大数据驱动下的数字古地理重建：现状与展望     

张蕾  钟瀚霆  陈安清  赵应权  黄可可  李凤杰  黄虎  刘宇  曹海洋  祝圣贤  穆财能  侯明才  JAMES G. Ogg 《高校地质学报》2020,26(1):73

古地理学是一门强数据依赖性学科,古地理重建作为古地理学的核心任务之一,着眼于研究地质历史时期地球表面的地理、生物、气候面貌及其演化规律。随着大数据时代的来临,海量古地理数据的不断积累和计算机技术的高速发展使得标准化、智能化的数字古地理重建成为可能。文章通过介绍国内外与古地理相关的代表数据库及团队,总结其优缺点,提出大数据驱动下的数字古地理重建核心思路:(1)建立标准化的古地理学知识体系;(2)建立开放互动、动态更新的古地理数据库,并利用机器阅读技术等拓展数据来源;(3)建立标准化的古地理学数据质量控制体系;(4)利用机器学习技术建立各类型古地理重建模型,深度挖掘数据;(5)以可实时更新的智能数字地图集或多维动画形式输出成果。  相似文献   

An integrated approach to assess the ecological and chemical status of lakes with HOD/AHOD: a case study of two lakes     

Serdar G?NCü  Erdem ALBEK 《中国海洋湖沼学报》2019,37(1):146-159

The thermal strati?cation of the lakes impedes the transfer of atmospheric oxygen into the lower layers of the lake. In lakes which are af fected by diverse anthropogenic in?uences, the increasing organic matter amounts lead to a sharp decrease in hypolimnetic oxygen amounts, aided by thermal strati?cation,and anaerobic conditions arise. The determination of hypolimnetic oxygen demand(HOD) and areal hypolimnetic oxygen demand(AHOD) and their monitoring represent an integrated approach to investigate the oxygenation of lakes, the nutrient conditions, and the physicochemical dynamics. In this study, two lakes dif fering by size and af fected by dif ferent anthropogenic sources, are investigated in this respect. At?rst, bathymetric studies were conducted to determine the depth, surface area, and volume relationships.Then, based on monitoring studies conducted in 2013 and 2014, the thermal strati?cation dynamics and layer properties were established using the relative thermal resistance to mixing(RTRM) index based on temperature and density pro?les. Following this, the oxygen depletion rates were determined by oxygen and temperature pro?ling in the hypolimnion. For the years of 2013 and 2014, the AHOD values for the Borabey Pond which is far from anthropogenic in?uences, were found to be 0.848 and 0.569 g O 2/(m·d), respectively.The AHOD values for the Porsuk Reservoir which was overburdened for years by industrial and domestic pollution were found to be 4.263 and 5.099 g O 2/(m·d), larger than its counterpart by almost sevenfold. The HOD and AHOD monitoring can be considered to a valuable tool for assessing the ecological and chemical status of lakes within Annex 5 of the Water Framework Directive and as an integrated approach to assess and monitor the status of lakes.  相似文献   

Forearc ophiolite in Havana-Matanzas, Western Cuba: evidence from serpentinized mantle peridotite REE geochemistry and Cr-spinel composition     

LLANES CASTRO Angélica Isabel  PROENZA Joaquín Antonio  CRUZ GáMEZ Esther María 《《地质学报》英文版》2018,92(Z2):19-21

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渤海海域浮游病毒和浮游细菌的丰度变化与环境因子之间的耦联关系     

王彩霞  吴霖  王毅波  Paterson James S.  Mitchell James G.  胡晓珂 《海洋学报(英文版)》2020,39(6):72-83

Uncovering the role of environmental factors and finding critical factors which harbor significant fractions in governing microbial communities remain key questions in coastal marine systems. To detect the interactions between environmental factors and distributions of virio-and bacterioplankton in trophic coastal areas, we used flow cytometry to investigate the abundance of virio-and bacterioplankton covering 31 stations in the Bohai Sea of China. Our results suggested that the average abundance of total virus(TV) in winter(～2.29×10~8 particles/mL)was slightly lower than in summer(～3.83×10~8 particles/mL). The mean total bacterial abundance(TB) was much lower in winter(～2.54×107 particles/mL) than in summer(～5.43×10~7 particles/mL). Correlation analysis via redundancy analysis(RDA) and network analysis among virioplankton, bacterioplankton and environmental factors revealed that the abundances of viral and bacterial subpopulations depend on environmental factors. In winter, only temperature significantly influenced the abundances of virio-and bacterioplankton. In summer, in addition to temperature, both salinity and nutrient(SiO_2) had a remarkable impact on the distribution of virioand bacterioplankton. Our results showed a clear seasonal and trophic pattern throughout the whole water system, which revealed that temperature and eutrophication may play crucial roles in microbial distribution pattern.  相似文献   

