Tectonic inversion assessed by integration of geological and geophysical data: The intracontinental Rio do Peixe Basin,NE Brazil     

David L. Vasconcelos  Fernando O. Marques  Francisco C. C. Nogueira  Yoe A. R. Perez  Francisco H. R. Bezerra  Rmulo C. Stohler  Jorge A. B. Souza 《Basin Research》2021,33(1):705-728

Common basin models assume that the post‐rift tectonic evolution of most basins is usually associated with tectonic quiescence. However, tectonic inversion during the post‐rift phase has been proposed for several sedimentary basins worldwide, but how and why it happens is still a matter of debate, especially in intracontinental settings where the lithosphere is old and thick. Here, we use geological and geophysical data from the Rio do Peixe Basin in NE Brazil to show evidence that intracontinental sedimentary basins can be tectonically inverted by far‐field compressive stresses acting on pre‐existing weakness zones of lithospheric‐scale where stresses can concentrate and inversion can occur. Geomorphological and field data combined with seismic reflection, gravimetric and borehole data show that: (a) inversion occurred along two main Precambrian lithospheric‐scale shear zones, the Patos (E‐W trending) and Portalegre (NE‐SW trending), which had already been reactivated as basin‐bounding faults during the earlier rift stage; (b) post‐rift reactivation affected (mostly) the original master normal faults with the largest rift displacements, and locally produced new reverse faults; (c) during contraction, deformation was partitioned between fault reactivation and buckling of the incompetent sediment pushed against the hard basement; (d) all these signs of inversion have been observed in the field and can be demonstrated on seismic reflection profiles; and (e) combined gravimetric and seismic data show that the main structures of the basin were followed by an inversion. These data are consistent with the operation of WSW‐ENE horizontal maximum compressive stress as a result of combined pushes of the Mid‐Atlantic Ridge (towards the W) and the Andes (towards the E), responsible for the post‐rift oblique inversion of normal faults inherited from the rift phase and formed with vertical maximum compressive stress.  相似文献   

基于Spearman秩相关系数的PWV与PM2.5相关性研究     

周永江  姚宜斌  熊永良  单路路 《大地测量与地球动力学》2020,40(3):236-241

在讨论大气可降水量(PWV)与细颗粒物(PM 2.5)之间的相关性时,传统方法未能很好地顾及连续数据中包含的非雾霾天气信息的影响,为此本文提出2个数据选取标准——时间标准和空气质量指数(AQI)等级标准,用于获取雾霾期间对应的PWV和PM 2.5序列。为解决数据筛选后不连续的问题,引入一种非参数性质的Spearman秩相关系数ρ,在北京市2014~2016年雾霾多发期,分析不同AQI等级对应时段的非连续等距的PWV和PM 2.5序列的相关性可知,筛选后3 a的ρ在第1、4季度的均值分别为0.6613和0.6280,整体均值为0.6447,表明雾霾天气下PWV和PM 2.5序列具有单调正向的相关性,而传统分析方法(未筛选)下两者的相关系数均较小,表明在对数据进行选取后的分析结果更具针对性和准确性。  相似文献   

青藏高原大尺度地表流体的重力效应特征分析     

朱传东  刘金钊  陈铭  陈兆辉  张品  张双喜 《大地测量与地球动力学》2020,40(9):947-951

基于2002~2017年三维大气再分析模型、水文模式及GRACE卫星重力数据,采用负荷格林函数和卫星重力反演方法分析青藏高原大尺度地表流体的重力效应特征。结果表明,青藏高原地区大气扣除季节项前后的重力效应峰对峰变化介于1.9~10.7 μGal和1.1~4.6 μGal,其负荷效应呈现出显著的季节性特征;土壤水和积雪扣除季节项前后的重力效应峰对峰变化介于0.9~9.9 μGal和0.7~8.3 μGal,其负荷效应呈现出显著的季节性和年际变化特征;GRACE时变重力场扣除季节项前后的重力变化峰对峰变化介于4.4~24.1 μGal和3.4~18.3 μGal,考虑观测误差、构造运动和信号泄漏误差的影响,其显著的季节性和年际变化反映了多种地表流体的综合影响。  相似文献   

