Journal of Geophysical Research: Solid Earth最新文献

{"title":"Continental Subduction and the Deep Carbon Cycle in Northern Tibet","authors":"Wenbin Zhao, Zhengfu Guo, Maoliang Zhang, Yutao Sun, Zhihui Cheng, Jujing Li, Donald B. Dingwell","doi":"10.1029/2024jb028999","DOIUrl":"https://doi.org/10.1029/2024jb028999","url":null,"abstract":"Degassing of volatiles within convergent plate margins, investigated through systematic variations in gas geochemistry, provides crucial insights into the recycling process, the lithospheric structure, and the dynamics of plateau growth. To date, such processes in the India-Asia continental collision zone remains poorly constrained in northern Tibet due to a dearth of detailed geochemical data on volatiles. Here, we report new data on chemical compositions and He–C isotopic ratios of hydrothermal volatiles in the northern plateau. CO₂-rich samples exhibit elevated ³He/⁴He ratios (0.11 <i>R</i>_A–0.39 <i>R</i>_A) compared to crustal values, as well as displaying heavy <i>δ</i>¹³C (−4.66–0.02‰) and high CO₂/³He ratios ((36–9,400) × 10⁹), indicating in summary the occurrence of carbonate in the mantle-derived components. We have developed a coupled He–C isotope model incorporating depleted mantle (DM), recycled carbonate (RC), and crustal carbon endmember (CCE) reservoirs to explore quantitatively the nature of the hydrothermal volatiles emitted. The results of model calculations reveal an increasing proportion of RC together with a decreasing proportion of CCE from south to north that is accompanied by an increasing contribution from DM, all suggesting the presence of a carbonated mantle beneath northern Tibet. Degassing of helium from hydrothermal activities exhibits relatively high fluxes of total ³He (10⁴–10⁵ atoms/m²/s), indicating a tectonically active degassing of volatiles in the Tibetan Plateau under ongoing continental convergence between India and Asia. Systematic variations in He–C isotopes, mantle helium fluxes and RC/CEE proportions along hydrothermal activities spanning from the Himalayas to the Qaidam-Gonghe basin are consistent with a dual continental subduction model acting beneath the whole Tibetan Plateau.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"74 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992341","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":"Impact of Fluids on the Mode I Fracture Toughness of Two Granites and One Sandstone","authors":"A. Muñoz-Ibáñez, M. Herbón-Penabad, Y. Li, J. Delgado-Martín","doi":"10.1029/2024jb030441","DOIUrl":"https://doi.org/10.1029/2024jb030441","url":null,"abstract":"Fluids affect the mechanical behavior of geomaterials, including properties such as unconfined compressive strength and brittleness. However, their impact on mode I fracture toughness (<i>K</i>_<i>Ic</i>) has been less explored. This study investigates the impact of saturating fluids on the <i>K</i>_<i>Ic</i> of three rock types: a porous siliceous sandstone (Corvio) and two high-strength, low-porosity granites (Blanco Mera and Blanco Alba). Pseudo-compact tension (<i>p</i>CT) specimens (diameter ∼50–54 mm, thickness ∼25 mm, notch depth ∼16 mm) were saturated with seven different fluids (deionized water, methanol, NaCl-saturated water, mineral oil, diesel fuel, an acidic HCl solution and a caustic NaOH solution) and tested under identical conditions. Results show that all fluids reduce <i>K</i>_<i>Ic</i>, but the extent varies with rock type and fluid properties. Aqueous fluids caused the most significant reductions, with deionized water having the greatest impact on granites (∼18%–30%) and the acid solution on sandstone (∼70%). Non-polar hydrocarbon fluids, despite their lack of reactivity, caused moderate effects attributed to poro-mechanical effects. Additionally, pH-shift experiments, involving sequential exposure to alkaline and acidic solutions, mitigated fluid-induced weakening. This behavior is hypothesized to stem from silica dissolution in the alkaline phase, followed by rapid nucleation and precipitation during the acidic phase, forming silica-rich coatings on mineral surfaces. Fracture energy was not equally distributed, with higher post-peak energy absorption due to crack bifurcation, grain rotation or friction. These findings underscore the interplay of lithological factors, fluid properties and chemical processes in fracture behavior, with implications for subsurface engineering and modeling of fluid-rock interactions.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"20 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992342","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":"Short-Period Mass Variations and the Next Generation Gravity Mission","authors":"P. L. Bender, J. W. Conklin, D. N. Wiese","doi":"10.1029/2024jb030290","DOIUrl":"https://doi.org/10.1029/2024jb030290","url":null,"abstract":"At the time that the 2017–2027 Decadal Survey for Earth Science and Applications from Space was released, there was a strong emphasis on reducing the possibility of a substantial gap between the GRACE Follow-On mission and a successor mission. This has led to the subsequent rapid development of a successor mission in partnership between NASA and DLR, GRACE-Continuity (GRACE-C), expected to launch in 2028, to continue the timeseries of Earth system mass change established by GRACE and GRACE-FO. In parallel, ESA continues development of a pair of satellites called Next Generation Gravity Mission (NGGM), targeted for an inclination between 65° and 75° to complement GRACE-C, launching in the early 2030s. NGGM offers the possibility for reduced noise in measuring short-period variations in the satellite separation using an improved accelerometer relative to what is flying on GRACE-C. One pathway for this is by using a simplified version of the Gravitational Reference Sensors demonstrated on the LISA Pathfinder Mission in 2016. And, if the measurement accuracy is much improved, it appears desirable to fly NGGM with a fixed ground track and an approximately 5-day orbit repeat period.