Physics of the Earth and Planetary Interiors最新文献

{"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}

{"title":"Rutile's pressure-temperature-time evolution dictates its role as a depth-dependent subduction-zone water regulator","authors":"Jing Gao ,&nbsp;Yue Wang ,&nbsp;Wanghua Wu","doi":"10.1016/j.pepi.2025.107418","DOIUrl":"10.1016/j.pepi.2025.107418","url":null,"abstract":"<div><div>The deep Earth water cycling is critically regulated by hydrogen storage capabilities of nominally anhydrous minerals (NAMs). Rutile TiO₂, a prevalent NAM in subduction zones, incorporates measurable hydrogen via defect-mediated mechanisms. However, its molecular-level structural evolution and hydrogen content variations under subduction-relevant conditions remain poorly constrained. This study integrates spatially resolved Raman imaging and Fourier transform infrared spectroscopy to quantitatively elucidate the microstructural and hydrogen dynamics in rutile across various pressure-temperature-time (P-T-t) trajectories. The results reveal that during prolonged cold subduction (geothermal gradient of ∼5 °C/km), pressure enhances microstructural ordering and crystallinity in rutile, leading to hydrogen loss. Conversely, thermal activation generates microstructural defects, which serves as additional sites for hydrogen incorporation. Quantitative hydrogen tracking demonstrates that rutile undergoes ∼50 % dehydration in anhydrous environments, which is inhibited by the rutile-to-akaogiite transformation. This transformation initiates at ∼8 GPa due to molecular heterogeneity, yet the kinetic stability provided by polar covalent Ti<img>O bonds enables rutile to persist up to ∼20 GPa. Notably, rutile exhibits ∼12 % hydrogen uptake upon prolonged fluid infiltration along cold-to-hot subduction pathways (geothermal gradients of ∼5–20 °C/km). In the continuous aqueous environments typical of subduction zones, these findings establish rutile as a depth-dependent water regulator. It can transport water beyond its initial content to mantle depths exceeding ∼300 km, thus advancing our understanding of how NAMs modulate water cycling in subduction zones.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"366 ","pages":"Article 107418"},"PeriodicalIF":2.4,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144663220","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":"Unveiling the prevalence of larger magnitude earthquakes preceding major shallow seismic events (M≥7.2) in Japan (1995–2021)","authors":"Daniel Amorese ,&nbsp;Jean-Robert Grasso ,&nbsp;Paul A. Rydelek","doi":"10.1016/j.pepi.2025.107405","DOIUrl":"10.1016/j.pepi.2025.107405","url":null,"abstract":"<div><div>We conducted a study using data from the Seismological Bulletin of Japan, which is maintained by the Japan Meteorological Agency. We focused on major earthquakes (with a magnitude of 7.2 or higher) that occurred in or around Japan, specifically within the coordinates of 18–50 °N and 119–158 °E, between 1995 and 2021. For each of these mainshocks, we analyzed seismic activity patterns within a 100 km radius, using two different time periods. To enhance our investigation, we also employed a space–time cluster detection method initially designed for identifying clusters in epidemiology, enabling us to reclassify earthquakes into sequences for further analysis. Unlike conventional fixed-window approaches, this method (SaTScan™) statistically detects spatio-temporal clusters without predefined spatial or temporal boundaries, allowing for a more flexible and data-driven classification. Our main discovery is a significant increase in the magnitude of the largest earthquake and the observed seismic energy during the 3–0 month interval, compared to the values during the 6–3 month interval before the mainshock respectively. However, we did not find any stable or significant differences in the numbers of events, mean magnitude values, median magnitude values, and <span><math><mi>b</mi></math></span>-values.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"366 ","pages":"Article 107405"},"PeriodicalIF":2.4,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665920","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":"A summary of paleomagnetic secular variation and excursions for the last 380 ky of the Brunhes Normal Polarity Chron – regional results from the Bering Sea (IODP Ex. 323)","authors":"Steve P. Lund","doi":"10.1016/j.pepi.2025.107417","DOIUrl":"10.1016/j.pepi.2025.107417","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This study describes high-resolution, full-vector paleomagnetic secular variation (PSV) records recovered from Integrated Ocean Drilling Program (IODP) Expedition 323 to the Bering Sea (58° N-60° N). The PSV records come from Sites U1343, U1344, and U1345 and cover marine isotope stages (MIS) 1–10 (last 380 ky). These records