Physics of the Earth and Planetary Interiors最新文献

{"title":"Remarkable variations in geomagnetic disturbances preceding the 2017 M 7.1 Jiuzhaigou earthquake","authors":"Yiliang Guan ,&nbsp;Xiaona Dong ,&nbsp;Lili Feng ,&nbsp;Manqiu He ,&nbsp;Yingfeng Ji","doi":"10.1016/j.pepi.2025.107438","DOIUrl":"10.1016/j.pepi.2025.107438","url":null,"abstract":"<div><div>With the rapid development of geomagnetic observation networks and the increased availability of geomagnetic data in China over the past decade, multistation geomagnetic data analyses have become widely used in studies of earthquake precursors with magnitudes &gt;6. Building on the single-station polarization algorithm, we propose a multistation daily sliding polarization correlation algorithm for detecting regional geomagnetic anomalies. This method can be applied to analyze the spatiotemporal evolution of geomagnetic field anomalies that are related to seismogenic processes before major earthquakes. In this study, we calculate polarization correlation time series data before and after the 2017 M 7.1 Jiuzhaigou earthquake. The results show that following the appearance of polarization anomalies, the regional correlations increase, then decrease, and subsequently increase again. Earthquakes occurred at the inflection points of these correlation trends. Our analysis suggests that changes in multistation polarization correlations directly reflect regional geomagnetic field anomalies that are caused by tectonic activity, thereby capturing the dynamic evolution during earthquake preparation. This method offers valuable insights into the mechanisms linking geomagnetic polarization anomalies with seismic events.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"368 ","pages":"Article 107438"},"PeriodicalIF":1.9,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Local flow estimation at the top of the Earth’s core using Physics Informed Neural Networks","authors":"Naomi Shakespeare-Rees ,&nbsp;Philip W. Livermore ,&nbsp;Christopher J. Davies ,&nbsp;Hannah F. Rogers ,&nbsp;William J. Brown ,&nbsp;Ciarán D. Beggan ,&nbsp;Christopher C. Finlay","doi":"10.1016/j.pepi.2025.107424","DOIUrl":"10.1016/j.pepi.2025.107424","url":null,"abstract":"<div><div>The Earth’s main geomagnetic field arises from the constant motion of the fluid outer core. By assuming that the field changes are advection-dominated, and that diffusion only plays a minor role, the fluid motion at the core surface can be related to the secular variation of the geomagnetic field, providing an observational approach to understanding the motions in the deep Earth. The majority of existing core flow models are global, showing features such as an eccentric planetary gyre, with some evidence of rapid regional changes. By construction, the flow defined at any location by such a model depends on all magnetic field variations across the entire core–mantle boundary: because of this nonlocal dependence of the flow on the magnetic field, it is very challenging to interpret local structures in the flow as due to specific local changes in magnetic field. Here we present an alternative strategy in which we construct regional flow models that rely only on local secular changes. We use a novel technique based on machine learning termed Physics-Informed Neural Networks (PINNs), in which we seek a regional flow model that simultaneously fits both the local magnetic field variation and dynamical conditions assumed satisfied by the flow. Although we present results using the Tangentially Geostrophic flow constraint, we set out a modelling framework for which the physics constraint can be easily changed by altering a single line of code. After validating the PINN-based method on synthetic flows, we apply our method to the CHAOS-8.1 geomagnetic field model, itself based on data from Swarm. Constructing a global mosaic of regional flows, we reproduce the planetary gyre, providing independent evidence that the strong secular changes at high latitude and in equatorial regions are part of the same global feature. Our models also corroborate regional changes in core flows over the last decade. In our models, we find that the azimuthal flow under South America has changed sign quasi-periodically, with a recent sign change in 2022. Furthermore, our models endorse the existence of a dynamic high latitude jet, which began accelerating around 2005 but has been weakening since 2017.