Earth and Planetary Science Letters最新文献

{"title":"Provenance of North Indian geoid ridge and its implication to collision evolution between India and Eurasia","authors":"Peilong Yan ,&nbsp;Nan Zhang ,&nbsp;Xi Liu ,&nbsp;Bo Wan","doi":"10.1016/j.epsl.2025.119248","DOIUrl":"10.1016/j.epsl.2025.119248","url":null,"abstract":"<div><div>The geoid minima in the Indian Ocean and Siberia are separated by the North Indian Geoid Ridge (NIGR), yet the origin of the NIGR remains inadequately understood. Spherical harmonic analysis and geoid kernels indicate that the NIGR has wavelengths of degrees 7–10 and is mainly driven by density anomalies of similar degrees within the mantle. By employing numerical geoid modelling with four different tomography-derived density structures, we determined that abundant high-density anomalies in the mantle transition zone beneath North India and the Himalayas are responsible for the NIGR. Additionally, two contrasting tectonic evolutions of the India-Tibet collision, namely subduction roll-back scenario through the collision vs. lithospheric dripping scenario through the collision, are evaluated through geoid calculation. The former scenario suggests abundant high-density structures in the transition zone, capable of generating a well-constrained NIGR, while the latter does not support this. Consequently, we consider the Indian lithosphere subduction roll-back to be the more plausible evolving scenario.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"655 ","pages":"Article 119248"},"PeriodicalIF":4.8,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403514","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":"Lower crustal thickening drives active uplift in Northern Tibet","authors":"Shaozhuo Liu ,&nbsp;Xiwei Xu ,&nbsp;Jean-Mathieu Nocquet ,&nbsp;Guihua Chen ,&nbsp;Xibin Tan ,&nbsp;Sigurjón Jónsson ,&nbsp;Yann Klinger","doi":"10.1016/j.epsl.2025.119245","DOIUrl":"10.1016/j.epsl.2025.119245","url":null,"abstract":"<div><div>Mountains in collisional orogens generally grow as crustal rocks are advected over low-angle thrust faults, suggesting a close relationship between tectonic uplift and upper crustal shortening. For example, the Himalayas, hosting large-scale thrust fault systems, undergoes ∼15–20 mm/year shortening and concomitant ∼5 mm/year active uplift. However, geodetic observations reveal an active uplift of 1–2 mm/year across the East Kunlun Shan mountain range, the northern margin of the Tibetan Plateau, where no active thrust fault has been identified. This active uplift is too fast to be explained by the limited horizontal shortening of at most 1.0 ± 0.2 mm/year. After quantifying and correcting for contributions arising from erosion, (de)glaciation, and recent earthquakes, the uplift rate across the East Kunlun Shan still amounts to 1.0 ± 0.5 mm/year. Our simulations show that mantle processes cannot explain the GPS-observed uplift. We find that lower crustal thickening, rather than upper crustal shortening alone, drives the ongoing uplift across the East Kunlun Shan, hence challenging our current views on mountain range dynamics.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"655 ","pages":"Article 119245"},"PeriodicalIF":4.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395795","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":"MgO miscibility in liquid iron","authors":"Leslie Insixiengmay ,&nbsp;Lars Stixrude","doi":"10.1016/j.epsl.2025.119242","DOIUrl":"10.1016/j.epsl.2025.119242","url":null,"abstract":"<div><div>We explore phase equilibria on the MgO-Fe join as a prototype of lithophile-core interaction in terrestrial planets. Our density functional theory simulations are based on a phase coexistence method: fluids of initially pure MgO and Fe compositions are allowed to establish a dynamic equilibrium across a near-planar interface. Methods for analyzing the composition and other properties of the two coexisting phases show that MgO behaves as a component, with indistinguishable Mg and O concentrations in Fe-rich and oxide-rich phases. The phase diagram is well described as that of a symmetric regular solution, a picture confirmed by independent one-phase determinations of the enthalpy, entropy, and volume of mixing. The critical temperature, above which there is complete miscibility across the MgO-Fe join is 7000 K at 68 GPa, and 9000 K and 172 GPa. The rate of MgO exsolution from the Fe-rich liquid on cooling is similar to that found in previous experimental studies, and is too small to drive a dynamo.