Institute of Geology and Geophysics, Chinese Academy of Sciences

Plain Language Summary The similarities and differences between slow and fast (regular) earthquakes at subduction zones are currently debated due to advances in precisely observing and isolating the signals of slow earthquakes, as well as in the numerical modeling of these signals. One key question is the relation between magnitudes and durations for large (Mw ≥ 7) and relatively infrequent earthquakes. By considering several data sources and examining worldwide subduction earthquakes from the past 500 years, we have collected data for over twice as many events as previous similar studies. This allows us to investigate the magnitude‐duration relationship in great detail. We find that larger earthquakes tend to last longer than previously thought, and this duration increases very rapidly with earthquake magnitude. For instance, events with 8.5 ≤ Mw < 9, on average, take approximately 28% times (about 1 min) longer than predictions from the previously widely accepted relationship. We propose that during their propagation, larger earthquakes may encounter unexpectedly more obstacles that slow down their rupture velocities, thus taking longer. Slow earthquakes may undergo a similar physical process, and our results therefore could help to understand both slow and fast earthquakes as a whole.

This study examines the impact of shale volume (Vsh) and clay mineral distribution on the petrophysical properties and reservoir quality of the Matulla Formation in the Gulf of Suez, a critical factor in global hydrocarbon exploration and production. Understanding how shale affects porosity, permeability, and fluid saturation enhances reservoir characterization, optimizing recovery techniques such as hydraulic fracturing and sustainable resource management. The evaluation process involved calculating shale volume using the neutron-density method, with values ranging from 1.9% to 11% across four wells (GS323-1, GS323-2A, GS323-3, GS323-4A). Clay minerals have been identified through Potassium-Thorium (K-Th) cross-plot include chlorite, illite, kaolinite, montmorillonite, and mixed-layer clays. Montmorillonite and chlorite negatively impact porosity and permeability, while kaolinite and illite improve hydrocarbon retention. Shale distribution analysis using the Thomas and Stieber model showed both laminated and dispersed forms, where laminated shales had minimal blockage, and dispersed clays significantly reduced the reservoir quality. Results reveal that wells with low Vsh (GS323-1 and GS323-4A) which ranges from 1.5 to 2% exhibit excellent reservoir quality, with high porosity (14%), high permeability (317–320.7 mD), and low water saturation (32–44%). Moderate Vsh wells (GS323-2A) show reduced porosity (13%), permeability (220 mD), and increased water saturation (46%), reflecting good but diminished quality. High Vsh well (GS323-3) display lower porosity (12%), permeability (140 mD), and moderate water saturation (37%), indicating challenges in fluid flow. This study highlights the need for tailored strategies to mitigate high shale content and swelling clays, offering valuable insights into optimizing hydrocarbon exploration and production in shale-influenced reservoirs worldwide.

Recent advancements in gas sensing technologies have significantly enhanced the detection and monitoring of gases across various applications, including environmental protection and industrial safety. This paper presents a novel metasurface-based sensor design that integrates advanced two-dimensional materials, such as graphene, copper, and MXene, to achieve high sensitivity and selectivity in terahertz gas detection. The proposed architecture features a central circular resonator surrounded by a square ring resonator, optimized for plasmonic modes, and an additional gold-coated circular ring to amplify detection capabilities. Through comprehensive modeling and simulation, the sensor’s performance was optimized, demonstrating remarkable sensitivity with a peak value of 800 GHz/RIU and robust responses across various gas concentrations. Moreover, the implementation of polynomial regression models further demonstrates the relationship between structural parameters and detection performance, achieving perfect predictive accuracy (R² = 1.00). The results indicate that this innovative design not only addresses the growing demand for efficient gas sensing solutions but also sets the stage for future developments in sensor technology, with implications for healthcare diagnostics and environmental monitoring.