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"367 ","pages":"Article 107424"},"PeriodicalIF":1.9,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144932544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling the lithospheric magnetic field masked by the Earth’s main field by estimating the magnetization and magnetic crustal thickness using a statistical approach","authors":"Erwan Thébault ,&nbsp;Gauthier Hulot","doi":"10.1016/j.pepi.2025.107421","DOIUrl":"10.1016/j.pepi.2025.107421","url":null,"abstract":"<div><div>Detailed mapping of Earth’s lithospheric magnetic field provides important insights into the composition, dynamics, and geological history of the crust. This field can be modeled using satellite and near-surface magnetic measurements. However, structures larger than approximately 2500 km in scale are obscured by the dominant magnetic signal generated by the Earth’s core. The superposition of core and crustal magnetic fields introduces ambiguities in both geodynamo and crustal magnetic source studies. Previous efforts to address this issue have included statistical estimates of upper and lower bounds on the long-wavelength components of the crustal field, as well as more deterministic predictions based on geophysical priors such as crustal magnetization and seismic Moho depth models. These approaches, however, have often produced contradictory results. In this study, we adopt a two-step strategy. The first step involves a series of regional spherical spectral analysis of the World Digital Magnetic Anomaly Grid (WDMAM2.2), without relying on any prior information from seismic or magnetization models. This approach, applied to the 5 km × 5 km WDMAM2.2 grid across 6000 regions uniformly distributed over the Earth’s surface, allows us to estimate the probability distributions of three key parameters statistically characterizing crustal magnetization in each of the 6000 regions: magnetization amplitude, magnetic layer thickness, and a power-law exponent. The resulting world map of magnetic layer thickness differs from existing Moho depth models but indicates that, statistically, there is no significant evidence of magnetic sources located below the Moho at the studied length scales. In the second step, the ensemble of regional magnetization models is used to generate a set of large-scale spherical harmonic models of the lithospheric magnetic field (degrees 1 to 50). This set allows us to quantify the extent to which the lithospheric field contaminates both the static and time-varying components of the core magnetic field. We find that this contamination is substantial between spherical harmonic degrees 12 and 15 for the static core field, and from degree 21 onward for the secular variation.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"367 ","pages":"Article 107421"},"PeriodicalIF":1.9,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144896060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detecting low-latitude outer core-surface waves with 25 years of satellite secular variation data","authors":"Carla R. Grüne ,&nbsp;Kathryn A. Whaler ,&nbsp;Frederik Dahl Madsen","doi":"10.1016/j.pepi.2025.107435","DOIUrl":"10.1016/j.pepi.2025.107435","url":null,"abstract":"<div><div>Fluid motion in the Earth’s liquid outer core generates most of the geomagnetic field, and its time changes over timescales of one year or longer, the secular variation (SV). Data from the satellite missions Ørsted, CHAMP, CryoSat-2 and Swarm, together with data from ground observatories, were combined to yield a SV dataset spanning from late 1997 to early 2023. These SV data were inverted for time-varying core surface fluid velocity assuming it is purely advective, with the main field specified by the CHAOS-7.16 field model. The inversion was regularised both in time and in space. In time, the difference in velocity between individual epochs was minimised. In space, small-scale velocity structures were penalised. Flow acceleration was then calculated from first differences of velocities at successive epochs. Time-longitude diagrams of azimuthal acceleration show sloping features at low latitudes, interpreted as signatures of propagating waves. Waves propagating both eastwards and westwards were observed, with propagation velocities of approximately 1700 km/yr which is in agreement with previous inferences of fast core waves. Power spectral density plots reveal that the energy is concentrated in modes with periods of 6–7 years, and azimuthal wavenumbers −5, −2 and 2, where negative wave numbers indicate westward motion. There is a higher energy content in the westward propagating waves than in those travelling eastwards. Finally, we find intermittent low-latitude standing waves, which coincide with times of recent equatorial geomagnetic jerks, consistent with inferences of magneto-Coriolis and Alfvén waves from other studies.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"367 ","pages":"Article 107435"},"PeriodicalIF":1.