identify 291 inclination features and 251 declination features that are common to all three sites. The average sedimentation rates are ∼20–45 cm/ky, which produce sampling intervals of ∼100–200 years. All three sites have been dated independently to the MIS level by oxygen-isotope stratigraphy. We have also developed relative paleointensity records for all three sites that have 34 features in common. The paleointensity features can also be correlated to the PISO-1500 global paleointensity record of Channell et al. (2009) that is itself dated by oxygen-isotope records. The relative paleointensity records provide an independent chronostratigraphy to the PSV records that is consistent with the MIS level oxygen-isotope stratigraphy but provides better constraint on the sub-MIS scale with an uncertainty of ∼ ± 2000 years. The directions have near Gaussian distributions with average inclinations about 2° higher than axial dipole expectation due to the ΔI anomaly. The intensities have a non-Gaussian distribution, with some bias to higher intensities that may be an artifact of environmental bias to the measurements. There is reproducible evidence for eight excursions in these records with good waveform detail. The excursions are, with one exception, short in duration lasting less than 1000 years. The exception is the Iceland Basin Excursion (196 ± 3 ka), which has a duration of ∼2500 years. All of the excursions are Class I excursions with out-of-phase inclination and declination variability that produces clockwise or counter-clockwise looping (circularity). We have complete full-vector PSV records that surround each of these excursions. Some of the excursions occur quickly with no distinctive pre- or post-excursion anomalous directional variability. However some of the excursions are preceded by 10–20 ky of anomalous directional variability (high angular dispersion). These features indicate a close relationship between normal PSV and the excursions themselves. Statistical PSV studies note distinctive features to the PSV over 3ky to 9 ky intervals. The most distinctive feature is that PSV angular dispersion on 3ky intervals has a bimodal distribution with high (low) values associated with low (high intensity). The high angular dispersion intervals have values ∼3 times that of the low angular dispersion intervals and all of the excursions occur within high angular dispersion intervals. The timing and number of these high angular dispersion intervals is almost exactly the same as recorded in the North Atlantic Ocean. There is evidence for three other excursions elsewhere in the world, but not in our records, that are also as","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"366 ","pages":"Article 107417"},"PeriodicalIF":2.4,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144678847","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":"Thermal conductivity and evolution of the Earth's and Mars' cores","authors":"Kenji Ohta ,&nbsp;Kei Hirose","doi":"10.1016/j.pepi.2025.107416","DOIUrl":"10.1016/j.pepi.2025.107416","url":null,"abstract":"<div><div>Precise determinations of the thermal conductivity of Fe alloys at high pressures and temperatures are essential for understanding the thermal history and dynamics of the metallic cores of the Earth and other terrestrial bodies. While it can be directly measured, the thermal conductivity of metal is obtained from its electrical resistivity <em>via</em> Wiedemann–Franz law. Here we review recent measurements of the electrical resistivity of Fe alloys in a diamond-anvil cell, considering the resistivity of Fe, impurity resistivity, and the resistivity saturation effect, as well as the direct measurements and calculations of their thermal conductivity (or diffusivity). We also discuss implications of the high thermal conductivity of the Earth's and Martian cores for their thermal and compositional evolutions.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"366 ","pages":"Article 107416"},"PeriodicalIF":2.4,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144632669","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":"Accounting for quiet-time magnetospheric field contributions in geomagnetic field modelling","authors":"Nils Olsen","doi":"10.1016/j.pepi.2025.107411","DOIUrl":"10.1016/j.pepi.2025.107411","url":null,"abstract":"<div><div>Accurate modelling of Earth’s core and lithospheric magnetic field requires minimising the influence of contributions from ionospheric and magnetospheric currents. This study examines different approaches for accounting for quiet-time magnetospheric contributions in geomagnetic field modelling, with a focus on the magnetospheric ring current. Traditional indices, such as the <span><math><msub><mrow><mi>D</mi></mrow><mrow><mi>st</mi></mrow></msub></math></span> or the <em>RC</em> indices, have been widely used