Nutrients in human milk,including minerals,relate growth and development of breast-fed infants.Tibetan mother-infant dyads possess unique characteristics on early nutrition due to their featured long-lasting lifestyle...Nutrients in human milk,including minerals,relate growth and development of breast-fed infants.Tibetan mother-infant dyads possess unique characteristics on early nutrition due to their featured long-lasting lifestyle.This study longitudinally investigated the relationship between the mineral composition in human milk and the Z-scores of infants among Tibetan mother-infant dyads during their first 6 months postpartum through a prospective cohort study.The results show that the minerals of Na,Mg,K,Ca,Cu,Zn,and Se were of higher levels in colostrum than other lactation stages.Several minerals were below the recommended values for infants according to Chinese dietary guidelines.Besides,a large proportion of infant Z-scores were below-2 as lactation period continued.Multivariate statistical analysis revealed that classifications and correlations in varying degrees were observed between minerals in human milk and infant Z-scores.These findings will be advantageous for research upon Chinese early nutrition and progress of tailor-made infant formula.展开更多
The Nadingcuo high-K calc-alkaline rocks mainly composed of trachyte and trachyandesite are the largest outcrop area of volcanic rocks in southern Qiangtang terrane in the Tibetan plateau. However,their exact source a...The Nadingcuo high-K calc-alkaline rocks mainly composed of trachyte and trachyandesite are the largest outcrop area of volcanic rocks in southern Qiangtang terrane in the Tibetan plateau. However,their exact source and peterogenesis are still debated.^(40)Ar-^(39)Ar and LAM-ICPMS zircon U-Pb isotopic dating confirm that these rocks erupted in Eocene.In addition,the Nadingcuo volcanic rocks are characterized by high Sr/Y content ratios,similar with the adakite derived from partial melting of oceanic crust.They can be further classified as high Mg~#(Mg~#=48-57) and low Mg~# (Mg~#=33-42) subtypes.The Nadingcuo adakitic rocks have relatively low(^(87)Sr/^(86)Sr)_i and highε_(Nd)(t), showing a trend of similarity to the Dongcuo ophiolite present in the Bangong-Nujiang oceanic crust. Simple modeling indicates that the Nadingcuo adakitic rocks are a mix resulting from the basalt of Bangong-Nujiang Ocean with 10%-20%crustal material of Lhasa terrane.On these bases we suggest that the low Mg~# Nadingcuo adakitic rocks are the product of partial melting of remnant oceanic crust with small sediment,and the high Mg~# rocks are the result of reaction between rising melt of remnant oceanic crust with subducted sediment and mantle wedge.Therefore,the origin of Nadingcuo adakitic rocks may be related to intracontinental subduction triggered by collision of India-Asia during Cenozoic.展开更多
In order to constrain the crustal wave velocity structure in the southernTibetan crust and provide insight into the contribution of crustal composition, geothermal gradientand partial melting to the velocity structure...In order to constrain the crustal wave velocity structure in the southernTibetan crust and provide insight into the contribution of crustal composition, geothermal gradientand partial melting to the velocity structure, which is characterized by low average crustalvelocities and widespread presence of low-velocity zone(s), the authors model the crustal velocityand density as functions of depth corresponding to various heat flow values in light of velocitymeasurements at high temperature and high pressure. The modeled velocity and density are regarded ascomparison standards. The comparison of the standards with seismic observations in southern Tibetimplies that the predominantly felsic composition at high heat flow cannot explain the observedvelocity structure there. Hence, the authors are in favor of attributing low average crustalvelocities and low-velocity zone(s) observed in southern Tibet mainly to partial melting. Modelingbased on the experimental results suggests that a melting percentage of 7-12 could account for thelow-velocity zone(s).展开更多
The work presents microparticle concentrations in snowpits from the East Rongbuk Glacier on Mt. Qomolangma (Everest) (ER) (28.02°N, 86.96°E, 6536 m a.s.l.), the Zhadang Glacier on Mt. Nyainqentanglha (NQ) (3...The work presents microparticle concentrations in snowpits from the East Rongbuk Glacier on Mt. Qomolangma (Everest) (ER) (28.02°N, 86.96°E, 6536 m a.s.l.), the Zhadang Glacier on Mt. Nyainqentanglha (NQ) (30.47°N, 90.65°E, 5800m a.s.l.), and the Guoqu Glacier on Mt. Geladaindong (GL) (33.95°N, 91.28°E, 5823m a.s.l.) over the Tibetan Plateau (TP). Variations of microparticle and major ions (e.g. Mg2+, Ca2+) concentrations in snowpits show that the values of the microparticles and ions in the non-monsoon seasons are much higher than those in the monsoon seasons. Annual flux of microparticle deposition at ER is lower than those at NQ and GL, which could be attributed to the long distance away from the possible dust source regions as well as the elevation for ER higher than the others. Compared with other remote areas, microparticle concentrations in the southern TP are much lower than those in the northern TP, but still much higher than those in Greenland and Antarctica. The seasonal and spatial microparticle variations are clearly related to the variations of atmospheric circulation according to the air mass 5-day backward trajectory analyses of HYSPLIT Model. Resultingly, the high microparticle values in snow are mainly attributed to the westerlies and the strong dust storm outbreaks on the TP, while the monsoon circulation brings great amount of precipitation from the Indian Ocean, thus reducing in the aerosol concentrations.展开更多
Snow water equivalent(SWE)is an important factor reflecting the variability of snow.It is important to estimate SWE based on remote sensing data while taking spatial autocorrelation into account.Based on the segmentat...Snow water equivalent(SWE)is an important factor reflecting the variability of snow.It is important to estimate SWE based on remote sensing data while taking spatial autocorrelation into account.Based on the segmentation method,the relationship between SWE and environmental factors in the central part of the Tibetan Plateau was explored using the eigenvector spatial filtering(ESF)regression model,and the influence of different factors on the SWE was explored.Three sizes of 16×16,24×24 and 32×32 were selected to segment raster datasets into blocks.The eigenvectors of the spatial adjacency matrix of the segmented size were selected to be added into the model as spatial factors,and the ESF regression model was constructed for each block in parallel.Results show that precipitation has a great influence on SWE,while surface temperature and NDVI have little influence.Air temperature,elevation and surface temperature have completely different effects in different areas.Compared with the ordinary least square(OLS)linear regression model,geographically weighted regression(GWR)model,spatial lag model(SLM)and spatial error model(SEM),ESF model can eliminate spatial autocorrelation with the highest accuracy.As the segmentation size increases,the complexity of ESF model increases,but the accuracy is improved.展开更多
