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Spatiotemporal changes in sunshine duration and its influential factors in Chongqing,China from 1961 to 2020

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Journal of Mountain Science 2024年第6期21卷 2005-2024页

作者： LI Jun XIA Hongxuan JIANG Jinge XU Weifeng WEN Di XU Junfeng College of Geography and Tourism Chongqing Normal UniversityChongqing 401331China Key Laboratory of GIS Application of Chongqing Chongqing 401331China Chongqing Key Laboratory of earth Surface Processes and Environmental Remote Sensing in Three Gorges Reservoir area Chongqing 401331China Institute of Remote Sensing and earth sciences School of Institute of Remote Sensing and Earth SciencesSchool of ScienceHangzhou Normal UniversityHangzhou 311121China

The surface solar radiation in most parts of the world has undergone a phenomenon known as global dimming and brightening,characterized by an initial decrease followed by an *** a result,the sunshine duration(SD)has decreased in the past 60 *** the backdrop of global dimming and brightening,SD has decreased to varying degrees in many regions of *** the observed data of SD,cloud amount(total cloud amount and low cloud amount,abbreviated as TCA and LCA),precipitation,and relative humidity(RH)from 34 meteorological stations in Chongqing during the period of 1961-2020,along with a digital elevation model(DEM)with a resolution of 90 m,this study analyzed the spatiotemporal variations and influencing factors of *** analysis employed methods such as linear regression,Mann-Kendall test,wavelet transformation,and DEM-based possible SD distributed *** results showed that the annual SD in Chongqing has significantly decreased over the last 60 years,with a decreasing interannual trend rate(ITR)of 40.4 h/*** for no obvious trend in spring,SD decreased significantly in summer,autumn and winter at the ITR of 21.1 h/10a,8.5 h/10a and 7.5 h/10a,*** abrupt decrease in the annual SD was found in *** difference before and after the abrupt decrease was 177.7 *** difference before and after the abrupt decrease was 177.7 *** annual SD possessed the oscillation period of *** spatial heterogeneity of the mean annual SD during the last 60 years was *** distribution of SD in Chongqing is high in the northeast and low in the *** addition,about 73%of the total area in Chongqing showed a significant and very significant decreasing *** regions with significant changes are mainly concentrated in the regions with altitudes of 200~1000 *** increasing LCA was the main cause of the decrease of the annual SD in the regions with 200-400 m altitude decreased the most and changed the *** LCA is the prim

关键词： Sunshine duration Spatiotemporal changes Mann-Kendall test Wavelet analysis Geodetector model

Quaternary integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

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Science China earth sciences 2024年第4期67卷 1360-1394页

作者： Yong WANG Mianping ZHENG Yuan LING Shuyuan XIANG Zhaogang SHAO Kexin ZHANG Xue KE Xiao LIN Fang HAN Jian’en HAN Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China Institute of Mineral Resources Chinese Academy of Geological SciencesBeijing 100037China Faculty of earth sciences China University of GeosciencesWuhan 430074China Chinese Academy of Geological sciences Beijing 100037China Institute of Geological Survey China University of GeosciencesWuhan 430074China school of earth sciences East China University of TechnologyNanchang 330013China Institute of Geomechanics Chinese Academy of Geological SciencesBeijing 100081China

The Quaternary strata on the Qinghai-Tibet Plateau contain rich information about the paleoclimate and environmental evolution,record the evolution process of the Quaternary regional tectonics,paleogeography,and geomorphology of the plateau,and are extremely important areas for studying the Quaternary geological events and regional environmental *** to a comprehensive analysis of the regional stratigraphic data and the development and evolution characteristics of the biota,based on the differences in the lithostratigraphic units,sedimentary characteristics,landforms,and drainage systems,the Quaternary strata on the Qinghai-Tibet Plateau and its surrounding areas are divided into five stratigraphic regions:the Tarim region,Loess Plateau region,Qinghai-Tibet Plateau region,Yunnan-Guizhou Plateau region,and India-Ganges *** Qinghai-Tibet Plateau stratigraphic region is divided into seven stratigraphic sub-regions:the West Kunlun-Karakorum,AltunQilian Mountains,Qaidam-Hehuang,East Kunlun-Bayan Har,Qiangtang,East Xizang-West Yunnan-West Sichuan,and Gangdise-Himalayan *** paper briefly describes the lithostratigraphic units of the seven stratigraphic sub-regions of the Qinghai-Tibet *** to the lithostratigraphic sequence and its sedimentary characteristics,stratigraphic contact relationship,formation age,and evolution of the biota in each stratigraphic sub-region,the Quaternary tectonic paleogeographic evolution of the Qinghai-Tibet Plateau is divided into four stages.(1)The inherited differential uplift stage since the Pliocene(2.6-1.8/1.5 Ma):the regional sedimentary differences were significant,and the stratigraphic distribution was limited,the alluvial-proluvial sandy conglomerate was widely developed along the piedmont,and fluvial and lacustrine deposits were developed in the low-lying areas between the mountains.(2)The mountain range flattening stage(1.8/1.5-1.2/0.8 Ma):the erosion unconformity surfaces around the pl

