From Landscape Evolution Modeling and the Geomorphic and Historical Record","authors":"Jessica A. Thompson Jobe,&nbsp;Nadine G. Reitman","doi":"10.1029/2024JB029966","DOIUrl":"https://doi.org/10.1029/2024JB029966","url":null,"abstract":"<p>Large surface-rupturing intraplate earthquakes in stable continental regions (SCRs) are uncommon globally and have recurrence intervals of thousands to hundreds of thousands of years based on the paleoseismic and geomorphic record, challenging accurate active fault identification in these regions. To constrain the timescales of preservation for scarps created by surface ruptures from dip-slip earthquakes, we use a two-dimensional scarp diffusion model for typical intraplate settings and explore which parameters influence fault scarp preservation. These parameters include the coseismic vertical surface offset, the recurrence interval of similar magnitude earthquakes, diffusivity (as a proxy for mean annual precipitation rate), and the erodibility of the surficial material. We constrain parameter ranges from a compilation of historical surface ruptures in intraplate settings in a variety of climates, including the Central and Eastern United States, Australia, Europe, Central Asia (Mongolia, China), India, and West Africa. The timescales of scarp preservation from landscape evolution modeling agree well with observations of scarp preservation in low-strain SCR and intraplate tectonic settings, with some notable exceptions for Australian scarps. We find that the erodibility of the surficial material and earthquake recurrence interval have a stronger effect on the timescales of scarp preservation than diffusivity or coseismic vertical surface offset. Our model results may aid in identifying and characterizing subtle, slow-moving active faults in low-strain SCR and intraplate tectonic settings for different tectonic, geomorphic, and climatic characteristics. Accurate fault locations and characterization from the landscape record has implications for both probabilistic seismic and fault displacement hazard analyses.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281419","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":"Channeling, Clogging and Permeability Oscillations: Different Macroscopic Regimes in Mineral Replacement","authors":"Agnieszka Budek,&nbsp;Piotr Szymczak","doi":"10.1029/2024JB031081","DOIUrl":"https://doi.org/10.1029/2024JB031081","url":null,"abstract":"<p>We consider a porous medium infiltrated by a reactive fluid which triggers coupled dissolution-precipitation reactions at pore surfaces. To study these processes, we model the medium as a system of interconnected pipes with the diameter of each segment changing in proportion to the local reactant consumption. With this model, we investigate different growth regimes in an evolving porous medium, allowing for both erosion and precipitation of the dissolved material. The interplay of flow, transport and reaction in such a system can give rise to a variety of patterns: from spontaneous channeling to nearly homogeneous transformation of the entire rock matrix into the product phase. Interestingly, even if the product phase has a larger molar volume than the parent phase, clogging in such a system can be avoided, due to the interplay of dissolution and precipitation resulting in the continuous creation of new flow paths. These results can be relevant for the analysis of carbonation reactions, in which an important goal is to avoid clogging of the pore space that can lead to permeability reduction and the overall slowdown of the process.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144264500","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":"3-D Mantle Flow and Structure of the Mediterranean From Combined P-Wave and Splitting Intensity Anisotropic Tomography","authors":"F. Rappisi,&nbsp;R. Lo Bue,&nbsp;B. P. Vanderbeek,&nbsp;J. M. Confal,&nbsp;C. Erman,&nbsp;P. Baccheschi,&nbsp;S. Pondrelli,&nbsp;T. Eken,&nbsp;S. Yolsal-Çevikbilen,&nbsp;M. Faccenda","doi":"10.1029/2024JB030883","DOIUrl":"https://doi.org/10.1029/2024JB030883","url":null,"abstract":"<p>We present a novel three-dimensional anisotropic seismic tomography model of the Mediterranean region, achieved through the simultaneous inversion of P-wave travel-times and SKS splitting intensity. This dual approach has allowed us to obtain a comprehensive tomographic model that not only delineates the primary structural features of the area but also sheds light on its tectonic evolution. Our findings reveal that the isotropic component of the model is dominated by fast anomalies associated with retreating, stagnant, and detached slab segments including the Alboran, Apennine, and Alpine slabs in the central and western Mediterranean, and the Dinaric, Carpathian, and Hellenic slabs in the east. Slower mantle structures are associated with slab windows and back-arc basin formation, such as those observed in the Tyrrhenian, Apennine and Hellenic regions. The recovered anisotropic patterns provide crucial insights into the tectonic history of the Mediterranean, highlighting periods of collision and tectonic relaxation. Notably, we observe a range of plunge angles, with both near-horizontal and steeply dipping anisotropic fabrics present in different regions, reflecting the influence of horizontal and vertical asthenospheric flow. By interpreting the high-velocity zones as subducting lithosphere, we construct a detailed 3-D model of the main slabs and analyzed the surrounding P-wave anisotropic patterns. This work represents the first comprehensive anisotropic tomography study of the entire Mediterranean region.