Journal of Geophysical Research: Solid Earth最新文献

{"title":"Implications of Thermal Weakening and Magma Compressibility for Volcano Monitoring","authors":"A. Spang,A. Piccolo,M. Gerbault,B. J. P. Kaus,M. Thielmann","doi":"10.1029/2026jb034071","DOIUrl":"https://doi.org/10.1029/2026jb034071","url":null,"abstract":"Abstract Magmatic intrusion and volcanic deformation are traditionally approximated with an inflating cavity in an elastic halfspace. Various analytical models predict surface displacement as a function of pressure or volume change, depth, and elastic crustal properties. While this approach allows for rapid inversion of monitoring data, it neglects important components such as the visco‐elastic behavior of thermally weakened host rock, magma transport, and magma compressibility. Here, we use 3D thermomechanical models to investigate the temporal evolution of overpressure and surface deformation due to magma influx into a pre‐existing reservoir. Instead of applying an internal source of pressure or volume in the magma body, we introduce a cylindrical feeding system which allows us to track the self‐consistent development of overpressure and investigate the effects of magma compressibility. Our model reproduces analytical solutions for an elastic host rock and a visco‐elastic shell. For thermally weakened, visco‐elastic host rock, we observe two effects: (a) The same overpressure causes more deformation, and (b) the same injected volume causes less overpressure. These effects partially cancel out, with a net uplift reduction due to thermal weakening. Considering magma compressibility further reduces the overpressure. Stacking all three effects results in up to 80% less surface deformation in our models compared to the elastic assumption. Consequently, intrusion volumes derived from surface deformation may be significantly underestimated, especially in young/cold magmatic systems. In thermally mature systems, magma overpressure is significantly overestimated. We propose modifications to the elastic solutions which can capture thermal weakening effects to first order.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"76 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148896026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Fractal Link Between Soil Water Retention and Freezing","authors":"Hao Wang,Sai K. Vanapalli","doi":"10.1029/2026jb034263","DOIUrl":"https://doi.org/10.1029/2026jb034263","url":null,"abstract":"Abstract Soils undergo wetting‐drying and freezing‐thawing cycles, yet their water retention and freezing behaviors are typically described within separate frameworks. This separation raises a fundamental question: do desaturation and freezing share comparable pore‐structure controls? A fractal formulation for the Soil Freezing Characteristic Curve (SFCC) is developed from a fractal pore‐size distribution in which characterizes pore‐size scaling. The proposed model provides good fits to 129 experimental SFCC data sets over wide temperature ranges. Combined with an existing fractal description of the Soil Water Characteristic Curve (SWCC), paired SWCC‐SFCC measurements for 14 materials show that the fractal dimensions, , inferred from the two curves are generally comparable. These results support a pore‐structure‐based connection between desaturation and freezing and provide a basis for describing water retention and freezing behavior within a common structural framework.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"32 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148895211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Emperor-Hawaiian Chain Magmatism: 80 Ma of Isothermal Melting","authors":"Nikolai Nekrylov,&nbsp;Vadim S. Kamenetsky,&nbsp;Dmitry P. Savelyev,&nbsp;Nikolay I. Baykov,&nbsp;Xiao-Yu Liu,&nbsp;Wei-Ran Li,&nbsp;Weidong Sun","doi":"10.1029/2026JB034790","DOIUrl":"10.1029/2026JB034790","url":null,"abstract":"<p>The Emperor–Hawaiian volcanic chain, which extends across the Pacific Plate, is a classic example of a structure formed through the interaction between a long-lived mantle melting anomaly and the moving oceanic lithosphere. Olivine-rich rocks sampled along the chain were examined using Cr-spinel and melt inclusions hosted in the most primitive olivine phenocrysts to constrain the characteristics of the mantle source and its melting conditions. The studied samples represent the Detroit (76–81 Ma), Suiko (61 Ma) and Koko (48–49 Ma) seamounts, as well as sand from Papakōlea Beach (&lt;150 Ka Puʻu Mahana tuff ring related to Mauna Loa volcano) on Hawai'i Island. Thermometric data derived from olivine–spinel and olivine–melt pairs indicate that there is no significant temperature difference between old Emperor seamounts and modern Hawai'i, whereas trace-element compositions of liquidus olivine and reconstructed melts suggest a progressive increase in melting depth. Mantle potential temperature of modern Hawai'i is estimated as ∼1,490 ± 84°C, which is in agreement with previous geophysical modeling.