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144906963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic reflectors in the mid-lower mantle beneath central Pacific: The relationship with the Pacific LLSVP","authors":"Satoshi Kaneshima","doi":"10.1016/j.pepi.2025.107437","DOIUrl":"10.1016/j.pepi.2025.107437","url":null,"abstract":"<div><div>Seismic signals in P coda originating from deep mantle heterogeneity have not yet been investigated extensively, except for the observations of the waves reflected presumably at the top of the D″ layer. We show in this study that array processing of seismograms of deep earthquakes at Tonga-Fiji and Solomon Islands recorded by seismograph networks at southern California reveals strong off-great circle arrivals in P coda 5 to 10 s after direct P waves. We also show that the large arrivals observed for the Tonga-Fiji events are P-to-P reflected waves at a dipping interface in the mid-lower mantle beneath central Pacific. The reflector is located south-southeast of Hawaii around 2000 km depth and dips down to southeast by nearly 35°. The observed amplitude and polarity of the reflected waves could be explained if the Vp of the underlying side of the reflector is 1 to 2 % faster than the overlying side. The small Vp anomaly may not necessarily contradict the absence of a noticeable Vp anomaly in previous seismic tomography models at the site of the reflector. We also find that the reflected wave is approximately concomitant with a weaker arrival from a mid-mantle scattering object located nearly 1000 km closer to the hypocenters. The heterogeneous object causing the anomalous arrivals for the Solomon Islands events, although the properties of the object are less well constrained than the Tonga-Fiji reflector, also likely represents another dipping reflector at 2400 km located approximately below the Hawaiian hotspot. As in the Tonga-Fiji case the signals are occasionally followed by a weaker signal from a mid-mantle scattering object located nearer to the hypocenters. The mid-mantle reflection/scattering objects do not indicate the presence of a global discontinuity but must represent localized strong heterogeneities. It is notable that the localized heterogeneities are all located near the edges of a large low Vs body (the Pacific LLSVP) resolved by global tomography, up to 500 km above the LLSVP itself. The relation between the locations of the reflector/scatterers and the large scale Vp structure is unclear, probably reflecting poorer tomography images of Vp structure associated with the LLSVP. We discuss possible tectonic implications of these mid-mantle heterogeneities on the structure and evolution of the LLSVP.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"368 ","pages":"Article 107437"},"PeriodicalIF":1.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144997579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Complex deformation mechanisms of the Qinling orogenic belt lithosphere and clockwise rotation of the Yangtze craton crust: Insights from Rayleigh wave azimuthally anisotropic tomography","authors":"Tengfei Wu ,&nbsp;Shuangxi Zhang ,&nbsp;Meng Chen","doi":"10.1016/j.pepi.2025.107436","DOIUrl":"10.1016/j.pepi.2025.107436","url":null,"abstract":"<div><div>The collision and convergence between the Yangtze Craton (YZC) and North China Craton (NCC) beneath the Qinling orogenic belt (QOB) have resulted in complex lithospheric deformation, the mechanisms of which remain unclear. In this study, we extracted 10–60 s Rayleigh-wave dispersion curves using the two-station method from vertical-component waveform data of 1087 teleseismic events, recorded at 110 seismic stations across the QOB and adjacent regions. Subsequently, anisotropic tomography was employed to reconstruct high-resolution isotropic and anisotropic phase velocity models of the crust and upper mantle beneath the QOB and surrounding regions. We focused on analyzing deformation patterns in four key subregions of the QOB. Our results demonstrated that crustal deformation is affected by multiple geological factors. Major tectonic activities, such as island arc collisions, oceanic basin closure, and orogenic events, have fundamentally shaped the regional structural framework. Building on this, crustal lithological features, thrust tectonic movements, and the strike of fault systems, which together control present-day deformation. Furthermore, our anisotropic model, in combination with previous geodetic and seismological observations, suggests that the clockwise rotation of the YZC during its convergence with the NCC plays a significant role in influencing crustal deformation. Upper mantle deformation is primarily driven by absolute plate motion, with additional influences from the northeastward escape of material in the Tibetan Plateau and mantle flow. Notably, our anisotropic model provides new seismological evidence supporting the clockwise rotation of the YZC crust, which is closely related to the tectonic development of the Sichuan basin and the formation of the Dabashan arcuate structure. Integrating with previous studies, we propose a conceptual model to explain the formation mechanism of the Dabashan arcuate structure, which we attribute to the combined effects of the clockwise rotation of the YZC crust during the Middle to Late Triassic and the ongoing convergence between the YZC and the NCC. These findings provide new insights into the lithospheric dynamic processes of the QOB.