关键词： Quaternary stratigraphic sedimentary

Hot versus cold subduction initiation

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National Science Review 2024年第2期11卷 101-102页

作者： Zhong-Hai Li Key Laboratory of Computational Geodynamics College of Earth and Planetary SciencesUniversity of Chinese Academy of Sciences

In the framework of plate tectonics, subduction initiation(SI) indicates the birth of a plate convergent boundary, which is a key point of plate tectonics and Wilson's cycle; however, its dynamic process is not well c... 详细信息

关键词： DRIVEN CRUST

An eikonal equation-based earthquake location method by inversion of multiple phase arrivals

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Science China earth sciences 2024年第6期67卷 1802-1817页

作者： Gaoyue LAO Dinghui YANG Shaolin LIU Guiju DONG Wenshuai WANG Kui LIU National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China school of earth sciences Yunnan UniversityKunming 650091China Department of Mathematical sciences Tsinghua UniversityBeijing 100084China school of Mathematics and Statistics Ningxia UniversityYinchuan 750021China

The precise determination of earthquake location is the fundamental basis in seismological community,and is crucial for analyzing seismic activity and performing seismic *** arrivals are generally used to practically determine earthquake ***,first-arrival traveltimes are not sensitive to focal ***,they cannot accurately constrain focal *** improve the accuracy,researchers have analyzed the depth phases of earthquake *** traveltimes of depth phases are sensitive to focal depths,and the joint inversion of depth phases and direct phases can be implemented to potentially obtain accurate earthquake ***,researchers can determine earthquake locations in layered *** layered models can only represent the first-order feature of subsurface structures,the advantages of joint inversion are not fully explored if layered models are *** resolve the issue of current joint inversions,we use the traveltimes of three seismic phases to determine earthquake locations in heterogeneous *** three seismic phases used in this study are the first P-,sPg-and *** calculate the traveltimes of the three seismic phases by solving an eikonal equation with an upwind difference scheme and use the traveltimes to determine earthquake *** verify the accuracy of the earthquake location method by the inversion of three seismic phases,we take the 2021 M_(S)6.4 Yangbi,Yunnan earthquake as an example and locate this earthquake using synthetic and real seismic *** tests demonstrate that the eikonal equation-based earthquake location method,which involves the inversion of multiple phase arrivals,can effectively improve earthquake location accuracy.

关键词： earthquake location Eikonal equation Fast marching method Heterogeneous model

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Plate tectonics in the Archean:Observations versus interpretations

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Science China earth sciences 2024年第1期67卷 1-30页

作者： YongFei ZHENG school of earth and Space sciences University of Science and Technology of ChinaHefei 230026China Key Laboratory of Crust-Mantle Materials and Environment Chinese Academy of SciencesHefei 230026China Center of Excellence for Comparative Planetology Chinese Academy of SciencesHefei 230026China

Plate tectonics theory,established in the 1960s,has been successful in explaining many geological phenomena,processes and events that occurred in the ***,the theory has often struggled to provide a coherent framework in interpreting geological records in continental interior and Precambrian *** dealing with the relationship between plate tectonics and continental geology,continental interior tectonics was often separated from continental margin tectonics in the inheritance and development of their structure and *** separation led to the illusion that the plate tectonics theory is not applicable to Precambrian geology,particularly in explaining the fundamental geological characteristics of Archean *** this illusion does not mean that the Archean continental crust did not originate from a regime of plate tectonics,it led to the development of alternative tectonic models,often involving vertical movements under a regime of stagnant lid tectonics,including not only endogenous processes such as gravitational sagduction,mantle plumes and heat pipes but also exogenous processes such as bolide *** vertical processes were not unique to the Archean but persisted into the *** result from mantle poloidal convection at different depths,not specific to any particular *** the plate tectonics theory from the traditional kinematic model in the 20th century to a holistic kinematic-dynamic model in the 21st century and systematically examining the vertical transport of matter and energy at plate margins,it is evident that plate tectonics can explain the common geological characteristics of Archean cratons,such as lithological associations,structural patterns and metamorphic *** deciphering the structure and composition of convergent plate margins as well as their dynamics,the formation and evolution of continental crust since the Archean can be divided into ancient plate tectonics in the Preca