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 9","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148895257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of Interannual and Fine-Scale Plate Coupling Variations Using Intraplate Earthquakes and Geodetic Data: Application to the Tohoku-Oki Plate Boundary","authors":"Kazutoshi Imanishi,&nbsp;Akemi Noda","doi":"10.1029/2025JB032509","DOIUrl":"10.1029/2025JB032509","url":null,"abstract":"<p>We propose a method to infer detailed spatiotemporal variations in interplate coupling by integrating geodetic and seismic data. It examines whether focal mechanisms of intraplate earthquakes occurring near the plate interface align with the stressing rates caused by a geodetically derived slip-deficit rate model, evaluating deviations from a steady coupling state. We apply this method to the Tohoku-Oki plate boundary region over a quarter-century period, including the 2011 M_w9.0 Tohoku-Oki earthquake. The analysis successfully detects previously reported features, such as the partial decoupling of the plate interface in the large slip area of the Tohoku-Oki earthquake in the years leading up to the event, and the decadal evolution of aseismic slip off the coast of central and southern Tohoku before the Tohoku-Oki earthquake. Additionally, it reveals complex variations in the interplate coupling, including temporal fluctuations and fine-scale spatial heterogeneities not clearly captured by geodetic data alone. These findings highlight the value of integrating focal mechanism and geodetic information for a refined understanding of the evolving coupling state along subduction zones. Our method allows detection of changes on interannual timescale and spatial variations at scales finer than those typically resolved by geodetic inversions. This provides a powerful new tool for monitoring interplate coupling evolution, offering potential improvements in seismic hazard assessment and early identification of anomalous coupling patterns that may precede large earthquakes.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 9","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JB032509","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148895264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lithospheric Cliff-Induced Asthenospheric Upwelling: Insights From High-Resolution Broadband Lg Attenuation Structure Beneath the Carpathian-Pannonian Region","authors":"Song-Jie Yang,&nbsp;Lian-Feng Zhao,&nbsp;Xiao-Bi Xie,&nbsp;Tuna Eken,&nbsp;Xiao-Bo Tian,&nbsp;Zhen-Xing Yao","doi":"10.1029/2026JB034023","DOIUrl":"10.1029/2026JB034023","url":null,"abstract":"<p>Although many intraplate basaltic volcanic eruptions are now recognized as unrelated to mantle plumes, the mechanisms driving these eruptions remain unclear, particularly in the Carpathian–Pannonian Region. A high-resolution broadband Lg-wave attenuation model for this region is constructed to constrain the underlying mechanisms of intraplate magmatism. Strong Lg attenuation is observed in late-Cenozoic magmatic provinces. The strong attenuation observed in the western Pannonian Basin is consistent with steep sub-lithospheric topography, suggesting that shear-driven asthenospheric upwelling beneath the Eastern Alps and European Platform triggers crustal partial melting and basaltic magmatism. In the southeastern Carpathians, enhanced attenuation is associated with mantle flow induced by slab rollback, which promotes lithospheric reworking, fluid release, and partial melting of the crust. Our findings link late Cenozoic magmatism to asthenospheric upwelling by characterizing the lithospheric thermal structure and provide new constraints on the mechanisms driving intraplate volcanism.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 9","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148895406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flat-Slab Subduction and Overriding Plate Architecture Beneath the Northwestern Andes Revealed by Receiver Functions","authors":"Gaspar Monsalve,&nbsp;Lara S. Wagner,&nbsp;David S. Avellaneda-Jiménez,&nbsp;William D. Frazer,&nbsp;Miguel A. Alzate","doi":"10.1029/2026JB034380","DOIUrl":"10.1029/2026JB034380","url":null,"abstract":"<p>The existence of flat-slab subduction beneath the northern Andes of Colombia, north of ∼5.5°N, has been inferred from the absence of active volcanism and from a Wadati–Benioff zone located &gt;400 km from the trench. Here we use new broadband seismic data from northwestern Colombia to constrain slab geometry, the structure of the overriding South American plate, and their interaction. Teleseismic radial receiver functions acquired along a WSW–ENE profile across the Western and Central Cordilleras image the main lithospheric interfaces. We identify two closely spaced crust–mantle boundaries beneath both cordilleras, vertically separated by &lt;∼20 km. The deeper interface is interpreted as the Moho of the subhorizontal slab, whereas the shallower interface corresponds to the Moho of the overriding plate, here associated with the accreted and underthrust Caribbean Oceanic Plateau (COP). Toward the Magdalena Valley, we image the preserved continental Moho of South America, indicating that the overriding plate Moho is laterally discontinuous and reflects tectonic juxtaposition of distinct crustal domains assembled during long-lived convergence. Within the overriding plate, an east-dipping low-velocity zone is interpreted as underplated, hydrated sediments related to progressive COP underthrusting beneath the Central Cordillera. These observations support prolonged Late Cretaceous–Paleogene collision and underthrusting of the COP, followed by westward migration of subduction and establishment of the present-day flat slab in the Late Miocene–early Pliocene.