The effect of the thermal anomaly of the underlying surface of the Tibetan Plateau in the previous win-ter and spring on the precipitation over the middle and lower reaches of the Yangtze River (MRYR) in the subsequen...The effect of the thermal anomaly of the underlying surface of the Tibetan Plateau in the previous win-ter and spring on the precipitation over the middle and lower reaches of the Yangtze River (MRYR) in the subsequent summer was investigated. Through data analysis, the influence of 'strong signal' features of the three-dimensional thermal anomaly of the Plateau upon the precipitation anomaly over MRYR in the sub-sequent summer was revealed. This feature of the signal shows that from 0 cm to 320 cm under the surface of the ground, the soil temperature anomalies of the Tibetan Plateau manifest out of phase distribution in flood years and drought years over MRYR. In flood years over MRYR, there is a positive soil temperature anomaly in the region of the southern Tibetan Plateau (to the south of 30癗) and a negative anomaly in the region of the middle and northern Tibetan Plateau (to the north of 30癗), while in drought years the distri-bution of the soil temperature anomaly is opposite to the one in flood years. The maximum value of the soil temperature anomaly lies in the levels between 40 cm and 160 cm under the surface of the ground. Mean-while, the data analysis also shows that the general circulation in the Northern Hemisphere may respond to the thermal anomaly of the Tibetan Plateau and form the propagation of a low frequency wave train with a seasonal time scale, and this wave train may affect the precipitation over MRYR in the subsequent summer. Analyses reveal that the thermal anomaly of the underlying surface of the Tibetan Plateau in the previous winter and spring is one of the key influencing factors for the subsequent summer precipitation over MRYR.展开更多
Community participation is one of the focuses of the research on ecotourism. The research on community participative model is of great theoretical and practical significance. Based on the former experts’ studies, thi...Community participation is one of the focuses of the research on ecotourism. The research on community participative model is of great theoretical and practical significance. Based on the former experts’ studies, this paper analyzes ecotourism demonstration areas in Diqing Shangri-La of Yunnan as a case study. It mainly expounds the relationship between ecotourism and community participation and puts forward such a community participative model of ecotourism in Shangri-La.展开更多
Since the Cenozoic,the Tibetan Plateau has experienced large-scale uplift and outgrowth due to the India-Asia collision.However,the mechanism and timing of these tectonic processes still remain debated.Here,using apat...Since the Cenozoic,the Tibetan Plateau has experienced large-scale uplift and outgrowth due to the India-Asia collision.However,the mechanism and timing of these tectonic processes still remain debated.Here,using apatite fission track dating and inverse thermal modeling,we explore the mechanism of different phases of rapid cooling for different batholiths and intrusions in the southeastern Tibetan Plateau.In contrast to previous views,we find that the coeval granitic batholith exposed in the same tectonic zone experienced differential fast uplift in different sites,indicating that the present Tibetan Plateau was the result of differential uplift rather than the entire lithosphere uplift related to lithospheric collapse during Cenozoic times.In addition,we also suggest that the 5-2 Ma mantle-related magmatism should be regarded as the critical trigger for the widely coeval cooling event in the southeastern Tibetan Plateau,because it led to the increase in atmospheric CO_(2)level and a hotter upper crust than before,which are efficient for suddenly fast rock weathering and erosion.Finally,we propose that the current landform of the southeastern Tibetan Plateau was the combined influences of tectonic and climate.展开更多
The Tibetan Plateau(TP)region,also known as the“Asian water tower”,provides a vital water resource for downstream regions.Previous studies of water cycle changes over the TP have been conducted with climate models o...The Tibetan Plateau(TP)region,also known as the“Asian water tower”,provides a vital water resource for downstream regions.Previous studies of water cycle changes over the TP have been conducted with climate models of coarse resolution in which deep convection must be parameterized.In this study,we present results from a first set of highresolution climate change simulations that permit convection at approximately 3.3-km grid spacing,with a focus on the TP,using the Icosahedral Nonhydrostatic Weather and Climate Model(ICON).Two 12-year simulations were performed,consisting of a retrospective simulation(2008–20)with initial and boundary conditions from ERA5 reanalysis and a pseudoglobal warming projection driven by modified reanalysis-derived initial and boundary conditions by adding the monthly CMIP6 ensemble-mean climate change under the SSP5-8.5 scenario.The retrospective simulation shows overall good performance in capturing the seasonal precipitation and surface air temperature.Over the central and eastern TP,the average biases in precipitation(temperature)are less than−0.34 mm d−1(−1.1℃)throughout the year.The simulated biases over the TP are height-dependent.Cold(wet)biases are found in summer(winter)above 5500 m.The future climate simulation suggests that the TP will be wetter and warmer under the SSP5-8.5 scenario.The general features of projected changes in ICON are comparable to the CMIP6 ensemble projection,but the added value from kilometer-scale modeling is evident in both precipitation and temperature projections over complex topographic regions.These ICON-downscaled climate change simulations provide a high-resolution dataset to the community for the study of regional climate changes and impacts over the TP.展开更多
As some of the greatest natural disasters in the cryosphere,ice avalanches(IAs)seriously threaten lives and cause catastrophic damage to the resource environment,but a comprehensive overview of the state of knowledge ...As some of the greatest natural disasters in the cryosphere,ice avalanches(IAs)seriously threaten lives and cause catastrophic damage to the resource environment,but a comprehensive overview of the state of knowledge on IAs remains lacking.We summarized 63 IAs on the Tibetan Plateau(TP)since the 20th century,of which,over 20 IAs occurred after the 21st century.The distributions of IAs are mainly concentrated in the southeastern and northwestern TP,and the occurrence time of IAs is mostly concentrated from July to September.We highlight recent advances in mechanical properties and genetic mechanisms of IAs and emphasize that temperature,rainfall,and seismicity are the inducing factors.The failure modes of IAs are summarized into 6 categories by examples:slip pulling type,slip toppling type,slip breaking type,water level collapse type,cave roof collapse type,and wedge failure type.Finally,we deliver recommendations concerning the risk assessment and prediction of IAs.The results provide important scientific value for addressing climate change and resisting glacier-related hazards.展开更多
The spring atmospheric heat source(AHS)over the Tibetan Plateau(TP)has been suggested to affect the Asian summer monsoon and summer precipitation over South China.However,its influence on the summer precipitation in N...The spring atmospheric heat source(AHS)over the Tibetan Plateau(TP)has been suggested to affect the Asian summer monsoon and summer precipitation over South China.However,its influence on the summer precipitation in Northeast China(NEC)remains unknown.The connection between spring TP AHS and subsequent summer precipitation over NEC from 1961 to 2020 is analyzed in this study.Results illustrate that stronger spring TP AHS can enhance subsequent summer NEC precipitation,and higher soil moisture in the Yellow River Valley-North China region(YRVNC)acts as a bridge.During spring,the strong TP AHS could strengthen the transportation of water vapor to East China and lead to excessive rainfall in the YRVNC.Thus,soil moisture increases,which regulates local thermal conditions by decreasing local surface skin temperature and sensible heat.Owing to the memory of soil moisture,the lower spring sensible heat over the YRVNC can last until mid-summer,decrease the land–sea thermal contrast,and weaken the southerly winds over the East Asia–western Pacific region and convective activities over the South China Sea and tropical western Pacific.This modulates the East Asia–Pacific teleconnection pattern,which leads to a cyclonic anomaly and excessive summer precipitation over NEC.展开更多