Investigating the Changes in Air Pollutant Emissions over the Beijing-Tianjin-Hebei Region in February from 2014 to 2019 through an Inverse Emission Method     

Xuechun LUO  Xiao TANG  Haoyue WANG  Lei KONG  Huangjian WU  Weiguo WANG  Yating SONG  Hongyan LUO  Yao WANG  Jiang ZHU  Zifa WANG 《大气科学进展》2023,40(4):601-618

In recent years, China has implemented several measures to improve air quality. The Beijing-Tianjin-Hebei(BTH)region is one area that has suffered from the most serious air pollution in China and has undergone huge changes in air quality in the past few years. How to scientifically assess these change processes remain the key issue in further improving the air quality over this region in the future. To evaluate the changes in major air pollutant emissions over this region, this paper employs ens...  相似文献   

情境驱动的室内位置地图动态表达     

游天  孙群  齐晓飞  孙卫新 《测绘科学技术学报》2017,34(1)

室内位置地图可以根据用户的"位置"及环境变化,动态地表达位置服务信息,是实现室内位置个性化和精准化服务的重要平台。重点研究情境驱动下室内位置地图的动态表达。在分析室内位置地图特征的基础上,提出影响室内位置地图表达的情境类型;设计地图表达图层及构成要素,提出情境驱动的室内位置地图表达过程与技术方法;给出商场购物活动中不同情境条件下地图动态表达的应用示例。  相似文献   

基于SuperMap的全球晕渲图设计与制作     

刘蕾  刘晓妮 《测绘与空间地理信息》2017,40(Z1)

晕渲图的设计与制作一直是地学工作者研究的热点问题,使用晕渲图展示地形直观、形象、立体感强.目前有多种思路被提出用于改善晕渲图的显示效果,但是在制作小比例尺晕渲图时,仍然存在一些问题,如地形破碎导致难以把握地形宏观骨架,缺少海洋地形或海洋地形过于具体干扰到陆地要素表达,传统的DEM与山影数据叠加的模式使得美观与地形清晰无法兼得,这就需要重新对这些问题进行思考.本文以晕渲图的基本理论为出发点,采用地貌晕渲与分层设色相结合的方法,讨论全球范围的晕渲图制作过程中,不同显示比例尺下DEM分辨率配置技巧、海洋地形展示方法与地形可视化新思路.实验证明,该方法可以保证晕渲图在每级显示比例尺下都能展示出良好的地形效果,为中小比例尺晕渲图增强表现力提供了参考.  相似文献   

Measuring land-use and land-cover change using the U.S. department of agriculture’s cropland data layer: Cautions and recommendations     

《International Journal of Applied Earth Observation and Geoinformation》2017

Monitoring agricultural land is important for understanding and managing food production, environmental conservation efforts, and climate change. The United States Department of Agriculture's Cropland Data Layer (CDL), an annual satellite imagery-derived land cover map, has been increasingly used for this application since complete coverage of the conterminous United States became available in 2008. However, the CDL is designed and produced with the intent of mapping annual land cover rather than tracking changes over time, and as a result certain precautions are needed in multi-year change analyses to minimize error and misapplication. We highlight scenarios that require special considerations, suggest solutions to key challenges, and propose a set of recommended good practices and general guidelines for CDL-based land change estimation. We also characterize a problematic issue of crop area underestimation bias within the CDL that needs to be accounted for and corrected when calculating changes to crop and cropland areas. When used appropriately and in conjunction with related information, the CDL is a valuable and effective tool for detecting diverse trends in agriculture. By explicitly discussing the methods and techniques for post-classification measurement of land-cover and land-use change using the CDL, we aim to further stimulate the discourse and continued development of suitable methodologies. Recommendations generated here are intended specifically for the CDL but may be broadly applicable to additional remotely-sensed land cover datasets including the National Land Cover Database (NLCD), Moderate Resolution Imaging Spectroradiometer (MODIS)-based land cover products, and other regional, national, and global land cover classification maps.  相似文献   