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 9","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148895310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Testing the Seismic Detectability of Magmatic Underplating Beneath the Hawaiian Ridge: A Synthetic Wavefield Approach","authors":"Megumi Fujimoto,&nbsp;Robert A. Dunn","doi":"10.1029/2026JB034096","DOIUrl":"10.1029/2026JB034096","url":null,"abstract":"<p>Magmatic underplating beneath the Hawaiian Ridge has been inferred from early active-source and teleseismic studies, whereas more recent active-source seismic imaging and reprocessed legacy data have not identified a distinct underplated layer. To evaluate whether underplating would be detectable in modern wide-angle data, we performed two-dimensional finite-difference elastic wavefield simulations using a velocity structure derived from recent active-source tomography located across Kaʻena Ridge. Synthetic records were generated for models with and without imposed underplated layers spanning the thicknesses and velocities proposed in earlier work and compared directly with observed wide-angle seismic data. The simulations show that a laterally extensive underplated layer would produce diagnostic seismic signatures not observed in the data or in other recent wide-angle studies along the Hawaiian-Emperor Seamount Chain. Sensitivity tests indicate that underplated bodies thinner than ∼1 km would generate weak or indistinguishable signatures. The simulations further demonstrate that wave propagation can produce crustal multiples with travel times and moveout similar to reflections expected from a thick underplated layer, providing a plausible alternative explanation for some earlier interpretations. Taken together, these results indicate that the dominant wide-angle seismic observations are consistent with normal oceanic crust and volcanic structure without requiring a thick, laterally extensive magmatic underplate. If underplating is present beneath Kaʻena Ridge, it likely to be thin, localized, gradational, or otherwise seismically subtle relative to the structures proposed in earlier studies.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 9","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JB034096","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148895312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wave Propagation in 3-D Poroelastic Media Accounting for Both Mesoscopic and Global Flow Effects","authors":"Zhiyu Hou,&nbsp;Yury Alkhimenkov,&nbsp;Beatriz Quintal","doi":"10.1029/2026JB034032","DOIUrl":"10.1029/2026JB034032","url":null,"abstract":"<p>Biot's theory of poroelasticity is widely recognized as a fundamental framework for describing wave-induced fluid flow in mesoscopic heterogeneous porous media. However, dynamic numerical modeling of velocity dispersion and attenuation in heterogeneous porous media remains challenging due to (a) the stiffness of Biot's equations and (b) the wavelength <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mi>λ</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation> $(lambda )$</annotation>\u0000 </semantics></math>-dependent behavior relative to heterogeneity size <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mi>L</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation> $(L)$</annotation>\u0000 </semantics></math>. The former, arising from the contrasting discretization requirements for fast and slow P waves, has largely been mitigated by semi-implicit schemes. The latter persists because accurate simulations require periodically repeated representative elementary volumes: when <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>λ</mi>\u0000 <mo>≫</mo>\u0000 <mi>L</mi>\u0000 </mrow>\u0000 <annotation> $lambda gg L$</annotation>\u0000 </semantics></math>, the domain becomes prohibitively large; when <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>λ</mi>\u0000 <mo>/</mo>\u0000 <mn>4</mn>\u0000 <mo>≤</mo>\u0000 <mi>L</mi>\u0000 </mrow>\u0000 <annotation> $lambda /4le L$</annotation>\u0000 </semantics></math>, scattering masks mesoscale fluid-flow effects. These constraints have led to a reluctant yet often questioned reliance on quasi-static simulations neglecting inertial effect. We introduce a dimensionless framework enabling dynamic simulations in the same domain by directly controlling the diffusive process, eliminating frequency sweeps and reproducing quasi-static analytical and numerical solutions while correctly including inertial effects. Our results demonstrate that quasi-static approximations remain physically valid for modeling mesoscale fluid flow when the total contribution of global flow is very small. These results enable a more flexible and informed selection of modeling and measurement approaches. Meanwhile, our numerical framework can be used to model wave propagation in 3D heterogeneous porous media, accounting for both mesoscopic and global flow effects, which has been impossible until now.