Plain Language Summary Although there is no evident global dipolar magnetic field, the strong local crustal fields on Mars can form mini‐magnetospheres and alter the global structure of its plasma environment. The crustal fields are strongest at latitudes of 30°–85°S and longitudes of 120°–210°E, which can push up these loops of crustal magnetism to higher altitudes. The planetary bow shock is at a higher altitude in the southern hemisphere compared to the northern hemisphere, suggesting crustal fields may influence bow shock location. However, the southern bow shocks above the regions without crustal fields are also larger. Therefore, there is an ongoing debate about whether the crustal fields influence the bow shock location. In this study, we built a large data set of manually identified bow shock crossings by the (MAVEN) spacecraft and found that the bow shock location depends on the underlying crustal field location. Based on the detailed analyses, we demonstrate that the crustal fields extend outward and stretch tailward, thus explaining why the southern bow shocks are larger even in regions without crustal fields.

Drought stress is a major environmental stress that impairs plant growth and development. The At14a‐like1 ( AFL1 ) gene encodes a stress‐induced membrane protein involved in endocytosis, signal transduction, and proline accumulation. The objective of the present study was to investigate biological functions and underlying mechanisms of AFL1 regulation of drought tolerance in a perennial grass species, creeping bentgrass ( Agrostis stolonifera ). AsAFL1 was cloned from creeping bentgrass, and its expression was induced by drought stress. Motif analysis showed that AsAFL1 has five epidermal growth factor structural domains and one β1‐integrin structural domain. Transient expression in tobacco epidermal cells indicated that AsAFL1 was localized at the plasma membrane. Overexpression of AsAFL1 in creeping bentgrass significantly enhanced drought tolerance, as manifested by significantly increased leaf relative water content, chlorophyll and proline contents but lower electrolyte leakage and malondialdehyde content. Comparative transcriptomic and weighted correlation network analysis (WGCNA) revealed that AsAFL1 ‐mediated drought tolerance was related to transcriptional regulation of genes involved in phytohormone (abscisic acid, auxin, and strigolactone) biosynthesis and signaling, redox homeostasis, and biosynthesis of second metabolites (lignin, cutin, suberin and wax), as well as nutrient transport and mobilization.

Grain morphology is a fundamental characteristic of lunar soil that influences its mechanical properties, sintering behavior, and in situ resource utilization. However, traditional two‐dimensional imaging methods are time‐consuming and lack full three‐dimensional (3D) structural information. This study presents an automated deep learning‐based segmentation and reconstruction algorithm for high‐resolution X‐ray computed tomography scans of Chang'e‐5 lunar soil samples. By integrating a U‐Net convolutional neural network with a watershed algorithm, this method enables efficient and accurate 3D reconstruction of 553,578 lunar soil particles, significantly reducing manual annotation time. The results reveal a median particle size of 63.73 µm, an average aspect ratio of 0.55, and an average sphericity of 0.87, providing key insights into lunar regolith morphology. A clustering analysis identified 30 representative particle types, whose STereoLithography models will be made publicly available for further research and numerical simulations. These findings offer crucial data for discrete element modeling, thermal analysis, and engineering applications, supporting future lunar exploration and the development of sustainable lunar infrastructure.

Groundwater tidal response analysis is a valuable tool for monitoring leakage in groundwater systems, yet the interpretation of this response has often been incomplete. Notably, the impact of anisotropic aquifer permeability on tidal response has not been addressed in existing models. This study presents an analytical model to examine the effect of anisotropy on the tidal response of an aquifer overlain by a semi‐confined aquitard with finite storage. After verifying our model against previous models and numerical simulations, we fund: (a) At high vertical aquifer conductivity and aquitard leakage, the amplitude ratio of the tidal response is small, and the phase shift is positive, making our solution closely align with the existing leaky aquifer model. (b) As the vertical aquifer conductivity decreases, the amplitude ratio increases and the phase shift decreases and becomes negative at relatively low leakage, similar to that of a confined aquifer. (c) When the vertical aquifer conductivity is smaller relative to the horizontal one, the existing leaky aquifer model tends to underestimate the amplitude and overestimate the phase shift. (d) The aquitard storage has a significant effect on the tidal response of the aquifer when the aquitard leakage is large, but a negligible impact when the vertical aquifer conductivity is small. Applying our model to field data from four monitoring wells in the North China Plain, we find that when the shale content in the aquifer reaches 40.09%, our anisotropic model more effectively fits the observed phase shift compared to the existing leaky aquifer model.