Satellite estimates and subpixel variability of rainfall in a semi-arid grassland          下载免费PDF全文

Yong Chen  Jing Duan  Junling An  Huizhi Liu  Ulrich G?rsdorf  Franz H.Berger 《大气和海洋科学快报》2021,14(5):24-29

卫星估雨精度的不确定性受到当地降雨类型和像元内降雨非均匀性影响,而结合这两个关键因素开展半干旱草原卫星估雨的研究有限.2009年夏,我们在中国锡林郭勒半干旱草原用多部微雨雷达和雨量计构建了9 km卫星像元降雨观测网,观测了像元内降雨非均匀性(空间变异系数CV),并评估了卫星估雨精度.结果表明:(1)CV值受像元内平均降雨量,降雨类型,降雨云面积及移向等影响,如高Cv值的降雨过程大多为平均降雨量小,对流性降雨过程,降雨云边缘像元CV值较高;(2)TRMM 3B42V7卫星估雨产品适用性较好,CMORPH和PERSIANN次之,但TRMM 3B42V7易在半干旱草原湖泊处高估降雨.  相似文献   

The development of the subduction channel and “turning on” of slab-to-mantle material exchanges at the start of subduction: insights from eruptive serpentinites (IODP Exp 366) from the forearc of the Mariana subduction system     

Jeffrey G. Ryan  Raymond Johnston  P. Fryer  C.G. Wheat  T. Williams 《《地质学报》英文版》2018,92(Z1):167-167

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Crustal Electrical Structure and Deep Metallogenic Potential in Northern Wuyi Area (South China), based on Magnetotelluric Data     

LUO Fan  LU Qingtian  ZHANG Kun  YAN Jiayong  Colin G. FARQUHARSON  ZHANG Chong  FU Guangming 《《地质学报》英文版》2022,96(3):791-805

The northern Wuyi area, which is located in the northern Wuyi metallogenic belt, has superior mineralization conditions. The Pingxiang–Guangfeng–Jiangshan–Shaoxing fault (PSF) extends across the whole region regardless of whether or how the PSF relates to the near-surface mineralization. We carried out an MT survey in the region and obtained a reliable 2D model of the crustal electrical structure to a depth of 30 km. In the resistivity model, we inferred that a continuous high conductivity belt that ranges from the shallow to deep crust is a part of the PSF. Then, we estimated the fluid content and pressure gradient to identify the deep sources of fluid as well as its pattern of motion pattern. Finally, we proposed a model for the deep metallogenic migration processes that combines geological data, fluid content data, pressure gradient data, and the subsurface resistivity model. The model analysis showed that the Jiangnan orogenic belt and the Cathaysia block formed the PSF during the process of com. The deep fluid migrated upward through the PSF to the shallow crust. Therefore, we believe that the PSF is an ore-forming fluid migration channel and that it laid the material basis for large-scale mineralization in the shallow crust.  相似文献   

泰国湾表层沉积物陆源碎屑的粒度特征及其展现的沉积动力环境     

冯铄  刘志飞  Penjai SOMPONGCHAIYAKUL  林宝治  Martin G. WIESNER 《地学前缘》2022,29(4):211-220