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 9","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JB034032","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148895314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compositional Controls on the Contribution of (Fe,Al)OOH Solid Solution to Core-Mantle Boundary Heterogeneities","authors":"Sparsh Sharma,&nbsp;Gaurav Shukla","doi":"10.1029/2026JB034429","DOIUrl":"https://doi.org/10.1029/2026JB034429","url":null,"abstract":"<p>Hydrous oxyhydroxides such as FeOOH and AlOOH have been proposed as potential carriers of hydrogen into Earth's deep mantle. However, these phases form extensive solid solutions in natural systems, and the influence of Al incorporation on the stability and elastic properties of Fe-bearing oxyhydroxides under lower-mantle conditions remains insufficiently constrained. Here we investigate the phase stability and thermoelastic properties of (Fe,Al)OOH solid solutions across ε/δ-type and pyrite-type (Py) structures using first-principles density functional theory calculations. An ideal two-phase solid-solution model constructed from the end members ε-FeOOH, Py-FeOOH, δ-AlOOH, and Py-AlOOH is used to quantify how Al incorporation modifies the ε-to-Py transition and its seismic expression along representative very cold slab geotherms. Our results show that Al significantly shifts the ε-to-Py transition to higher pressures and broadens the transition interval. For compositions containing ∼40–70% Al, the phase transition exhibits a broad transition interval of ∼20–30 GPa along the very cold slab geotherm, spanning the core-mantle boundary (CMB) pressure range. Fe-rich compositions produce large reductions in seismic velocities and increased density, whereas Al-rich compositions exhibit elastic properties close to the ambient mantle. These contrasting signatures suggest that compositional variations in slab-derived (Fe,Al)OOH may contribute to seismic heterogeneities in the lowermost mantle, potentially influencing the geophysical expression of deep-mantle structures near the CMB.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 9","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148849348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Imaging the Alpine Collision With Seismic Radial Anisotropy","authors":"Henrique Berger Roisenberg,&nbsp;Felix Eckel,&nbsp;Amr El-Sharkawy,&nbsp;Claudio Rosenberg,&nbsp;Lapo Boschi,&nbsp;Thomas Meier,&nbsp;Fabio Cammarano","doi":"10.1029/2025JB033428","DOIUrl":"https://doi.org/10.1029/2025JB033428","url":null,"abstract":"&lt;p&gt;The Alpine region and the adjacent Northern Apennines (NA) and Northern Dinarides record the complex tectonic evolution associated with the collision between the Eurasian and Adriatic plates. We combine Rayleigh and Love surface waves from ambient noise and earthquake data recorded at over 3,300 seismic stations to construct a high-resolution 3D model of shear-wave velocity and radial anisotropy &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;ξ&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $(xi )$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; of the crust and upper mantle down to 250 km depth (AlpRA25). The model reveals pronounced spatial variations in &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;ξ&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $xi $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; that reflect the complex collisional dynamics between the two plates. Within the crust, negative radial anisotropy &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;0.6&lt;/mn&gt;\u0000 &lt;mo&gt;&gt;&lt;/mo&gt;\u0000 &lt;mi&gt;ξ&lt;/mi&gt;\u0000 &lt;mo&gt;&lt;&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $(0.6 &gt; xi &lt; 1)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; is associated with steeply dipping fabrics and fault zones in the hanging wall of the Alpine and Apenninic deformation fronts and with the Eurasian–Adriatic plate interface. The so-called negative anisotropy is also present near the Ivrea body &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;0.92&lt;/mn&gt;\u0000 &lt;mo&gt;&gt;&lt;/mo&gt;\u0000 &lt;mi&gt;ξ&lt;/mi&gt;\u0000 &lt;mo&gt;&lt;&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $(0.92 &gt; xi &lt; 1)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and in the oceanic crust and uppermost mantle of the Ligurian Sea &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;0.8&lt;/mn&gt;\u0000 &lt;mo&gt;&gt;&lt;/mo&gt;\u0000 &lt;mi&gt;ξ&lt;/mi&gt;\u0000 &lt;mo&gt;&lt;&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $(0.8 &gt; xi &lt; 1)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. In contrast, the Eurasian lower crust througho","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 9","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JB033428","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148849191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}