Earth and Planetary Science Letters最新文献

{"title":"Role of hydrothermal alteration and thermally activated healing on earthquake dynamics along oceanic transform faults","authors":"Mingqi Liu,&nbsp;Sylvain Barbot","doi":"10.1016/j.epsl.2025.119765","DOIUrl":"10.1016/j.epsl.2025.119765","url":null,"abstract":"<div><div>The generation of earthquakes is primarily governed by the thermo-mechanical and structural properties of fault zones. However, the influence of lithological and hydrothermal factors on the rupture style, size, and recurrence patterns of seismic activity remains poorly understood. Here, we explore the role of hydrothermal alteration on the spatial distribution and source characteristics of earthquakes along oceanic transform faults. We perform three-dimensional seismic cycle simulations calibrated with thermal profiles from thermo-mechanical geodynamic models and laboratory-derived frictional properties of crust and mantle rocks to elucidate the seismic patterns of oceanic transform faults. The thermally activated healing of antigorite in serpentinized mantle pockets may facilitate the spontaneous generation of seismic swarms, depending on the intensity of shear heating and the activation energy of the healing process. Fluid circulation influences seismic behavior by driving local alteration, affecting fault frictional properties. The unstable nature of gabbro friction over a finite range of temperature supports a narrow seismogenic zone within the oceanic crust, with a lateral extent of seismic ruptures limited by patches of hydrothermal alteration products (e.g., talc and chlorite) within the fault zone. Abundant microseismicity may occur within partially altered, heterogeneous barrier zones. These findings highlight the critical interplay between lithology, hydrothermal processes, and fault mechanics, providing new insights into the tectonic framework of seismicity along oceanic transform faults.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"675 ","pages":"Article 119765"},"PeriodicalIF":4.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145693386","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":"Enhanced marine primary productivity during the long-term Ordovician cooling: A barium isotope perspective from South China","authors":"Shengchao Yang ,&nbsp;Junxuan Fan ,&nbsp;Chao Li ,&nbsp;Yi-Bo Lin ,&nbsp;Yiying Deng ,&nbsp;Zongyuan Sun ,&nbsp;Jian Cao ,&nbsp;Shu-zhong Shen","doi":"10.1016/j.epsl.2025.119783","DOIUrl":"10.1016/j.epsl.2025.119783","url":null,"abstract":"<div><div>Global cooling has been strongly associated with the Great Ordovician Biodiversification Event (GOBE), but the underlying mechanisms remain unexplored. To assess whether enhanced biological pump contributed to global cooling during the GOBE, we performed δ¹³⁸Ba_carb-δ¹³C_carb analyses on an Ordovician shallow marine limestone section from South China. Our results show that δ¹³⁸Ba_carb in the Ordovician (median 0.73‰) is significantly higher than in other geological periods and reservoirs (median values ranging from –0.18‰ to 0.29‰), indicating exceptionally high δ¹³⁸Ba values in the surface ocean in South China, possibly due to plankton radiation, which increased the removal of Ba during the GOBE. Furthermore, shifts in δ¹³⁸Ba_carb correlated with long-term increases in δ¹³C_carb, with positive correlation during the early Tremadocian (Stage 1), followed by negative correlation during the late Tremadocian to Dapingian (Stage 2), and positive correlation from the Darriwilian to Katian (Stage 3). These δ¹³⁸Ba_carb-δ¹³C_carb covariations suggest that marine primary productivity was enhanced during the Ordovician in South China. Additionally, the gradual increase in δ¹³C_carb is strongly correlated with global cooling and an increase in marine biodiversity, suggesting that plankton radiation during the GOBE may be an important cause of the increased marine primary productivity, thus enhancing organic carbon burial, contributing to the long-term Ordovician cooling, and linking the GOBE and contemporaneous environmental changes.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"675 ","pages":"Article 119783"},"PeriodicalIF":4.