for this but exhibit limitations. The study explores variations of the <em>RC</em> index, incorporating ground-based observatory data from different latitude ranges, and evaluates their effect on geomagnetic field modelling. Additionally, approaches based on a combined analysis of ground and satellite data are assessed for their ability to provide a more accurate representation of magnetospheric contributions, going beyond its usual approximation by a uniform field (the so-called <span><math><msubsup><mrow><mi>P</mi></mrow><mrow><mn>1</mn></mrow><mrow><mn>0</mn></mrow></msubsup></math></span>-<em>approximation</em>). Results indicate that including mid-latitude ground observatory data and utilising higher spherical harmonic for describing magnetospheric contributions lead to improved geomagnetic field models and reduced data misfit.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"366 ","pages":"Article 107411"},"PeriodicalIF":2.4,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144563616","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":"Constraining temporal changes in seismic velocity at the Xinfengjiang Reservoir using ambient seismic noise interferometry","authors":"Runqing Huang ,&nbsp;Yangfan Deng ,&nbsp;Zhou Zhang ,&nbsp;Jiangtao Li ,&nbsp;Ying Chen ,&nbsp;Qiu Zhong ,&nbsp;Min Xu","doi":"10.1016/j.pepi.2025.107414","DOIUrl":"10.1016/j.pepi.2025.107414","url":null,"abstract":"<div><div>Changes in seismic velocity at the water reservoir are crucial for understanding the underground media environment and monitoring seismic activity. Notably, Xinfengjiang Reservoir (XFJR) is one of the four reservoirs worldwide known to have induced earthquakes exceeding magnitude 6.0, raising great concerns on its seismic triggering environment. However, there has been a notable lack of research on monitoring the stress variations that contribute to seismic activity. Here, we applied ambient seismic noise interferometry to study relative changes in seismic velocity (dv/v) in the XFJR using data recorded from permanent seismic stations between 2013 and 2021. We identified significant seasonal variations in the dv/v and discussed these changes with seismic activity, ocean tidal response, reservoir water level, and underground water level. Our findings indicate that changes in the reservoir water level play a significant role in the seasonal variations of dv/v, with a strong positive correlation to the reservoir water level gradient, and an anti-correlation to the underground water level gradient, corresponding to the loading and pore pressure effects, respectively. This study demonstrates that ambient seismic noise is an effective tool for monitoring changes in the underground medium of water reservoirs.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"366 ","pages":"Article 107414"},"PeriodicalIF":2.4,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704244","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":"An investigation on the crustal structure using coda wave attenuation and surface wave tomography in Western part of Iran","authors":"Somayeh Shakiba ,&nbsp;Rouhollah Amiri Fard ,&nbsp;Mojtaba Namvaran ,&nbsp;Samane Asadi ,&nbsp;Majid Mahood","doi":"10.1016/j.pepi.2025.107407","DOIUrl":"10.1016/j.pepi.2025.107407","url":null,"abstract":"<div><div>We interpret coda wave attenuation and Rayleigh wave group velocity to investigate the processes controlling the crustal structure beneath the western part of Iranian plateau and to determine the relevance of the Sahand and Sabalan to shallow crustal hot spot-like structures. Given that seismic wave attenuation is more sensitive to the thermal structure than the velocity, it provides additional information on the seismic velocity and helps identify compositional and thermal structures.</div><div>A total of 370 events recorded at 24 broadband seismic stations were used to create Rayleigh wave tomographic maps for six periods: 5, 10, 15, 20, 25, and 30 s. Moreover, more than 9800 local events were investigated to estimate lateral variations of the coda wave attenuation using multiple-scattering method. After examining different lapse times from the origin time with a fixed window length of 20 s, the results showed that a lapse time of 70 s provides stable QC indices, which were independent of the distance to the epicenter. After estimating the velocity and attenuation within the area, it was figured out that the low-velocity (high-attenuation) region underlying the Sahand Mountain (detected with a 5-s period) is related to the magma chamber beneath the crust resulting from the Anatolian and Arabian plates' collision. A shallow low-velocity region in the eastern part of the study area (detected with a 5-s period and disappeared for longer periods) might be associated with the Quaternary near-surface magma accumulations and/or upper crustal warm-ups.