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030883","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144255943","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":"High Resolution Shallow Structure of Ebao Basin Revealed With DAS Ambient Noise Tomography and Its Relation to Earthquake Ground Motion","authors":"Song Wang,&nbsp;Zhenghong Song,&nbsp;Xiangfang Zeng,&nbsp;Benxin Chi,&nbsp;Jun Xie,&nbsp;Feng Bao","doi":"10.1029/2024JB029874","DOIUrl":"https://doi.org/10.1029/2024JB029874","url":null,"abstract":"<p>The Ebao Basin, which locates along the northwest segment of the Qilian-Haiyuan fault, has experienced several destructive earthquakes in past decades. A 10 km long distributed acoustic sensing (DAS) array was deployed with an existing telecom fiber-optic cable after the 2022 Mw6.6 Menyuan earthquake, which destroyed high-speed railways and highways in this region. The DAS array continuously recorded ambient noise and earthquake signals during the 5-day deployment period. Noise cross-correlation functions (NCFs) were calculated, and the Rayleigh wave signal clearly emerged on the NCFs. The phase velocities of the fundamental mode between 2.5 and 17 Hz were measured with the modified Frequency-Bessel transform method. The S-wave velocity structure along the cable, extending to a depth of 200 m, was constructed using the surface wave tomography method. It consists of three blocks, with velocity variations of up to 12%. P-wave delay times of regional earthquakes support the lateral variation among the three blocks. Both Vs30 and site amplification predicted with our S-wave velocity model correlate well with the ground motion induced by local earthquakes. Precursor and coda waves on the NCFs reveal four possible faults, and fault zone scattered waves are also observed on the record of local earthquakes.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144244812","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":"Magma-Assisted Flexure of Hawaiian Lithosphere Inferred From Three-Dimensional Models of Lithospheric Flexure Constrained by Active Source Seismic Data","authors":"D. Douglas,&nbsp;G. Ito,&nbsp;B. Boston,&nbsp;R. Dunn,&nbsp;J. Naliboff,&nbsp;P. Wessel,&nbsp;A. B. Watts,&nbsp;D. Shillington,&nbsp;P. Cilli","doi":"10.1029/2024JB030376","DOIUrl":"https://doi.org/10.1029/2024JB030376","url":null,"abstract":"<p>Reprocessed and newly acquired seismic data provide new constraints on lithospheric flexure profiles beneath the Hawaiian Islands. We use these new observations and three-dimensional numerical models of lithospheric deformation combining elasticity, brittle failure, low-temperature plasticity (LTP) and high-temperature creep deformation mechanisms to constrain the thermal structure and rheology of the oceanic lithosphere. When simulating normal oceanic lithospheric conditions with experimentally-derived LTP flow laws, the lithosphere flexes with too little amplitude and over too large a wavelength compared to observations. This result supports prior studies which call on the need to (a) adjust the LTP flow laws or, alternatively, to (b) account for magma-assisted flexural weakening of the lithosphere. Here, models that explore reductions in the activation energy of LTP are able to explain the observations of flexure with a smaller reduction than previously suggested. Models that explore elevated temperatures attributed to hotspot magmatism localized beneath the island edifices also produce close fits to the observed flexural profiles. Although the two factors cannot be distinguished based on fits to the flexure profiles, localized magma-assisted flexural weakening is supported by recent studies of geothermobarometry of pyroxenite xenoliths from O'ahu, seismic structure and patterns of seismicity beneath the Hawaiian chain. If magma-assisted flexure is a common phenomenon at other ocean islands and seamounts, it could explain similarities in elastic plate thickness with subduction zones as well as differences with fracture zones globally.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030376","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144255870","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":"Pre-Existing Structures Control the Orientation of Strike-Slip Faulting During the 2021 Dike Intrusion at Fagradalsfjall, Iceland","authors":"E. Glastonbury-Southern,&nbsp;T. Winder,&nbsp;N. Rawlinson,&nbsp;R. S. White,&nbsp;T. Greenfield,&nbsp;C. A. Bacon,&nbsp;T. Ágústsdóttir,&nbsp;B. Brandsdóttir,&nbsp;E. Á. Gudnason,&nbsp;G. P. Hersir,&nbsp;T. J. Fischer,&nbsp;J. Doubravová,&nbsp;P. Hrubcová,&nbsp;E. P. S. Eibl","doi":"10.1029/2024JB030162","DOIUrl":"https://doi.org/10.1029/2024JB030162","url":null,"abstract":"<p>The 2021 Fagradalsfjall inflation and dike intrusion marked the initiation of a new era of volcanism on Iceland's Reykjanes Peninsula. We present a large automatic catalog consisting of more than 80,000 earthquake hypocenters spanning the full period of the dike intrusion, which were derived