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Characteristics of regional crustal deformation before 2016 Menyuan Ms6.4 earthquake

Geodesy and Geodynamics 2016年第4期7卷 275-283页

作者： Weitao Chen Weijun Gan Genru Xiao Yuebing Wang Weiping Lian Shiming liang Keliang Zhang National Earthquake Infrastructure Service China Earthquake AdministrationBeijing 100036China State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China Faculty of Geomatics East China University of TechnologyFuzhou 344000China

On January 21, 2016, a strong earthquake with a magnitude of Ms6.4 happened at Menyuan, Qinghai Province of China. In almost the same place, there was another strong earthquake happened in 1986, with similar magnitude and focal mechanism. In this paper, we analyze the characteristics of regional crustal deformation before the 2016 Menyuan Ms6.4 earth- quake by using the data from 10 continuous Global Positioning System （GPS） stations and 74 campaign-mode GPS stations within 200 km of this event：（a） Based on the velocity field from over ten years GPS observations, a regional strain rate field is calculated. The results indicate that the crustal strain rate and seismic moment accumulation rate of the qilian- Haiyuan active fault, which is the seismogenic tectonics of the event, are significantly higher than the surrounding regions. In a 20 km~ 20 km area around the seismogenic region, the maximum and minimum principal strain rates are 21.5 nanostrain/a （NW-SE extension） and -46.6 nanostrain/a （NE-SW compression）, respectively, and the seismic moment accumulation rates is 17.4 Nm/a. The direction of principal compression is consistent with the focal mechanism of this event. （b） Based on the position time series of the continuous GPS stations for a time-span of about 6 years before the event, we calculate the strain time series. The results show that the dilatation of the seismogenic region is continuously reduced with a ＂non-linear＂ trend since 2010, which means the seismogenic region has been in a state of compression. However, about 2-3 months before the event, both the dilatation and maximum shear strain show significant inverse trends. These abnormal changes of crustal deformation may reflect the non-linear adjustment of the stress-strain accumulation of the seismogenic region, when the accumulation is approaching the critical value of rupture.

关键词： 2016 Menyuan Ms6.4 earthquake GPS observation Crustal deformation Seismic moment accumulation rate Dilatation Maximum shear strain

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Gravity variations before the Menyuan Ms6.4 earthquake

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Geodesy and Geodynamics 2016年第4期7卷 223-229页

作者： Weifeng liang Guoqing Zhang Yiqing Zhu Yunma Xu Shusong Guo Yunfeng Zhao Fang Liu Lingqiang Zhao The Second Monitoring and Application Center China Earthquake AdministrationXi'an710054China

In order to study the relationship between gravity variation and Menyuan Ms6.4 earth- quake, gravity variation characteristics in mid-eastern of qilian Mountain were analyzed based on the 2012-2015 relative gravity datasets. The results indicated that the gravity changes in mid-eastern of qilian Mountain increased gradually, while gravity changes around Menyuan remarkably. Besides, great positive-negative gravity changing gradients appeared along the Lengiongling Fault which was located at the north of Menyuan, and the 2016 Menyuan Ms6.4 earthquake occurred near the junction of positive and negative gravity changes.

关键词： Mid-eastern of qilian Mountain Gravity changes Menyuan Ms6.4 earthquake Lenglongling Fault Hexi

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Spatiotemporal changes of land desertification sensitivity in northwest China from 2000 to 2017

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Journal of Geographical Sciences 2021年第1期31卷 46-68页

作者： WEI Wei GUO Zecheng SHI Peiji ZHOU liang WANG Xufeng LI Zhenya PANG Sufei XIE Binbin College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730070China College of Earth and Environmental Sciences Lanzhou UniversityLanzhou 730000China Faculty of Geomatics Lanzhou Jiaotong UniversityLanzhou 730070China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China Key Laboratory of Ecohydrology of Inland River Basin/Gansu qilian Mountains Ecological Research Center Northwest Institute of Eco-environment and ResourcesCASLanzhou 730000China School of Urban Economics and Tourism Culture Lanzhou City UniversityLanzhou 730070China