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"654 ","pages":"Article 119242"},"PeriodicalIF":4.8,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143300330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Uphill diffusion of lithium along phosphorus gradients in olivine from mafic layered intrusions","authors":"Chang-Ming Xing ,&nbsp;Christina Yan Wang ,&nbsp;Wei Tan ,&nbsp;Fang-Yue Wang","doi":"10.1016/j.epsl.2024.119182","DOIUrl":"10.1016/j.epsl.2024.119182","url":null,"abstract":"<div><div>Lithium (Li) concentration and Li isotopes of olivine have been widely adopted to decipher the mantle-crust interaction and short-lived magmatic processes in the shallow magma chambers. However, the diffusion behavior of Li in olivine has not yet been fully understood, which may bias the interpretation of Li concentration and Li isotopes observed in natural olivine. In this study, high-resolution elemental mapping (Li, P, Fe, Mn, Ca, Al, and Ni) combined with in situ Li concentration and Li isotope analyses were conducted for olivine grains from two ca. 260 Ma mafic layered intrusions in SW China, to decode the origin of coupled Li-P zoning and multi-mode diffusion of Li in natural olivine. The 2-D elemental maps and compositional profiles reveal complex, coupled Li-P zoning patterns. The Li-P-rich zones contain 3.5 to 6.1 ppm Li and 187 to 776 ppm P, higher than those of Li-P-poor olivine domains that contain 0.7 to 2.8 ppm Li and 29 to 166 ppm P. Particularly, the Li-P-rich zones in each grain commonly have lower <em>δ</em>⁷Li* than that of the Li-P-poor domains, with the maximum fractionation of Li isotopes in a single grain being up to 15‰. Numerical modeling shows that rapid olivine growth can result in variable degrees of Li and P enrichment in concentration and an increase of <em>δ</em>⁷Li* in the Li-P-rich zone of olivine, which is inconsistent with our observations. Instead, the inverse variations of Li concentration and Li isotopic profiles can be well simulated in an uphill diffusion mode of Li along pre-existing sharp P gradients, accompanying by simultaneous coupled and non-coupled diffusion of Li within a single olivine. The large variation of <em>δ</em>⁷Li* is thus interpreted as kinetic fractionation, which may be caused by dehydration of olivine due to exsolution of a fluid phase from the interstitial liquid of a crystal mush. Three distinct Li-P variation trends of olivine are summarized in this study and can be used to distinguish the process of crystal growth from post-crystallization diffusion. Our results should have important bearings on the understanding of complex crystallization and solidification processes of crustal magma chambers.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119182"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143157738","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":"Insight into climate and hydrology of the late cretaceous western interior basin from clumped isotope Paleothermometry and strontium isotopes","authors":"Allison N. Curley ,&nbsp;Sierra V. Petersen ,&nbsp;Henry Fricke ,&nbsp;James Gleason","doi":"10.1016/j.epsl.2024.119180","DOIUrl":"10.1016/j.epsl.2024.119180","url":null,"abstract":"<div><div>High sea levels in the Late Cretaceous led to the formation of vast seaways on every continent. These shallow seaways are without modern analogs and many fundamental aspects of their oceanography are poorly understood. In the Campanian (∼83–72 Ma), the Western Interior Seaway (WIS) of North America linked the proto-Gulf of Mexico and Arctic Ocean. Given its shallow depth, freshwater inputs to the WIS could have had a greater influence on conditions in the seaway compared to a deeper ocean and would have become increasingly important as the WIS regressed through the Maastrichtian. The isotopic composition of mollusk shells in freshwater facies can help constrain the composition and temperature of these inputs, improving our understanding of surface temperature, hydrological dynamics, and paleoelevation. Here we measure Δ₄₇ temperature, δ¹⁸O_water, and ⁸⁷Sr/⁸⁶Sr in late Campanian (∼75 Ma) unionid bivalve shells from fluvial and pond deposits near the western shore of the WIS (∼42°N-56°N). Sample mean surface water temperatures spanned 22–44 °C, with a mean of 30 ± 2.7 °C. The latitudinal temperature gradient across this region is reduced compared to today, at ∼7 °C across these 14° of latitude based