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797726","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":"Fixation of atmospheric nitrogen on present-day Mars during dust events","authors":"Wenshuo Mao ,&nbsp;Xiaohui Fu ,&nbsp;Zhongchen Wu ,&nbsp;Jiang Zhang ,&nbsp;Zongcheng Ling ,&nbsp;Yang Liu ,&nbsp;Yu-Yan Sara Zhao ,&nbsp;Jiacheng Liu ,&nbsp;He Cui ,&nbsp;Hitesh G. Changela ,&nbsp;Yuheng Ni ,&nbsp;Lifang Li ,&nbsp;Joseph R. Michalski","doi":"10.1016/j.epsl.2025.119786","DOIUrl":"10.1016/j.epsl.2025.119786","url":null,"abstract":"<div><div>N₂ is the second most abundant gas in the present-day Martian atmosphere and hosts the essential biochemical element N. Nitrate and (per)chlorate have been detected in numerous aeolian sediments in Gale crater. Thus, a potential nitrogen fixation may be active on present-day Mars. Interactions between Martian atmosphere and surface during dust events can trigger electrostatic discharge (ESD) and complex electrochemical reactions. By simulating this process in a Mars chamber, nitrate and (per)chlorate were produced under present-day Martian atmospheric conditions. Notably, the obtained nitrate/(per)chlorate abundance ratio is in agreement with Gale crater observations (&lt; 1.0), but much lower than those in terrestrial Mars analogues and the products of other pathways proposed for Mars. The results strongly indicate that electrochemical reactions during Mars dust events represents a new nitrogen fixation mechanism on present-day Mars. It is different from other fixation processes on Earth and early Mars, expanding the knowledge of nitrogen cycle and nitrogen fixation in solar system. Electrochemical reactions may also play crucial roles in global nitrogen cycling throughout the Amazonian period. These nitrate salts in Martian dusts potentially provide an accessible source of nitrogen for possible organic molecule formation on present-day Mars.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"675 ","pages":"Article 119786"},"PeriodicalIF":4.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797772","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":"Using rate-and-state friction constitutive laws to predict seismicity rates for ice rifts on the Ross Ice Shelf in Antarctica","authors":"Kathrine Udell-Lopez,&nbsp;Mong-Han Huang,&nbsp;Vedran Lekić","doi":"10.1016/j.epsl.2025.119790","DOIUrl":"10.1016/j.epsl.2025.119790","url":null,"abstract":"<div><div>Determining what fault characteristics and applied stress conditions modulate the occurrence of seismicity is a key question in the field of seismology. Here we analyze the seismicity measured at two ice shelf rift zones of different maturity in the Ross Ice Shelf, which are subjected to long-term dilatational stress modulated by tidal stress variations. We analyze the periodicity of the seismicity and its relationship to tidal stress variations and find that the seismicity rate at both rifts is controlled by tidal stress rate variations. We compare the observed icequake occurrence times with analytical predictions from rate-and-state friction constitutive laws that have been used to model frictional behavior on terrestrial faults. We find that seismicity rate is predicted well by an analytical model based on rate-and-state friction, confirming that it can be used to understand ice rift seismicity. We constrain for the first time the characteristic time of seismicity rate, <span><math><msub><mi>t</mi><mi>a</mi></msub></math></span>, for both rifts, and find that ice rifts have a faster recovery time than continental faults, and that their responses to stress and characteristic times are age dependent. This implies that the strength of the rift changes with time and determines the amount of stress or stress rate dependency of the system. Our results can be used to understand seismicity occurrence across other ice rifts in Antarctica and Greenland and holds implications for seismicity on icy satellites.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"675 ","pages":"Article 119790"},"PeriodicalIF":4.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797771","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":"Apatite records mechanical and chemical processes over the lifetime of a subduction interface, Andros Island, Greece","authors":"Eirini M. Poulaki ,&nbsp;Cailey B. Condit ,&nbsp;Margaret L. Odlum ,&nbsp;Jason N. Ott ,&nbsp;Megan E. Ferrell","doi":"10.1016/j.epsl.2025.119779","DOIUrl":"10.1016/j.epsl.2025.119779","url":null,"abstract":"<div><div>The subduction plate interface accommodates deformation between the downgoing and overriding plates and features a range of mechanical and chemical processes that influence the strength and slip behavior of this zone. Apatite, a calcium phosphate accessory mineral, records these subduction processes including metamorphism, metasomatism, and