海洋碎屑沉积物的粒度特征是海底沉积动力环境的直接体现,是用来研究海洋动力环境变化的重要手段,尤其是陆架海底表层沉积物的粒度分布,对于研究沿岸和水柱底边界层现今海洋动力环境可起到重要作用。该项研究通过调查遍布泰国湾至湄公河口海底表层沉积物陆源碎屑的粒度分布特征,以期获得影响现今特定海域沉积作用的海洋动力环境过程。粒度分析的结果显示,泰国湾表层沉积物的陆源碎屑以细砂-细粉砂为主,分选总体较差,频率分布以正偏为主。其中,细砂-极细砂组分主要分布在曼谷湾和柬埔寨沿岸。湄公河岸外沉积物为细砂,且分选比泰国湾区域的沉积物要好。这些表层沉积物的粒度特征具有良好的环境变化指示作用。湄公河岸外分选较好、近于正态分布的中砂沉积物指示了波浪作用下的沉积环境。曼谷湾和柬埔寨沿岸分选较差的中砂-细砂粗粒沉积物反映了潮汐和波浪的共同作用;泰国湾东西沿岸区域分选中等、呈正偏态的极细砂-中粉砂沉积物体现了潮汐的控制作用;而泰国湾中部分选较差的沉积物则指示了表层洋流作用。研究表明,泰国湾和湄公河岸外表层沉积物陆源碎屑的粒度分布特征可用于区分不同海洋动力因素的控制作用,揭示出泰国湾的沉积动力环境主要受潮汐、波浪和洋流的共同影响,湄公河岸外的沉积动力环境主要受波浪的影响。  相似文献   

南秦岭柞水—山阳矿集区金铜矿床成矿规律与找矿方向     

王瑞廷  冀月飞  成欢  刘凯  张启  李弦  任涛 《现代地质》2021,35(6):1487-1503

南秦岭柞水—山阳矿集区地质构造和岩浆活动强烈,矿床(点)成群成带分布,成矿条件良好。在长期找矿实践、成矿地质背景分析和典型矿床解剖的基础上,综合研究认为,区内金矿主要受EW向断裂或EW向韧-脆性剪切带与NE向张扭性叠加构造控制,寒武系水沟口组、泥盆系星红铺组与大枫沟组是金的赋矿地层。金矿体呈近EW向大致等间距展布,单个矿体在延伸方向呈透镜状、哑铃状、囊状等,具尖灭再现特征,构造叠加部位矿体厚大、品位较高。区内金矿床类型多为中-低温热液型、远成低温热液型,成矿时代为印支—燕山期。夏家店等已知金矿床深部及外围、区域断裂旁侧次级近EW向与NNE向断裂交汇部位、构造转折端、构造虚脱部位等是寻找金矿的有利靶区。铜矿分布于山阳—凤镇大断裂两侧,成矿类型以斑岩型-矽卡岩型为主,构造热液改造型、隐爆角砾岩型次之。斑岩型-矽卡岩型铜(钼)矿受燕山期构造-岩浆活动控制,赋存于燕山期斑岩体与围岩接触带内;矿体产状多受岩体与围岩接触面控制,呈似层状、透镜状产出。燕山期中酸性小岩体及其与围岩的接触部位、东西向三级断裂带附近是寻找铜(钼)矿的首选靶区。本次研究建立了柞水—山阳矿集区金铜矿床区域成矿模式,总结了找矿标志,通过成矿规律、成矿作用及物探、化探、遥感异常特征系统分析,认为区内找矿潜力巨大,并提出了3片金铜(钼)成矿远景区,指出下一步的找矿方向。  相似文献   

Backward automatic calibration for three-dimensional landslide models     

Giacomo Titti  Giulia Bossi  Gordon G.D.Zhou  Gianluca Marcato  Alessandro Pasuto 《地学前缘(英文版)》2021,12(1):231-241

Back-analysis is broadly used for approaching geotechnical problems when monitoring data are available and information about the soils properties is of poor quality.For landslide stability assessment back-analysis calibration is usually carried out by time consuming trial-and-error procedure.This paper presents a new automatic Decision Support System that supports the selection of the soil parameters for three-dimensional models of landslides based on monitoring data.The method considering a pool of possible solutions,generated through permutation of soil parameters,selects the best ten configurations that are more congruent with the measured displacements.This reduces the operator biases while on the other hand allows the operator to control each step of the computation.The final selection of the preferred solution among the ten best-fitting solutions is carried out by an operator.The operator control is necessary as he may include in the final decision process all the qualitative elements that cannot be included in a qualitative analysis but nevertheless characterize a landslide dynamic as a whole epistemological subject,for example on the base of geomorphological evidence.A landslide located in Northeast Italy has been selected as example for showing the system potentiality.The proposed method is straightforward,scalable and robust and could be useful for researchers and practitioners.  相似文献