Sensitivity assessment is useful for monitoring land desertification. Research into how to prevent and control desertification is also important. In the arid region of northwest China, desertification is becoming worse and is a serious problem that affects local sustainable development. Based on remote-sensing and geographic information system technology, this study establishes a 'soil-terrain-hydrology-climate-vegetation' desertification sensitivity comprehensive evaluation system to reflect the spatiotemporal changes of land desertification, and proposes a spatial distance model to calculate a desertification sensitivity index. The spatiotemporal change characteristics of land desertification sensitivity in northwest China are quantitatively assessed from 2000 to 2017. Moreover, the main driving factors are analyzed using the geographical detector method. The results show the following.(1) Terrain, soil, climate, vegetation and hydrology affect and restrict each other, and constitute the background conditions of the distributions and changes of sensitivity to desertification in northwest China.(2) Desertification sensitivity generally displays a low distribution characteristic on the periphery of the area and a high one in the interior. The low-sensitivity regions are mainly in the five major mountain ranges(Altai Mountains, Tianshan Mountains, Kunlun Mountains, Altun Mountains and qilian Mountains), while the high-sensitivity regions are mainly in regions such as the Junggar Basin, the Tarim Basin and the Inner Mongolia Plateau, as well as the Taklimakan Desert, Badain Jaran Desert and Tengger Desert. The spatial distribution of desertification sensitivity is obviously regional, and the high-and low-sensitivity regions have clear boundaries and a concentrated distribution.(3) With regard to spatiotemporal evolution, changes in desertification sensitivity since 2000 have been predominantly stable, and the overall sensitivity has displayed a slowly decreasing trend

关键词： desertification sensitivity spatiotemporal change geographical detector GIS northwest China

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Observed permafrost thawing and disappearance near the altitudinal limit of permafrost in the qilian Mountains

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Advances in Climate Change Research 2022年第5期13卷 642-650页

作者： Wen SUN Tingjun ZHANG Gary D.CLOW Yan-Hua SUN Wen-Yu ZHAO Ben-Ben liang Cheng-Yan FAN Xiao-Qing PENG Bin CAO Key Laboratory of Western China's Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China Institute of Arctic and Alpine Research University of Colorado BoulderBoulder 80303USA National Tibetan Plateau Data Center Key Laboratory of Tibetan Environmental Changes and Land Surface ProcessesInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

Permafrost degradation has been widely reported on the Tibetan Plateau(TP).However,directly observed evidence of permafrost thawing processes and degradation rates are very limited,although it is expected to be prevalent near the periphery of a permafrost ***,we report permafrost changes and disappearance in the qilian Mountains(northeastern TP)based on three boreholes instrumented along a 100 m transect during 2014–*** results show that permafrost has significantly degraded in the study area:the mean downward thawing rate from the permafrost table was about 0.16 m per year while the mean upward thawing rate from the permafrost base was about 0.23 m per *** estimate the mean lateral degradation rate of permafrost in this area was∼4.14 m per *** dramatically,the 1.5 m thick permafrost layer at one of the boreholes thawed completely between April of 2018 and December of *** results indicate that changes in climatic condition may have played only a limited role in controlling the active layer thickness in the vicinity of the altitudinal limit of permafrost;moisture content and soil conditions play key roles in site-specific permafrost *** study provides new quantitative insights for understanding changes near the altitudinal limit of permafrost,and we suggest that land surface models or Earth system model studies of the lateral heat exchanges should be implemented in order to better represent permafrost thawing processes.

关键词： Permafrost Permafrost degradation Permafrost lateral thawing qilian Mountains

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祁连山南坡鸟类物种多样性与垂直分布格局

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生态学报 2024年第19期44卷 8826-8843页

作者：张萌李斌高红梅梁程博宋鹏飞顾海峰覃雯张婧捷刘道鑫江峰蔡振媛徐波张同作中国科学院西北高原生物研究所高原生物适应与进化重点实验室西宁810001 中国科学院大学北京100049 青海省动物生态基因组学重点实验室西宁810001 青海大学西宁810001

祁连山位于中国青藏高原东北部,是中国西北重要生态屏障,具有丰富的野生动物资源和地貌类型。为探究祁连山南坡鸟类组成与垂直分布特征,于2019年5月和9月采用样线法和直接计数法对不同生境、季节和分布海拔的鸟类资源进行了全面调查。... 详细信息