deformation. It can deform, recrystallize, and archive chemical processes through its trace elements across the pressure and temperatures conditions that span the depths at the bottom of the subduction seismogenic zone. We leverage these apatite characteristics in a metabasite within an exhumed subduction complex on Andros Island, Greece to demonstrate that apatite grains show multiple deformation mechanisms and inform on fluid’s composition and role in deformation processes. Apatite deformation mechanisms are dependent on the surrounding mineral phases, with grains within the chlorite matrix exhibiting evidence of dissolution-precipitation while grains in contact with strong mineral phases (e.g., clinozoisite, albite) deform by dislocation-accommodated deformation. Dislocations formed by prism 〈c〉 slip in apatite act as pathways for fluid mobile elements during deformation while dislocations formed by basal 〈a〉 slip did not facilitate trace element diffusivity, likely due to a crystallographic control. We also show that apatite is a powerful geochemical archive recording infiltration of aqueous sedimentary fluids with small amounts of CO₂ during metasomatism. We highlight the utility of in-situ apatite geochemistry in polymetamorphic and polydeformed rocks. We show that even at the grain scale, lattice impurities will control the geochemical signatures.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"675 ","pages":"Article 119779"},"PeriodicalIF":4.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145734590","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":"The lithosphere - asthenosphere system seen by surface waves: New insights from radial anisotropy","authors":"S. Durand,&nbsp;E. Debayle,&nbsp;Y. Ricard","doi":"10.1016/j.epsl.2025.119720","DOIUrl":"10.1016/j.epsl.2025.119720","url":null,"abstract":"<div><div>We propose a conceptual model of the lithosphere-asthenosphere system that reconciles a number of surface wave observations. It comes in the context of the development of a new SV wave velocity, <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>s</mi><mi>v</mi></mrow></msub></math></span>, and radial anisotropy, <em>ξ</em>, global model based on multi-mode Rayleigh and Love wave data. The Rayleigh dataset has also been used in previous studies to constrain the azimuthal anisotropy, the quality factor <em>Q</em> and the melt content. All these models are based on self-consistent datasets and use the same waveform modeling and tomographic approaches, with similar regularization and smoothing. The first important finding of this study is the fact that a 1-D <em>ξ</em> model close to PREM but including a 3D crust structure explains our dataset almost everywhere, except in oldest parts of the continents (mainly Archean and Proterozoic terrains) and youngest parts of the Pacific ridge (mainly ages ≤ 50 Ma) where 3-D variations of <em>ξ</em> are required. Based on this, we build an hybrid model, Hybrid 1D/3D, where <em>ξ</em> is fixed to a 1-D profile when sufficient to fit the data, and inverted for when the dataset requires lateral variations. Our radially anisotropic model shows that there is no age dependance of the radial anisotropy <em>ξ</em> in the oceanic lithosphere while age is the main parameter controlling <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>s</mi><mi>v</mi></mrow></msub></math></span>, melt content and azimuthal anisotropy, particularly under fast plates. We also find that positive radial anisotropy (<span><math><mi>ξ</mi><mo>&gt;</mo><mn>1</mn></math></span>) extends deeper beneath oceans (down to 350 km depth) than beneath continents. We propose that the thicker radially anisotropic layer under the oceans compared to the continent indicates a change in origin from frozen-only anisotropy under the continent to a more complex situation under the oceans. Cratons appear fast, melt-free and anisotropic, down to 200-250 km depth, and anomalies with <em>ξ</em>≤ 1 are present in the deeper part of the cratonic roots (around 250 km) that could reflect past delamination or compression of the deep lithospheric roots.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"673 ","pages":"Article 119720"},"PeriodicalIF":4.