The active layer,acting as an intermediary of water and heat exchange between permafrost and atmosphere,greatly influences biogeochemical cycles in permafrost areas and is notably sensitive to climate fluctuations.Uti...The active layer,acting as an intermediary of water and heat exchange between permafrost and atmosphere,greatly influences biogeochemical cycles in permafrost areas and is notably sensitive to climate fluctuations.Utilizing the Chinese Meteorological Forcing Dataset to drive the Community Land Model,version 5.0,this study simulates the spatial and temporal characteristics of active layer thickness(ALT)on the Tibetan Plateau(TP)from 1980 to 2020.Results show that the ALT,primarily observed in the central and western parts of the TP where there are insufficient station observations,exhibits significant interdecadal changes after 2000.The average thickness on the TP decreases from 2.54 m during 1980–1999 to 2.28 m during 2000–2020.This change is mainly observed in the western permafrost region,displaying a sharp regional inconsistency compared to the eastern region.A persistent increasing trend of ALT is found in the eastern permafrost region,rather than an interdecadal change.The aforementioned changes in ALT are closely tied to the variations in the surrounding atmospheric environment,particularly air temperature.Additionally,the area of the active layer on the TP displays a profound interdecadal change around 2000,arising from the permafrost thawing and forming.It consistently decreases before 2000 but barely changes after 2000.The regional variation in the permafrost active layer over the TP revealed in this study indicates a complex response of the contemporary climate under global warming.展开更多
The transform fault is essentially a displacement fault whose terminal part is adjusted by other tectonic types, its displacement component is absorbed by other structures intersected with it by high angles or meet at...The transform fault is essentially a displacement fault whose terminal part is adjusted by other tectonic types, its displacement component is absorbed by other structures intersected with it by high angles or meet at right angles. The main elements of transform fault are the sleep\|dipping displacement faults and the adjusted structures intersected with it at high angles. According to the combination of tectonic features formed by its two ends of displacement fault and the structures intersected with it, the transform fault can be divided into three types, including the adjusted transform fault of extensional normal fault, the adjusted transform fault of compressive fold and thrust fault, and the compound transform fault. The transform fault is different from the displacement fault, its horizontal displacement may be increased or decreased or not be changed at all as the time of fault movement extended, but for parallel displacement the dislocation will be increased. Therefore, the study of transform fault is very important for the recognition of long time disputed displacement components of huge displacement fault. The traditional Altyn fault is the adjusting fault of the compression deformation of the Western Kunlun and Northern Qilian mountains of the northern margin of the Tibetan Plateau since Cenozoic.展开更多
The Tibetan Plateau(TP)is a prevalent region for convection systems due to its unique thermodynamic forcing.This study investigated isolated deep convections(IDCs),which have a smaller spatial and temporal size than m...The Tibetan Plateau(TP)is a prevalent region for convection systems due to its unique thermodynamic forcing.This study investigated isolated deep convections(IDCs),which have a smaller spatial and temporal size than mesoscale convective systems(MCSs),over the TP in the rainy season(June-September)during 2001–2020.The authors used satellite precipitation and brightness temperature observations from the Global Precipitation Measurement mission.Results show that IDCs mainly concentrate over the southern TP.The IDC number per rainy season decreases from around 140 over the southern TP to around 10 over the northern TP,with an average 54.2.The initiation time of IDCs exhibits an obvious diurnal cycle,with the peak at 1400–1500 LST and the valley at 0900–1000 LST.Most IDCs last less than five hours and more than half appear for only one hour.IDCs generally have a cold cloud area of 7422.9 km^(2),containing a precipitation area of approximately 65%.The larger the IDC,the larger the fraction of intense precipitation it contains.IDCs contribute approximately 20%–30%to total precipitation and approximately 30%–40%to extreme precipitation over the TP,with a larger percentage in July and August than in June and September.In terms of spatial distribution,IDCs contribute more to both total precipitation and extreme precipitation over the TP compared to the surrounding plain regions.IDCs over the TP account for a larger fraction than MCSs,indicating the important role of IDCs over the region.展开更多
Extreme snowfall events over the Tibetan Plateau(TP)cause considerable damage to local society and natural ecosystems.In this study,the authors investigate the projected changes in such events over the TP and its surr...Extreme snowfall events over the Tibetan Plateau(TP)cause considerable damage to local society and natural ecosystems.In this study,the authors investigate the projected changes in such events over the TP and its surrounding areas based on an ensemble of a set of 21st century climate change projections using a regional climate model,RegCM4.The model is driven by five CMIP5 global climate models at a grid spacing of 25 km,under the RCP4.5 and RCP8.5 pathways.Four modified ETCCDI extreme indices-namely,SNOWTOT,S1mm,S10mm,and Sx5day-are employed to characterize the extreme snowfall events.RegCM4 generally reproduces the spatial distribution of the indices over the region,although with a tendency of overestimation.For the projected changes,a general decrease in SNOWTOT is found over most of the TP,with greater magnitude and better cross-simulation agreement over the eastern part.All the simulations project an overall decrease in S1mm,ranging from a 25%decrease in the west and to a 50%decrease in the east of the TP.Both S10mm and Sx5day are projected to decrease over the eastern part and increase over the central and western parts of the TP.Notably,S10mm shows a marked increase(more than double)with high cross-simulation agreement over the central TP.Significant increases in all four indices are found over the Tarim and Qaidam basins,and northwestern China north of the TP.The projected changes show topographic dependence over the TP in the latitudinal direction,and tend to decrease/increase in low-/high-altitude areas.展开更多