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"367 ","pages":"Article 107436"},"PeriodicalIF":1.9,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative assessment of tomographic proxies for lowermost mantle composition and mineralogy","authors":"Justin Leung ,&nbsp;Andrew M. Walker ,&nbsp;Paula Koelemeijer ,&nbsp;Federica Restelli ,&nbsp;D. Rhodri Davies","doi":"10.1016/j.pepi.2025.107423","DOIUrl":"10.1016/j.pepi.2025.107423","url":null,"abstract":"<div><div>Large low velocity provinces (LLVPs) dominate Earth’s lowermost mantle, but their detailed thermochemical nature remains a topic of discussion. In particular, it is unclear to what extent the bridgmanite to post-perovskite phase transition is able to explain their seismic velocity characteristics. Robust constraints on the origin of these seismic structures would shed light on large-scale mantle dynamics and Earth’s thermal and chemical evolution. Here, we examine the combined effects of temperature, chemical heterogeneity and phase transitions on lowermost mantle tomographic signatures. To investigate this, we calculate synthetic seismic velocities expected from a range of scenarios for the stability of post-perovskite combined with models of different lowermost mantle temperatures and compositions using recent thermodynamic data. These are filtered to account for limited tomographic resolution, allowing for quantitative comparisons between our synthetic seismic velocities and a recent Backus-Gilbert based tomography model. Crucially, this model provides robust ratios and correlations of velocity anomalies derived from nearly identical <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span> and <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span> resolution, and includes uncertainty quantification that accounts for both data and theoretical errors. Given the tomographic uncertainties and limited resolution, our comparisons focus on globally and depth averaged seismic characteristics, which capture the effects of lateral compositional and mineralogical variability. By rejecting synthetic models that do not fit within tomographic uncertainties, we quantitatively eliminate the following: (i) models containing LLVPs with an iron-rich primordial composition, as these generate anomalously high root mean square seismic velocity anomalies; and (ii) models without post-perovskite in the lowermost mantle, as these cannot explain observations of elevated ratios of shear-wave to compressional-wave velocity (<span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>s</mi><mo>/</mo><mi>p</mi></mrow></msub></math></span>) and a negative correlation between variations in shear-wave and bulk sound velocity (<span><math><msub><mrow><mi>r</mi></mrow><mrow><mi>s</mi><mo>−</mo><mi>c</mi></mrow></msub></math></span>). Additionally, we demonstrate that observations of <span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>s</mi><mo>/</mo><mi>p</mi></mrow></msub></math></span> and <span><math><msub><mrow><mi>r</mi></mrow><mrow><mi>s</mi><mo>−</mo><mi>c</mi></mrow></msub></math></span> in the lowermost mantle cannot be explained by thermochemical LLVPs alone, but require bridgmanite and post-perovskite to co-occur at depth in the mantle. As such, we demonstrate that globally averaged seismic velocity characteristics can distinguish between composition and mineralogy in the lowermost mantle.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"368 ","pages":"Article 107423"},"PeriodicalIF":1.9,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145011038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crustal anisotropy as evidence for hydration of the Martian upper mantle","authors":"William D. Frazer ,&nbsp;Jeffrey Park ,&nbsp;Frederik Link","doi":"10.1016/j.pepi.2025.107434","DOIUrl":"10.1016/j.pepi.2025.107434","url":null,"abstract":"<div><div>Constraining the structure of the Martian lithosphere below the InSight lander is essential to our understanding of Elysium Planitia and the evolution of the whole planet. Previously, seismic imaging using data recorded by the SEIS instrument suggested three crustal interfaces at ∼8, ∼20, and ∼ 43 km depth. Additionally, a shallower small interface at ∼2 km has been identified. We estimate multiple-taper correlation receiver functions from records for 34 seismic events on Mars. We extend the bandwidth of frequencies considered and offer the finest vertical resolution yet. We conduct shear-wave splitting analysis and stochastic inversion of P-to-s converted phases to estimate anisotropic parameters of the major crustal layers. Our analysis identifies anisotropy (12–14 %) in the lower layers of the Martian crust. We suggest that the deepest layer of the Martian crust beneath InSight formed during modification of the upper mantle during volcanism, not differentiation generated by Borealis impactor. Our proposed underplating process could have been metasomatic and involved hydration from an early ocean on Mars.