新仙女木期黄河晋陕峡谷古风成沙层年代及其物质来源   总被引：2，自引：2，他引：0  

张玉柱  黄春长  陈莹璐  谭志海  杨利荣  张云翔  邱海军  刘波  赵发珠 《地理学报》2017,72(5):790-803

通过对黄河晋陕峡谷壶口至龙门段开展广泛细致的野外考察,发现了典型的晚更新世以来黄土—土壤层夹古风成沙层剖面—北桑峪剖面（BSY）。结合不同类型沉积物的野外宏观特征、磁化率、粒度成分、石英颗粒表面特征和地球化学元素的对比分析,确定黄河晋陕峡谷壶口至龙门段BSY剖面中所夹古风成沙层的性质为中沙质细沙,是在干旱多风环境下形成的沙质沉积物。基于光释光（OSL）测年数据,确定其沉积年代为12.5-11.6 ka,记录了黄河中游发生在末次冰消期的极端干旱事件,其与相邻区域沙漠/黄土过渡带中湖沼沉积和风成黄土—古土壤剖面记录的新仙女木事件相对应。该剖面中古风成沙沉积物的物质来源,主要来自黄河晋陕峡谷的古河床相沙层物质。这是因为该河段处于干旱半干旱季风气候区,在新仙女木时期,黄河晋陕峡谷处于极端干冷的环境之中,冬季风强盛、夏季风衰弱,黄河水位下降明显,河漫滩和江心洲将大面积出露,大量的沙物质在风力作用下向岸边输移,成为河谷两侧缓坡台地上古风成沙沉积层出现的主要沙源地。这个研究成果对于进一步揭示黄河中游流域极端干旱事件发生的时间性规律及其与季风气候变化的关系,具有重要的科学意义。  相似文献   

基于统计动力反演的东亚亚热带季风变化驱动机制研究     

侯立春  林振山  刘翔  罗虎明 《地理科学》2017,37(3):445-454

利用观测数据,运用非线性统计-动力学方法,反演系统各因子之间的相互关系,建立了东亚亚热带季风变化的动力方程,为研究东亚亚热带季风的驱动机制提供了量化参考。研究发现：过去2 000 a东亚亚热带季风是多因子通过反馈机制相互作用影响且具有耦合效应的复杂非线性动力系统,其驱动力主要来源于普若岗日冰芯δ¹⁸О代表的青藏高原热力作用强迫、太阳黑子活动、ENSO、温室气体单因子CO₂和CH₄浓度、北极温度和CH₄及北极温度与7月太阳辐射的耦合作用机制;反馈调节作用主要源于7月太阳辐射与太阳黑子活动、CH₄浓度、中国陆地地表温、CH₄与7月太阳辐射以及CO₂和CH₄的耦合调节作用。并通过动力反演机制推论热带西太平洋对亚热带季风有一定驱动作用,但并不是主要驱动力,即驱动亚热带季风变化的主源地并不在热带西太平洋海区,石笋δ¹⁸О指代的也主要是夏季风信息。  相似文献   

A LIMITED-LENGTH-SCALE k-ε MODEL FOR THE NEUTRAL AND STABLY-STRATIFIED ATMOSPHERIC BOUNDARY LAYER     

DAVID D. APSLEY  IAN P. CASTRO 《Boundary-Layer Meteorology》1997,83(1):75-98

Analytical and numerical models of the neutral and stably-stratifiedatmospheric boundary layer are reviewed. Theoretical arguments andcomputational models suggest that a quasi-steady state is attainable in aboundary layer cooled from below and it is shown how this may be incorporatedwithin a time-steady, one-dimensional model. A new length-scale-limitedk- model is proposed for flows where a global maximum mixing length isimposed by the finite boundary-layer depth or, in stably-stratifiedconditions, by the Obukhov length, whilst still reducing to a form consistentwith the logarithmic law in the surface layer. Simulations compare favourablywith data from the Leipzig experiment and from Cardington airfield inEngland.  相似文献