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"37 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991606","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":"Evidence for an Upper Crustal Melt Lens Beneath Tianchi (Changbaishan) Volcano","authors":"Weiqian Yu, Wei Wei, James O. S. Hammond, Cunrui Han, Jiandong Xu, He Tan, Yan Zhan, Yanming Yang","doi":"10.1029/2024jb029884","DOIUrl":"https://doi.org/10.1029/2024jb029884","url":null,"abstract":"Changbaishan volcanic field (CBVF) located on the border of China and the Democratic People's Republic of Korea (DPRK) is famous for intense volcanism in the Cenozoic. Many studies show evidence for partial melt beneath the volcano, but details on the structure of the magmatic system are lacking, due to a lack of data in the region. In this study, we obtained a high-resolution crust and upper mantle shear wave velocity (Vs) model beneath the CBVF by ambient noise tomography and receiver functions using a new dense seismic array. The absence of velocity anomalies beneath Wangtian'e and Namphothe volcanoes suggests a lack of magma within the crust. However, our models reveal two low Vs anomalies beneath Tianchi associated with magma reservoirs. The shallow low velocity anomaly (&lt;4 km) overlaps with petrological estimates of the assembly depth of erupted rhyolite magma reservoir and the depth inferred for a hydrothermal reservoir from a recent MT study. The deeper one is located between 7 and 14 km depth with a lateral extent of ∼30 km, with a melt fraction of ∼6%–12%. Underlying the deeper low velocity zone in the lower crust is a region of faster velocity compared to the surrounding region. We interpret this as a low melt fraction crystal mush. This structure is similar to that seen at other large caldera volcanoes worldwide, suggesting a possible common mechanism underlying magmatism at these volcanoes.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"9 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990604","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":"Quantifying Magma Water Contents: A New Entrainment Model for Charnockite Formation","authors":"Hang Yang, Jinlong Yao, Peter A. Cawood, Guochun Zhao, Yigui Han, Xiaochun Li, Qian Liu, Donghai Zhang, Xiangsong Wang, Yu Guo","doi":"10.1029/2024jb029753","DOIUrl":"https://doi.org/10.1029/2024jb029753","url":null,"abstract":"Water is essential for the formation of granites and continental crust, whereas charnockite, being an important component of deep crust, is inferred to be formed in low-water environments. Charnockite is an orthopyroxene-bearing felsic rock, its origin, generation, and preservation remain hotly debated. Quantifying the magma water content of charnockite and further determining the orthopyroxene preservation mechanism is crucial to understanding the petrogenesis of charnockite. Here, we report a ca. 431 Ma peraluminous Gaozhou charnockite with granulitic enclaves in South China. The body displays A-type characteristics with crustal reworking zircon isotopic features (δ¹⁸O = 8.0–9.8 ‰; <i>ε</i>_Hf(<i>t</i>) = −11.5 to −3.4). The charnockite and its enclaves show identical mineral assemblages and comparable orthopyroxene chemical compositions. The two anhydrous minerals of orthopyroxene and garnet are identified as of peritectic and magmatic origins given their textural features and geochemical compositions. Moreover, petrographic observations and bulk geochemical data argue that the peritectic minerals were derived from the entrainment of their granulitic sources. Crystallization phase modeling indicates orthopyroxene would have been completely hydrated and formed biotite when water contents exceed ∼0.3 wt.% near the solidus. Water-in-zircon analysis and thermodynamic modeling indicate low magma water conditions (∼0.15 wt.%; 135 ppm, zircon water medians) for the Gaozhou charnockite from early crystallization to final solidification. CO₂-rich fluids flushed the charnockite reservoir further contributing to the stabilization of the orthopyroxene. Therefore, we propose a new entrainment model for the formation of charnockite that requires low-water environments achieved by high-temperature melting of dehydrated lower crust granulitic rocks.