Precipitation projections over the Tibetan Plateau(TP)show diversity among existing studies,partly due to model uncertainty.How to develop a reliable projection remains inconclusive.Here,based on the IPCC AR6–assesse...Precipitation projections over the Tibetan Plateau(TP)show diversity among existing studies,partly due to model uncertainty.How to develop a reliable projection remains inconclusive.Here,based on the IPCC AR6–assessed likely range of equilibrium climate sensitivity(ECS)and the climatological precipitation performance,the authors constrain the CMIP6(phase 6 of the Coupled Model Intercomparison Project)model projection of summer precipitation and water availability over the TP.The best estimates of precipitation changes are 0.24,0.25,and 0.45 mm d^(−1)(5.9%,6.1%,and 11.2%)under the Shared Socioeconomic Pathway(SSP)scenarios of SSP1–2.6,SSP2–4.5,and SSP5–8.5 from 2050–2099 relative to 1965–2014,respectively.The corresponding constrained projections of water availability measured by precipitation minus evaporation(P–E)are 0.10,0.09,and 0.22 mm d^(−1)(5.7%,4.9%,and 13.2%),respectively.The increase of precipitation and P–E projected by the high-ECS models,whose ECS values are higher than the upper limit of the likely range,are about 1.7 times larger than those estimated by constrained projections.Spatially,there is a larger increase in precipitation and P–E over the eastern TP,while the western part shows a relatively weak difference in precipitation and a drier trend in P–E.The wetter TP projected by the high-ECS models resulted from both an approximately 1.2–1.4 times stronger hydrological sensitivity and additional warming of 0.6℃–1.2℃ under all three scenarios during 2050–2099.This study emphasizes that selecting climate models with climate sensitivity within the likely range is crucial to reducing the uncertainty in the projection of TP precipitation and water availability changes.展开更多
Mt. Yulong, located in the eastern part of Tibetan Plateau, is the southmost present glaciation area both in China and Europe\|Asia continent,where distributes 19 typical sub\|tropics temperate glaciers. In the summer...Mt. Yulong, located in the eastern part of Tibetan Plateau, is the southmost present glaciation area both in China and Europe\|Asia continent,where distributes 19 typical sub\|tropics temperate glaciers. In the summer of 1999, a firn core, 10 10m long to the glacier ice, was successfully recovered in the accumulation area at the largest glacier (No.1 Baishui) on Mt. Yulong. Annual and seasonal variations of different climatic signals above the depth of 7 8m are apparent and five\|year snow accumulation can be clearly identified by the seasonal changes of isotopic and ionic composition, some higher values of electrical conductivity and pH values. These annual boundaries can be also verified by the positions of dirty refrozen ice layers at summer surface of each year. The mean annual net accumulation between the balance years of 94/95 and 97/98 are calculated to about 900mm water equivalent. The amplitude of isotopic changes becomes smaller with the increasing depth of the core and isotopic homogenization occurred below the depth of 7 8m. Concentrations of Ca 2+ and Mg 2+ are much higher than those of Na + and K +, reflecting that the air masses for precipitation came far from their marine sources and passed over a longer continental route. Cl - and Na + show well corresponding variation patterns in the firn profile,indicating their same genesis. Concentrations of SO 2- 4 and NO - 3 are low, reflecting very slight pollution caused by human activities in this area. According to the sum of net income recovered from the firn core and the estimated ablation amount, the average annual precipitation above the equilibrium line is estimated in the scope of 2250mm and 3200mm but it needed to be verified by long\|term observation of mass balance. As indicated by the trend of local climatic changes in last 50years, climatic signals in the firn core and recent observation at the terminal of glacier No.1 Baishui, the glaciers in Mt. Yulong start to advance in 1998 after continuous retreat from early 1980’s to late 1990’s.展开更多
On December 18,2023,an M_(s)6.2 earthquake occurred in Jishishan,Gansu Province,China.This earthquake happened in the eastern region of the Qilian Orogenic Belt,which is situated at the forefront of the NE margin of t...On December 18,2023,an M_(s)6.2 earthquake occurred in Jishishan,Gansu Province,China.This earthquake happened in the eastern region of the Qilian Orogenic Belt,which is situated at the forefront of the NE margin of the Tibetan Plateau(i.e.,Qinghai-Tibet Plateau),encompassing a rhombic-shaped area that intersects the Qilian-Qaidam Basin,Alxa Block,Ordos Block,and South China Block.In this study,we analyzed the deep tectonic pattern of the Jishishan earthquake by incorporating data on the crustal thickness,velocity structure,global navigation satellite system(GNSS)strain field,and anisotropy.We discovered that the location of the earthquake was related to changes in the crustal structure.The results showed that the Jishishan M_(s)6.2 earthquake occurred in a unique position,with rapid changes in the crustal thickness,Vp/Vs,phase velocity,and S-wave velocity.The epicenter of the earthquake was situated at the transition zone between high and low velocities and was in proximity to a low-velocity region.Additionally,the source area is flanked by two high-velocity anomalies from the east and west.The principal compressive strain orientation near the Lajishan Fault is primarily in the NNE and NE directions,which align with the principal compressive stress direction in this region.In some areas of the Lajishan Fault,the principal compressive strain orientations show the NNW direction,consistent with the direction of the upper crustal fast-wave polarization from local earthquakes and the phase velocity azimuthal anisotropy.These features underscore the relationship between the occurrence of the Jishishan M_(s)6.2 earthquake and the deep inhomogeneous structure and deep tectonic characteristics.The NE margin of the Tibetan Plateau was thickened by crustal extension in the process of northeastward expansion,and the middle and lower crustal materials underwent structural deformation and may have been filled with salt-containing fluids during the extension process.The presence of this weak layer makes it easier for strong earthquakes to occur through the release of overlying rigid crustal stresses.However,it is unlikely that an earthquake of comparable or larger magnitude would occur in the short term(e.g.,in one year)at the Jishishan east margin fault.展开更多
Over the past 71 years since Tibet’s peaceful liberation,consultative democracy has been gradually integrated into every aspect of Tibetan people’s lives.UNDER China’s socialist system,the essence of the people’s ...Over the past 71 years since Tibet’s peaceful liberation,consultative democracy has been gradually integrated into every aspect of Tibetan people’s lives.UNDER China’s socialist system,the essence of the people’s democracy is that the people get to discuss their own affairs so as to reach the greatest common ground based on the wishes and needs of the whole of society.Soon after the founding of the People’s Republic of China in 1949,under the leadership of the Communist Party of China(CPC),Tibet was successfully and peacefully liberated in 1951.展开更多
The time-honoured and distinctive Tibetan culture is an important part of the Chinese civilisation.Tibet is home to nearly 800 intangible cultural heritages,1,177 intangible cultural heritage inheritors,and more than ...The time-honoured and distinctive Tibetan culture is an important part of the Chinese civilisation.Tibet is home to nearly 800 intangible cultural heritages,1,177 intangible cultural heritage inheritors,and more than 80 performing organisations of traditional dramas.There are 4,277 registered cultural relic sites of various kinds in Tibet,including 1,985 protected ones.An ocean of literature written in Tibetan language has been passed on from ancient times.展开更多
基金supported by the National Natural Science Foundation of China(32272316)Beijing Innovation Team of Livestock Industry Technology System(BAIC05-2022)Guangxi Science and Technology Project(AD20297088).