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"366 ","pages":"Article 107407"},"PeriodicalIF":2.4,"publicationDate":"2025-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365629","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":"Unveiling the crustal structure beneath the Chotanagpur Granite Gneiss Complex, eastern India: Interpretation from the 3-D magnetotelluric study","authors":"K. Naganjaneyulu ,&nbsp;B. Pradeep Naick ,&nbsp;Kusham ,&nbsp;A. Pratap ,&nbsp;V. Pooja Bhargavi","doi":"10.1016/j.pepi.2025.107406","DOIUrl":"10.1016/j.pepi.2025.107406","url":null,"abstract":"<div><div>The Proterozoic Chotanagpur Granite Gneiss Complex (CGGC) is economically rich with mineral deposits such as Uranium, Bauxite, Iron, Copper, Gold, Diamond etc. Thermo-tectonic events, including the timing and mechanism of attendant magmatism, metamorphism, and metallogeny, remain poorly constrained in the CGGC. To examine the effect of magmatic processes that have originated from the mantle or deeper levels of the lower crust, a comprehensive magnetotelluric (MT) survey is being conducted in the CGGC region. This study aims to provide a detailed understanding of subsurface electrical conductivity to assess the impact of mantle-derived magmatic activity and subduction on the region's crustal structure. The crustal electrical resistivity structure of the CGGC is imaged using 16 magnetotelluric stations. The phase tensor skew shows the three-dimensional (3-D) nature of subsurface structures beneath the study region. 3-D modelling results show the resistive upper crust along the profile up to the depth of approximately 5 km and map several less resistive features in the mid-crust. The process of subduction significantly contributes to the buildup of magmatic fluids within the mid-crust. As the subducting slab releases fluids, it lowers the melting point of the overlying mantle rocks, facilitating partial melting. This resulting molten material can rise towards the mid-crust, transporting dissolved gases and volatiles, such as carbon, along with it. The low resistive features are observed from approximately 5–15 km depth with ∼10 Ω-m resistivity value. The uppermost crust is resistive due to the presence of granite and gneissic composition. Subduction related magmatic fluids at depths that accelerate carbon enrichment could be one reason for the less resistive features mapped in the mid-crust. From the 3-D inversion model, we conclude that no deep-seated faults are present in the study region. Faults extend up to the mid-crustal level, featuring layered structures. The low resistive zone in the mid crust corresponds to the corridors of paleo-fluid flow along crustal-scale structures established in response to terrane amalgamations.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"366 ","pages":"Article 107406"},"PeriodicalIF":2.4,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144471313","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":"Exceptional secular variation recorded in Neolithic hearths, Orkney and Swedish lake sediments","authors":"Neil Suttie ,&nbsp;Sam Harris ,&nbsp;Catherine M. Batt ,&nbsp;Andreas Nilsson ,&nbsp;Ian Snowball ,&nbsp;Nick Card ,&nbsp;Zoe Outram","doi":"10.1016/j.pepi.2025.107412","DOIUrl":"10.1016/j.pepi.2025.107412","url":null,"abstract":"<div><div>Geomagnetic field models constrained by direct observations extend back some 400 years and the magnitude of decadal to centennial variations that they display is often assumed to be typical of the secular variation over longer timescales. Here we present archaeomagnetic directions from layered Neolithic hearths in Orkney, dating to around 3000 BCE, that challenge this assumption. Combining stratigraphic controls with radiocarbon dates allows for a precise chronology, which, in turn, implies directional change of more than 12°/century lasting for 200 years, far in excess of anything seen at this latitude over the era of historical observations. These archaeomagnetic data are complemented by similarly rapid changes in inclination recorded in two high temporal resolution sediment cores from Kälksjön, Sweden. As well as raising the possibility of using archaeomagnetic dating within this important archaeological period, the new data pose questions regarding our understanding of the secular variation, the limitations of the historic field as a proxy for the past, and the underlying dynamical processes within the core. This research highlights the importance of archaeology to the wider scientific community and the potential of archaeological material to further our understanding of Earth processes.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"366 ","pages":"Article 107412"},"PeriodicalIF":2.4,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144320824","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}