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"18 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990603","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":"Seismic Signatures of Fluctuating Fragmentation in Volcanic Eruptions","authors":"Katherine R. Coppess, Fredric Y. K. Lam, Eric M. Dunham","doi":"10.1029/2024jb029050","DOIUrl":"https://doi.org/10.1029/2024jb029050","url":null,"abstract":"Fragmentation plays a critical role in eruption explosivity by influencing the eruptive jet and plume dynamics that may initiate hazards such as pyroclastic flows. The mechanics and progression of fragmentation during an eruption are challenging to constrain observationally, limiting our understanding of this important process. In this work, we explore seismic radiation associated with unsteady fragmentation. Seismic force and moment tensor fluctuations from unsteady fragmentation arise from fluctuations in fragmentation depth and wall shear stress (e.g., from viscosity variations). We use unsteady conduit flow models to simulate perturbations to a steady-state eruption from injections of heterogeneous magma (specifically, variable magma viscosity due to crystal volume fraction variations). Changes in wall shear stress and pressure determine the seismic force and moment histories, which are used to calculate synthetic seismograms. We consider three heterogeneity profiles: Gaussian pulse, sinusoidal, and stochastic. Fragmentation of a high-crystallinity Gaussian pulse produces a distinct very-long-period seismic signature and associated reduction in mass eruption rate, suggesting joint use of seismic, infrasound, and plume monitoring data to identify this process. Simulations of sinusoidal injections quantify the relation between the frequency or length scale of heterogeneities passing through fragmentation and spectral peaks in seismograms, with velocity seismogram amplitudes increasing with frequency. Stochastic composition variations produce stochastic seismic signals similar to observed eruption tremor, though computational limitations restrict our study to frequencies less than 0.25 Hz. We suggest that stochastic fragmentation fluctuations could be a plausible eruption tremor source.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"99 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142989054","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 Driving Mechanisms of Megathrust Seismicity With Explainable Artificial Intelligence","authors":"Juan Carlos Graciosa, Fabio A. Capitanio, Adam Beall, Mitchell Hargreaves, Thyagarajulu Gollapalli, Titus Tang, Mohd Zuhair","doi":"10.1029/2024jb028774","DOIUrl":"https://doi.org/10.1029/2024jb028774","url":null,"abstract":"The correlation between subduction zone features and megathrust seismicity provides relevant clues on what controls the generation, location and clustering of mega-earthquakes (magnitudes M_w ≥ 8.0). Thus far, weak correlations are found between subduction zone parameters and seismicity through bivariate statistical analyses. Here, we used Explainable Artificial Intelligence (XAI) to assess the relevance of geophysical properties and tectonic motions along major subduction zones, paired with novel proxies of slab stress from calculations of buoyancy-driven subduction. The features derived from these data sets, describing the physical state, kinematics, and dynamics, served as inputs to a Fully Connected Network (FCN) trained to classify segments according to the largest earthquake magnitude that ruptured it. The subsequent use of Layer-wise Relevance Propagation, an XAI technique, on a trained FCN provides an estimate of the relevance of the input, identifying the features most relevant to the classification. The XAI procedure confirmed the importance of subduction interface curvature, sediment thickness, long wavelength bathymetric roughness, and free-air gravity anomalies, as previously proposed. Interestingly, our procedure revealed the importance of slabs extending to the upper mantle as well as the trench-parallel slab stress, showing how three-dimensional subduction forces may control large earthquakes. This suggests the preferential occurrence of large earthquakes on megathrust segments around slab steps and edges, where the slab depth measured along trench varies abruptly. At these steps, the trench-parallel forcing is maximized by the excess load of neighboring deeper slabs.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"27 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987998","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":"Adjoint-State Reflection Traveltime Tomography for Velocity and Interface Inversion With Its Application in Central California Near Parkfield","authors":"Guoxu Chen, Jing Chen, Tianjue Li, Mijian Xu, Qi Zhao, Ping Tong","doi":"10.1029/2024jb029918","DOIUrl":"https://doi.org/10.1029/2024jb029918","url":null,"abstract":"Traveltime tomography considering reflection arrivals is a promising approach for investigating interface topography and near-interface velocity heterogeneity. In this study, we formulate this inverse problem as an eikonal equation-constrained optimization problem, in which the traveltime field of the reflection wave is accurately described by a two-stage eikonal equation. The novelty lies in deriving the Fréchet derivative with respect to interface topography. By employing the coordinate transformation technique to convert an irregular physical domain with an undulating interface to a regular computational