文摘Nutrients in human milk,including minerals,relate growth and development of breast-fed infants.Tibetan mother-infant dyads possess unique characteristics on early nutrition due to their featured long-lasting lifestyle.This study longitudinally investigated the relationship between the mineral composition in human milk and the Z-scores of infants among Tibetan mother-infant dyads during their first 6 months postpartum through a prospective cohort study.The results show that the minerals of Na,Mg,K,Ca,Cu,Zn,and Se were of higher levels in colostrum than other lactation stages.Several minerals were below the recommended values for infants according to Chinese dietary guidelines.Besides,a large proportion of infant Z-scores were below-2 as lactation period continued.Multivariate statistical analysis revealed that classifications and correlations in varying degrees were observed between minerals in human milk and infant Z-scores.These findings will be advantageous for research upon Chinese early nutrition and progress of tailor-made infant formula.
基金supported by the following projects:National Basic Research Program of China (2009CB421004,2009CB421003)Natural Science Foundation of China(41073033,40872055,and 40930316)+1 种基金Chinese Academy of Sciences(KZCX2-YW-Q04)China Geological Survey(1212010818098)
文摘The Nadingcuo high-K calc-alkaline rocks mainly composed of trachyte and trachyandesite are the largest outcrop area of volcanic rocks in southern Qiangtang terrane in the Tibetan plateau. However,their exact source and peterogenesis are still debated.^(40)Ar-^(39)Ar and LAM-ICPMS zircon U-Pb isotopic dating confirm that these rocks erupted in Eocene.In addition,the Nadingcuo volcanic rocks are characterized by high Sr/Y content ratios,similar with the adakite derived from partial melting of oceanic crust.They can be further classified as high Mg~#(Mg~#=48-57) and low Mg~# (Mg~#=33-42) subtypes.The Nadingcuo adakitic rocks have relatively low(^(87)Sr/^(86)Sr)_i and highε_(Nd)(t), showing a trend of similarity to the Dongcuo ophiolite present in the Bangong-Nujiang oceanic crust. Simple modeling indicates that the Nadingcuo adakitic rocks are a mix resulting from the basalt of Bangong-Nujiang Ocean with 10%-20%crustal material of Lhasa terrane.On these bases we suggest that the low Mg~# Nadingcuo adakitic rocks are the product of partial melting of remnant oceanic crust with small sediment,and the high Mg~# rocks are the result of reaction between rising melt of remnant oceanic crust with subducted sediment and mantle wedge.Therefore,the origin of Nadingcuo adakitic rocks may be related to intracontinental subduction triggered by collision of India-Asia during Cenozoic.
基金supported by the Key Basic Research and Development Program of China(G19980407000)the National Natural Science Foundation of China(40072062)+1 种基金the Foundation of the Open Laboratory of Tectonophysics,China Seismological Bureauthe Post-Doctoral Grant of Ministry of Education,China.
文摘In order to constrain the crustal wave velocity structure in the southernTibetan crust and provide insight into the contribution of crustal composition, geothermal gradientand partial melting to the velocity structure, which is characterized by low average crustalvelocities and widespread presence of low-velocity zone(s), the authors model the crustal velocityand density as functions of depth corresponding to various heat flow values in light of velocitymeasurements at high temperature and high pressure. The modeled velocity and density are regarded ascomparison standards. The comparison of the standards with seismic observations in southern Tibetimplies that the predominantly felsic composition at high heat flow cannot explain the observedvelocity structure there. Hence, the authors are in favor of attributing low average crustalvelocities and low-velocity zone(s) observed in southern Tibet mainly to partial melting. Modelingbased on the experimental results suggests that a melting percentage of 7-12 could account for thelow-velocity zone(s).
基金supported by the National Natural Science Foundation of China (40830743,40771187)the National Basic Research Program of China (2005CB422004)the State Key Laboratory of Gryospheric Sciences (SKLCS- ZZ-2008-01)
文摘The work presents microparticle concentrations in snowpits from the East Rongbuk Glacier on Mt. Qomolangma (Everest) (ER) (28.02°N, 86.96°E, 6536 m a.s.l.), the Zhadang Glacier on Mt. Nyainqentanglha (NQ) (30.47°N, 90.65°E, 5800m a.s.l.), and the Guoqu Glacier on Mt. Geladaindong (GL) (33.95°N, 91.28°E, 5823m a.s.l.) over the Tibetan Plateau (TP). Variations of microparticle and major ions (e.g. Mg2+, Ca2+) concentrations in snowpits show that the values of the microparticles and ions in the non-monsoon seasons are much higher than those in the monsoon seasons. Annual flux of microparticle deposition at ER is lower than those at NQ and GL, which could be attributed to the long distance away from the possible dust source regions as well as the elevation for ER higher than the others. Compared with other remote areas, microparticle concentrations in the southern TP are much lower than those in the northern TP, but still much higher than those in Greenland and Antarctica. The seasonal and spatial microparticle variations are clearly related to the variations of atmospheric circulation according to the air mass 5-day backward trajectory analyses of HYSPLIT Model. Resultingly, the high microparticle values in snow are mainly attributed to the westerlies and the strong dust storm outbreaks on the TP, while the monsoon circulation brings great amount of precipitation from the Indian Ocean, thus reducing in the aerosol concentrations.
基金funded by the National Key S&T Special Projects of China(grant number:2018YFB0505302)the National Nature Science Foundation of China(grant number:41671380)。
文摘Snow water equivalent(SWE)is an important factor reflecting the variability of snow.It is important to estimate SWE based on remote sensing data while taking spatial autocorrelation into account.Based on the segmentation method,the relationship between SWE and environmental factors in the central part of the Tibetan Plateau was explored using the eigenvector spatial filtering(ESF)regression model,and the influence of different factors on the SWE was explored.Three sizes of 16×16,24×24 and 32×32 were selected to segment raster datasets into blocks.The eigenvectors of the spatial adjacency matrix of the segmented size were selected to be added into the model as spatial factors,and the ESF regression model was constructed for each block in parallel.Results show that precipitation has a great influence on SWE,while surface temperature and NDVI have little influence.Air temperature,elevation and surface temperature have completely different effects in different areas.Compared with the ordinary least square(OLS)linear regression model,geographically weighted regression(GWR)model,spatial lag model(SLM)and spatial error model(SEM),ESF model can eliminate spatial autocorrelation with the highest accuracy.As the segmentation size increases,the complexity of ESF model increases,but the accuracy is improved.