关键词： Plate tectonics Archean geology Continental origin Crustal reworking Plate interior Plate margin

^(15)N tracers and microbial analyses reveal in situ N_(2)O sources in contrasting water regimes of a drained peatland forest

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Pedosphere 2024年第4期34卷 749-758页

作者： Mohit MASTA Mikk ESPENBERG Laura KUUSEMETS Jaan PÄRN Sandeep THAYAMKOTTU Holar SEPP Kalle KIRSIMÄE Fotis SGOURIDIS Kuno KASAK Kaido SOOSAAR Ülo MANDER Institute of Ecology and earth sciences University of TartuVanemuise Street 46Tartu 51003Estonia school of Geographical sciences University of BristolUniversity RoadBristol BS81SSUK

Managed peatlands are a significant source of nitrous oxide(N_(2)O),a powerful greenhouse gas and stratospheric ozone *** to the complexity and diversity of microbial N_(2)O processes,different methods such as tracer,isotopomer,and microbiological technologies are required to understand these *** combined application of different methods helps to precisely estimate these processes,which is crucial for the future management of drained peatlands,and to mitigate soil degradation and negative atmospheric *** this study,we investigated N_(2)O sources by combining tracer,isotopomer,and microbial analysis in a drained peatland forest under flooded and drained *** average,the nitrification genes showed higher abundances in the drained treatment,and the denitrification genes showed higher abundances in the flooded *** is consistent with the underlying chemistry,as nitrification requires oxygen while denitrification is *** observed significant differences in labelled N_(2)O fluxes between the drained and flooded *** emissions of N_(2)O from the flooded treatment were nearly negligible,whereas the N_(2)O evolved from the nitrogen-15(^(15)N)-labelled ammonium(^(15)NH4+)in the drained treatment peaked at 147μg ^(15)N m^(-2) h^(-1).This initially suggested nitrification as the driving mechanism behind N_(2)O fluxes in drained peatlands,but based on the genetic data,isotopic analysis,and N_(2)O mass enrichment,we conclude that hybrid N_(2)O formation involving ammonia oxidation was the main source of N_(2)O emissions in the drained *** on the ^(15)N-labelled nitrate(^(15)NO3-)tracer addition and gene copy numbers,the low N_(2)O emissions in the flooded treatment came possibly from complete denitrification producing inert *** atomic level,we observed selective enrichment of mass 45 of N_(2)O molecule under ^(15)NH4+amendment in the drained treatment and enrichment of both masses 45 and 46 under

关键词： denitrification nitrification N_(2)O quantitative polymerase chain reaction

Microstructures,Deformation Mechanisms and Seismic Properties of Synkinematic Migmatite from Southeastern Tibet:Insights from the Migmatitic Core of the Ailao Shan-Red River Shear Zone,Western Yunnan,China

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Journal of earth Science 2024年第4期35卷 1149-1169页

作者： Weiwei Ma Bo Zhang Fulong Cai Baoyou Huang Lei Zhang Key Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking UniversityBeijing100871China Institute of Tibetan Plateau Research Chinese Academy of SciencesBeijing100085China

Seismic anisotropy originating within the continental crust is commonly used to determine the deformation and kinematic flow within active orogens and is attributed to regionally oriented mica or hornblende ***,naturally deformed rocks usually contain compositional layers(e.g.,parallel compositional banding).It is necessary to understand how both varying mineral contents and differing intensities of compositional layering influence the seismic properties of the deep *** this study,we analyzed the seismic response of migmatitic amphibolite with compositional banding *** present the microstructures,fabrics,calculated seismic velocities,and seismic anisotropies of mylonitic amphibolite from a horizontal shear layer preserved within the Ailao Shan-Red River shear zone,southwestern Yunnan,*** investigated sample is characterized by pronounced centimeter-scale compositional *** microstructures and fabrics suggest that migmatitic amphibolite rocks within deep crust may delineate regions of deformation-assisted,channelized,reactive,porous melt *** origin of compositional banding in the studied migmatitic amphibolite is attributed primarily to partial melting together with some horizontal shearing *** microfabrics and structures investigated in this study are considered to be typical for the base of active horizontal shear layers in the deep crust of southeastern *** responses are modeled by using crystal preferred orientations for minerals of the migmatitic amphibolite by applying the Voigt-Reuss-Hill homogenization *** P-wave and S-wave velocities are largely consistent in the various layers of the ***,seismic anisotropies of P-wave(AV_(p))and S-wave(AVs)are higher in the melanosomes(AV_(p)=5.6%,AV_(s)=6.83%)than those in the leucosomes and the whole rock(AV_(p)=4.2%–4.6%,AV_(s)=3.1%–3.2%).In addition,there is pronounced,S-wave splitting oblique to the foliation plane in the migm