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145570215","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":"Final differentiation of the lunar magma ocean: genesis of KREEP and the limited role of silicate liquid immiscibility","authors":"Weronika Ofierska,&nbsp;Max W. Schmidt,&nbsp;Christian Liebske,&nbsp;Paolo A. Sossi","doi":"10.1016/j.epsl.2025.119691","DOIUrl":"10.1016/j.epsl.2025.119691","url":null,"abstract":"<div><div>Owing to the incompatibility of K, rare-earth elements (REE) and P in silicate minerals relative to melt, the KREEP component, found on the near-side of the Moon, is thought to have formed through protracted crystallisation of the Lunar Magma Ocean (LMO). Our fractional crystallisation experiments simulate the final stages of LMO crystallisation, from plagioclase onset to the last eutectic melt remnants. Results show the LMO liquid to remain saturated in olivine ± orthopyroxene ± Cr-spinel up to 74 % solidification (PCS), transitioning to plagioclase+clinopyroxene (cpx) from 1200 °C (74 PCS) to 1120 °C (88 PCS). The plagioclase+cpx+quartz cotectic is reached at 1080 °C (92.3 PCS), with liquid immiscibility and a crystal assemblage of plagioclase+augite+Ti-spinel+ilmenite+quartz occurring at 1030 °C (98.8 PCS), until nearly complete crystallization is reached at 1000 °C (99.5 PCS). Mineral/melt (plagioclase, pigeonite, high-Ca cpx) and melt/melt partition coefficients for K, REE, P, Zr, Hf, Nb, Th, and U were determined. They are used to model melt evolution to 99.5 PCS, showing that fractional crystallisation alone replicates KREEP’s REE profile and the above trace elements, yet, distinct Lu/Hf (and U/Pb) ratios suggest additional processes. Assuming a finite oxygen budget in the LMO and incompatible behaviour of Fe³⁺, the Eu anomaly of KREEP is best reproduced by a model in which oxygen fugacity (<span><math><msub><mi>f</mi><msub><mi>o</mi><mn>2</mn></msub></msub></math></span>) evolves from one log unit below to 1.5 log units above the iron-wustite buffer (IW-1 to IW+1.5) from 0 PCS to 99.4 PCS. Minor dacitic melt separation (1–5 % of the melt remaining at 1030 °C) sequestering K from REE+<em>P</em> is consistent with but unnecessary for KREEP formation; nevertheless, a second-stage partial re-melting of these dacites could match observed FeO and incompatible element abundances of lunar granites.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"673 ","pages":"Article 119691"},"PeriodicalIF":4.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145519335","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 topography of continental large igneous provinces: Crucial role of crustal flow and intrusion dynamics","authors":"Xiaochuan Tian ,&nbsp;W. Roger Buck","doi":"10.1016/j.epsl.2025.119726","DOIUrl":"10.1016/j.epsl.2025.119726","url":null,"abstract":"<div><div>The Ethiopian and Columbia Plateaus, surface expressions of the two youngest continental Large Igneous Provinces (LIPs), exhibit contrasting topographies: the Ethiopian Plateau rises ∼1.5 km above its surroundings, while the Columbia Plateau sits ∼0.7 km below. Using semi-analytic and numerical models, we show that these differences may arise from the interplay between intrusion dynamics and geotherm dependent lower crustal flow—without requiring mantle plume buoyancy (uplift) or deep crust eclogitization (subsidence). The semi-analytic models show that slow lower crustal flow leads to long-lived uplift regardless of intrusion style. Subsidence, in contrast, requires both moderately fast flow and mechanically coupled mafic intrusions in the brittle upper crust. More realistic numerical simulations incorporating evolving geotherms and sill intrusion depths reveal that cold crust promotes uplift through thickening, consistent with Ethiopia, while hot crust allows mechanically coupled denser intrusions to drive lateral flow and surface subsidence, as seen in Columbia. Together with intrusion induced crustal densification for triggering main-phase eruption, the models may explain the synchronized subsidence and flood basalt eruptions inferred from Columbia. Through scaling, a characteristic time for lower crustal flow emerges to quantitatively predict continental LIP topographic developments among all models. These results highlight the lower crust as a dynamic buffer zone that governs surface response to magmatic emplacements, overriding effects of deeper crustal or mantle loads.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"673 ","pages":"Article 119726"},"PeriodicalIF":4.