基金Acknowledgments, This work was supported by the National Natural Science Foundation of China under Grant No. 40175017, and the Innovation Project of the Chinese Academy of Sciences under Grant No, KZCX2-208.
文摘The effect of the thermal anomaly of the underlying surface of the Tibetan Plateau in the previous win-ter and spring on the precipitation over the middle and lower reaches of the Yangtze River (MRYR) in the subsequent summer was investigated. Through data analysis, the influence of 'strong signal' features of the three-dimensional thermal anomaly of the Plateau upon the precipitation anomaly over MRYR in the sub-sequent summer was revealed. This feature of the signal shows that from 0 cm to 320 cm under the surface of the ground, the soil temperature anomalies of the Tibetan Plateau manifest out of phase distribution in flood years and drought years over MRYR. In flood years over MRYR, there is a positive soil temperature anomaly in the region of the southern Tibetan Plateau (to the south of 30癗) and a negative anomaly in the region of the middle and northern Tibetan Plateau (to the north of 30癗), while in drought years the distri-bution of the soil temperature anomaly is opposite to the one in flood years. The maximum value of the soil temperature anomaly lies in the levels between 40 cm and 160 cm under the surface of the ground. Mean-while, the data analysis also shows that the general circulation in the Northern Hemisphere may respond to the thermal anomaly of the Tibetan Plateau and form the propagation of a low frequency wave train with a seasonal time scale, and this wave train may affect the precipitation over MRYR in the subsequent summer. Analyses reveal that the thermal anomaly of the underlying surface of the Tibetan Plateau in the previous winter and spring is one of the key influencing factors for the subsequent summer precipitation over MRYR.
文摘Community participation is one of the focuses of the research on ecotourism. The research on community participative model is of great theoretical and practical significance. Based on the former experts’ studies, this paper analyzes ecotourism demonstration areas in Diqing Shangri-La of Yunnan as a case study. It mainly expounds the relationship between ecotourism and community participation and puts forward such a community participative model of ecotourism in Shangri-La.
基金supported by National Natural Science Foundation of China(Grant Nos.42025301,41730213 and 41890831)the Second Tibetan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK0702)+2 种基金Hong Kong RGC GRF(Grant No.17307918)HKU Internal Grants for Member of Chinese Academy of Sciences(Grant No.102009906)for Distinguished Research Achievement Award(Grant No.102010100)。
文摘Since the Cenozoic,the Tibetan Plateau has experienced large-scale uplift and outgrowth due to the India-Asia collision.However,the mechanism and timing of these tectonic processes still remain debated.Here,using apatite fission track dating and inverse thermal modeling,we explore the mechanism of different phases of rapid cooling for different batholiths and intrusions in the southeastern Tibetan Plateau.In contrast to previous views,we find that the coeval granitic batholith exposed in the same tectonic zone experienced differential fast uplift in different sites,indicating that the present Tibetan Plateau was the result of differential uplift rather than the entire lithosphere uplift related to lithospheric collapse during Cenozoic times.In addition,we also suggest that the 5-2 Ma mantle-related magmatism should be regarded as the critical trigger for the widely coeval cooling event in the southeastern Tibetan Plateau,because it led to the increase in atmospheric CO_(2)level and a hotter upper crust than before,which are efficient for suddenly fast rock weathering and erosion.Finally,we propose that the current landform of the southeastern Tibetan Plateau was the combined influences of tectonic and climate.
基金jointly supported by the National Key Research and Development Program of China (Grant No. 2022YFF0802004)the National Natural Science Foundation of China (Grant Nos. 41988101 and 42275182)+2 种基金the K.C. Wang Education Foundation (Grant No. GJTD-2019-05)the Jiangsu Collaborative Innovation Center for Climate Changethe National Key Scientific and Technological Infrastructure project “Earth System Science Numerical Simulator Facility” (Earth Lab)
文摘The Tibetan Plateau(TP)region,also known as the“Asian water tower”,provides a vital water resource for downstream regions.Previous studies of water cycle changes over the TP have been conducted with climate models of coarse resolution in which deep convection must be parameterized.In this study,we present results from a first set of highresolution climate change simulations that permit convection at approximately 3.3-km grid spacing,with a focus on the TP,using the Icosahedral Nonhydrostatic Weather and Climate Model(ICON).Two 12-year simulations were performed,consisting of a retrospective simulation(2008–20)with initial and boundary conditions from ERA5 reanalysis and a pseudoglobal warming projection driven by modified reanalysis-derived initial and boundary conditions by adding the monthly CMIP6 ensemble-mean climate change under the SSP5-8.5 scenario.The retrospective simulation shows overall good performance in capturing the seasonal precipitation and surface air temperature.Over the central and eastern TP,the average biases in precipitation(temperature)are less than−0.34 mm d−1(−1.1℃)throughout the year.The simulated biases over the TP are height-dependent.Cold(wet)biases are found in summer(winter)above 5500 m.The future climate simulation suggests that the TP will be wetter and warmer under the SSP5-8.5 scenario.The general features of projected changes in ICON are comparable to the CMIP6 ensemble projection,but the added value from kilometer-scale modeling is evident in both precipitation and temperature projections over complex topographic regions.These ICON-downscaled climate change simulations provide a high-resolution dataset to the community for the study of regional climate changes and impacts over the TP.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK0201)the National Natural Science Foundation of China(Grant No.42377199,No.41941019)+1 种基金State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Independent Research Project(Grant No.SKLGP2021Z005)Chengdu University of Technology Postgraduate Innovative Cultivation Program(Grant No.CDUT2023BJCX008).
文摘As some of the greatest natural disasters in the cryosphere,ice avalanches(IAs)seriously threaten lives and cause catastrophic damage to the resource environment,but a comprehensive overview of the state of knowledge on IAs remains lacking.We summarized 63 IAs on the Tibetan Plateau(TP)since the 20th century,of which,over 20 IAs occurred after the 21st century.The distributions of IAs are mainly concentrated in the southeastern and northwestern TP,and the occurrence time of IAs is mostly concentrated from July to September.We highlight recent advances in mechanical properties and genetic mechanisms of IAs and emphasize that temperature,rainfall,and seismicity are the inducing factors.The failure modes of IAs are summarized into 6 categories by examples:slip pulling type,slip toppling type,slip breaking type,water level collapse type,cave roof collapse type,and wedge failure type.Finally,we deliver recommendations concerning the risk assessment and prediction of IAs.The results provide important scientific value for addressing climate change and resisting glacier-related hazards.