from seismic data recorded by a dense network of seismometers. The 9–10 km long dike exhibits a two-segment geometry of similar lengths. Linear regression on a relatively relocated subset of over 12,000 earthquakes revealed a strike of 029° with a standard deviation of 2° in the southern segment, and 046° with a standard deviation of 1° in the northern segment of the dike. A total of 97 detailed fault plane solutions from selected subsets of events provide new insight into the controls on faulting, showing almost exclusively right-lateral strike-slip/oblique-slip faulting associated with the dike intrusion, and a lack of left-lateral strike-slip fault motion. The alignment of fault planes is consistent with the orientation of pre-existing structures, within uncertainty estimates. In light of these observations, we conclude that the dominant controlling factor on the orientation of dike-related faulting is the extensive network of pre-existing structures formed by the active transtensional plate boundary along the Reykjanes Peninsula.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030162","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144245056","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":"Crustal Structure Along and Surrounding the Hawaiian Islands: Volcanic Island Construction Across Scarred Oceanic Crust","authors":"Brian Boston,&nbsp;Donna J. Shillington,&nbsp;Anthony B. Watts,&nbsp;Philip Cilli,&nbsp;Robert Dunn,&nbsp;Garrett Ito,&nbsp;Paul Wessel,&nbsp;Uri ten Brink","doi":"10.1029/2024JB030377","DOIUrl":"https://doi.org/10.1029/2024JB030377","url":null,"abstract":"<p>The Hawaiian Ridge is a classic example of an intraplate volcanic island chain emplaced on oceanic lithosphere. We seek to constrain both the deformation from island loading around the Hawaiian Ridge and the influence of the oceanic lithosphere, including the Molokaʻi fracture zone (MFZ), on off-axis volcanic emplacement. To examine these processes, we conducted a marine geophysical experiment in 2018 that included the acquisition of eight multichannel seismic reflection lines and used a 6,600 in³ tuned air gun array and an ultra-long hydrophone streamer cable towed behind R/V <i>Marcus G. Langseth</i> across and around the southern Hawaiian Ridge. We image both the top of igneous oceanic crust and the Moho, and we observe significant variations in regional crustal structure and thickness variations, Moho characteristics, the locations of the buried MFZ, and the flexure of the Pacific oceanic lithosphere under the Hawaiian Ridge. We observe up to ∼4.5 km of deflection of the igneous oceanic crust in response to the volcanic load with sediment thickness increasing to ∼3–3.4 km near the ridge but not correlating with the deflection. A systematic difference in igneous oceanic crustal thickness is found north (average ∼5.2 km) and south (average ∼5.9 km), of the MFZ that also correspond to changes in Moho characteristics. The MFZ itself is associated with the largest crustal thickness variations (∼3.7–7.6 km). Magma ascent through these different crustal regions may account for some variations of magmatic flux to the surface along the Hawaiian Ridge.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030377","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144255901","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 Dynamics of Fast and Slow Earthquake Ruptures in Viscoelastic Materials","authors":"Huihui Weng","doi":"10.1029/2024JB030663","DOIUrl":"https://doi.org/10.1029/2024JB030663","url":null,"abstract":"<p>Classical theories using linear elasticity predict that crack propagation asymptotically approaches a limiting speed, beyond which the energy balance becomes unphysical. However, geophysical and laboratory observations show that ruptures can propagate at either a very low, stable speed or a significantly high speed. Here, we first use numerical simulations to show that frictional ruptures in viscoelastic materials can steadily propagate at a terminal speed, rather than asymptotically approaching the classical speed limit. The simulated terminal speed spans a continuum of values, ranging from slow ruptures to supershear ruptures. We then develop a new theory incorporating viscoelasticity to predict all simulated rupture speeds. In addition to the ratio of fracture energy to static energy release rate, we find that three length scales also play a crucial role in governing the energy balance during rupture in viscoelastic materials. The theory predicts that stable rupture speeds are energetically allowed to be very small, which helps explain the widespread occurrence of slow earthquakes. Beyond the classical speed limit, the energy balance becomes independent of macroscopic length scales, being controlled solely by the local properties around the rupture tip. Furthermore, we find that the effects of viscoelasticity in fault zones are significant in earthquake rupture propagation, even when the fault-zone geometrical scales are short relative to other fault dimensions. These numerical and theoretical findings fundamentally advance our understanding of dynamic rupture propagation.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030663","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144244813","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}