祁连山位于中国青藏高原东北部,是中国西北重要生态屏障,具有丰富的野生动物资源和地貌类型。为探究祁连山南坡鸟类组成与垂直分布特征,于2019年5月和9月采用样线法和直接计数法对不同生境、季节和分布海拔的鸟类资源进行了全面调查。结果显示,祁连山南坡共观测到鸟类17目41科157种,其中留鸟81种(51.59%)、夏候鸟61种(38.85%)、冬候鸟3种(1.91%)、旅鸟12种(7.64%);在区系组成上以古北界鸟类为主,共102种(64.97%),其次为广布种34种(21.66%)、东洋界21种(13.38%)。在季节变化中,夏季鸟类物种多样性显著高于秋季(P<0.001);在划分的8种生境类型中,草地生境鸟类丰富度最高(108种),且与湿地生境鸟类群落最相似,而与荒漠生境鸟类群落相似度最低;在鸟类垂直分布格局上,祁连山南坡鸟类丰富度随海拔升高呈现为中锋模式,在海拔3100—3400 m处达到最大值。另外,该地区留鸟垂直分布特征存在季节性变化,随着夏季向秋季的季节变换,鸟类的垂直分布范围主要向下或向上移动。物种本底数据的调查是开展生物多样性保护工作的基础,了解该地区鸟类物种多样性数据及其随海拔梯度变化的规律,对保护祁连山南坡地区生物多样性具有重要意义。

关键词：祁连山南坡鸟类多样性垂直分布格局

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青藏高原人口地域分异规律及“胡焕庸线”思想应用

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地理学报 2020年第2期75卷 255-267页

作者：戚伟刘盛和周亮中国科学院地理科学与资源研究所中国科学院区域可持续发展分析与模拟重点实验室北京100101 中国科学院大学资源与环境学院北京100049 兰州交通大学测绘与地理信息学院兰州730070

青藏高原是中国乃至全球典型的人口稀疏区之一,但内部人口地域分异明显。通过构建青藏高原乡镇街道尺度的人口空间数据集,系统核算青藏高原人口数量及其空间密度,从经度、纬度、极向和垂直4个维度解析青藏高原人口地域分异规律,并基于"... 详细信息

青藏高原是中国乃至全球典型的人口稀疏区之一,但内部人口地域分异明显。通过构建青藏高原乡镇街道尺度的人口空间数据集,系统核算青藏高原人口数量及其空间密度,从经度、纬度、极向和垂直4个维度解析青藏高原人口地域分异规律,并基于"胡焕庸线"思想,提出青藏高原的"祁吉线"人口地理划分方案。结论包括:①青藏高原人口空间分布不均衡,具有"东南密、西北疏"的总体空间分布特征,距离"寒旱核心区"近疏远密的极向地域分异明显;②青藏高原人口地域分异与海拔、土壤、水资源、气候、植被等自然环境本底具有高度耦合关系,自然因素间交互作用加强了人口地域分异;③青藏高原人口地域分异可以通过连接祁连县与吉隆县的"祁吉线"体现,两侧地域面积大致相同,但是东南半壁与西北半壁人口比例达到93∶7的悬殊;④"祁吉线"长期稳定,但是东南半壁人口持续微降,西北半壁人口持续微增,未来时期,东南半壁依然是青藏高原城镇化及人类活动的主要区域,而西北半壁应当重视人口增长与生态环境压力的矛盾。

关键词：人口分布青藏高原地域分异胡焕庸线祁吉线

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Variations of albedo and spectral reflectance on Qiyi Glacier in qilian Mountains during the ablation season

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Research in Cold and Arid Regions 2009年第1期1卷 59-70页

作者： Xi Jiang NingLian Wang JianChen Pu JianQiao He liang Chen State Key Laboratory of Cryospheric Science Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of SciencesLanzhouGansu 73000China. Graduate University of the Chinese Academy of Sciences Beijing 100049China.