on stream sample means. These temperatures are outside the optimal growth conditions of modern unionids in North America, indicating a shift in niche. Following this finding, we recalculate δ¹⁸O_water values from previously published δ¹⁸O_carb values using new Δ₄₇ temperatures instead of assumed growth temperatures. Our findings support previous observations of a bimodal distribution in freshwater δ¹⁸O_water values in this region although the absolute values shift higher. Spatial patterns of δ¹⁸O_water are consistent with a Campanian Proto-North American Monsoon and the lowest δ¹⁸O_water values we report are consistent with paleoelevation of &gt;3500 m in the Proto-Cordillera. ⁸⁷Sr/⁸⁶Sr values broadly align with different facies, with more radiogenic values occurring in major trunk rivers draining the highlands and less radiogenic values in streams recharged by low-elevation precipitation. Predominance of a ⁸⁷Sr/⁸⁶Sr signature consistent with weathering Paleozoic carbonates could be consistent with seasonal increases in rock weathering associated with a monsoon.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119180"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143158956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Wetted two-grain boundaries in olivine aggregates and seismic velocities in the oceanic upper mantle","authors":"Andrew J. Berry ,&nbsp;Ulrich H. Faul ,&nbsp;Qiheng Yang ,&nbsp;Harri Kokkonen ,&nbsp;Andrew M. Kingston ,&nbsp;Ajay Limaye ,&nbsp;Martin D. de Jonge","doi":"10.1016/j.epsl.2024.119119","DOIUrl":"10.1016/j.epsl.2024.119119","url":null,"abstract":"<div><div>The distribution of basaltic melt between crystals of olivine (Mg_1.8Fe_0.2SiO₄), after equilibration at 1350 °C and 1 GPa for up to 14 days, was investigated by fluorescence tomography. The system is an analogue for low-degree partial melts in the Earth's upper mantle, the connectivity of which controls the rate at which magmas are transported from the source to the surface by porous flow. In fluorescence tomography the distribution of an incompatible element that partitions almost exclusively into the melt can be used to map the distribution of melt. We chose to use Nb (0.7 wt%) because of its high incompatibility and the high energy of its Kα fluorescence, which allowed samples with a thickness of up to 300 μm to be studied. The tomographic reconstructions showed not only melt pockets at four-grain corners and melt channels on three-grain edges, as predicted, but also melt sheets corresponding to wetted two-grain boundaries. The spatial resolution of the method is controlled by the size of the excitation beam (in this case 2–3 μm), but smaller features can be observed and their thickness inferred from the intensity of the fluorescence signal. The melt sheets identified have a thickness of ∼0.5 μm, but there is also evidence for thinner sheets. Better resolution of thin sheets could be achieved by increasing the concentration of Nb in the melt. Fluorescence tomography is an ideal approach for determining the distribution of melt at low melt fractions since only the melt is imaged. The speed of data acquisition opens up the possibility of systematically studying the evolution of melt connectivity as a function of melt fraction. A melt distribution that includes wetted two-grain boundaries has a lower permeability and would be more visible seismically than the expected tubule geometry. The presence of melt can hence explain the significant drop in seismic velocity observed in the oceanic upper mantle.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119119"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143158930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Evolution of the subcontinental lithospheric mantle beneath accretionary orogens: Implications for the stabilization of cratons","authors":"Yuchen Liu ,&nbsp;Gongcheng Tian ,&nbsp;Yong Xu ,&nbsp;James M. Scott ,&nbsp;D．