Subduction initiation is fundamental to our understanding of plate tectonics. However, the mechanisms and processes of subduction initiation, especially at passive continental margins, are poorly understood due to limited geological records. Here we identify a magmatic sequence resembling the Izu‐Bonin‐Mariana (IBM) forearc crust in the Mandula area of Inner Mongolia that recorded the subduction initiation of the Paleo‐Asian Ocean (PAO) along the northern margin of the North China Craton (NCC). Geochemical analysis indicates that basalts and sheeted diabase dikes originated from partial melting of the upwelling asthenosphere at a forearc spreading center, succeeded by incipient arc volcanic and intrusive rocks, with increasing input of subducted slab‐derived hydrous fluids. Zircon U‐Pb ages reveal that the magmatic events in the Mandula area have taken place in a relatively short time interval between ∼284 Ma and ~272 Ma, similar to the duration of IBM forearc magmatism. The new results integrated with available data suggest that the southward subduction initiation of the PAO along the northern NCC was diachronous from early Carboniferous to early Permian and propagated from east to west following arc‐continent collision. Therefore, our study provides a four‐dimensional spatiotemporal perspective for tectonic transition from passive to active continental margin along the northern NCC.

Research into metamorphism plays a pivotal role in reconstructing the evolution of continent, particularly through the study of ancient rocks that are highly susceptible to metamorphic alterations due to multiple tectonic activities. In the big data era, the establishment of new data platforms and the application of big data methods have become a focus for metamorphic rocks. Significant progress has been made in creating specialized databases, compiling comprehensive datasets, and utilizing data analytics to address complex scientific questions. However, many existing databases are inadequate in meeting the specific requirements of metamorphic research, resulting from a substantial amount of valuable data remaining uncollected. Therefore, constructing new databases that can cope with the development of the data era is necessary. This article provides an extensive review of existing databases related to metamorphic rocks and discusses data-driven studies in this. Accordingly, several crucial factors that need to be taken into consideration in the establishment of specialized metamorphic databases are identified, aiming to leverage data-driven applications to achieve broader scientific objectives in metamorphic research.

Tonalite–trondhjemite–granodiorite (TTG) gneisses are the dominant component of Archaean continental crust, with their parent magmas generally thought to have formed due to the partial melting of hydrated basalts; however, this process typically produces melts with a notably lower Mg# than most natural TTGs. By contrast, ultramafic volcanic rocks commonly preserved in Archaean greenstone belts may represent an alternative source of TTG magma that has been largely overlooked. Here, we use petrological modelling to investigate anatexis of komatiites and komatiitic basalts from the Warrawoona Group of the Pilbara craton. In all cases, komatiite is refractory and generates no melt within the pressure‐temperature range considered. Komatiitic basalts, however, could produce 20–25 vol. % of MgO‐rich melts during greenstone belt sinking and hot subduction. Anatexis of komatiitic basalts generates melt fractions too depleted in large ion lithophile elements to represent natural TTGs; however, hybridization of melts produced by partial melting of tholeiitic basalts and komatiitic basalts during crustal overturn would generate magma that resembles natural TTGs. All calculated melts are felsic in composition, and TTGs with high Mg# could have been generated entirely within the crust, with no requirement for the assimilation of mantle materials. By contrast, Archaean sanukitoids require some assimilation of mantle materials with crustal melts, indicating that the oldest sanukitoids preserved in each Archaean craton may record temporary and localized subduction on the early earth. The ubiquitous occurrence of sanukitoids worldwide by c. 2.7 Ga may provide a minimum age for the onset of global plate tectonics.