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"367 ","pages":"Article 107434"},"PeriodicalIF":1.9,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144895873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crustal deformation characteristics and tectonic implications on the northeastern margin of the Tibetan Plateau","authors":"MengYa Li ,&nbsp;HuaJian Yao ,&nbsp;JiKun Feng ,&nbsp;XianWei Zeng ,&nbsp;GuoFu Luo ,&nbsp;ChenXi Wang ,&nbsp;Rui Ma","doi":"10.1016/j.pepi.2025.107420","DOIUrl":"10.1016/j.pepi.2025.107420","url":null,"abstract":"<div><div>This study utilizes continuous waveform data from 50 portable stations and 38 permanent stations deployed on the northeastern margin of the Tibetan Plateau. Using ambient noise cross-correlation, we obtained Rayleigh wave phase velocities for periods ranging from 1 to 35 s and subsequently inverted these data to obtain the 3D azimuthally anisotropic shear wave velocity model. The results indicate a clear zonation of azimuthal anisotropy characteristics within the study area. Using the Haiyuan-Liupanshan fault zone as the dividing line, the shallow crust of the eastern Ordos block exhibits weak anisotropy due to sedimentary layer, with fast wave direction-oriented NS. In the middle and lower crust, the fast wave directions are oriented NE. On the western side, the shallow crust exhibits fast wave directions consistent with the regional tectonic orientations. The middle and lower crust exhibits two dominant fast wave directions influenced by regional principal tectonic stress: NE-SW, primarily distributed at the eastern end of the Haiyuan fault zone, and NWW-SEE, mainly found near the northern side of the North Qinling fault zone. These two differing directions result in the left-lateral strike-slip movement of the Haiyuan fault zone and the clockwise rotation of the Longzhong Basin. The average azimuthal anisotropy results show significant tectonic influence on the shallow parts of the northeastern margin of the Tibetan Plateau, with consistent deep fast wave directions in the Haiyuan-Liupanshan area, suggesting a possible coupling deformation mechanism. The North Qinling fault zone area shows significant changes in anisotropy amplitude and fast wave directions around 45 km depth, indicating a decoupling layer and discontinuous deformation mechanisms between the upper and lower crust.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"366 ","pages":"Article 107420"},"PeriodicalIF":1.9,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144756863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stability and thermoelasticity of iron-rich FenO compound at earth's inner core condition","authors":"Guilin Liu ,&nbsp;Mei Tang ,&nbsp;Zhenwei Niu ,&nbsp;Zaixiu Yang","doi":"10.1016/j.pepi.2025.107419","DOIUrl":"10.1016/j.pepi.2025.107419","url":null,"abstract":"<div><div>Oxygen is one of the possible light elements in Earth's core, and it is of crucial importance for understanding the evolution of the inner core. Here, we report the stability and thermoelastic properties of iron-rich Fe_<em>n</em>O compounds at 360 GPa up to 7000 K. A series of metastable structures of Fe_<em>n</em>O compounds are predicted with stoichiometric ratio of <em>n</em> = 1–9 at 360 GPa using particle swarm optimization algorithm. Through the analysis of phonon spectra at finite temperatures, we find a new Fe₃O compound with P4/mmm symmetry, which is the only structure that can exist stably at the Earth's inner core condition for Fe_<em>n</em>O (<em>n</em> = 1–9). The thermoelastic properties of Fe₃O at 360 GPa up to 7000 K indicate that the calculated elastic properties, including sound velocities, agree well with those from seismology due to significant anisotropy and elastic softening. However, the density of Fe₃O is much lower than the geophysical data. Therefore, Fe₃O cannot be the major component of the Earth's inner core, and only can be regarded as a minor component.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"366 ","pages":"Article 107419"},"PeriodicalIF":2.4,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}