Based on the data observed at two sites (site H1, 4,473 m a.s.l., and site H2, 4,696 m a.s.l.) on Qiyi Glacier in qilian Mountains, China, by automatic weather station and spectral pyranometer during the period of June 9 through September 27, 2006, we investigated the temporal and spatial variations in surface albedo and spectral reflectance on the glacier. At site H1, the daily mean surface albedos fluctuated between 0.233 and 0.866, which were significantly affected by the air temperature on the glacier. It was found that the albedos clearly showed a diurnal cycle with the lowest value at noon at the two observation sites over the study period, and the difference of albedos between the upper site H2 and the lower site H1 also showed diurnal cycle but with the highest value at noon. The reflectance on the glacier was higher in the ultraviolet (0.28–0.4 μm) and visible (0.4–0.76 μm) wavelengths, lower in the near infrared wavelength (0.76–3 μm), which is quite contrary to the spectral reflectance on other ground surfaces. At the two observation sites, the spectral reflectance declined in all wavelengths with the ablation of snow generally. However, it declined drastically in ultraviolet (0.28–0.4 μm) and 0.6–0.7 μm wavelength, and declined less in 0.4–0.5 μm wavelength. On fresh snow surface, the spectral reflectance had the high values of 0.983 and 0.815 in the ultraviolet and visible (0.4–0.76 μm) wavelengths, respectively; but it had a relatively lower value of 0.671 in near infrared (0.76–3 μm) wavelengths. However, on dirty and melting ice surfaces, the reflectance had the very low values of 0.305 and 0.256 in the ultraviolet and visible wavelengths, with the lowest value of 0.082 in near infrared wavelengths. The spectral reflectance also showed a diurnal cycle like that of albedo. The diurnal variations of spectral reflectance on snow surface in ultraviolet and visible wavelength changed to a greater degree than that on ice surface. The diurnal variation curv

关键词： Qiyi Glacier albedo spectral reflectance temporal and spatial variations ablation season

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祁连山国家公园甘肃片区雪豹栖息地廊道研究

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动物学杂志 2024年第4期59卷 493-504页

作者：朱高红胡大志马堆芳张俊涛王东武张广文阿诚王亮马晨迪戴强王义弘中国科学院成都生物研究所成都610041 中国科学院西北高原生物研究所西宁810001 中国科学院大学北京100049 甘肃祁连山国家级自然保护区管护中心张掖734099 深圳市一个地球自然基金会深圳518000

雪豹(Panthera uncia)是高山流石滩等山地生境生物多样性的旗舰物种,对维持高山生态系统结构和功能稳定性起着重要作用。近年来雪豹种群数量有所恢复,但多种因素导致的栖息地破碎化仍对雪豹的种群生存造成威胁。建立廊道可将分散的栖息... 详细信息

雪豹(Panthera uncia)是高山流石滩等山地生境生物多样性的旗舰物种,对维持高山生态系统结构和功能稳定性起着重要作用。近年来雪豹种群数量有所恢复,但多种因素导致的栖息地破碎化仍对雪豹的种群生存造成威胁。建立廊道可将分散的栖息地斑块连接起来,提高雪豹抵抗干扰的能力,并为雪豹的长期生存提供重要保障。本研究以祁连山国家公园甘肃张掖分局保护片区及其15 km缓冲区为研究区域,基于祁连山国家公园甘肃张掖分局保护片区雪豹分布点数据,选取气候、地形和土地利用等环境变量,运用MaxEnt模型对雪豹栖息地适宜度进行分析并划定生态源地,而后基于最小代价路径原理识别雪豹廊道。结果显示,研究区域内雪豹适宜栖息地面积为13432.066 km^(2),分布在片区内的适宜栖息地面积为7086.195 km^(2),占适宜栖息地总面积的52.756%。崎岖度、最干季度平均温度和季节降雨变异系数是影响雪豹栖息地选择的关键因子。通过分析,最终划定9个生态源地用于后续廊道识别规划。在研究区域内共识别10条潜在生态廊道,廊道最长为18.725 km,最短为0.368 km,平均廊道长度为5.676 km。其中3条廊道连接片区内雪豹适宜栖息地斑块,5条廊道连接该片区与青海片区雪豹栖息地。基于上述结果,我们建议在提升片区内雪豹适宜栖息地之间整体连接度的同时,与青海省共同开展跨界保护工作,以制定更加科学合理的保护与管理计划。