Plain Language Summary The eastern CAOB, shaped by the closure of the Paleo‐Asian Ocean (PAO), features alternating blocks and suture zones, making it an ideal area for studying fossil suture zones. It includes the Solonker suture and the Heihe‐Hegenshan suture (HHS), where tectonic controversies of these two suture zones have hindered reconstructions of the region's tectonic evolution. This study conducts receiver function imaging to investigate the deep structures of these suture zones. The results reveal remnants of fossil subducted slabs from both southward and northward subduction along the Solonker suture, and a Moho offset associated with the northward subducted slabs beneath the HHS. These findings, combined with geological evidence, suggest that the Solonker suture marks the closure of the main PAO's basin, while the HHS corresponds to the closure of a branch ocean basin. Therefore, the identification of fossil suture zones underscores the effectiveness of dense short‐period seismic arrays in providing cost‐effective constraints on “frozen‐in” crustal information, essential for understanding tectonic evolution.

Modeling and forecasting of the geomagnetic variation are important research topics concerning geomagnetic navigation and space environment monitoring. We propose a combined forecasting model using a dynamic recursive neural network called echo state network (ESN), the method of complementary ensemble empirical mode decomposition (EEMD) and the complexity theory of sample entropy (SampEn). Firstly, we use EEMD-SampEn to decompose the geomagnetic variation time series into many series of geomagnetic variation subsequences whose complexity degrees are transparently different. Then, we use ESN to build a forecasting model for each subsequence, selecting the optimal model parameters. Finally, we use the real data collected from the geomagnetic observatory to conduct simulations. The results show that the forecasting value of the combined model can closely conform to the tendency of geomagnetic variation field, and is superior to the least square support vector machine (LSSVM) model. The mean absolute error of the model for three-hour forecasting is less than 1.40nT when Kp index is less than 3.

Halite minerals, widespread across Mars, have captured significant attention from geologists and astrobiologists for their potential to preserve biosignatures. Here, we report the preservation of organic matter within primary fluid inclusions in a halite duricrust, dated to 197.8 ± 36.2 ∼ 226.0 ± 29.0 ka BP, obtained from the Mars‐analog Qaidam Basin, NW China. Employing transmitted and fluorescent light microscopy alongside Raman spectroscopy, we identified abundant β‐carotene, lipids, and kerogen within these fluid inclusions. Notably, lipids were detected in situ and non‐destructively within fluid inclusions in salts. The presence of genes associated with microbial synthesis of carotenoids, such as β‐carotene, across diverse prokaryotes suggests that these microorganisms could be a potential source of β‐carotene preserved in halite salts. The consistent spatial co‐occurrence of β‐carotene and anhydrite within all identified anhydrite‐containing inclusions in this study implies potential interactions between carotenoid‐producing microorganisms and sulfate minerals. This study underscores the significance of the preservation of biosignatures in near‐surface salts in the search for life on Mars.

Accurate reconstruction of paleo‐crustal and lithospheric thicknesses is crucial for understanding the deep geodynamic processes driving the uplift and growth of the Tibetan Plateau (TP) and their association with Cenozoic magmatism. We reconstruct the Cenozoic crustal thickness evolution of the north‐central TP using a machine learning model for intermediate to felsic rocks, and estimate the lithospheric thickness based on geobarometers for mafic magmas. We find that the northern Qiangtang terrane (QT) underwent crustal thickening during the late Cretaceous‐early Eocene, with the crust thickening to 60.2 ± 4.8 km by 45 Ma, while the lithospheric thickness was only 60.9 ± 4.5 km. This suggests wholesale delamination of the lithospheric mantle shortly before ∼45 Ma, explaining the formation of high MgO adakitic rocks and the uplift of the Tanggula Mountain to ≥5 km. To the south, the southern QT crust thickened by ∼16 km during the late Eocene‐early Oligocene, contributing to ≥2 km uplift of the valley south of the Tanggula Mountain. To the north the Songpan‐Ganzi terrane (SGT) had a crustal thickness of 60.6 ± 3.6 km at ∼18 Ma and underwent ∼25 km of lithospheric thinning during ∼16–13 Ma. This process contributed to the formation of Miocene shoshonitic mafic rocks and adakitic rocks in the SGT, and the uplift of the Hoh‐Xil Basin to its present elevation. The recovered crustal and lithospheric thickness evolution demonstrates that progressive removal of the lower lithosphere following crustal shortening is the main driver for the uplift and magmatism of different regions in the TP.