domain, we successfully encode the interface topography into the anisotropic parameters in the eikonal equation. This approach enables us to derive explicit forms of the Fréchet derivatives related to interface topography and velocity based on the adjoint-state method, which is not only computationally efficient but also avoids potential inaccuracy in ray tracing. Several numerical experiments are conducted to verify our new method. Finally, we apply this method to central California near Parkfield by inverting traveltimes of both first-P and Moho-reflected waves (named PmP). The low-velocity anomalies imaged in the lower crust are consistent with the along-strike variations of low-frequency earthquakes (LFEs) beneath the San Andreas Fault (SAF), suggesting the presence of fluids that may influence the occurrence of LFEs in this region.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"3 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987151","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":"High Stress Drop and Slow Rupture During the 2020 MW6.4 Intraplate Petrinja Earthquake, Croatia","authors":"Iva Žilić, Mathieu Causse, Martin Vallée, Snježana Markušić","doi":"10.1029/2024jb029107","DOIUrl":"https://doi.org/10.1029/2024jb029107","url":null,"abstract":"Here we analyze the rupture process of the 29 December 2020 M_W6.4 Petrinja earthquake (Croatia), the largest event instrumentally recorded in this area characterized by a moderate strain-rate intraplate setting. We use foreshocks and aftershocks, recorded at more than 80 broadband stations located 70–420 km from the earthquake, as empirical Green's functions (EGFs) to separate source effects from propagation and local site effects. First, we deconvolve the mainshock P-wave time windows from the EGFs in the frequency domain to obtain the corner frequency (<i>f</i>_<i>c</i>). Spectral analysis based on the Brune's source model reveals a large stress drop of 24 MPa. Next, by deconvolving the Love waves in the time domain, we calculate the Apparent Source Time Functions (ASTFs). We find that the average duration of the source is ∼5 s, with no significant directivity effects, indicating a bilateral rupture. To extract physical rupture parameters such as rupture velocity, slip distribution and rise time, we deploy two techniques: (a) Bayesian inversion and (b) backprojection onto isochrones of ASTFs. Both techniques show a low rupture velocity (40%–50% of the shear wave velocity) and a rupture length of less than 10 km, that is, much less than would typically be expected for a magnitude 6.4 earthquake. This apparent anticorrelation between stress drop and rupture velocity may be attributed to the complex and segmented fault system characteristic of immature intraplate settings.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"27 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987154","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":"Hydrogen Dissolution Mechanisms in Bridgmanite by First-Principles Calculations and Infrared Spectroscopy","authors":"Yanyao Zhang, Jun Tsuchiya, ChingChien Li, Zefang Ye, Wei Yan, Takuo Okuchi, Shun-ichiro Karato, Jennifer Kung, Jung-Fu Lin","doi":"10.1029/2024jb030403","DOIUrl":"https://doi.org/10.1029/2024jb030403","url":null,"abstract":"Understanding hydrogen dissolution mechanisms in bridgmanite (Bgm), the most abundant mineral in the lower mantle, is essential for understanding water storage and rheological and transport properties in the region. However, interpretations of O-H bands in Fourier transform infrared spectroscopy (FTIR) spectra of Bgm crystals remain uncertain. We conducted density functional theory (DFT) calculations on vibrational characteristics of O-H dipoles and performed polarized FTIR measurements to address this issue. DFT calculations for four substitution models—Mg vacancies, Si vacancies, Al³⁺ + H⁺ substitution for Si⁴⁺, and Al substitution with Mg vacancies—reveal distinct O-H bands with different polarizations. Deconvolution of polarized FTIR spectra on Mg_0.88Fe²⁺_0.035Fe³⁺_0.065Al_0.14Si_0.90O₃ and Mg_0.95Fe²⁺_0.033Fe³⁺_0.027Al_0.04Si_0.96O₃ crystals shows five major O-H bands with distinct polarizations along principal crystallographic axes. These experimental and calculated results attribute O-H bands centered at 3,463–3,480, 2,913–2,924, and 2,452–2,470 cm⁻¹ to Mg vacancies, Si vacancies, and Al³⁺ + H⁺ substitution for Si⁴⁺, respectively. The total absorbance coefficient of bridgmanite was calculated to be 82,702(6,217) L/mol/cm². Mg and Si vacancies account for 43%–74% of the total water content, making them dominant hydrogen dissolution mechanisms in Bgm. The band frequencies for the Mg and Si vacancies in Bgm are drastically different from those in olivine and ringwoodite, corresponding to the significant changes in O-H bond strengths and in the Si and Mg coordination environments from upper-mantle to lower-mantle minerals. These results highlight the need to incorporate hydrogen dissolution mechanisms in Bgm for understanding electrical conductivity and rheology of the lower mantle.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"29 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987171","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}