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145518896","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":"Density and viscosity variations due to plume melting of a bilithologic mantle: Implications for asthenosphere and hotspot swell root dynamics","authors":"Jia Shao ,&nbsp;Jason P. Morgan","doi":"10.1016/j.epsl.2025.119724","DOIUrl":"10.1016/j.epsl.2025.119724","url":null,"abstract":"<div><div>Geochemical and petrological observations indicate that mantle plumes consist mainly of peridotite with ∼10–30% embedded pyroxenite veins or blobs. However, the consequences of preferential deeper pyroxenite-rich melting followed by shallower peridotite-rich melting on mantle density and viscosity have yet to be systematically explored. Using 1-D numerical simulations, we investigate density and viscosity changes during upwelling and pressure-release melting of a damp bilithologic mantle aggregate. We find that denser pyroxenite begins melting deeper than its surrounding peridotite. Preferential early pyroxenite melting significantly reduces mantle density by decreasing the volume fraction of this denser component, but only slightly increases mantle viscosity (&lt;3-fold) as the weaker damp peridotite matrix dominates the overall rheology. When peridotite melts and dries at shallower depths, its compositional depletion continues reducing density but to a lesser extent than prior pyroxenite removal, while its dehydration significantly increases the mantle’s viscosity (1–2 orders of magnitude). When dry peridotite melting begins, its higher productivity and latent heat extraction also typically suppresses additional pyroxenite melting. After deep pyroxenite melting, residues of relatively colder material near plume rims have fluid (damp peridotite) viscosity and compositionally buoyant (pyroxenite-poor) density. This tends to form a low-viscosity, compositionally buoyant layer beneath oceanic lithosphere that could be preferentially sampled by subsequent mid-ocean ridge upwelling and melting. In contrast, the hottest plume fractions undergo both pyroxenite and peridotite melting during upwelling beneath oceanic lithosphere. This extensive melting generates a high-viscosity, buoyant restite fraction that adheres to and moves with overlying lithosphere as a hotspot swell root.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"673 ","pages":"Article 119724"},"PeriodicalIF":4.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145518931","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":"Significant crustal uplift attributed to contemporary glacier loss over laterally heterogeneous mantle","authors":"Zhengyang Wang ,&nbsp;Wei Feng ,&nbsp;Zhongshan Jiang ,&nbsp;Zhou Wu ,&nbsp;Baoming Tian ,&nbsp;Haipeng Luo ,&nbsp;Min Zhong ,&nbsp;Hao Wei","doi":"10.1016/j.epsl.2025.119725","DOIUrl":"10.1016/j.epsl.2025.119725","url":null,"abstract":"<div><div>Contemporary ice mass loss from the Northern and Southern Patagonian icefields, overlying a slab window from Chile Ridge subduction, drives exceptional crustal uplift through combined glacio-isostatic and tectonic responses. To capture the spatially detailed deformation field, we employed sparse GNSS stations to accomplish the mosaicking and calibration of InSAR-derived velocity fields through block adjustment. The calibrated deformation field exhibits pronounced spatial heterogeneity, with uplift rates increasing southward to a maximum of 40 mm/yr over the northern sector of the Southern Icefield, before decreasing to 0–10 mm/yr toward its southern margin. In the east-west direction, velocities average 12 mm/yr in the western sector, contrasting sharply with rates of 25 mm/yr in the east, spatially coinciding with the slab window boundary. By modeling transient elastic deformation from contemporary ice melt, we find that the elastic component accounts for only 23 % of the observed InSAR signal. We further conducted viscoelastic deformation modeling under varying mantle viscosities and fitted the results to the calibrated velocity field to identify optimal viscosity settings in different regions. The fitting results confirm viscosity contrast in both the north-south and east-west directions, characterized by four subdomains exhibiting upper mantle viscosity variations from 3 × 10¹⁸ to 1.7 × 10¹⁹ Pa s. The viscosity heterogeneity provides critical constraints for further refining three-dimensional (3-D) rheological structures. Our findings promote the development of more accurate regional GIA models and contribute to a better understanding of the underlying geodynamic process.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"673 ","pages":"Article 119725"},"PeriodicalIF":4.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145518930","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}