关键词： deformation-assisted melt flow seismic anisotropy microstructure compositional banding migmatite deep crust southeastern Tibet

Monitoring shear deformation of sliding zone via fiber Bragg grating and particle image velocimetry

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 231-241页

作者： Deyang Wang Honghu Zhu Guyu Zhou Wenzhao Yu Baojun Wang Wanhuan Zhou school of earth sciences and Engineering Nanjing UniversityNanjing210023China Institute of earth Exploration and Sensing Nanjing UniversityNanjing210023China State Key Laboratory of Internet of Things for Smart City University of MacaoMacaoChina

Monitoring shear deformation of sliding zones is of great significance for understanding the landslide evolution mechanism,in which fiber optic strain sensing has shown great ***,the cor-relation between strain measurements of quasi-distributed fiber Bragg grating(FBG)sensing arrays and shear displacements of surrounding soil remains *** this study,a direct shear model test was conducted to simulate the shear deformation of sliding zones,in which the soil internal deformation was captured using FBG strain sensors and the soil surface deformation was measured by particle image velocimetry(PIV).The test results show that there were two main slip surfaces and two secondary ones,developing a spindle-shaped shear band in the *** formation of the shear band was successfully captured by FBG sensors.A sinusoidal model was proposed to describe the fiber optic cable deformation *** this basis,the shear displacements and shear band widths were calculated by using strain *** work provides important insight into the deduction of soil shear deformation using soil-embedded FBG strain sensors.

关键词： Landslide Shear band Fiber bragg grating(FBG) Particle image velocimetry(PIV) Sinusoidal model Strain‒displacement proportional coefficient

An Overview on the Composition and Age of Upper Crust of Proto-Tethyan Lajishan Intra-oceanic Arc,NE Tibet Plateau

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 285-302页

作者： FU Changlei HE Xiaohu YAN Zhen Jonathan CAITCHISON XIAO Wenjiao WANG Bingzhang LI Wufu LI Yusen SinoProbe Laboratory Institute of GeologyChinese Academy of Geological SciencesBeijing 100037China Key Laboratory of the Northern Qinghai–Tibet Plateau Geological Processes and Mineral Resources Qinghai Geological Survey InstituteXining 810012China Department of Geology School of Earth SciencesYunnan UniversityKunming 650091China school of earth and Environmental sciences University of QueenslandBrisbane 4072Australia Xinjiang Institute of Ecology and Geography Chinese Academy of SciencesUrumqi 830011China State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China school of earth Science and Resources China University of GeosciencesBeijing 100083China

Identification and anatomy of oceanic arcs within ancient orogenic belt are significant for better understanding the tectonic framework and closure process of paleo-ocean *** article summarizes the geological,geochemical,and geochronological characteristics of upper crust of Proto-Tethyan Lajishan intra-oceanic arc and provides new data to constrain the subduction evolution of the South Qilian *** intra-oceanic arc volcanic rocks,including intermediate-mafic lava,breccia,tuff,and minor felsic rocks,are distributed along southern part of the Lajishan ophiolite *** and isotopic compositions indicate that the intermediate-mafic lava were originated from depleted mantle contaminated by sediment melts or hydrous fluids,whereas the felsic rocks were likely generated by partial melting of juvenile mafic crust in intra-oceanic arc *** from felsic rocks yield consistent and concordant ages ranging from 506 to 523 Ma,suggesting these volcanic rocks represent the relicts of upper crust of the Cambrian intra-oceanic *** with the Cambrian forearc ophiolite and accretionary complex,we suggest that the Cambrian intra-oceanic arc in the Lajishan ophiolite belt is belonging to the intra-oceanic arc system which was generated by south-directed subduction in the South Qilian Ocean at a relatively short interval between approximately 530 and 480 Ma.

关键词： volcanic rocks intra-oceanic arc U-Pb age Lajishan ophiolite belt South Qilian Ocean Proto-Tethyan realm