Understanding the heterogeneity within a subducting slab is essential for elucidating its rheological properties, which can significantly affect subduction dynamics. Despite the importance, the fine structure of the slab has remained largely enigmatic due to the limited resolution of seismic tomography. Here, we utilize a deep learning approach, PickNet, to collect a comprehensive data set of arrival‐times of the first P and S waves from local earthquakes in Northeast Japan. This enables the determination of a high‐resolution (0.2°×0.2°×30km $0.2\mathit{{}^{\circ}}\times 0.2\mathit{{}^{\circ}}\times 30\,\text{km}$) model of P‐wave velocity (Vp), S‐wave velocity (Vs), and Vp/Vs ratio within the subducting Pacific slab. Our model reveals a distinct intraslab structure characterized by relatively high Vp (>+3%), slightly high Vs (<+1%), and a high Vp/Vs ratio (>+1%), extending deep into the lithospheric mantle of the slab, approximately 0.4°×0.4°×80km $0.4\mathit{{}^{\circ}}\times 0.4\mathit{{}^{\circ}}\times 80\,\text{km}$ in size between longitudes 140.6°E and 142.0°E, and latitudes 39.8°N and 40.2°N beneath Northeast Japan. This anomalous structure is associated with a decrease or absence in lower‐plane intermediate‐depth seismicity of the double seismic zone within the slab. This result suggests that the presence of intrusive minerals, potentially affected by increased iron (Fe) content due to hot mantle upwelling, may reduce the viscosity of the slab at lithospheric depths and subsequently diminish the lower‐plane seismicity. Our results highlight the presence of rheological heterogeneity within the subducting slab, providing new insights into its role in impacting the deep structure and geodynamics of the Earth, potentially facilitating slab detachment or tearing.

The absence of reliable paleomagnetic constraints from the Lhasa Block has led to alternative interpretations of its late Paleozoic position and timing of rifting from Gondwana, reflecting uncertainties in early Neo‐Tethyan paleogeography. This study presents paleomagnetic and geochronological data from the middle Permian Luobadui Formation, providing a new paleogeographic constraint on the Lhasa Block. Despite possible remagnetization, the dual‐polarity magnetization, hosted in different minerals and lithologies, likely represents a middle Permian remanence. This constraint implies the Lhasa Block was located at 16.7 ± 5.3°S at 267.8 ± 5 Ma, following its rifting from Gondwana. New U‐Pb detrital zircon ages from sandstones further suggest the Lhasa Block was located along the northwestern margin of Australia prior to rifting. Integrating other geological evidence, we propose that the Bangong Co‐Nujiang and Yarlung‐Zangbo oceans, now preserved as sutures flanking the Lhasa Block, both opened before the middle Permian, potentially representing branches of the same nascent oceanic corridor (Neo‐Tethys).