Graham Pearson ,&nbsp;Jingao Liu","doi":"10.1016/j.epsl.2025.119244","DOIUrl":"10.1016/j.epsl.2025.119244","url":null,"abstract":"<div><div>Thick lithospheric roots characterized by low density and high viscosity are crucial for the long-term stability of cratons. Examining the thick lithospheric roots currently developing in young continental terranes provides valuable insights into the processes driving cratonic stabilization. This study presents a comprehensive elemental and Re-Os isotopic investigation of 103 mantle peridotite xenoliths from the western Xing'an Mongolia Orogenic Belt (XMOB), a component of the Central Asian Orogenic Belt. Most peridotites experienced low to moderate degrees of polybaric fractional melt extraction (4–25%), while hydrous melting (∼30 %) was superimposed on a few refractory residues with low densities similar to cratonic counterparts. Geothermobarometry and geophysical observations indicate that the lithospheric root beneath the western XMOB is up to 60 km thicker than at its initial stage. The peridotites with Mesoproterozoic to Phanerozoic Re-depletion Os model ages match temporally with overlying crust, while those with Archean model ages represent mantle fragments derived from either heterogeneous asthenosphere or adjacent Archean cratonic roots. During the Mesoproterozoic to Neoproterozoic, this mixture of ancient fragments and ambient mantle underwent decompressional melting at spreading centers. With further hydrous re-melting and thickening, these newly formed blocks were assembled during a major Phanerozoic accretionary orogeny. This model is interpreted to indicate that since the onset of plate tectonics, accretionary orogenesis has contributed to both lithospheric thickening and enhancement of lithospheric mantle compositional buoyancy and viscosity, thereby laying a structural foundation for the stabilization of potential cratons.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"654 ","pages":"Article 119244"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143300331","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":"High-resolution seismic tomography of the transition zone from normal to flat slab subduction in central Chile: Implications for volcanoes, plate coupling and flat subduction","authors":"Lei Gao ,&nbsp;Zixin Chen ,&nbsp;Ying Liu ,&nbsp;Haijiang Zhang ,&nbsp;Jiashun Hu ,&nbsp;Diana Comte ,&nbsp;Francisco Hernán Ortega Culaciati","doi":"10.1016/j.epsl.2024.119167","DOIUrl":"10.1016/j.epsl.2024.119167","url":null,"abstract":"<div><div>To better understand factors controlling the distribution of volcanoes, plate coupling along the subducting plate interface, and the transition from normal to flat slab subduction, we have determined high-resolution Vp, Vs and Vp/Vs models in the central Chile subduction zone where normal slab subduction transits to flat slab subduction. In the study region spanning latitudes of 22° to 31°S, volcanoes to the north of latitude 25.5°S are underlaid by intensive intermediate-depth earthquakes, but those to the south are correlated with very few. Based on velocity features, we proposed that volcanoes to the north are likely caused by partial melting of mantle wedge by incorporation of fluids released during the dehydration reactions of various hydrous minerals in the slab that are responsible for inducing intermediate-depth earthquakes, while volcanoes to the south are likely caused by sub-slab hot materials migrating upwards through the tear or gap due to the transition from normal subduction to flat subduction. Along the plate surface constructed based on our inverted velocity models and relocated earthquakes, higher plate coupling is spatially correlated with lower Vp/Vs values and fewer earthquakes, whereas lower plate coupling is correlated with relatively higher Vp/Vs values and intensive small earthquakes. These features suggest that the plate coupling state is controlled by the existence of fluids along the plate interface, with high degree of fluids reducing plate coupling and causing the creep deformation. In the region where the flat slab subduction is evident, there exist apparent high velocity anomalies above the intraslab seismicity. This indicates that some buoyant materials such as oceanic plateaus, aseismic ridges and seamount chains that featured high velocity anomalies were subducted with the slab and caused the nominal flat subduction.