基金supported by the Open Research Fund of TPESER(Grant No.TPESER202205)the Second Tibetan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK0101)。
文摘The spring atmospheric heat source(AHS)over the Tibetan Plateau(TP)has been suggested to affect the Asian summer monsoon and summer precipitation over South China.However,its influence on the summer precipitation in Northeast China(NEC)remains unknown.The connection between spring TP AHS and subsequent summer precipitation over NEC from 1961 to 2020 is analyzed in this study.Results illustrate that stronger spring TP AHS can enhance subsequent summer NEC precipitation,and higher soil moisture in the Yellow River Valley-North China region(YRVNC)acts as a bridge.During spring,the strong TP AHS could strengthen the transportation of water vapor to East China and lead to excessive rainfall in the YRVNC.Thus,soil moisture increases,which regulates local thermal conditions by decreasing local surface skin temperature and sensible heat.Owing to the memory of soil moisture,the lower spring sensible heat over the YRVNC can last until mid-summer,decrease the land–sea thermal contrast,and weaken the southerly winds over the East Asia–western Pacific region and convective activities over the South China Sea and tropical western Pacific.This modulates the East Asia–Pacific teleconnection pattern,which leads to a cyclonic anomaly and excessive summer precipitation over NEC.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program[grant number 2019QZKK0102]the Youth Innovation Promotion Association CAS[grant number 2021073]the special fund of the Yunnan University“double firstclass”construction.
文摘The active layer,acting as an intermediary of water and heat exchange between permafrost and atmosphere,greatly influences biogeochemical cycles in permafrost areas and is notably sensitive to climate fluctuations.Utilizing the Chinese Meteorological Forcing Dataset to drive the Community Land Model,version 5.0,this study simulates the spatial and temporal characteristics of active layer thickness(ALT)on the Tibetan Plateau(TP)from 1980 to 2020.Results show that the ALT,primarily observed in the central and western parts of the TP where there are insufficient station observations,exhibits significant interdecadal changes after 2000.The average thickness on the TP decreases from 2.54 m during 1980–1999 to 2.28 m during 2000–2020.This change is mainly observed in the western permafrost region,displaying a sharp regional inconsistency compared to the eastern region.A persistent increasing trend of ALT is found in the eastern permafrost region,rather than an interdecadal change.The aforementioned changes in ALT are closely tied to the variations in the surrounding atmospheric environment,particularly air temperature.Additionally,the area of the active layer on the TP displays a profound interdecadal change around 2000,arising from the permafrost thawing and forming.It consistently decreases before 2000 but barely changes after 2000.The regional variation in the permafrost active layer over the TP revealed in this study indicates a complex response of the contemporary climate under global warming.
基金theNationalNaturalScienceFoundationofChina (No .4 980 2 0 19)
文摘The transform fault is essentially a displacement fault whose terminal part is adjusted by other tectonic types, its displacement component is absorbed by other structures intersected with it by high angles or meet at right angles. The main elements of transform fault are the sleep\|dipping displacement faults and the adjusted structures intersected with it at high angles. According to the combination of tectonic features formed by its two ends of displacement fault and the structures intersected with it, the transform fault can be divided into three types, including the adjusted transform fault of extensional normal fault, the adjusted transform fault of compressive fold and thrust fault, and the compound transform fault. The transform fault is different from the displacement fault, its horizontal displacement may be increased or decreased or not be changed at all as the time of fault movement extended, but for parallel displacement the dislocation will be increased. Therefore, the study of transform fault is very important for the recognition of long time disputed displacement components of huge displacement fault. The traditional Altyn fault is the adjusting fault of the compression deformation of the Western Kunlun and Northern Qilian mountains of the northern margin of the Tibetan Plateau since Cenozoic.
基金supported by the National Natural Science Foundation of China[grant number 42105064]the Second Tibetan Plateau Scientific Expedition and Research(STEP)program[grant number 2019QZKK0102]the special fund of the Yunnan University“double first-class”construction.
文摘The Tibetan Plateau(TP)is a prevalent region for convection systems due to its unique thermodynamic forcing.This study investigated isolated deep convections(IDCs),which have a smaller spatial and temporal size than mesoscale convective systems(MCSs),over the TP in the rainy season(June-September)during 2001–2020.The authors used satellite precipitation and brightness temperature observations from the Global Precipitation Measurement mission.Results show that IDCs mainly concentrate over the southern TP.The IDC number per rainy season decreases from around 140 over the southern TP to around 10 over the northern TP,with an average 54.2.The initiation time of IDCs exhibits an obvious diurnal cycle,with the peak at 1400–1500 LST and the valley at 0900–1000 LST.Most IDCs last less than five hours and more than half appear for only one hour.IDCs generally have a cold cloud area of 7422.9 km^(2),containing a precipitation area of approximately 65%.The larger the IDC,the larger the fraction of intense precipitation it contains.IDCs contribute approximately 20%–30%to total precipitation and approximately 30%–40%to extreme precipitation over the TP,with a larger percentage in July and August than in June and September.In terms of spatial distribution,IDCs contribute more to both total precipitation and extreme precipitation over the TP compared to the surrounding plain regions.IDCs over the TP account for a larger fraction than MCSs,indicating the important role of IDCs over the region.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences[grant number XDA2006040102]the National Natural Science Foundation of China[grant number 42175037].
文摘Extreme snowfall events over the Tibetan Plateau(TP)cause considerable damage to local society and natural ecosystems.In this study,the authors investigate the projected changes in such events over the TP and its surrounding areas based on an ensemble of a set of 21st century climate change projections using a regional climate model,RegCM4.The model is driven by five CMIP5 global climate models at a grid spacing of 25 km,under the RCP4.5 and RCP8.5 pathways.Four modified ETCCDI extreme indices-namely,SNOWTOT,S1mm,S10mm,and Sx5day-are employed to characterize the extreme snowfall events.RegCM4 generally reproduces the spatial distribution of the indices over the region,although with a tendency of overestimation.For the projected changes,a general decrease in SNOWTOT is found over most of the TP,with greater magnitude and better cross-simulation agreement over the eastern part.All the simulations project an overall decrease in S1mm,ranging from a 25%decrease in the west and to a 50%decrease in the east of the TP.Both S10mm and Sx5day are projected to decrease over the eastern part and increase over the central and western parts of the TP.Notably,S10mm shows a marked increase(more than double)with high cross-simulation agreement over the central TP.Significant increases in all four indices are found over the Tarim and Qaidam basins,and northwestern China north of the TP.The projected changes show topographic dependence over the TP in the latitudinal direction,and tend to decrease/increase in low-/high-altitude areas.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program[grant number 2019QZKK0102]the Chinese Academy of Sciences[grant number 060GJHZ2023079GC].