关键词：雪豹栖息地 MaxEnt模型最小代价路径原理廊道

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桂西铝土矿中火山灰特征及其地质意义

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地质论评 2022年第2期68卷 531-550页

作者：张启连陈有斌刘希军黄文芳韦访黄光琼黎家龙徐海棚梁国科叶宝月广西地质调查院南宁530023 广西环境地质调查院南宁530023 广西274地质队广西北海536005 桂林理工大学广西桂林541004

岩溶型铝土矿中火山物质参与成矿的直接证据需要进一步明确。通过线路调查和剖面研究,在桂西大范围内的铝土矿及其早期的铝土质岩中观察到大量的火山灰,含量大于30%;火山灰种类有岩屑、晶屑、玻屑和火山尘,塑性—半塑性变形及刚性爆裂显... 详细信息

岩溶型铝土矿中火山物质参与成矿的直接证据需要进一步明确。通过线路调查和剖面研究,在桂西大范围内的铝土矿及其早期的铝土质岩中观察到大量的火山灰,含量大于30%;火山灰种类有岩屑、晶屑、玻屑和火山尘,塑性—半塑性变形及刚性爆裂显著,自由降落为主,属原地—准原地沉积;火山灰易于分解为水铝石、高岭石、赤铁矿等微细矿物,屑状火山灰相对尘状火山灰更易于矿化,大量火山灰主要以直接铝土矿化作用成矿。元素地球化学特征显示铝土矿和铝土质岩具有亲岩浆性,不活动元素图解判别及铝土矿测年数据显示火山灰原岩浆以碱性玄武岩为主,与岛弧火山岩一致,主要来自于哀牢山—松马造山带的二叠纪岛弧,铝土矿层具有穿时性,部分火山灰可来源于峨眉山火成岩。铝土矿层中的火山灰丰富,跨度长,可能是瓜德鲁普世末生物灭绝的肇凶。

关键词：铝土矿火山灰岛弧火山岩地质意义桂西

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从阿巴拉契亚--阿钦塔造山带看中国北方大陆南缘古生代的油气前景

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地学前缘 2011年第4期18卷 193-200页

作者：梁传茂美国金石通公司纽约奥尔巴尼NY 12188USA

阿巴拉契亚—阿钦塔造山带是北美乃至世界著名的大陆边缘挤压碰撞推覆造山带,是地质学研究的经典地区之一,也是许多经典地学理论和概念的发源地。其中,对地质学影响最大的当属地槽学说。继20世纪60年代由深海钻探带来地学革命之后,由COC... 详细信息

阿巴拉契亚—阿钦塔造山带是北美乃至世界著名的大陆边缘挤压碰撞推覆造山带,是地质学研究的经典地区之一,也是许多经典地学理论和概念的发源地。其中,对地质学影响最大的当属地槽学说。继20世纪60年代由深海钻探带来地学革命之后,由COCORP实施的地震反射剖面和深钻揭示了该造山带的巨大推覆构造。人们惊奇地发现,在巨大推覆体之下的大陆边缘,广泛分布着古生代浅水碳酸盐岩地层并具有巨大油气潜力。于是很多油气公司调整了这些地区油气勘探的战略部署,很快在推覆体之下早古生代地层中得到油气勘探的突破。其中,威尔伯顿(Wilburton)油气田就是当时美国发现的最大油气田之一,其单井天然气日产量有的超过1亿立方英尺。通过综合对比,笔者认为中国北方大陆南部边缘的大别—秦(岭)祁(连)—昆仑这一东西延伸的造山带与美国阿巴拉契亚—阿钦塔推覆大陆边缘在地层、岩相和盆地构造演化史等诸多方面有着惊人的相似性和可比性,是发生在中国北方巨大大陆南缘的古生代挤压碰撞推覆造山带。在许多大洋深水盆地相推覆体之下的早古生代浅水碳酸盐岩地层也具有良好的油气前景。粗略估算,我国北方大陆边缘推覆体之下早古生代碳酸盐岩地层很可能达几十万km2或更多,这一潜力是不可忽视的。

关键词：阿巴拉契亚—阿钦塔大陆边缘推覆造山带及油气中国北方大陆边缘早古生代油气潜力

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