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119167"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143157730","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":"Mantle induced hydration and oxidation of intracontinental granite sources in the North China Craton","authors":"Chuan-Mao Yang ,&nbsp;Yi-Gang Xu ,&nbsp;Xiao-Ping Xia ,&nbsp;Jin-Hui Yang ,&nbsp;Xiao-Long Huang ,&nbsp;Christopher J. Spencer ,&nbsp;Jin-Feng Sun ,&nbsp;Ze-Xian Cui ,&nbsp;Meng-Jing Li ,&nbsp;Wan-Feng Zhang ,&nbsp;Qing Yang","doi":"10.1016/j.epsl.2024.119177","DOIUrl":"10.1016/j.epsl.2024.119177","url":null,"abstract":"<div><div>Arc magmatism is typically highly oxidized, due to the influx of oxidizing aqueous fluids released from the subducting plate. The observation that some intracontinental A- and I-type granites also exhibit high oxidation presents a significant challenge in igneous petrology and geodynamics. This is particularly true for regions such as the North China Craton (NCC), situated over 1000 km from the trench. In this study, we measured water content, oxygen fugacity (<span><math><mrow><mi>f</mi><msub><mi>O</mi><mn>2</mn></msub></mrow></math></span>), and O-Hf isotopes in zircons from the late Mesozoic granites from the NCC. The results reveal positive correlations between water content and <span><math><mrow><mi>f</mi><msub><mi>O</mi><mn>2</mn></msub></mrow></math></span>, and between water content and <span><math><mrow><msub><mrow><mi>ε</mi></mrow><mtext>Hf</mtext></msub><mrow><mo>(</mo><mi>t</mi><mo>)</mo></mrow></mrow></math></span>, indicating the predominant control of primary magma composition, rather than magmatic differentiation, on water content and <span><math><mrow><mi>f</mi><msub><mi>O</mi><mn>2</mn></msub></mrow></math></span> of zircon. The Early Cretaceous A-type and I-type granites, which involved greater amount of mantle-derived melts, exhibit more elevated water, Nb, Ta, and <span><math><mrow><mi>f</mi><msub><mi>O</mi><mn>2</mn></msub></mrow></math></span> than the Jurassic granites. This suggests that the hydration and oxidization of intracontinental granitoids of the NCC are strongly influenced by the ingress of mantle-derived oxidized hydrous melts/aqueous fluids to the granitoid source, which were likely released from the Paleo-Pacific plate at a greater depth than the sub-arc mantle. The proposed model involves significant water in intracontinental crustal melting, thereby challenging the paradigm of intraplate A- and I-type granite genesis and shedding light on the crustal and mantle processes during cratonic destruction.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119177"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143157732","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":"Hydrologically-induced crustal stress changes and their association with seismicity rates in Taiwan","authors":"Ya-Ju Hsu ,&nbsp;Roland Bürgmann ,&nbsp;Zhongshan Jiang ,&nbsp;Chi-Hsien Tang ,&nbsp;Christopher W. Johnson ,&nbsp;Da-Yi Chen ,&nbsp;Hsin-Hua Huang ,&nbsp;Miao Tang ,&nbsp;Xinghai Yang","doi":"10.1016/j.epsl.2024.119181","DOIUrl":"10.1016/j.epsl.2024.119181","url":null,"abstract":"<div><div>Studying crustal stress changes associated with hydrological cycles and their influence on seismicity rate illuminates the complex interplay between crustal stress conditions, faulting orientations, and earthquake nucleation. By analyzing GNSS position time series in 2006–2021 across Taiwan, we reveal a prevailing NW-SE trending seasonal contraction and expansion of the Earth's crust in response to hydrological loading and unloading in SW Taiwan, consistent with the maximum annual water storage change inferred from hydrological data. Inspection of seismicity rates in SW Taiwan indicates a positive correlation between excess seismicity rate and reduced NW-SE compression and/or decreasing vertical loading. Though hydrologically-induced contraction aligns with the tectonic compressive stress axis in the wet season, this alignment does not lead to more frequent earthquakes during peak water storage. Instead, seismicity peaks during the dry months, coinciding with maximum uplift and water unloading. This suggests that hydrologically-induced vertical stress or pressure changes play the dominant role in triggering earthquakes, as evidenced by vertical stress amplitudes 2∼4 times greater than the horizontal stress changes. The statistical correlation evaluating the timing of earthquakes and hydrologically-induced stress changes further affirms that the seismicity rate increases with reduced tectonic compression and enhanced vertical unloading in SW Taiwan. The observed relationship also implies the earthquake nucleation time is comparable to the stressing period of annual water cycles in SW Taiwan. Hydrologically-triggered earthquakes appear to be more sensitive to pressure variations than to shear stress changes, similar to tidally-modulated seismicity.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119181"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143158957","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}