The intensification of Northern Hemisphere Glaciation (iNHG) with the onset of glacial‐interglacial cycles at ∼2.7 Ma had a profound impact on the global climate system. However, there have been few systemic assessments of the response of orbital‐scale East Asian summer monsoon (EASM) variability to the iNHG, partly due to controversies regarding the interpretation of the dominant orbital rhythms of the EASM. Here, we present grain size and other proxy records from mainly silt‐sized lacustrine‐fluvial deposits in northern China. The results shows that the EASM underwent stepwise weakening at ∼2.7 and ∼1.8 Ma, coincident with two major cooling steps of the global climate and that its dominant orbital periodicity changed from ∼41 kyr during ∼3.6–2.7 Ma, to ∼100 kyr during ∼2.7–1.8 Ma. However, these findings are inconsistent with the strengthening of the 41‐kyr cyclicity in marine δ¹⁸O records after the iNHG, whereas they are consistent with northern high‐latitude sea surface temperature records that bear the imprint of local climate signals when the Arctic ice sheets were of limited extent during the Early Pleistocene. We propose that the dominant ∼41‐kyr cyclicity during the Late Pliocene resulted from obliquity‐induced changes in the meridional insolation gradient, or in heat and moisture transport from low latitudes; whereas the dominant ∼100‐kyr cyclicity during ∼2.7–1.8 Ma reflects an increased response to northern high‐latitude forcing. Our findings, combined with previous studies, highlight the importance of eccentricity in modulating the EASM and other key climate system components prior to the Mid‐Pleistocene Transition during the course of Northern Hemisphere Glaciation.

We analyzed the three‐dimensional (3‐D) ionosphere response to the 14 October 2023 solar eclipse via assimilating multisource total electron content (TEC), including dense global navigation satellite system and the Constellation Observing System for Meteorology, Ionosphere, and Climate. The assimilations reveal a latitudinal dependency of the eclipse‐induced TEC depletion, with larger reductions occurring at middle latitudes. In contrast to the electron density depletion throughout all ionosphere heights at middle latitudes, the equatorial ionization anomaly (EIA) region exhibits an altitudinal variation and an asymmetry pattern in density response. The implemented National Center for Atmospheric Research Thermosphere Ionosphere Electrodynamics General Circulation Model simulations align well with the 3‐D electron density assimilations. Diagnostic analysis indicates that the photo‐chemical process plays a primary role in the larger depletion at middle latitudes, and the neutral wind transport provides a minor secondary contribution. In contrast, wind transport emerges as a dominant factor near the EIA region. The transequatorial plasma transport associated with northward neutral wind, driven by eclipse‐induced local cooling, combined with partly enhanced upward ExB drift, mitigates the total TEC depletion near the EIA region. This study highlights the importance of the dynamic coupling for a self‐consistent I‐T system between the neutral atmosphere and the ionosphere during eclipses.

Most great earthquakes on subduction zone plate boundaries have large coseismic slip concentrated along the contact between the subducting slab and the upper plate crust. On 4 March 2021, a magnitude 7.4 foreshock struck 1 hr 47 min before a magnitude 8.1 earthquake along the northern Kermadec island arc. The mainshock is the largest well‐documented underthrusting event along the ∼2,500‐km long Tonga‐Kermadec subduction zone. Using teleseismic, geodetic, and tsunami data, we find that all substantial coseismic slip in the mainshock is located along the mantle/slab interface at depths from 20 to 55 km, with the large foreshock nucleating near the down‐dip edge. Smaller foreshocks and most aftershocks are located up‐dip of the mainshock, where substantial prior moderate thrust earthquake activity had occurred. The upper plate crust is ∼17 km thick in northern Kermadec with only moderate‐size events along the crust/slab interface. A 1976 sequence with MW values of 7.9, 7.8, 7.3, 7.0, and 7.0 that spanned the 2021 rupture zone also involved deep megathrust rupture along the mantle/slab contact, but distinct waveforms exclude repeating ruptures. Variable waveforms for eight deep M6.9+ thrusting earthquakes since 1990 suggest discrete slip patches distributed throughout the region. The ∼300‐km long plate boundary in northern Kermadec is the only documented subduction zone region where the largest modeled interplate earthquakes have ruptured along the mantle/slab interface, suggesting that local frictional properties of the putatively hydrated mantle wedge may involve a dense distribution of Antigorite‐rich patches with high slip rate velocity weakening behavior in this locale.