文摘Precipitation projections over the Tibetan Plateau(TP)show diversity among existing studies,partly due to model uncertainty.How to develop a reliable projection remains inconclusive.Here,based on the IPCC AR6–assessed likely range of equilibrium climate sensitivity(ECS)and the climatological precipitation performance,the authors constrain the CMIP6(phase 6 of the Coupled Model Intercomparison Project)model projection of summer precipitation and water availability over the TP.The best estimates of precipitation changes are 0.24,0.25,and 0.45 mm d^(−1)(5.9%,6.1%,and 11.2%)under the Shared Socioeconomic Pathway(SSP)scenarios of SSP1–2.6,SSP2–4.5,and SSP5–8.5 from 2050–2099 relative to 1965–2014,respectively.The corresponding constrained projections of water availability measured by precipitation minus evaporation(P–E)are 0.10,0.09,and 0.22 mm d^(−1)(5.7%,4.9%,and 13.2%),respectively.The increase of precipitation and P–E projected by the high-ECS models,whose ECS values are higher than the upper limit of the likely range,are about 1.7 times larger than those estimated by constrained projections.Spatially,there is a larger increase in precipitation and P–E over the eastern TP,while the western part shows a relatively weak difference in precipitation and a drier trend in P–E.The wetter TP projected by the high-ECS models resulted from both an approximately 1.2–1.4 times stronger hydrological sensitivity and additional warming of 0.6℃–1.2℃ under all three scenarios during 2050–2099.This study emphasizes that selecting climate models with climate sensitivity within the likely range is crucial to reducing the uncertainty in the projection of TP precipitation and water availability changes.
文摘Mt. Yulong, located in the eastern part of Tibetan Plateau, is the southmost present glaciation area both in China and Europe\|Asia continent,where distributes 19 typical sub\|tropics temperate glaciers. In the summer of 1999, a firn core, 10 10m long to the glacier ice, was successfully recovered in the accumulation area at the largest glacier (No.1 Baishui) on Mt. Yulong. Annual and seasonal variations of different climatic signals above the depth of 7 8m are apparent and five\|year snow accumulation can be clearly identified by the seasonal changes of isotopic and ionic composition, some higher values of electrical conductivity and pH values. These annual boundaries can be also verified by the positions of dirty refrozen ice layers at summer surface of each year. The mean annual net accumulation between the balance years of 94/95 and 97/98 are calculated to about 900mm water equivalent. The amplitude of isotopic changes becomes smaller with the increasing depth of the core and isotopic homogenization occurred below the depth of 7 8m. Concentrations of Ca 2+ and Mg 2+ are much higher than those of Na + and K +, reflecting that the air masses for precipitation came far from their marine sources and passed over a longer continental route. Cl - and Na + show well corresponding variation patterns in the firn profile,indicating their same genesis. Concentrations of SO 2- 4 and NO - 3 are low, reflecting very slight pollution caused by human activities in this area. According to the sum of net income recovered from the firn core and the estimated ablation amount, the average annual precipitation above the equilibrium line is estimated in the scope of 2250mm and 3200mm but it needed to be verified by long\|term observation of mass balance. As indicated by the trend of local climatic changes in last 50years, climatic signals in the firn core and recent observation at the terminal of glacier No.1 Baishui, the glaciers in Mt. Yulong start to advance in 1998 after continuous retreat from early 1980’s to late 1990’s.
基金the National Natural Science Foundation of China(Project Nos.41804046 and 41974050)the Special Fund of the Key Laboratory of Earthquake Prediction,China Earthquake Administration(No.CEAIEF2022010100).
文摘On December 18,2023,an M_(s)6.2 earthquake occurred in Jishishan,Gansu Province,China.This earthquake happened in the eastern region of the Qilian Orogenic Belt,which is situated at the forefront of the NE margin of the Tibetan Plateau(i.e.,Qinghai-Tibet Plateau),encompassing a rhombic-shaped area that intersects the Qilian-Qaidam Basin,Alxa Block,Ordos Block,and South China Block.In this study,we analyzed the deep tectonic pattern of the Jishishan earthquake by incorporating data on the crustal thickness,velocity structure,global navigation satellite system(GNSS)strain field,and anisotropy.We discovered that the location of the earthquake was related to changes in the crustal structure.The results showed that the Jishishan M_(s)6.2 earthquake occurred in a unique position,with rapid changes in the crustal thickness,Vp/Vs,phase velocity,and S-wave velocity.The epicenter of the earthquake was situated at the transition zone between high and low velocities and was in proximity to a low-velocity region.Additionally,the source area is flanked by two high-velocity anomalies from the east and west.The principal compressive strain orientation near the Lajishan Fault is primarily in the NNE and NE directions,which align with the principal compressive stress direction in this region.In some areas of the Lajishan Fault,the principal compressive strain orientations show the NNW direction,consistent with the direction of the upper crustal fast-wave polarization from local earthquakes and the phase velocity azimuthal anisotropy.These features underscore the relationship between the occurrence of the Jishishan M_(s)6.2 earthquake and the deep inhomogeneous structure and deep tectonic characteristics.The NE margin of the Tibetan Plateau was thickened by crustal extension in the process of northeastward expansion,and the middle and lower crustal materials underwent structural deformation and may have been filled with salt-containing fluids during the extension process.The presence of this weak layer makes it easier for strong earthquakes to occur through the release of overlying rigid crustal stresses.However,it is unlikely that an earthquake of comparable or larger magnitude would occur in the short term(e.g.,in one year)at the Jishishan east margin fault.
文摘Over the past 71 years since Tibet’s peaceful liberation,consultative democracy has been gradually integrated into every aspect of Tibetan people’s lives.UNDER China’s socialist system,the essence of the people’s democracy is that the people get to discuss their own affairs so as to reach the greatest common ground based on the wishes and needs of the whole of society.Soon after the founding of the People’s Republic of China in 1949,under the leadership of the Communist Party of China(CPC),Tibet was successfully and peacefully liberated in 1951.
文摘The time-honoured and distinctive Tibetan culture is an important part of the Chinese civilisation.Tibet is home to nearly 800 intangible cultural heritages,1,177 intangible cultural heritage inheritors,and more than 80 performing organisations of traditional dramas.There are 4,277 registered cultural relic sites of various kinds in Tibet,including 1,985 protected ones.An ocean of literature written in Tibetan language has been passed on from ancient times.